In every test the robot pilot has steered an accurate course for hours at a time and over distances up to 400 miles while human members of the crew have been concerned with other duties.
The basis of the mechanical pilot is a gyroscope that controls pistons connected with the rudder and elevators of the plane. These pistons are actuated by compressed air.
Once a course is set the robot pilot keeps the machine on that route and errors of even a fraction of a degree are instantly and automatically detected and corrected. All the human pilot has to do in a plane so equipped is to take off and land the machine.
The Pilot's Assister is the official name of the new English device. It weighs about 120 pounds.
Flights have been made with the mechanical pilot in all sorts of weather. In dense fog and clouds, when a human pilot would have found it almost impossible to maintain straight or level flight because of the absence of any visible horizon by which to steer, the mechanical pilot flew the plane with absolute accuracy. On one test flight the automatic pilot steered a dead true course from Farnborough in South England, to Newcastle, 270 miles farther north. The human pilot did not touch the controls until it was necessary to land the plane at the destination.
Hans and I hauled out the heavy casket.