NASA's YO-3A parked on the Dryden ramp.

NASA's ultra-quiet YO-3A acoustics research aircraft taxis out from the ramp at the Dryden Flight Research Center before a pilot checkout flight.

NASA's converted YO-3A observation plane, now used for acoustics research, touches down at Edwards Air Force Base following a pilot checkout flight.

The slow-speed wooden propeller and long wings are evident as NASA's YO-3A acoustics research aircraft performs a low-level flyover at Edwards Air Force Base.

YO-3A (NASA 718) prepares for flight test on S-76C out of Modesto, CA

YO-3A (NASA-718) & MD-900 AIR TO AIR OVER MODESTO/CROWS LANDING.

YO-3A (NASA 718) and BO-105 helicopter over Livermore Valley, CA: In-flight rotorcraft acoustics program (distance versus noise calibration)

YO-3A (NASA 718) prepares for flight test on S-76C out of Modesto, CA - showing wooden propellers of the quiet plane

YO-3A (NASA-718) Flying Acoustic Platform: The Quiet Plane is used as a flying microphone platform to study aircraft noise, especially helicopter noise.

YO-3A (NASA-718) Flying Acoustic Platform: The Quiet Plane is used as a flying microphone platform to study aircraft noise, especially helicopter noise.

YO-3A during in flight rotorcraft acoustics program Distance Versus Noise Calibration test on BO-105 over Livermore - Central Valley, CA

YO-3A (NASA-718) and SH-3G (NASA-735) in flight at Crows Landing during Helicopter Airborne Laser Positioning System

YO-3A (NASA-718) & BO-105 helicopter over Livermore Valley for in flight Rotorcraft Acoustics Program - distance versus noise calibration

YO-3A Quiet Plane (NASA-718) parked on ramp This aircraft is a flying acoustic platform used as a microphone to study aircraft noise, especially helicopter noise.

YO-3A (NASA-718) and SH-3G (NASA-735) in flight over Ames on way to Crows Landing during Helicopter Airborne Laser Positioning System flight tests

NASA pilot Ed Lewis (rear) briefs NASA test pilot Dick Ewers on the flight instruments of NASA's YO-3A acoustics research aircraft prior to a checkout flight.

Megan McCluer in cockpit of YO-3A (NASA 718) during IRAP (inflight rotorcraft acoustics program) tests with XV-15 (NASA 703) over Bell Helicopter Textron Co.,

Ames Aircraft complement on Ramp in front of N-211 hangar: DC-8, C-141, C-130, ER-2, Lear Jet, YO-3A, T-38, AH-1G, AV-8B, UH-60

Ames Aircraft complement on ramp DC-8, C-130, QSRA, RSRA, C-141, U-2, SH-3G, King Air, YO-3A, T-38, CH-47, Lear Jet, AH-1G, AV-8B Harrier, OH-58A, XV-15, UH-1H

UH-60 Blackhawk (NASA 748) and YO-3A (NASA-718) inflight over Altamont Pass, CA - Blade Vortex Interaction Noise experiment

NASA Aircraft on ramp (Aerial view) Sides: (L) QSRA (R) C-8A AWJSRA - Back to Front: CV-990 (711) C-141 KAO, CV-990 (712) Galileo, T-38, YO-3A, Lear Jet, X-14, U-2, OH-6, CH-47, SH-3G, RSRA, AH-1G, XV-15, UH-1H

NASA Aircraft on ramp (Aerial view) Sides: (L) QSRA (R) C-8A AWJSRA - Back to Front: CV-990 (711) C-141 KAO, CV-990 (712) Galileo, T-38, YO-3A, Lear Jet, X-14, U-2, OH-6, CH-47, SH-3G, RSRA, AH-1G, XV-15, UH-1H

view of YO-3A from cockpit of BO-105 helicopter during in flight rotorcraft acoustics program Distance Versus Noise Calibration over Livermore - Central Valley, CA

Bell XV-15 (NASA 703) and YO-3A (NASA 718) fly IRAP (inflight rotorcraft acoustics program) tests over Bell Helicopter Textron Co., Arlingtron, Texas

BO-105 helicopter pilot & cockpit during in flight rotorcraft acoustics program Distance Versus Noise Calibration over Livermore - Central Valley, CA. The YO-3A flying the acoustics test can just be seen through cockpit window.

Lockheed YO-3A (USA 69-18010 NASA 718) A/C & BELL COBRA HELICOPTER FLIGHT & GROUND TESTS AT EDWARDS AIR FORCE BASE. Rotorcraft Research. NASA SP-1998-3300 Flight Research at Ames: 57 Years of Development and Validation of Aeronautical Technology Fig. 143

The single-seat F-16XL, NASA 849, joins up with an SR-71A, NASA 844, as crews set up for one of the flights in the recent sonic boom research program conducted by the Dryden Flight Research Center, Edwards, California. During the missions, the F-16XL probed the shockwaves generated by the SR-71, while at lower altitudes sensors on an F-18 and on a YO-3A, and also on the ground, recorded data from the same shockwave.

Lockheed YO-3A (USA 69-18010 NASA 718) TEST FLIGHT AT EDWARDS AIRFORCE BASE (FLIGHT RESEARCH CENTER). Rotorcraft Research. Acoustics Research Team from left to right: Don Boxwell, Fred Schmitz, Bob Williams, Lee Jones, Bob George, Vance Duffy. NASA SP Flight Research at Ames: 57 Years of Development and Validation of Aeronautical Technology Fig. 142

The single-seat F-16XL, NASA 849, joins up with an SR-71A, NASA 844, as crews set up for one of the flights in the recent sonic boom research program conducted by the Dryden Flight Research Center, Edwards, California. During the missions, the F-16XL probed the shockwaves generated by the SR-71, while at lower altitudes sensors on an F-18 and on a YO-3A, and also on the ground, recorded data from the same shockwave.

The single-seat F-16XL, NASA 849, joins up with an SR-71A, NASA 844, as crews set up for one of the flights in the recent sonic boom research program conducted by the Dryden Flight Research Center, Edwards, California. During the missions, the F-16XL probed the shockwaves generated by the SR-71, while at lower altitudes sensors on an F-18 and on a YO-3A, and also on the ground, recorded data from the same shockwave.

Edwin W. Lewis Jr. is a research pilot in the Airborne Science program, Flight Crew Branch, Dryden Flight Research Center, Edwards, California. He currently flies the DC-8, F/A-18, Lear Jet 24, King Air, and T-34C in support of Dryden's flight operations and is mentor pilot for the King Air and the Lear Jet. Prior to accepting this assignment Lewis was a pilot for eight years at NASA's Ames Research Center, Moffett Field, California, flying 10 different aircraft C-130B, DC-8-72, UH-1, SH-3, King Air, Lear 24, T-38A, T-39G and YO-3A in support of NASA flight missions. Lewis also flew the Kuiper Airborne Observatory (a modified civilian version of the Lockheed C-141 Starlifter). He was project pilot for Ames' 747 and T-38 programs. Lewis was born in New York City on May 19, 1936, and began flight training as a Civil Air Patrol cadet in 1951, ultimately earning his commercial pilot's certificate in 1958. He received a bachelor of arts degree in biology from Hobart College, Geneva, N.Y., and entered the U.S. Air Force through the Reserve Officer Training Corps. Following pilot training he was assigned to Moody Air Force Base, Ga., as an instructor pilot, for both the T-33 and T-37 aircraft. He served in Vietnam in 1965 and 1966, where he was a forward air controller, instructor and standardization/evaluation pilot, flying more than 1,000 hours in the O-1 "Bird Dog." Lewis separated from the regular Air Force and joined Pan American World Airways and the 129th Air Commando Group, California Air National Guard (ANG) based in Hayward, California. During his 18-year career with the California ANG he flew the U-6, U-10, C-119, HC-130 aircraft and the HH-3 helicopter. He retired as commander, 129th Air Rescue and Recovery Group, a composite combat rescue group, in the grade of colonel. During his 22 years as an airline pilot, he flew the Boeing 707, 727 and 747. He took early retirement from Pan American in 1989 to become a pilot with NASA.