Lockheed YO-3 Quiet Star

Photo: NASA Photo / Tony Landis, public domain (cropped)

A stop on Hiller Aviation Museum: Unofficial Guide, a free self-guided tour.

The Lockheed YO-3A Quiet Star was built to fly over enemy territory at night without being heard. Only 11 were made, and they served in Vietnam in 1970 and 1971.

It was based on a glider. Lockheed added a heavily muffled engine and a slow-turning, multi-bladed propeller driven by a belt, so that the airplane made very little noise. Flying at low altitude, it could not be heard from the ground, and its crew used night-vision equipment to spot enemy movement.

After the war, a few were used by the FBI and NASA, which used one to study the noise of helicopters and other aircraft.

Notice how long and slender its wings are, a reminder of its glider ancestry.

More on Wikipedia: Lockheed YO-3 Quiet Star

Stops on this tour

1. Boeing 747-100 Cockpit and Forward Fuselage
2. Hiller Flying Platform
3. Boeing Condor High-Altitude Reconnaissance UAV
4. NASA AD-1 Oblique Wing Research Aircraft
5. Wright Flyer Replica and Early Flight Exhibit
6. Black Diamond - 1910 California Pioneer Aircraft
7. Grumman HU-16 Albatross Amphibious Aircraft
8. Boeing 737-200 Cockpit
9. Flight Sim Zone
10. Women in Aviation Gallery
11. Aircraft Engine Collection
12. Lockheed YO-3 Quiet Star
13. San Francisco Airport Control Tower Beacon
14. Drone Plex and Future of Flight Exhibit
15. Michael King Smith Research Library and Museum Store