3. POWER BRAKES

Power Brake test

The United States Army H-21 had been in service for some time when they reported that under some conditions the brakes were not adequate to stop the helicopter in a down hill situation when the rotors were not turning. The corrective action was to change the brake system from manual brakes to power brakes. This was accomplished and a test installation was installed.

The test program was proceeding very well, however, one of the test points was to taxi the aircraft down the runway at 60 knots and apply the brakes. The test pilot on this program was my good  friend Bob Gangwish. He performed the test as programed. The brakes worked very well, the landing gear stopped and the helicopter kept going and of course, with no landing gear it rolled over.

There was an article about the accident in the local newspaper and Bob’s age was printed  2 years older then he really was. He was not pleased about that and wondered who gave the reporter the wrong age. It was some time before I told him it was me. An honest mistake.

Charles Kessler is a retired flight test engineer for Boeing’s Vertol helicopter division (formerly Piasecki Helicopter Co.). He joined Piesecki in 1947, in the company’s fourth year, and retired from Boeing in 1983. During his 37-year career he took part in the testing of prototypes and alterations of such models as the CH-47 Chinook and Sea Knight, the H-16, HRP-2, and the V-107. He taught the stability augmentation system to the German Luftwaffe. He has written about his experience in a blog called “Early Helicopter Years,” which can be found at http://helicopterstory.blogspot.com/.