7. ROTOR TEST STAND FOR THE XHRP

The rotor test stand was used to test the dynamic system used in the XHRP helicopter. All the components were the same as the helicopter except it only utilized one rotor, but since the rotors were the same, it didn’t matter.

A flywheel was installed to simulate the load of the second rotor.  The engine was a Pratt & Whitney R1340 AN-1. The test stand was built on the chassis of an old White truck, which would still run but would only make about 30 MPH.

We had to put many hours on the components so we, at times, would run it 24 hours a day. We had many noise complaints and it was not unusual to see the police car come driving up. We would shut it down and listen to the complaint. Sometimes the policeman would go to the location and listen. We would run in flat pitch and he would come back and say it wasn’t bad, go ahead and run.

The winter was pretty bad and very cold especially at night. We would cover our legs and put a heat lamp under the cover. (Visible in the attached photo)

We finally had to move it to the lot behind the Philadelphia airport.

Following the Bud Felt accident the test stand was used for part of the investigation. There was need to simulate a flare so we towed the test stand down the runway with our old fire truck at 60 knots with the rotor running.

It was a sight to behold and prompted a comment on the radio from one of the airline pilots “Tell those guys they are never going to get that three dollar bill off the ground”.

It served its purpose and I lost track of it, no idea what happened to it.

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/.