NEW TESTING MACHINE
September 2, 1943
Approved for release by Army Air Forces --Wright Field Nash-Kelvinator's
new testing machine in operation, which, by use of timing mechanisms
accurate to a ten thousandth of a second, can measure the performance
of a propeller governor to within one RPM.
The machines, made in Nash-Kelvinator's own research laboratories,
are the only ones of their kind in existence.
Original Caption by Science Service
© Nash-Kelvinator Corporation
A refined version of the R-4, the R-6A, was powered by a 245 hp
Franklin engine and first flew on 15 October 1943, as the XR-6A.
Severe vibration and control problems, however, took months to resolve.
The Army Air Force ordered 26 YR-6A prototypes, which were built under
license by Nash-Kelvinator in order for Vought to continue production
of other more critical wartime aircraft. In September 1943, contracts
were awarded for 731 production vehicles, including 36 for the Navy.
Deliveries began in February 1944, but when the war ended in September,
all contracts were cancelled.
At the end of the war, 128 R-4s, 65 R-5s and 219 R-6s had been delivered
for operational use by the Army. 209 additional R-6s were accepted
and placed in storage. Thus, a total of 617 Sikorsky helicopters were
delivered between May 1942 and September 1945.
2/4/2008 Courtesy American Helicopter Society, International
Originally presented at the AHS German Chapter Meeting on 7 July 2000
in Bückeburg, Germany
Michael J. Hirschberg and David K. Daley