HIV Testing

What Is HIV Testing?HIV testing tells you if you are infected with the Human Immunodeficiency Virus (HIV) which causes AIDS. These tests look for "antibodies" to HIV. Antibodies are proteins produced by the immune system to fight a specific germ.
Other "HIV" tests are used when people already know they are infected with HIV. These measure how quickly the virus is multiplying (a viral load test, see Fact Sheet 125) or the health of your immune system (a CD4 count, see Fact Sheet 124).

How Do I Get Tested?You can arrange for HIV testing at any Public Health office, or at your doctor's office. Test results are usually available within two weeks. In the U.S., call the National AIDS Hotline, 1-800-342-2437.
The most common HIV test is a blood test. Newer tests can detect HIV antibodies in mouth fluid (not the same as saliva), a scraping from inside the cheek, or urine. "Rapid" HIV test results are available within 10 to 30 minutes after a sample is taken. One of these tests has produced a high rate of fasle positives. A positive result on any HIV test should be confirmed with a second test.
Home test kits: You can't test yourself for HIV at home. The "Home Access" test kit is only designed to collect a sample of your blood. You send the sample to a laboratory where it is tested for HIV.
When Should I Get Tested?If you become infected with HIV, it usually takes between three weeks and two months for your immune system to produce antibodies to HIV. If you think you were exposed to HIV, you should wait for two months before being tested. You can also test right away and then again after two or three months. During this "window period" an antibody test may give a negative result, but you can transmit the virus to others if you are infected.
About 5% of people take longer than two months to produce antibodies. There is one documented case of a person exposed to HIV and hepatitis C at the same time. Antibodies to HIV were not detected until one year after exposure. Testing at 3 and 6 months after possible exposure will detect almost all HIV infections. However, there are no guarantees as to when an individual will produce enough antibodies to be detected by an HIV test. If you have any unexplained symptoms, talk with your health care provider and consider re-testing for HIV.
Do Any Tests Work Sooner After Infection?Viral load tests detect pieces of HIV genetic material. They show up before the immune system manufactures antibodies. Also, in early 2002, the FDA approved "nucleic acid testing." It is similar to viral load testing. Blood banks use it to screen donated blood.
The viral load or nucleic acid tests are generally not used to see if someone has been infected with HIV because they are much more expensive than an antibody test. They also have a slightly higher error rate.

What Does It Mean if I Test Positive?A positive test result means that you have HIV antibodies, and are infected with HIV. You will get your test result from a counselor who should tell you what to expect, and where to get health services and emotional support.
Testing positive does not mean that you have AIDS (see Fact Sheet 101, What Is AIDS?). Many people who test positive stay healthy for several years, even if they don't start taking medication right away.
If you test negative and you have not been exposed to HIV for at least three months, you are not infected with HIV. Continue to protect yourself from HIV infection (see Fact Sheet 150, Stopping the Spread of HIV).

Can I Keep the Test Result Confidential?
You can be tested anonymously in many places. You do not have to give your name when you are tested at a public health office, or when you receive the test results. You can be tested anonymously for HIV as many times as you want.
If you get a positive HIV test that is not anonymous, or if you get any medical services for HIV infection, your name may be reported to the Department of Health.
The Centers for Disease Control (CDC) proposed in late 1998 that all states keep track of the names of HIV-infected people. This proposal has not yet taken effect.

How Accurate Are the Tests?
Antibody test results for HIV are accurate more than 99.5% of the time. Before you get the results, the test has usually been done two or more times. The first test is called an "EIA" or "ELISA" test. Before a positive ELISA test result is reported, it is confirmed by another test called a "Western Blot."
Two special cases can give false results:
Children born to HIV-positive mothers may have false positive test results for several months because mothers pass infection-fighting antibodies to their newborn children. Even if the children are not infected, they have HIV antibodies and will test positive. Other tests, such as a viral load test, must be used.
As mentioned above, people who were recently infected may test negative if they get tested too soon after being infected with HIV.

The Bottom Line
HIV testing generally looks for HIV antibodies in the blood, or saliva or urine. The immune system produces these antibodies to fight HIV. It usually takes two to three months for them to show up. In rare cases, it can take longer than three months. During this "window period" you may not test positive for HIV even if you are infected. Normal HIV tests don't work for newborn children of HIV-infected mothers.
In many places, you can get tested anonymously for HIV. Once you test positive and start to receive health care for HIV infection, your name may be reported to the Department of Health. These records are kept confidential.
A positive test result does not mean that you have AIDS. If you test positive, you should learn more about HIV and decide how to take care of your health.

HIV Antibody Testing Options

The Centers for Disease Control and Prevention estimate that between 850,000 and 900,000 Americans are infected with HIV. An estimated 180,000 to 280,000 Americans do not know they are infected and may continue to engage in behavior that could jeopardize their health and the health of others.
Testing Programs: Voluntary counseling, testing, and referral programs (CTR) provide people an opportunity to learn their current HIV status, receive counseling about any behavioral changes needed to avoid infection or infecting others, and receive information and referrals to additional prevention programs, medical care or other services.
Confidential HIV Testing means you give your name when getting tested. Only medical personnel or state health departments have access to the test results. You must provide written permission before this information can be revealed to others.
Anonymous HIV testing means that no name is given to the testing center and only you are aware of the results. Anonymous testing is available in 39 states, the District of Columbia and Puerto Rico. Test results are given by randomly assigned numbers at the time of testing.
Types of HIV Antibody TestsThere are several HIV antibody tests being used today. All testing options are not available in all areas. Contact your local health department for the tests available in your area.
Standard blood test: This was the first HIV antibody test developed and made available, and is the most widely used. With this test, an initial assay is used (the ELISA) and confirmed using a more specific test (the Western Blot).
Oral mucosal transudate test: This test, an alternative to the standard blood test, uses a specially treated pad placed in a person's mouth and gently rubbed between the lower cheek and gum. The pad collects an oral fluid called oral mucosal transudate (OMT). This fluid contains HIV antibodies in an HIV- infected person. This test does not test for HIV in saliva.
Urine HIV antibody test: The urine HIV-1 testing method is a painless, non-evasive option for getting an HIV antibody test. This test uses the urine EIA (ELISA) and urine Western Blot technique to detect HIV antibodies and is FDA-licensed as an alternative to the blood test system. This test eliminates accidental needle sticks and exposure-related dangers, protecting the patient and healthcare worker.
Rapid HIV antibody tests: Where the standard HIV antibody testing procedure requires up to two weeks for results, the rapid test gives results in 5-60 minutes. For rapid blood testing the fingertip is cleaned with alcohol and pricked with a lancet to get a small drop of blood. The blood is collected with a specimen loop and transferred to a vial, where it is mixed with a developing solution. For oral testing oral fluid specimens are obtained by swabbing gums with test devices and placed in a solution. In as little as 20 minutes, the test device will indicate if HIV-1 antibodies are present in the solution.Although the results of rapid screenings will be reported in point-of-care settings, as with all screening tests for HIV, if the test gives a reactive test result, that result must be confirmed with an additional specific test.To determine which type of rapid testing is being performed, call the organization directly.
Home Testing Kit: This do-it-yourself test kit uses the same technology as the standard blood test. Individual blood samples are collected at home and mailed to a laboratory. Test results are provided over the telephone. The serum home testing kit is available at many drug stores. Currently there is only one FDA approved home sample collection kit.
For more information about testing options in your area, contact your local health department or CDC-INFO (formerly the National AIDS Hotline) at 1-800-CDC-INFO (1-800-232-4636).

Auto Pistol of the 20th Century

Pistol of the century?that's easy. for nine decades the Colt goverment model 1911 has been without challenge the most recognize, most imitated, most influential and most used semiauto handgun in the world. it is to autoloaders what the Colt single Action army is to revolvers
It's Basic mechanical design, based on John Browning Original 1898 patent for a recoil-operated autoloader mechanism, has been the foundation or point of reference for virtually every other centerfire autoloading pistol subsequently produced by handgun manufacturers everywhere for the entire 20th century, and it is more widely copied and imitated than any other pistol ever made. it held it's position as the official sidearm of the U.S armed services for 75 years which is longer than any other continuous-use military arm in any nations history.

due to it's extremely widespread use by military forces in many nations, more people have handled or fired some form of the model 1911 pistol at least once in their lives than any other sidearm ever made. worldwide dozens of parts assemblers and manufacturers are presently producing clones and semi-clones of the model 1911, including at least four based in the US, plus a gazilion parts and component makers, and not to mention the real, authentic, official version still offered by Colt Firearms itself.
even at the turn into the 21st century, when high-tech double-action autoloaders with space-age polymer components firing high-pressure metric-designation cartridges have swept many military and law enforcement markets, the venerable all-steel Goverment Model single-action semiauto in original .45 ACP chambering remains a strong seller.

F-117A Nighthawk Stealth Fighter

Nighthawk BackgroundThe first F-117A Nighthawk was delivered in 1982, and the last delivery was in the summer of 1990. The Nighthawk production decision was made in 1978 with a contract awarded to Lockheed Advanced Development Projects, the "Skunk Works," in Burbank, Calif. The first flight was in 1981, only 31 months after the full-scale development decision. Air Combat Command's only F-117A unit, the 4450th Tactical Group, (now the 49th Fighter Wing, Holloman Air Force Base, N.M.), achieved operational capability in October 1983.
Streamlined management by Aeronautical Systems Center, Wright-Patterson AFB, Ohio, combined breakthrough stealth technology with concurrent development and production to rapidly field the aircraft. The F-117A Nighthawk program has demonstrated that a stealth aircraft can be designed for reliability and maintainability. The aircraft maintenance statistics are comparable to other tactical fighters of similar complexity. Logistically supported by Sacramento Air Logistics Center, McClellan AFB, Calif., the Nighthawk is kept at the forefront of technology through a planned weapon system improvement program located at USAF Plant 42 at Palmdale, Calif.
Nighthawk HistoryExtracted From F-117A Nighthawk to fly at Air Expo '01 by Nick Minecci NAS PATUXENT RIVER PUBLIC AFFAIRS DEPARTMENT
Officially named F-117A Nighthawk, but better known to the world as the stealth fighter, the Nighthawk made its combat debut Dec. 19, 1989, when six F-117As left their base in Nevada, headed for Panama. Two of the F-117As were turned back when their mission was canceled, two flew as back-up and returned to base when it was seen they were not needed, and the last pair flew to the Central American nation in support of U.S. combat operations in progress.
The stealth fighter would earn fame, however, over a year later when several struck deep into the heart of Iraq, striking Baghdad live on television during the opening hours of Operation Desert Storm. Throughout the Gulf War, the F-117As would be assigned the toughest and highest priority targets, including SAM and SCUD launchers, radar sites, Iraqi command/control/ communications facilities, bridges, and hardened aircraft shelters and bunkers.
By the end of the war the stealth fighter had performed over 40 percent of the allies' strategic bombing raids in more than 1,200 sorties, delivering more than 2,000 tons of ordnance without the loss of a single plane. Not one was even fired upon as the revolutionary plane flew into the aviation history books.
The F-117A Nighthawk began its life in 1978 when Lockheed Advanced Development Projects, famously known as "Skunk Works," was awarded the contract to develop an aircraft that would be almost invisible to radar. The prototype flew the same year, but was lost when the pilot had to eject at 10,000 feet over the Nevada desert. The second prototype was more successful and achieved as near a state of radar invisibility as possible.
In 1981, 31 months after the decision was made to go ahead with full-scale development the first flight of the super-secret plane was made, and in October 1983 the Air Force's only F-117A unit, the 4450th Tactical Group (now designated the 45th Fighter Wing) achieved operational capability.
The F-117A Nighthalk is a unique aircraft, with its surfaces and edge profiles optimized to reflect enemy radar away from the radar detectors. Coated with radar absorbing materials, the radar cross-section of the F-117A has been estimated at between 10 and 100 square cm, or about the size of a small bird, making it nearly invisible to enemy air defenses.
Close in size to the F-14 Tomcat, the Nighthawk is powered by a pair of 48 k-N General Electric F404-GE-F1D2 turbofans, which are derivatives of the F404-GE-400 engines used to power the F/A-18 Hornet. To keep the aircraft as invisible as possible, the engine exhaust area is wide and flat, with the air intakes on both sides of the fuselage covered by gratings coated with radar absorbent material. The Nighthawk's two large tail fins lean outwards, obstructing infrared and radar returns of the engine exhaust area.
The Nighthawk has a one-man crew, and the cockpit is outfitted with a Kaiser Electronics heads-up display (HUD). The flight deck is equipped with a large video monitor displaying infrared images from the plane's onboard sensors and a full-color moving map developed by the Harris Corporation.
To keep the plane as invisible as possible to enemy detection the F-117A does not rely on radar for navigation or targeting. The plane is equipped with a forward-looking infrared (FLIR) and a downward looking infrared (DLIR) with a laser designator, and uses a Honeywell inertial navigation system.
Along the front of the aircraft are multi-channel pitot-static tubes, with multiple ports along the length of the tubes that provide differential pressure readings that the flight control computers compare to provide the Nighthawk's flight data.
When going into battle, the F-117A can carry up to 4,000 pounds and a variety of weapons in the internal weapons bay, including the BLU-109B low-level laser guided bomb, GBU-10 and GBU-27 laser-guided bomb units and the AGM-65 and AGM-88 HARM air-to-surface missiles
The F-117A's top speed has been released as high subsonic, with its cruising speed as 684 mph. The Nighthawk has an unlimited range for operations when using aerial refueling.
MissionThe F-117A Nighthawk is the world's first operational aircraft designed to exploit low-observable stealth technology.
Nighthawk FeaturesThe unique design of the single-seat F-117A Nighthawk provides exceptional combat capabilities. About the size of an F-15 Eagle, the twin-engine aircraft is powered by two General Electric F404 turbofan engines and has quadruple redundant fly-by-wire flight controls. Air refuelable, it supports worldwide commitments and adds to the deterrent strength of the U.S. military forces.
The F-117A can employ a variety of weapons and is equipped with sophisticated navigation and attack systems integrated into a state-of-the-art digital avionics suite that increases mission effectiveness and reduces pilot workload. Detailed planning for missions into highly defended target areas is accomplished by an automated mission planning system developed, specifically, to take advantage of the unique capabilities of the F-117A.
General CharacteristicsPrimary Function: Fighter/attack Contractor: Lockheed Aeronautical Systems Co. Power Plant: Two General Electric F404 engines Length: 65 feet, 11 inches (20.3 meters) Height: 12 feet, 5 inches (3.8 meters) Weight: 52,500 pounds (23,625 kilograms) Wingspan: 43 feet, 4 inches (13.3 meters) Speed: High subsonic Range: Unlimited with air refueling Armament: Internal weapons carriage Unit Cost: $45 million Crew: One Date Deployed: 1982 Inventory: Active force, 54; ANG, 0; Reserve, 0
Image Provided by U.S.A.F.
F-117A: The Black Jet The F-117A Nighthawk, the world's first stealth fighter.
Stealth Secrets of the F-117 Nighthawk Its development was kept under wraps for 14 years, but by 1991, the F-117 Nighthawk had become a household word.
History of the NightHawk History and photos.
Weapons of Operation Enduring Freedom The history behind some of the jets and weapons being used in today's military conflicts.

F-14 Tomcat

Background: The F-14 Tomcat entered the fleet in 1973, replacing the F-4 Phantom II. The F-14B, introduced in November 1987, incorporated new General Electric F-110 engines. In 1995, an upgrade program was initiated to incorporate new digital avionics and weapon system improvements to strengthen its multi-mission competitive edge. The F-14D, delivered in 1990, was a major upgrade with F-110 engines, new APG-71 radar system, Airborne Self Protection Jammer (ASPJ), Joint Tactical Information Distribution System (JTIDS) and Infrared Search and Track (IRST). Additionally, all F-14 variants were given precision strike capability using the LANTIRN targeting system, night vision compatibility, new defensive countermeasures systems and a new digital flight control system.

F-14 Tomcat Description: The Grumman F-14 Tomcat is a supersonic, twin-engine, variable sweep wing, two-place strike fighter. The Tomcat's primary missions are air superiority, fleet air defense and precision strike against ground targets.
F-14 Tomcat Features: The F-14 Tomcat has visual and all-weather attack capability to deliver Phoenix and Sparrow missiles as well as the M-61 gun and Sidewinder missiles for close in air-to-air combat. The F-14 also has the LANTIRN targeting system that allows delivery of various laser-guided bombs for precision strikes in air-to-ground combat missions. The F-14, equipped with Tactical Air Reconnaissance Pod System (TARPS) is the Navy's only manned tactical reconnaissance platform.

General Characteristics of the F-14 Tomcat

Function: Carrier-based multi-role strike fighter

Contractor: Grumman Aerospace Corporation

Unit Cost: $38 million

Propulsion:

F-14A: Two Pratt & Whitney TF-30P-414A turbofan engine with afterburners

F-14B and F-14D: Two General Electric F110-GE-400 turbofan engines with afterburners

Thrust:

TF-30P-414A: 20,900 pounds (9,405 kg) static thrust per engine

F110-GE-400: 27,000 pounds (12,150 kg) static thrust per engine

Length: 61 feet 9 inches (18.6 meters)

Height: 16 feet (4.8 meters)

Maximum Takeoff Weight: 72,900 pounds (32,805 kg)

Wingspan: 64 feet (19 meters) unswept, 38 feet (11.4 meters)

swept Ceiling: Above 50,000 feet

Speed: Mach 2+

Crew: Two: pilot and radar intercept officer

Armament: Up to 13,000 pounds to include AIM-54 Phoenix missile, AIM-7 Sparrow missile, AIM-9 Sidewinder missile, air-to-ground precision strike ordnance, and one M61A1/A2 Vulcan 20mm cannon.

Date Deployed: First flight: December 1970
Information and photos provided by the United States Navy
Weapons of Operation Enduring Freedom The history behind some of the jets and weapons being used in today's military conflicts.

Background of the F-16

The F-16A, a single-seat model, first flew in December 1976. The first operational F-16A was delivered in January 1979 to the 388th Tactical Fighter Wing at Hill Air Force Base, Utah.
The F-16B, a two-seat model, has tandem cockpits that are about the same size as the one in the A model. Its bubble canopy extends to cover the second cockpit. To make room for the second cockpit, the forward fuselage fuel tank and avionics growth space were reduced. During training, the forward cockpit is used by a student pilot with an instructor pilot in the rear cockpit.
All F-16s delivered since November 1981 have built-in structural and wiring provisions and systems architecture that permit expansion of the multirole flexibility to perform precision strike, night attack and beyond-visual-range interception missions. This improvement program led to the F-16C and F-16D aircraft, which are the single- and two-place counterparts to the F-16A/B, and incorporate the latest cockpit control and display technology. All active units and many Air National Guard and Air Force Reserve units have converted to the F-16C/D.
The F-16 was built under an unusual agreement creating a consortium between the United States and four NATO countries: Belgium, Denmark, the Netherlands and Norway. These countries jointly produced with the United States an initial 348 F-16s for their air forces. Final airframe assembly lines were located in Belgium and the Netherlands. The consortium's F-16s are assembled from components manufactured in all five countries. Belgium also provides final assembly of the F100 engine used in the European F-16s. Recently, Portugal joined the consortium. The long-term benefits of this program will be technology transfer among the nations producing the F-16, and a common-use aircraft for NATO nations. This program increases the supply and availability of repair parts in Europe and improves the F-16's combat readiness.
USAF F-16 multi-mission fighters were deployed to the Persian Gulf in 1991 in support of Operation Desert Storm, where more sorties were flown than with any other aircraft. These fighters were used to attack airfields, military production facilities, Scud missiles sites and a variety of other targets.
Most recently in the Spring of 1999 during Operation Allied Force, USAF F-16 multi-mission fighters flew a variety of missions to include suppression of enemy air defense, offensive counter air, defensive counter air, close air support and forward air controller missions. Mission results were outstanding as these fighters destroyed radar sites, vehicles, tanks, MiGs and buildings.
Mission of the F-16 Fighting Falcon
The F-16 Fighting Falcon is a compact, multi-role fighter aircraft. It is highly maneuverable and has proven itself in air-to-air combat and air-to-surface attack. It provides a relatively low-cost, high-performance weapon system for the United States and allied nations.
Features of the F-16 Fighting Falcon
In an air combat role, the F-16's maneuverability and combat radius (distance it can fly to enter air combat, stay, fight and return) exceed that of all potential threat fighter aircraft. It can locate targets in all weather conditions and detect low flying aircraft in radar ground clutter. In an air-to-surface role, the F-16 can fly more than 500 miles (860 kilometers), deliver its weapons with superior accuracy, defend itself against enemy aircraft, and return to its starting point. An all-weather capability allows it to accurately deliver ordnance during non-visual bombing conditions.
In designing the F-16, advanced aerospace science and proven reliable systems from other aircraft such as the F-15 and F-111 were selected. These were combined to simplify the airplane and reduce its size, purchase price, maintenance costs and weight. The light weight of the fuselage is achieved without reducing its strength. With a full load of internal fuel, the F-16 can withstand up to nine G's -- nine times the force of gravity -- which exceeds the capability of other current fighter aircraft.
The cockpit and its bubble canopy give the pilot unobstructed forward and upward vision, and greatly improved vision over the side and to the rear. The seat-back angle was expanded from the usual 13 degrees to 30 degrees, increasing pilot comfort and gravity force tolerance. The pilot has excellent flight control of the F-16 through its "fly-by-wire" system. Electrical wires relay commands, replacing the usual cables and linkage controls. For easy and accurate control of the aircraft during high G-force combat maneuvers, a side stick controller is used instead of the conventional center-mounted stick. Hand pressure on the side stick controller sends electrical signals to actuators of flight control surfaces such as ailerons and rudder.
Avionics systems include a highly accurate inertial navigation system in which a computer provides steering information to the pilot. The plane has UHF and VHF radios plus an instrument landing system. It also has a warning system and modular countermeasure pods to be used against airborne or surface electronic threats. The fuselage has space for additional avionics systems.
General Characteristics
Primary Function: Multirole fighter Builder: Lockheed Martin Corp. Power Plant: F-16C/D: one Pratt and Whitney F100-PW-200/220/229 or General Electric F110-GE-100/129 Thrust: F-16C/D, 27,000 pounds Length: 49 feet, 5 inches (14.8 meters) Height: 16 feet (4.8 meters) Wingspan: 32 feet, 8 inches (9.8 meters) Speed: 1,500 mph (Mach 2 at altitude) Ceiling: Above 50,000 feet (15 kilometers) Maximum Takeoff Weight: 37,500 pounds (16,875 kilograms) Range: More than 2,000 miles ferry range (1,740 nautical miles) Armament: One M-61A1 20mm multibarrel cannon with 500 rounds; external stations can carry up to six air-to-air missiles, conventional air-to-air and air-to-surface munitions and electronic countermeasure pods Unit cost: F-16A/B , $30.1 million; F-16C/D, $34.3 million (2000 dollars) Crew: F-16C, one; F-16D, one or two Date Deployed: January 1979
Information and photo provided by United States Army
Weapons of Operation Enduring Freedom The history behind some of the jets and weapons being used in today's military conflicts.

Features F-15 Eagle

The Eagle's air superiority is achieved through a mixture of unprecedented maneuverability and acceleration, range, weapons and avionics. It can penetrate enemy defense and outperform and outfight any current enemy aircraft. The F-15 has electronic systems and weaponry to detect, acquire, track and attack enemy aircraft while operating in friendly or enemy-controlled airspace. The weapons and flight control systems are designed so one person can safely and effectively perform air-to-air combat.
The F-15's superior maneuverability and acceleration are achieved through high engine thrust-to-weight ratio and low wing loading. Low wing-loading (the ratio of aircraft weight to its wing area) is a vital factor in maneuverability and, combined with the high thrust-to-weight ratio, enables the aircraft to turn tightly without losing airspeed.
A multimission avionics system sets the F-15 apart from other fighter aircraft. It includes a head-up display, advanced radar, inertial navigation system, flight instruments, ultrahigh frequency communications, tactical navigation system and instrument landing system. It also has an internally mounted, tactical electronic-warfare system, "identification friend or foe" system, electronic countermeasures set and a central digital computer.
The head-up display projects on the windscreen all essential flight information gathered by the integrated avionics system. This display, visible in any light condition, provides the pilot information necessary to track and destroy an enemy aircraft without having to look down at cockpit instruments.
The F-15's versatile pulse-Doppler radar system can look up at high-flying targets and down at low-flying targets without being confused by ground clutter. It can detect and track aircraft and small high-speed targets at distances beyond visual range down to close range, and at altitudes down to treetop level. The radar feeds target information into the central computer for effective weapons delivery. For close-in dogfights, the radar automatically acquires enemy aircraft, and this information is projected on the head-up display. The F-15's electronic warfare system provides both threat warning and automatic countermeasures against selected threats.
A variety of air-to-air weaponry can be carried by the F-15. An automated weapon system enables the pilot to perform aerial combat safely and effectively, using the head-up display and the avionics and weapons controls located on the engine throttles or control stick. When the pilot changes from one weapon system to another, visual guidance for the required weapon automatically appears on the head-up display.
The Eagle can be armed with combinations of four different air-to-air weapons: AIM-7F/M Sparrow missiles or AIM-120 advanced medium range air-to-air missiles on its lower fuselage corners, AIM-9L/M Sidewinder or AIM-120 missiles on two pylons under the wings, and an internal 20mm Gatling gun in the right wing root.
Low-drag, conformal fuel tanks were especially developed for the F-15C and D models. Conformal fuel tanks can be attached to the sides of the engine air intake trunks under each wing and are designed to the same load factors and airspeed limits as the basic aircraft. Each conformal fuel tank contains about 114 cubic feet of usable space. These tanks reduce the need for in-flight refueling on global missions and increase time in the combat area. All external stations for munitions remain available with the tanks in use. AIM-7F/M Sparrow missiles, moreover, can be attached to the corners of the conformal fuel tanks.
The F-15E is a two-seat, dual-role, totally integrated fighter for all-weather, air-to-air and deep interdiction missions. The rear cockpit is upgraded to include four multi-purpose CRT displays for aircraft systems and weapons management. The digital, triple-redundant Lear Siegler flight control system permits coupled automatic terrain following, enhanced by a ring-laser gyro inertial navigation system.
For low-altitude, high-speed penetration and precision attack on tactical targets at night or in adverse weather, the F-15E carries a high-resolution APG-70 radar and low-altitude navigation and targeting infrared for night pods.
General CharacteristicsPrimary function: Tactical fighter Contractor: McDonnell Douglas Corp. Power plant: Two Pratt & Whitney F100-PW-220 or 229 turbofan engines with afterburners Thrust: (C/D models) 23,450 pounds each engine Wing span: 42.8 feet (13 meters) Length: 63.8 feet (19.44 meters) Height: 18.5 feet (5.6 meters) Speed: 1,875 mph (Mach 2.5 plus) Maximum takeoff weight: (C/D models) 68,000 pounds (30,844 kilograms) Ceiling: 65,000 feet (19,812 meters) Range: 3,450 miles (3,000 nautical miles) ferry range with conformal fuel tanks and three external fuel tanks Crew: F-15A/C: one. F-15B/D/E: two Armament: One internally mounted M-61A1 20mm 20-mm, six-barrel cannon with 940 rounds of ammunition; four AIM-9L/M Sidewinder and four AIM-7F/M Sparrow air-to-air missiles, or eight AIM-120 AMRAAMs, carried externally. Unit Cost: A/B models - $30.1 million;C/D models - $34.3 million (flyaway costs) Date deployed: July 1972 Inventory: Active force, 396; Reserve, 0; ANG,126.
F-15E Strike Eagle Aircraft
Images Provided by U.S.A.F.
F-15 History The McDonnell Douglas F-15 Eagle is a U.S.A.F. jet fighter plane that was deployed in western Europe by NATO forces in the year 1977. A two-seat, dual-role version, the F-15E, was delivered to the U.S. Air Force in the year 1988.

History F-15 Eagle

The F-15 Eagle history is long and distinguished. It began as a Air Force fighter study in the early 1960s and was known as the Fighter Experimental (FX). By 1967 the Air Force began development of a new high performance fighter aircraft that would be extremely agile and would be capable of gaining and maintaining air superiority through air-to-air combat. The new design had to be optimized for combat with the power and agility to overcome any current or projected Soviet threat. The F-15 was the first air-to-air fighter requested by the Air Force since the F-86 Sabre. The resulting F-15 Eagle had an unequaled combination of performance, firepower, and avionics. It was the benchmark--the plane to beat.
To succeed in the air-to-air role, a plane needs the right airframe in combination with strong powerplant and avionics. The plane�s designers understood this and stretched technology to the limits. It was determined that a very low wing loading combined with heavy thrust from the engines would be required. U.S. fighter aircraft of the period were going faster (Mach 2 plus), but were heavy and lacked maneuverability compared to their Soviet counterparts. When combined with a capable airframe, better maneuverability can be achieved by maximizing thrust, thereby maximizing energy. The Pratt & Whitney F100 Turbofan engine provides the needed thrust. Each engine is capable of producing 15,000 pounds of thrust at maximum power, and 25,000 pounds of thrust in afterburner. This gives the Eagle a total of 50,000 pounds of thrust. In other words, a nominally loaded F-15 Eagle of 48,000 pounds has a thrust-to-weight ratio of 1.04 pounds of thrust to each pound of aircraft weight. Thrust of this caliber allows an F-15 to accelerate while going straight up! A specially modified F-15A Eagle known as the "Streak Eagle" was able to outclimb a Saturn V Moon Rocket to almost 60,000 feet. This same aircraft flew to 98,430 feet (30,000 meters) in 207.80 seconds (less than 3 minutes and 30 seconds).
The lightly loaded airframe is combined with an equally impressive flight control system. A hydraulically actuated, mechanically controlled flight control system is augmented by an electronic system known as the Control Augmentation System (CAS). This system takes the stick inputs from the pilot and deflects the flight controls in the proper direction at the proper rate for optimal aircraft handling. This system allows the pilot to fly the aircraft to the limits of its capabilities without losing control of the aircraft. The CAS can also actuate the flight controls via pilot input if the hydro-mechanical system is damaged.
In order to win air-to-air battles, the pilot must be able to see, shoot, evade, and destroy the adversary first. The Eagle has an impressive array of weapons and avionics which allow it to get the advantage. The APG-63 and 70 radars allow crews to see targets that are as far away as 100 miles. These "Eyes" are able to ferret out the targets even if the targets are flying at high speeds at low altitudes. A Tactical Electronic Warfare System (TEWS) lets the aircrew know if any threat is present. The Heads-up-Display (HUD), and the Hands on Throttle and Stick (HOTAS), allow the Pilot to select, track and shoot the adversary without having to look back into the cockpit.
The impressive avionics suite is backed up by an equally impressive weapons capability. For close air-to-air combat the Eagle carries the six barreled 20mm M61A1 Vulcan cannon. The Vulcan fires rounds at rates of 66 or 100 rounds per second. Further distances are covered by the heat seeking AIM-9 Sidewinder, AIM-7 Sparrow, and the deadly AIM-120 Advanced Medium Range Air-to-Air Missile.
The F-15 Eagle has been produced in five models. The single seat A and C models, the two seat B and D models, and the formidable F-15E Strike Eagle. The A through D models are air-to-air versions but the E Model can carry out an air-to-ground mission in addition to the original air-to-air mission.
The F-15E is capable of delivering over 20,000 pounds of air-to-ground ordinance while traveling at high speeds at very low altitudes (as low as 100 feet) at night. To perform this role the aircraft utilizes the sophisticated LANTIRN system (Low Altitude Navigation Targeting Infrared for Night). This multi-role aircraft was conceived early in the development of the F-15 because it was easier to convert a thoroughbred air-to-air fighter into a ground attack platform than to complete this function in the opposite manner. The rear cockpit has become a dedicated air-to-ground crew station, housing several sophisticated multi-function display screens and two hand controllers. Added fuel is carried in conformal side fuselage tanks that increase the range without adding excessive aircraft drag. These conformal fuel tanks, fully integrated into the aircraft structure, contain hard point stations for additional air-to-ground ordinance loads.
Mission F-15 EagleThe F-15 Eagle is an all-weather, extremely maneuverable, tactical fighter designed to permit the Air Force to gain and maintain air superiority in aerial combat.

F-15 Eagle Aircraft

Background F-15 Eagle Aircraft
The first F-15A flight was made in July 1972, and the first flight of the two-seat F-15B (formerly TF-15A) trainer was made in July 1973. The first Eagle (F-15B) was delivered in November 1974. In January 1976, the first Eagle destined for a combat squadron was delivered.
The single-seat F-15C and two-seat F-15D models entered the Air Force inventory beginning in 1979. These new models have Production Eagle Package (PEP 2000) improvements, including 2,000 pounds (900 kilograms) of additional internal fuel, provision for carrying exterior conformal fuel tanks and increased maximum takeoff weight of up to 68,000 pounds (30,600 kilograms).
The F-15 Multistage Improvement Program was initiated in February 1983, with the first production MSIP F-15C produced in 1985. Improvements included an upgraded central computer; a Programmable Armament Control Set, allowing for advanced versions of the AIM-7, AIM-9, and AIM-120A missiles; and an expanded Tactical Electronic Warfare System that provides improvements to the ALR-56C radar warning receiver and ALQ-135 countermeasure set. The final 43 included a Hughes APG-70 radar.
F-15C, D and E models were deployed to the Persian Gulf in 1991 in support of Operation Desert Storm where they proved their superior combat capability with a confirmed 26:0 kill ratio. F-15 fighters accounted for 36 of the 39 Air Force air-to-air victories. F-15Es were operated mainly at night, hunting SCUD missile launchers and artillery sites using the LANTIRN system.
They have since been deployed to support Operation Southern Watch, the patrolling of the UN-sanctioned no-fly zone in Southern Iraq; Operation Provide Comfort in Turkey; in support of NATO operations in Bosnia, and recent air expeditionary force deployments.

Gatling Gun-Description Model

Models 1862-1871
Model 1862. In 1862, at the age of 44, Richard Gatling had demonstrated his first working model of the Gatling gun in Indianapolis, Indiana. He patented the Gatling gun on November 4, 1862. Its key elements were a lock cylinder containing six strikers which revolved with six gun barrels, powered by a hand crank. The gun used separate .58 cal. paper cartridges and percussion caps, which resulted in gas leakage. The model 1862 Gatling gun attained a very high rate of fire of 200 spm (shots per minute) for that time.
Model 1865. By changing to a unitary cartridge, Gatling overcame the problem with gas leakage only to encounter problems in the ammunition feed mechanism. Gatling designed a new breech mechanism which fixed the feed problem, leading to the development of the much improved model 1865 six-barrel 1 inch Gatling gun, the forerunner of all later model Gatling guns. Model 1865 1 inch caliber Gatling gun on artillery carriage (Copyright Arco Publishing)
Model 1866. After successful trials at Frankford Arsenal and Fort Monroe, the U.S. Army ordered 50 1 inch cal. and 50 .50 cal. model 1866 six-barrel Gatling guns. All but five of the .50 cal. guns were converted to .45 cal. beginning in August 1866. The gun used a simple tin box to hold cartridges. These guns were all fixed-mounted on an artillery carriage.
Model 1871 had improved breech bolts that could be easily removed for maintenance in the field used a new curved cartridge magazine. In 1872 a new hopper design permitted use of a 400 round Broadwell drum. The Broadwell drum was a circular cluster of 20 vertical feed magazines containing 20 cartridges each. When a magazine emptied, the gunner manually turned the drum to align the next full magazine. The U.S. Army purchased one 1 inch cal. and nine .50 cal model 1871 ten-barrel weapons.

Models 1874-1877
Model 1874 featured a shorter, lighter bronze breech that resulted in a lighter and sturdier .45 cal. gun. The gun had an automatic or manual traversing mechanism and for the first time, an adjustable set screw which permitted head space adjustment. A right hand mounting sight permitted the feed hopper to be shifted from 45� to a vertical feed, using a new box magazine. The guns were made in two lengths, a musket length and a smaller shorter length "Camel" gun. This ten-barrel .45 cal. gun had an improved automatic or manual traversing mechanism. The U.S. Army bought eight musket length guns. The lighter "Camel" gun could be mounted on a new lighter cavalry cart, tripod, or camel saddle. The "Camel" name was more a marketing ploy than a practical application. The U.S. Army bought 11 model 1874 guns. Model 1874 "Camel" gun with Broadwell drum on tripod mount
Model 1875 had an improved hopper, new magazine, and a beveled bolt face to correct some jamming problems experienced with the model 1874 gun. A new vertical feed 40 round magazine, trapezoidal in cross-section, was introduced at this time. The U.S. Army bought 44 long barrel and four "Camel" guns.
Model 1876 featured relocation of the hopper to the left of center, cartridge guides, improved breech, and altered breech bolt bevel.
Model 1877 long barrel had a new feed hopper for easier ejection and a higher rate of fire.
Model 1877 "Bulldog" was the first Gatling gun to feature a fully enclosed bronze housing over the barrels and breech. The "Bulldog" was a five-barrel .45 cal. tripod mounted weapon. A few were mounted on a light cavalry cart. A rear mounting hand crank permitted a very high rate of fire of up to 1,000 spm, almost twice the rate of a typical World War II machine gun.


Models 1879-1881
Model 1879 was the first Gatling gun with a flexible mount that could traverse through an arc like a true machine gun. Head spacing could be adjusted using a notched adjusting knob without using any tools. Most model 1879 guns were mounted on artillery carriages, but a few were mounted on tripods. The model 1879 was a ten-barrel .45 cal. fully encased gun using the standard 40 round trapezoidal magazine. The U.S. Army purchased 32 model 1879 Gatlings. Model 1879 Gatling gun on flexible tripod mount (Copyright Arco Publishing)
Model 1881 was similar to the model 1879, but had a modified feed hopper to accept the new Bruce feeder. The U.S. Army bought 27 model 1881 guns.
Bruce feeder, named after it's inventor, L.F. Bruce, permitted the Gatling gun to be loaded directly from 20 round cardboard cartons into a two slot vertical bar. When one slot emptied, gravity forced a full slot over the feed hopper. By alternately loading the empty slot, a continuous fire could be sustained. The Bruce feeder was a favorite of the U.S. Army.

Models 1883-1889
Model 1883 was a ten-barrel .45 cal. gun fully encased in a bronze jacket. A side mounting hand crank produced a rate of fire of up to 800 spm, but could be rear mounted to increase the rate up to 1,500 spm. Internal components were strengthened to withstand the punishment from the higher rate of fire. The model 1883 had a new flexible yoke that permitted a wider angle of traverse and elevation than previous models. However, the vertical feed magazine did not work as well with wider range in elevation. A new flat donut-shaped Accles mechanical drum feeder was developed for use with this gun. The standard mount was a heavy steel Army carriage, but it could also be mounted on a light folding steel tripod. The Accles feeder was a complex mechanism subject to jamming. In 1898, the U.S. Army refitted it's model 1883 Gatlings with a Bruce feeder adapter. Model 1883 with Accles feeder on flexible yoke on Army steel carriage
Models 1885, 1886, and 1887 were modifications to the model 1883 with improvements in the ejector and cartridge guides. The Army purchased 100 model 1885-1887 Gatling guns.
Model 1889 went back to an improved version of the model 1881 that could use either a Bruce feeder or the older style gravity feed magazine. This model featured a heavy steel gunner's shield and ten exposed .45 cal. barrels. The U.S. Army bought 53 model 1889-1892 Gatlings.


Models 1893-1903
Model 1893 was similar to models 1889-1892, but the caliber was changed to the new Army standard .30/40 cartridge. A new horizontal strip feeder was introduced with the model 1893. The strip feeder fed from the left side. Wedges in the hopper stripped each round from its retaining prongs into the hopper. The empty feeder ejected to the right side. The U.S. Army bought 18 ten-barrel .30 cal. model 1893 guns. The strip feeder was also subject to jamming. In 1897 the Army converted all of it's .30 cal. Gatlings to accept the Bruce feeder. In 1893 the Gatling Gun Company introduced a six-barrel version of the model 1893 that was the smallest of all the Gatling guns.
Model 1895 was similar to the model 1893, but was designed to accept only the Bruce feeder. All previous model were unpainted, but this model was painted olive drab, with some parts blued.
Model 1900 was very similar to the model 1895, but only a few parts were painted olive drab. Models 1895-1903 could be mounted on an armored field carriage. The U.S. Army bought 94 model 1895 Gatlings and many model 1900s.
Model 1903. In 1903, the Army converted their model 1900 guns to fit the .30-03 cartridge that became the Army standard with the introduction of their new model 1903 Springfield rifle.
Model 1903-06. Later, all model 1903 Gatlings were converted to cal. .30-06. This conversion was done mostly at the Army's Springfield Armory.
Obsolescence. With a advent of the automatic machine gun, the U.S. Army declared their Gatling gun obsolete in 1911, after 45 years of service to the U.S. Army.


Evolution of the M61 Vulcan Gatling Gun
World War II fighters and bombers were commonly equipped with Browning M2 heavy barrel .50 cal. machine guns which had a maximum firing rate of 1,200 spm. The Gatling gun had exceeded that rate of fire in 1880.
In 1946, U.S. Army Ordnance Research and Development Service engineers dusted-off the old Gatling principle and adapted it to create the 6,000 spm M61 series Vulcan 20mm Gatling gun that now arms many of our U.S. Air Force and U.S. Navy supersonic fighters, including the F-14, F-15, F-16, F/A-18 and the F-111A. The Gatling principle permitted a high rate of fire while reducing heat and barrel erosion. M61 20mm Vulcan aircraft gun in SUU-16 external gun pod (Copyright Arco Publishing)
In June 1946, the General Electric Company was awarded the contract for "Project Vulcan". In 1950, GE delivered ten initial model A .60 cal. T45 guns for evaluation. Thirty-three model C T45 guns were delivered in 1952 in three calibers: .60 cal., 20mm, and 27mm, for additional testing. After extensive testing, the T171 20mm gun was selected for further development. In 1956 the T171 20mm gun was standardized by the U.S. Army and U.S. Air Force as the M61 20mm Vulcan aircraft gun. The M61 20mm Vulcan is an externally powered, six-barrel, rotary-fire gun having a rate of fire of up to 7200 spm. The firing rate is selectable at 4,000 spm or 6,000 spm. The gun fires standard electrically primed 20mm ammunition. The M61A1 is hydraulically or ram-air driven, electrically controlled, and uses a linkless ammunition feed system. The M61A1 is used in the Air Force GAU-8 and the Navy Phalanx CIWS (SeeWiz).
Source material:The Gatling Gun by Paul F. Wahl and Donald R. Toppel, Arco Publishing Company, New York, NY, 1965. The Gatling Gun is the best and possibly only definitive work that has ever been written on the Gatling gun.

Development of a light Gatling Gun for use on helicopters
The M61 Vulcan was modified into a lighter three-barrel version by removing three of the barrels, shortening the barrels, and changing the ammunition feed mechanism. The light weight modified Vulcan was type classified as the M197 20mm automatic gun now in use on the Modernized AH-1F "Huey" Cobra light attack helicopter. A modified Vulcan was also pintle mounted for use as a door gun on the UH-1 series "Huey" utility helicopter. The M197 has a selectable firing rate of 2000 spm or 3000 spm. Modified three-barrel M61 Vulcan (M197) door gun on HU-1B "Huey" M197 20mm door gun on UH-1B "Huey" M195 20mm automatic gun on XM35 armament subsystem for AH-1G Cobra M197 20mm automatic gun on AH-1F Modernized Cobra (Copyright Butch Lottman)
Near the end of the Vietnam war, the XM134 was tested experimentally for use on combat vehicles and as a infantry weapon. These programs were terminated in the early 1970s due to lack of funding.
The Air Force GAU-2B/A (Army M134) 7.62mm "minigun" was designed to provide a light weight high rate of fire armament package for use on helicopters and light fixed-wing aircraft. The basic M61 Vulcan has been simplified and redesigned to fire percussion primed 7.62mm ammunition. The basic M134 can be readily modified to fire other smaller caliber ammunition, such as the XM214 5.56mm "mini-minigun". See table below for a cross-reference to specific armament subsystems. M134 7.62mm "minigun"

XM214 5.56mm "mini-minigun"

Pintle mounted M134 minigun on UH-1H Nighthawk gunship

(Copyright Mike Austin at http://www.vietvet.org/bg23.htm) M134 Minigun firing (viewed thru pilot's window of UH-1M gunship) (Copyright Butch Lottman)


Phalanx CIWS (Close-In Weapon System)
Phalanx CIWS (SeeWiz) is a rapid-fire, computer-controlled radar and gun system to defeat anti-ship missiles, as well as other close-in surface and air threats. The Phalanx system automatically carries out search, detection, target acquisition, firing and kill assessment. The system's unique defensive capability is based on closed-loop spotting, a radar technology breakthrough. This technique uses advanced radar and computer technology to locate, identify and direct a stream of Armor Piercing Discarding Sabot (APDS) rounds to the target. The system uses an electrically-controlled, pneumatically-driven M61A1 Vulcan 20mm six-barrel Gatling-type gun capable of firing at a selectable 3,000 or 4,500 spm rate. Initially deployed in 1979, Phalanx is installed on every U.S. combatant ship, as well as combatant ships of 16 allied nations (Source: Raytheon Company).

Phalanx 20mm high rate of fire Close-In Weapon System (Copyright Raytheon Company) Phalanx video [phalanx.mpg] 258k, 11 sec (Copyright Raytheon Company) Phalanx video, with sound bit [phalanx.avi] 138k, 2 sec (Video provided by Robert Maddog Moland)

History of the Gatling Gun

In 1861, Doctor Richard Gatling patented the Gatling Gun
In 1861, Doctor Richard Gatling patented the Gatling Gun, a six-barreled weapon capable of firing a (then) phenomenal 200 rounds per minute. The Gatling gun was a hand-driven, crank-operated, multi-barrel, machine gun. The first machine gun with reliable loading, the Gatling gun had the ability to fire sustained multiple bursts.
Richard Gatling created his gun during the American Civil War, he sincerely believed that his invention would end war by making it unthinkable to use due to the horrific carnage possible by his weapons. At the least, the Gatling Gun's power would reduce the number of soldiers required to remain on the battlefield.
The 1862 version of the gatling gun had reloadable steel chambers and used percussion caps. It was prone to occasional jamming. In 1867, Gatling redesigned the Gatling gun again to use metallic cartridges - this version was bought and used by the United States Army.
Born September 12, 1818 in Hertford Count, North Carolina, Richard Gatling was the son of planter and inventor, Jordan Gatling, who held two patents of his own. Besides the Gatling gun, Richard Gatling also patented a seed-sowing rice planter in 1839 that was later adapted into a successful wheat drill.
In 1870, Richard Gatling and his family moved to Hartford, Connecticut, home of the Colt Armory where the Gatling gun was being manufactured.

How to Conduct a Patent Search

To get a basic understanding of patent searches read Searching For Students and in particular read Searching Using Key Words. It was written for students; however, if you can look past the cute language it will quickly get you reading and searching patents online within minutes. It will not be enough to do a diligent (complete) search for prior art by only using the Internet. For that you would need to understand the patent classification system and be prepared to do days or even weeks of research.

Turning an Invention Idea Into Money(How Do I Know if My Idea is Patentable?)

When an inventor files a patent application, the patent examiner looks at the patent application to determine if it qualifies. It should be remembered that even if the examiner grants your application, anything disqualifying that the examiner missed overturns your patent.
Your patent application will be examined to determine that your intellectual property is novel, useful, and nonobvious. Your patent application must adequately describe your invention.
Novelty or NewYour invention is not new as defined by U.S. patent law if:
an identical (or too similiar) invention was known or used by others in this country, or patented or described in a printed publication in this or a foreign country, before your invention was; or
your invention was patented or described in a printed publication in this or a foreign country or in public use or on sale in this country more than one year prior to your application for a patent in the United States.If the same intellectual property has been described in a printed publication anywhere in the world, or if it has been in public use or on sale in the United States before the date that you did your inventing, your patent application will be rejected.
Or if what you invented has been described in a printed publication anywhere, or has been in public use or on sale in this country more than one year before the date on which you filed an application in the U.S., your patent application will be rejected.
It does not matter if the printed publication or public use was by you or by someone else.

f you described your intellectual property in a printed publication or used it publicly, or placed it on sale, you must apply for a patent before one year has gone by, otherwise you lose any rights to one.

UsefulAn invention must serve some useful function. The term useful means that your intellectual property has a useful purpose and it must be operative. You must accurately describe what its use is and your invention must live up to your claims in order to be called useful.
NonobviousThe invention you are seeking to patent must be sufficiently different from what has been used or described before that it is nonobvious to a person having ordinary skill in the area of technology related to the invention. For example, the substitutions of one material for another, or changes in size, are ordinarily not patentable.
Nolo Law gives this example of nonobviousness: A baseball player invents an electronic device that can signal whether a pitch is a ball or a strike. The patent application is rejected on the ground that similar technology has already been developed for television commentators.
Reduced to Practice - Prove it on PaperIn your written patent application you must fully describe your invention to such a degree that a person skilled in the same field as the invention could make or use that invention. A person skilled in the same field as the invention should be able to read your patent application and understand it. The inventor must be able to make claims about his/her invention in clear and definite terms.
The part of a patent application that describes and reveals your invention is called the specification and includes various types of descriptions, claims, and drawings depending on the type of invention and type of patent involved. Remember, ideas alone can not be patented. In other words - you can't just write, "I have an idea for a new alarm clock." You must be able to describe how your alarm works so that an expert in alarm clocks would understand how it would work and that it would indeed work.
As a novice, to file your first patent application yourself is often unwise. However, you could write your own descriptions and then pass them over to your attorney. The attorney could use your writings as a guide and a time-saver, and that will save you money. You should present your inventor's logbook, prototype, and any prior art searches to the attorney (more about those later.)
You must write a complete and thorough description of your intellectual property as you cannot add any new information to your patent application once it is filed. You can only make changes to the subject matter that could be reasonably inferred from the original drawings or description.
"Claimed by the inventor in clear and definite terms" is not as easy as it sounds. Claims define the intellectual property and are what are legally enforceable by law. Claim writing can make or break a successful patent application.
Before even beginning the patent application process - you must search for news about similar inventions to yours that have already been publicly disclosed called prior art. More about that next.

Turning an Invention Idea Into Money(Patents and Inventions)

Creative ideas come from our minds, and inventions are the physical manifestation of those ideas. The part of intellectual property law that covers inventions are patents.
Patents are granted by a national government office (i.e. USPTO) after reviewing an inventor's application for patent, an application that describes your new machine or process and what it can do.
Three Basic Types of Patents
Utility patents protect useful processes, machines, articles of manufacture, and compositions of matter, or improvements to any of the above. Examples: fiber optics, computer hardware, medications.
Design patents guard the unauthorized use of new, original, and ornamental designs for articles of manufacture.
The look of an athletic shoe, a bicycle helmet, and the Star Wars characters are all protected by design patents.
Plant patents are the way we protect invented or discovered, asexually reproduced plant varieties. Hybrid tea roses, Silver Queen corn, Better Boy tomatoes are all types of plant patents.You can file for both a utility and a design patent for the different aspects of the same invention.
Do Not Patent
Laws of nature (wind, gravity)
Physical phenomena (sand, water)
Abstract ideas (mathematics, a philosophy)
Literary, dramatic, musical, and artistic works. These can be copyright protected.
The USPTO will not patent perpetual motion machines as they are considered impossible.
The USPTO excludes the patenting of things useful solely in the utilization of special nuclear material or atomic energy for atomic weapons. Also anything designed for an illegal activity.
You Can Only PatentInventions that are:
Novel or New
Nonobvious - This means an invention must be sufficiently different. For example, the substitution of one material for another, or changes in size, are ordinarily not patentable. So even if the invention you seek to patent has not exactly been made before, if the differences between it and the next similar thing already known are too obvious (too close to being the same) your patent will be refused.
Inventions which are useful. Your gadget must do something and serve some practical purpose. And it must be able to perform its declared purpose.More about the above points next and how to determine if your idea is patentable.

Turning an Invention Idea Into Money(Understanding Intellectual Property)

Patents, trademarks, copyrights, and trade secrets are " intellectual property " - referring to products that come from the creative mind. Intellectual property is imagination made real. Intellectual property is an asset just like your home, your car, or your bank account.
Just like other kinds of property, intellectual property needs protection from theft and misuse and you can profit from it. Some people confuse patents, copyrights, and trademarks. Although there may be some similarities among these kinds of intellectual property protection, they are different and serve different purposes.
PatentsA patent gives an inventor the right to exclude all others from making, using, importing, selling or offering to sell his/her invention for up to 20 years without the inventor's permission.

This gives the inventor the opportunity to produce and market his/her idea, or license others to do so, and to make a profit.
In the U.S., a patent is issued by the United States Patent and Trademark Office or USPTO after reviewing a patent application. A United States patent only protects and provides exclusive rights in the United States. Similar patent protection is offered in other countries.
One thing to remember is even if you are issued a patent if someone else has had a patent issued for the same invention before you - your patent rights could be contested or you could contest a patent issued after yours that infringes on your invention. That is called patent infringement and inventors sometimes have to go to court to settle disputes and damages. One way to avoid this is to do a very complete prior art search - more about prior art and patent searching later.
TrademarksTrademarks protect words, names, symbols, sounds, or colors that distinguish goods and services. Trademarks, unlike patents, can be renewed forever as long as they are being used in business. The roar of the MGM lion, the pink of the insulation made by Owens-Corning (who uses the Pink Panther in advertising by permission from its owner!), and the shape of a Coca-Cola bottle are familiar trademarks. These are brand names and identities and are important in marketing a product or service.
You can register a trademark or claim common law use (no official registration). Trademark rights may be used to prevent others from using a confusingly similar mark, but not to prevent others from making the same goods or from selling the same goods or services under a clearly different mark.
CopyrightsCopyrights protect works of authorship, such as writings, music, and works of art that have been tangibly expressed. In the United States the Library of Congress registers copyrights, which last for the life of the author plus 70 years. Gone With The Wind (the book and film), Back Street Boys' recordings, and video games are all works that are copyrighted. Only the copyright holder can reproduce or profit from his/her works or transfer those rights.
Trade SecretsTrade secrets are information that companies keep secret to give them an advantage over their competitors. The formula for Coca-Cola is the most famous trade secret.
The above should give you a basic understanding of the different types of intellectual property. The rest of these lessons will be concerned with the intellectual property of patents only - since patents are what protect inventions.

Lessons on Turning a New Invention Idea Into Money

I Know Nothing about Inventing - What Do I Do?
How does an inventor turn their new invention ideas into money? This is probably the single most often asked question I receive from people who have no clue as to how to proceed. They often hope that they can sell their brilliant new idea to somebody who will hand them money. Sorry, it just does not work that way and you often end up handing a fistful of money in the other direction.
The best answer I can give is to get educated in how the whole process works - how to potentially turn an idea into a money making invention. Upfront, you need to know that only a minority of ideas eventually make money. However, that should not stop you from inventing, after all even Thomas Edison had his failures.

How To Use These Money LessonsThis tutorial covers the very basics for people who know nothing at all.However, once completed you will have a good outline of the entire invention process. Each lesson is written in very simple terms (we are writing for beginners) and each lesson includes links to more advanced material.
We would suggest that you read just the lessons once from beginning to end and then later repeat the process and look at the more advanced materials offered in the right hand column. For example on this page we have additional material on how to deal with invention promoters that just might help you keep your fistful of money.As an alternative, you can also receive this tutorial as a newsletter course.
Take your time, spend at least a day or two on each lesson.
Become an Educated ConsumerWhile this tutorial can help you do more yourself. You will need to hire professional help for many of the tasks that you cannot do for yourself. However, it is always better not to go shopping in the dark.
You might not have the legal know-how to execute a patent search or fill out a patent application. But there is no excuse for you not to know what a patent is and what searching for prior art means. You need to understand what patenting is all about.
And if you have no money everything you can do yourself or preliminarily prepare saves you money and prevents you from being taken advantage of.

The Dynamics of Airplane Flight

Air is a physical substance which has weight. It has molecules which are constantly moving. Air pressure is created by the molecules moving around. Moving air has a force that will lift kites and balloons up and down. Air is a mixture of different gases; oxygen, carbon dioxide and nitrogen. All things that fly need air. Air has power to push and pull on the birds, balloons, kites and planes. In 1640, Evangelista Torricelli discovered that air has weight. When experimenting with measuring mercury, he discovered that air put pressure on the mercury.
Francesco Lana used this discovery to begin to plan for an airship in the late 1600s. He drew an airship on paper that used the idea that air has weight. The ship was a hollow sphere which would have the air taken out of it. Once the air was removed, the sphere would have less weight and would be able to float up into the air. Each of four spheres would be attached to a boat-like structure and then the whole machine would float. The actual design was never tried.
Hot air expands and spreads out and it becomes lighter than cool air. When a balloon is full of hot air it rises up because the hot air expands inside the balloon. When the hot air cools and is let out of the balloon the balloon comes back down.
How Wings Lift the Plane
Airplane wings are curved on the top which make air move faster over the top of the wing. The air moves faster over the top of a wing. It moves slower underneath the wing. The slow air pushes up from below while the faster air pushes down from the top. This forces the wing to lift up into the air.
Laws of Motion
Sir Isaac Newton proposed three laws of motion in 1665. These Laws of Motion help to explain how a planes flies.
If an object is not moving, it will not start moving by itself. If an object is moving, it will not stop or change direction unless something pushes it.
Objects will move farther and faster when they are pushed harder.
When an object is pushed in one direction, there is always a resistance of the same size in the opposite direction.
Forces of Flight
Four Forces of FlightLift - upward
Drag - down and backward
Weight - downward
Thrust - forward
Controlling the Flight of a Plane
How does a plane fly? Let's pretend that our arms are wings. If we place one wing down and one wing up we can use the roll to change the direction of the plane. We are helping to turn the plane by yawing toward one side. If we raise our nose, like a pilot can raise the nose of the plane, we are raising the pitch of the plane. All these dimensions together combine to control the flight of the plane. A pilot of a plane has special controls that can be used to fly the plane. There are levers and buttons that the pilot can push to change the yaw, pitch and roll of the plane. To roll the plane to the right or left, the ailerons are raised on one wing and lowered on the other. The wing with the lowered aileron rises while the wing with the raised aileron drops.
Pitch is to make a plane descend or climb. The pilot adjusts the elevators on the tail to make a plane descend or climb. Lowering the elevators caused the airplane's nose to drop, sending the plane into a down. Raising the elevators causes the airplane to climb.
Yaw is the turning of a plane. When the rudder is turned to one side, the airplane moves left or right. The airplane's nose is pointed in the same direction as the direction of the rudder. The rudder and the ailerons are used together to make a turn
How does a Pilot Control the Plane?
To control a plane a pilot uses several instruments...
The pilot controls the engine power using the throttle. Pushing the throttle increases power, and pulling it decreases power.

The ailerons raise and lower the wings. The pilot controls the roll of the plane by raising one aileron or the other with a control wheel. Turning the control wheel clockwise raises the right aileron and lowers the left aileron, which rolls the aircraft to the right.

The rudder works to control the yaw of the plane. The pilot moves rudder left and right, with left and right pedals. Pressing the right rudder pedal moves the rudder to the right. This yaws the aircraft to the right. Used together, the rudder and the ailerons are used to turn the plane.

The elevators which are on the tail section are used to control the pitch of the plane. A pilot uses a control wheel to raise and lower the elevators, by moving it forward to back ward. Lowering the elevators makes the plane nose go down and allows the plane to go down. By raising the elevators the pilot can make the plane go up.
The pilot of the plane pushes the top of the rudder pedals to use thebrakes. The brakes are used when the plane is on the ground to slow down the plane and get ready for stopping it. The top of the left rudder controls the left brake and the top of the right pedal controls the right brake.
If you look at these motions you can see that each type of motion helps control the direction and level of the plane when it is flying.
Sound Barrier
Sound is made up of molecules of air that move. They push together and gather together to form sound waves . Sound waves travel at the speed of about 750 mph at sea level. When a plane travels the speed of sound the air waves gather together and compress the air in front of the plane to keep it from moving forward. This compression causes a shock wave to form in front of the plane.
In order to travel faster than the speed of sound the plane needs to be able to break through the shock wave. When the airplane moves through the waves, it is makes the sound waves spread out and this creates a loud noise or sonic boom. The sonic boom is caused by a sudden change in the air pressure. When the plane travels faster than sound it is traveling at supersonic speed. A plane traveling at the speed of sound is traveling at Mach 1or about 760 MPH. Mach 2 is twice the speed of sound.

The Wright Brothers - First Flight

In 1899, after Wilbur Wright had written a letter of request to the Smithsonian Institution for information about flight experiments, the Wright Brothers designed their first aircraft: a small, biplane glider flown as a kite to test their solution for controlling the craft by wing warping. Wing warping is a method of arching the wingtips slightly to control the aircraft's rolling motion and balance.
The Wrights spent a great deal of time observing birds in flight. They noticed that birds soared into the wind and that the air flowing over the curved surface of their wings created lift. Birds change the shape of their wings to turn and maneuver. They believed that they could use this technique to obtain roll control by warping, or changing the shape, of a portion of the wing.
Over the next three years, Wilbur and his brother Orville would design a series of gliders which would be flown in both unmanned (as kites) and piloted flights. They read about the works of Cayley, and Langley, and the hang-gliding flights of Otto Lilienthal. They corresponded with Octave Chanute concerning some of their ideas. They recognized that control of the flying aircraft would be the most crucial and hardest problem to solve.
Following a successful glider test, the Wrights built and tested a full-size glider. They selected Kitty Hawk, North Carolina as their test site because of its wind, sand, hilly terrain and remote location.
In 1900, the Wrights successfully tested their new 50-pound biplane glider with its 17-foot wingspan and wing-warping mechanism at Kitty Hawk, in both unmanned and piloted flights. In fact, it was the first piloted glider. Based upon the results, the Wright Brothers planned to refine the controls and landing gear, and build a bigger glider.
In 1901, at Kill Devil Hills, North Carolina, the Wright Brothers flew the largest glider ever flown, with a 22-foot wingspan, a weight of nearly 100 pounds and skids for landing. However, many problems occurred: the wings did not have enough lifting power; forward elevator was not effective in controlling the pitch; and the wing-warping mechanism occasionally caused the airplane to spin out of control. In their disappointment, they predicted that man will probably not fly in their lifetime.
In spite of the problems with their last attempts at flight, the Wrights reviewed their test results and determined that the calculations they had used were not reliable. They decided to build a wind tunnel to test a variety of wing shapes and their effect on lift. Based upon these tests, the inventors had a greater understanding of how an airfoil (wing) works and could calculate with greater accuracy how well a particular wing design would fly. They planned to design a new glider with a 32-foot wingspan and a tail to help stabilize it.
During 1902, the brothers flew numerous test glides using their new glider. Their studies showed that a movable tail would help balance the craft and the Wright Brothers connected a movable tail to the wing-warping wires to coordinate turns. With successful glides to verify their wind tunnel tests, the inventors planned to build a powered aircraft.
After months of studying how propellers work the Wright Brothers designed a motor and a new aircraft sturdy enough to accommodate the motor's weight and vibrations. The craft weighed 700 pounds and came to be known as the Flyer.
The brothers built a movable track to help launch the Flyer. This downhill track would help the aircraft gain enough airspeed to fly. After two attempts to fly this machine, one of which resulted in a minor crash, Orville Wright took the Flyer for a 12-second, sustained flight on December 17, 1903. This was the first successful, powered, piloted flight in history.
In 1904, the first flight lasting more than five minutes took place on November 9. The Flyer II was flown by Wilbur Wright.
In 1908, passenger flight took a turn for the worse when the first fatal air crash occurred on September 17. Orville Wright was piloting the plane. Orville Wright survived the crash, but his passenger, Signal Corps Lieutenant Thomas Selfridge, did not. The Wright Brothers had been allowing passengers to fly with them since May 14, 1908.
In 1909, the U.S. Government bought its first airplane, a Wright Brothers biplane, on July 30. The airplane sold for $25,000 plus a bonus of $5,000 because it exceeded 40 mph.
In 1911, the Wrights' Vin Fiz was the first airplane to cross the United States. The flight took 84 days, stopping 70 times. It crash-landed so many times that little of its original building materials were still on the plane when it arrived in California. The Vin Fiz was named after a grape soda made by the Armour Packing Company.
In 1912, a Wright Brothers plane, the first airplane armed with a machine gun was flown at an airport in College Park, Maryland. The airport had existed since 1909 when the Wright Brothers took their government-purchased airplane there to teach Army officers to fly.
On July 18, 1914, an Aviation Section of the Signal Corps (part of the Army) was established. Its flying unit contained airplanes made by the Wright Brothers as well as some made by their chief competitor, Glenn Curtiss.
That same year, the U.S. Court has decided in favor of the Wright Brothers in a patent suit against Glenn Curtiss. The issue concerned lateral control of aircraft, for which the Wrights maintained they held patents.
Although Curtiss's invention, ailerons (French for "little wing"), was far different from the Wrights' wing-warping mechanism, the Court determined that use of lateral controls by others was "unauthorized" by patent law.

19th And 20th Century Flight Efforts

1891 Otto Lilienthal German engineer, Otto Lilienthal, studied aerodynamics and worked to design a glider that would fly. Otto Lilienthal was the first person to design a glider that could fly a person and was able to fly long distances.
Otto Lilienthal was fascinated by the idea of flight. Based on his studies of birds and how they fly, he wrote a book on aerodynamics that was published in 1889 and this text was used by the Wright Brothers as the basis for their designs.
After more than 2500 flights, Otto Lilienthal was killed when he lost control because of a sudden strong wind and crashed into the ground.
1891 Samuel Langley Samuel Langley was physicist and astronomer who realized that power was needed to help man fly. Langley conducted experiments using whirling arms and steam motors. He built a model of a plane, which he called an aerodrome, that included a steam-powered engine. In 1891, his model flew for 3/4s of a mile before running out of fuel.
Samuel Langley received a $50,000 grant to build a full sized aerodrome. It was too heavy to fly and it crashed. He was very disappointed. He gave up trying to fly. His major contributions to flight involved attempts at adding a power plant to a glider. He was also well known as the director of the Smithsonian Institute in Washington, DC.

Model of Langley Aerodrome
1894 Octave Chanute Octave Chanute was a successful engineer who undertook the invention of airplanes as a hobby, after being inspired by Otto Lilienthal. Chanute designed several aircraft, the Herring - Chanute biplane was his most successful design and formed the basis of the Wright biplane design.
Octave Chanute published "Progress in Flying Machines" in 1894. It gathered and analyzed all the technical knowledge that he could find about aviation accomplishments. It included all of the world's aviation pioneers. The Wright Brothers used this book as a basis for much of their experiments. Chanute was also in contact with the Wright Brothers and often commented on their technical progress.
1903 The Wright Brothers - First Flight Orville Wright and Wilbur Wright were very deliberate in their quest for flight. First, they spent many years learning about all the early developments of flight. They completed detailed research of what other early inventors had done. They read all the literature that was published up to that time. Then, they began to test the early theories with balloons and kites. They learned about how the wind would help with the flight and how it could affect the surfaces once up in the air. The next step was to test the shapes of gliders much like George Cayley did when he was testing the many different shapes that would fly. They spent much time testing and learning about how gliders could be controlled. The Wright Brothers designed and used a wind tunnel to test the shapes of the wings and the tails of the gliders. After they found a glider shape that consistently would fly in the tests in the North Carolina Outer Banks dunes, then they turned their attention to how to create a propulsion system that would create the lift needed to fly.
The early engine that they used generated almost 12 horsepower.
The "Flyer" lifted from level ground to the north of Big Kill Devil Hill, at 10:35 a.m., on December 17, 1903. Orville piloted the plane which weighed six hundred and five pounds. The first heavier-than-air flight traveled one hundred twenty feet in twelve seconds. The two brothers took turns during the test flights. It was Orville's turn to test the plane, so he is the brother that is credited with the first flight.
Humankind was now able to fly! During the next century, many new airplanes and engines were developed to help transport people, luggage, cargo, military personnel and weapons. The 20th century's advances were all based on this first flight at Kitty Hawk by the American Brothers from Ohio.

Early History of Flight

Around 400 BC - Flight in China The discovery of the kite that could fly in the air by the Chinese started humans thinking about flying. Kites were used by the Chinese in religious ceremonies. They built many colorful kites for fun, also. More sophisticated kites were used to test weather conditions. Kites have been important to the invention of flight as they were the forerunner to balloons and gliders.
Humans Try to Fly like Birds For many centuries, humans have tried to fly just like the birds and have studied the flight of birds. Wings made of feathers or light weight wood have been attached to arms to test their ability to fly. The results were often disastrous as the muscles of the human arms are not like a birds and cannot move with the strength of a bird.
Hero and the Aeolipile The ancient Greek engineer, Hero of Alexandria, worked with air pressure and steam to create sources of power. One experiment that he developed was the aeolipile which used jets of steam to create rotary motion.
Hero mounted a sphere on top of a water kettle. A fire below the kettle turned the water into steam, and the gas traveled through pipes to the sphere. Two L-shaped tubes on opposite sides of the sphere allowed the gas to escape, which gave a thrust to the sphere that caused it to rotate. The importance of the aeolipile is that it marks the start of engine invention - engine created movement will later prove essential in the history of flight.
1485 Leonardo da Vinci - The Ornithopter and the Study of Flight. Leonardo da Vinci made the first real studies of flight in the 1480's. He had over 100 drawings that illustrated his theories on bird and mechanical flight. The drawings illustrated the wings and tails of birds, ideas for man carrying machines, and devices for the testing of wings.
The Ornithopter flying machine was never actually created. It was a design that Leonardo da Vinci created to show how man could fly. The modern day helicopter is based on this concept. Leonardo da Vinci's notebooks on flight were reexamined in the 19th century by aviation pioneers.
1783 - Joseph and Jacques Montgolfier - The Flight of the First Hot Air Balloon The brothers, Joseph Michel and Jacques Etienne Montgolfier, were inventors of the first hot air balloon. They used the smoke from a fire to blow hot air into a silk bag. The silk bag was attached to a basket. The hot air then rose and allowed the balloon to be lighter-than-air.
In 1783, the first passengers in the colorful balloon were a sheep, rooster and duck. It climbed to a height of about 6,000 feet and traveled more than one mile.
After this first success, the brothers began to send men up in hot air balloons. The first manned flight was on November 21, 1783, the passengers were Jean-Francois Pilatre de Rozier and Francois Laurent.
1799-1850's - George Cayley - Gliders Sir George Cayley is considered the father of aerodynamics. Cayley experimented with wing design, distinguished between lift and drag, formulated the concepts of vertical tail surfaces, steering rudders, rear elevators, and air screws. George Cayley worked to discover a way that man could fly. Cayley designed many different versions of gliders that used the movements of the body to control. A young boy, whose name is not known, was the first to fly one of Cayley's gliders, the first glider capable of carrying a human.
For over 50 years, George Cayley made improvements to his gliders. Cayley changed the shape of the wings so that the air would flow over the wings correctly. Cayley designed a tail for the gliders to help with the stability. He tried a biplane design to add strength to the glider. George Cayley also recognized that there would be a need for machine power if the flight was to be in the air for a long time.
George Cayley wrote "On Ariel Navigation" that showed that a fixed wing aircraft with a power system for propulsion, and a tail to assist in the control of the airplane, would be the best way to allow man to fly.

The History of Flight

Orville Wright and Wilbur Wright - Inventors of the First Engined Airplane Orville Wright (1871-1948) and Wilbur Wright (1867-1912) requested a patent application for a "flying machine" nine months before their successful flight in December 1903, which Orville Wright recorded in his diary. As part of the Wright Brothers' systematic practice of photographing every prototype and test of their various flying machines, they had persuaded an attendant from a nearby lifesaving station to snap Orville Wright in full flight. The craft soared to an altitude of 10 feet, traveled 120 feet, and landed 12 seconds after takeoff. After making two longer flights that day, Orville and Wilbur Wright sent this telegram to their father, instructing him to "inform press."
Earlier in 1900, Wilbur Wright wrote to French aviation pioneer Octave Chanute (1832-1910) and expressed the belief that "flight is possible to man...[and] I feel that it will soon cost me an increased amount of money if not my life". More on the Wright Brothers' invention of the airplane.

HIV Testing 101

Detecting Acute HIV InfectionShortly after getting infected with HIV, many patients have an acute (or "primary") HIV infection, a period of flu-like illness with symptoms like fever and malaise that could be caused by influenza or many other diseases. Many scientists and physicians believe it is important to treat during this acute HIV infection (provided, of course, that it gets diagnosed then). But there are still questions remaining about treating acute infection.1, 2
To confirm an acute HIV infection in symptomatic individuals with potential HIV risk factors, current guidelines2 recommend use of HIV RNA (viral load) tests. [The regular HIV antibody test will not detect acute HIV infection because the patient is still in the "window period" before antibodies have been produced.] False positives can occur with viral load tests, but a review of the data in the August, 1999 American Family Physician1 suggests it is usually possible to differentiate these from the real thing: "During the symptomatic phase of acute HIV infection, the viral RNA shows in excess of 50,000 copies per mL. Three instances of false-positive HIV-1 RNA tests have been reported; in each instance, however, the person was not having symptoms and the viral load [reported] was less than 2,000 copies per ml. The presence of high-titer HIV-1 RNA (more than 50,000 copies per mL) in the absence of HIV antibodies establishes diagnosis of acute HIV infection."
At present there is no viral load test approved by the FDA for the purpose of diagnosing HIV infection in individual patients. In September the FDA did approve a viral load test developed by National Genetics Institute for screening large pools of donated blood plasma.
If viral load testing is not available, current treatment guidelines2 recommend testing for p24 antigen, a viral protein. In either case, the diagnosis should be confirmed by antibody testing once the window period has elapsed.
"Detuned" ELISAA variation of standard antibody testing, presently approved in the U.S. only for research, is the sensitive/less sensitive or "detuned" ELISA. The detuned test takes advantage of the fact that antibody levels rise in a predictable pattern during roughly the first four to six months after infection, eventually reaching a plateau that often stays roughly constant for many years.
Current ELISAs can detect relatively low levels of antibodies. The detuned testing approach involves taking samples that are confirmed HIV-positive by these tests, but then retesting them with a less sensitive, diluted ELISA. This less sensitive test can only detect antibodies at the higher levels achieved during the period six months or more after infection. Thus, the detuned approach distinguishes between recent and established infections, so it is a potentially valuable tool for epidemiologists trying to chart the pattern of new infections. It is not used in patient care at this time.
Accuracy of Antibody Testing -- and Denialist ArgumentsConstantine3 sums up the general consensus among experts and institutions such as the CDC when he says "The antibody tests are nearly 100 percent sensitive (unless a person is in the window period) and about 99 percent specific." Such levels of accuracy have been documented in a number of studies, including periodic evaluations of commercially available test kits conducted by the World Health Organization.
Still, AIDS denialists (the self-styled "AIDS dissidents" who claim that HIV is either harmless or doesn't exist) continue to claim that HIV antibody tests are unreliable. Many of their arguments seem to derive from a series of articles written by Christine Johnson in the mid-1990s, several of which are available on denialist web sites.4, 5, 6
Johnson's argument boils down to two key points: 1) HIV has never been properly isolated, so the HIV proteins used in the tests haven't been proven to actually come from HIV, 2) Even if HIV is real, the proteins are not unique and cross-react with many other antigens, rendering a positive result meaningless. Johnson's list of some 60 factors she describes as "known to cause false-positive HIV-antibody test results" turns up regularly in denialist literature.
The claim that HIV has never been properly isolated, based on the writing of a group in Perth, Australia, is too technical and complex to examine thoroughly here. However, it is elegantly demolished in Michael Coon's article, "HIV, AIDS and the Distortion of Science," available on the AEGIS web site.7 In short, Coon argues that the Perth Group set up artificial, phony criteria for "proof" of HIV's isolation that bear no relation to how virology works in the real world.
The second argument, though, contains a grain of truth. Cross-reactions are possible, and a number of factors can, on occasion, produce false-positive HIV antibody test results. What Johnson fails to address in any detail is that such effects are typically transient and rare, affecting few individuals.
For example, one well-known cause of false-positives Johnson lists is influenza vaccination.8, 9 But she neglects to mention that a key reference she cites described the phenomenon as "infrequent" and "of short duration," while in another only 10 false-positives were found among 133,000 individuals who had flu shots prior to testing, with half of those reverting to negative within six months.9
Constantine adds, "I doubt very much that it has been firmly documented that 60 factors can interfere with antibody tests. In fact, it has been long sought to try and identify the causes of false positive results, and only a few have really been documented to consistently interfere (e.g., pregnancy, certain autoimmune diseases, some infectious diseases). However, even these do not consistently cause problems with the tests. . . . There are very few false positives that can't be resolved with further testing."
Consent, Anonymity, and Counseling
Anonymous TestingPrior to HIV, blood testing was considered a routine procedure, with such minimal dangers that formal informed consent was rarely required. But because HIV presented massive psychosocial risks, from employment discrimination to rejection by family and reduced access to health care, special procedures were widely adopted.10 These included specific informed consent and pre- and post-test counseling. Many states set up test sites where people could get tested anonymously, without ever giving their name.
Anonymous testing (other than the home test, below) was never universally available, Morin notes, but was and is offered in many places, despite the recent move by numerous states to adopt a system of names-based HIV reporting (a few, including California, are implementing HIV reporting via codes that don't reveal the person's name). The CDC and others urged that the option for anonymous testing should be kept available, believing fear of disclosure would keep some from being tested, and most states have followed this recommendation.
Because local laws and procedures vary, Morin recommends that anyone concerned about anonymity or disclosure contact their local health department to check. A number of AIDS service organizations operate hotlines, which should also be able to provide this information.
Those living in areas with no anonymous test sites can still be tested anonymously via home collection test kits, which are sold in many drug stores. Introduced in the mid-'90s, the kits were controversial because counseling is provided by telephone rather than in person. Morin says fears that telephone counseling would prove inadequate haven't been borne out, but sales of the kits have been less than expected. Still, "the FDA ruled that you cannot bar their sale in any state, so even in states that don't have anonymous testing people can use home test kits to anonymously be tested," he says.
But, he adds, things change when the individual seeks treatment: "If you go to your doctor and the doctor does a viral load test, you get reported through the viral load test to the health department. So there's no way to keep treatment for HIV anonymous."
Consent and CounselingAs with anonymity, requirements for consent and counseling vary from state to state. Most, but not all, states require specific informed consent -- sometimes in writing -- for HIV testing. Approximately one-fifth of states require pre-test counseling, with many listing specifically what that counseling must include. The U.S. Department of Health and Human Services recommends that all HIV testing include counseling that covers the test itself, basic information about HIV and AIDS, how to avoid spreading the virus, the confidentiality of the results, the possible impact of the results on the person being tested, and discussion of to whom results should be disclosed, such as sex or needle-sharing partners.11 Counselors should also be able to give referrals to medical and psychosocial support services.
Counseling and consent procedures vary greatly, remain controversial and may continue to change. Even states that require informed consent may allow HIV testing without consent in special circumstances. For example, many permit involuntary testing of a patient when health workers have been exposed to the person's blood. Some test prisoners or people accused of sex crimes, and at least two, New York and Connecticut, require mandatory testing of newborns, which indirectly reveals the mother's HIV status, but does not tell if the infant has been infected.
In October 2000 the Institute of Medicine recommended that HIV testing be included as a routine part of prenatal care. Women would be informed of the test and could opt out, but specific consent would not be required. Thus far the U.S. Public Health Service has stopped short of urging an end to informed consent in such cases, simply suggesting that providers recommend HIV testing to all pregnant patients.
References
Perlmutter, Barbara Lee et al., "How to Recognize and Treat Acute HIV Syndrome," American Family Physician, August, 1999, http://www.aafp.org/afp/990800ap/535.html.
U.S. Public Health Service, "Guidelines for the Use of Antiretroviral Agents in HIV-Infected Adults and Adolescents" (August 13, 2001), http://www.hivatis.org/trtgdlns.html.
Constantine, Niel, "HIV Antibody Assays," HIV Knowledge Base, HIV InSite Sept. 2001, http://hivinsite.ucsf.edu/InSite.jsp?page=kb-02-02-01.
Johnson, Christine, "Whose Antibodies Are They Anyway?" Continuum, Sept./Oct., 1996, http://www.virusmyth.net/aids/data/cjtestfp.htm.
Johnson, Christine, "Is Anybody Really Positive?" Heal Magazine, 1995, http://www.virusmyth.net/aids/data/chjtests2.htm.
Johnson, Christine, "Playing Russian Roulette in the Laboratory," Virusmyth, http://www.virusmyth.net/aids/data/chjroulette.htm.
Coon, Michael, "HIV, AIDS and the Distortion of Science," Misc Health AIDS, August, 2000, http://www.aegis.org/topics/hiv_exist.html.
MacKenzie, William, et al, "Multiple False-positive Serologic Tests for HIV, HTLV-1 and Hepatitis C Following Influenza Vaccination, 1991," Journal of the American Medical Association, Vol. 268, No. 8, Aug. 26, 1992, p. 1015-1017.
Arnold, N.L., and others. "Donor Follow-up of Influenza Vaccine-Related Multiple Viral Enzyme Immunoassay Reactivity," Vox Sang, Vol. 67, No. 2, 1994, p. 191-194.
Wolf, Leslie, and Lo, Bernard, "Ethical Dimensions of HIV/AIDS," AIDS Knowledge Base, HIV InSite, http://hivinsite.ucsf.edu/InSite.jsp?page=kb-08-01-05.
U.S. Department of Health and Human Services, "Voluntary HIV Counseling and Testing: Facts, Issues and Answers," http://hivinsite.ucsf.edu/InSite.jsp?doc=2098.2099&page=pr-04-03.
Food and Drug Administration, "HIV and AIDS," http://www.fda.gov/oashi/aids/test.html (this regularly updated page contains information about FDA actions relating to HIV-related tests).
ISSN # 1052-4207
Copyright 2001 by John S. James. Permission granted for noncommercial reproduction, provided that our address and phone number are included if more than short quotations are used.