People assume that its easier to fly an airplane during the day because we can look out of the window and see where we are going, the same way we do in a car to navigate and keep clear of other traffic. But flying an airplane is very different from driving a car and much more precise. An airplane has sophisticated navigation technology on board that allows a pilot to fly without visual sightings by relying entirely on the aircraft’s instruments. This is known as instrument flight rules, and commercial pilots abide by it very frequently during a flight, such as when flying through clouds or flying at night.
Jimmy Doolittle in 1929. National Air and Space Museum
Instrument flying, or blind flying, was first demonstrated by aviation pioneer Jimmy Doolittle in 1929. Doolittle was one of the very few preeminent pilots at that time. He was a flying instructor during World War I and a reserve officer in the United States Army Air Corps. He was recalled to active duty during World War II, where he earned the Medal of Honor for his daring raid on Japan following the attack on Pearl Harbor. Doolittle was also one of the first pilots to fly coast-to-coast across the United States for which he was awarded the Distinguished Flying Cross for flying. His biggest contribution to aeronautical technology, however, was his early advancement of instrument flying.
Doolittle was the first to understand that genuine operational freedom in aviation could only be achieved if pilots could control and navigate aircraft from takeoff to landing, regardless of visibility limitations. He envisioned that pilots could be trained to use instruments to fly through various weather conditions and situations where visual cues were unavailable. As aircraft became faster and more agile, pilots were increasingly at risk of becoming disoriented without external visual references, as their senses were unable to accurately interpret the aircraft's movements.
Doolittle initiated the study of the relationships between the psychological effects of visual cues and motion senses. His research resulted in programs that trained pilots to read and understand navigational instruments. Thanks to his work, pilots have learned to ignore what they ‘feel’ and trust their instruments, as visual cues and motion sense inputs could be incorrect or unreliable.
Doolittle’s experiments with blind flying began in 1926 with the establishing of the Fund for the Promotion of Aeronautics and its Full Flight Laboratory at Mitchel Field, by Daniel Guggenheim, a wealthy industrialist and philanthropist. Like Doolittle, Guggenheim also believed that if aircraft instruments could be perfected and supplemented with radio, perhaps the mysteries of aircraft flight in bad weather could be solved.
The Laboratory experimented with various test instruments and found that an artificial horizon (a small instrument which indicates the airplane’s longitudinal and lateral position in relation to the ground) and a directional gyroscope (that informs the pilot of the aircraft's heading) were the right combination for directional control, along with a sensitive barometric altimeter that was so delicate that it could measure the altitude of an airplane within a few feet of the ground. These three instruments would soon become universal on aircrafts.
Jimmy Doolittle’s instrumentation panel. Photo: Smithsonian Institution
On September 24, 1929, Doolittle and his check pilot, Ben Kelsey, climbed into a heavily modified NY-2 Husky. Aside from a directional gyro, an artificial horizon, and an altimeter fitted into the cockpit, Doolittle received additional directional guidance from a radio range course aligned with the airport runway, while radio marker beacons indicated his distance from the runway.
To prevent Doolittle from ‘cheating’, a hood was placed over the cockpit, completely shutting him off from any view of the world outside, and forcing him to rely only on his instruments and radio. The check pilot was there only to intervene in an emergency. However, Kelsey had to keep his hands held high in the slipstream so all could see he was not doing the flying.
Doolittle took off effortlessly, circled the airfield, crossed, re-crossed the field, then landed only a short distance away from his starting point. The flight took only 10 minutes, but those minutes proved that a plane could be flown with only instruments.
After the flight, Doolittle said with an embarrassed grin, “Despite all my previous practice, the approach and landing were sloppy. So far as I know.”
In 1989, on the occasion of the 60th anniversary of the flight, a sculpture of Doolittle was unveiled near the Jimmy Doolittle Hangar at the former Aircraft Radio Corp.’s airfield at Boonton, N. J., where Doolittle consulted many times with ARC’s experts during the Full Flight Laboratory experiments.
References:
# 24 September 1929, This Day in Aviation
# Flying Blind, FAA.gov
# Flying Blind, Air & Space Forces Magazine
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