20. VERTICAL TAKE OFF & LANDING (VTOL)

The Vertol VTOL aircraft was our first attempt to design and build an aircraft that could hover like a helicopter and fly like an airplane.  The basic  fuselage was a 47 Bell helicopter.  Power was provided by a T-53 Gas Turbine engine. The wing containing the two rotors would tilt from vertical to horizontal. The tail rotor was a ducted  fan.

My association with this program was for a short period when I was a supervisor in the R&D Flight Test shop.  The picture with my crew includes the inspector, electrician, mechanic, and crew chief on the right, who we called Mr. Clean after a TV commercial character. The second from the left committed suicide some  years later, he had an alcohol problem.

The aircraft was initially flown by Leonard LaVassar and it was very difficult to hover, although he tried for several weeks.  The control was very difficult until a version of the Stability Augmentation System was installed.  Following that, hover was possible, take off  and landing in airplane mode down the runway was also possible.  No flight beyond the runway was attempted.

                                     

The major test to be accomplished was a conversion from helicopter to airplane.  This was a major event, the plan was to hover at the end of the runway, transition to airplane mode  going down the runway and land as an airplane.  All went well in the transition to airplane but instead of landing he converted back to hover.  This was great, he said it did that because he was going to run out of runway.

The next step would be to fly the aircraft out of the airport as an airplane, that phase would not be attempted until an ejection seat was installed.  It would be impossible to parachute from this aircraft without going into the rotor.  The seat was installed, it would break through the bubble when fired.  La Vassar was ejected on the training device at the Navy Yard. Quite a ride.

Eventually it became  routine to convert and fly out of the airport by La Vassar and some NASA pilots.  Overall it was successful. 

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/.