VINTAGE FLYING MACHINES
FLYING MUSEUM
Waco YPT-13
The Waco Model UPF-7/VPF-7 of 1937 were the culmination of the Model F series of
aircraft. These aircraft would be the last of the Model F series and were designed as a
three seat sport biplane intended for the sportsman pilot. The UPF/VPF designs
borrowed heavily from the previous UMF and YMF designs. By nature, the UPF-7 was
an all-around airplane that had all the traits of an excellent pilot training ship. Six of the
Continental 240 hp powered VPF-7s were delivered to the Army Air Corps of
Guatemala during the summer of 1937. The U.S. Civil Aeronautics Authority order for
31 of the UPF-7s equipped with NACA-type engine cowl, painted black with orange
wings for their new private-flying inspection department. The CAA would monitor civilian
operations with these new ships before World War Two.
In early 1939, as war clouds were forming over Europe, Waco began negotiations with
the U.S. Army Air Corps for engineering changes on the UPF-7. These engineering
changes were required to make the UPF-7 comply with the requirements of the Army
Air Corps Civilian Training Program. The landing gear width was changed from 74.50 to
100.68 inches. The front cockpit seat was changed to a single bucket type from a two-
passenger seat, enlarged the wing cut-out over the center section and the installation of
a tail wheel lock were the major changes. There were numerous other minor changes
plus the requirement that all F-7 trainers be powered with 220 hp Continental W670-6A
engine and the metal Curtiss-Reed 55501 propeller.
In August 1939, 13 service test models of the UPF-7 were sold to the U.S. Army Air Corps and were designated YPT-14. Waco UPF-7, NC-20901, s/n 4659 was delivered to the U.S. Army Air Corps as XPT-14, USAAC serial no. 39-702 and was test flown at Wright Field. Vintage Flying Museum’s is the third YPT-14 delivered to Wright Field, Ohio for testing. It bears USAAC Serial Number 40-19 and was accepted on September 7, 1939. It would later be transferred to Maxwell AFB, Alabama before the USAAF determined that the YTP-14s should be transferred to the Civilian Pilot Training Program. Heasty Flying Service in Ardmore, Oklahoma is where it would reside in CPTP service as NC219.