The Model 48 was designed in 1938 by a team headed by Richard Palmer.
The first of two prototypes made its maiden flight in September 1940
under the designation 48C. Sweden ordered 144 airframes with the
Flygvapnet (Swedish AF) designation J 10 (J standing for Jakt =
Fighter). The US sales embargo of 1940 prevented any delivery to
Sweden, and they were put on strength of the USAAF, s/ns
42-6832 to 42-6975.
The RAF became interested and s/ns for 100 were allocated, this
being BW208 to BW307. Only three, BW208 to BW210, were ever flown in
British markings; the type was not accepted into RAF Service. Still
in production, it was decided that 15 would go to USAAF training
units, the remainder would go to the Chinese Nationalist Forces of
The airframes for China were shipped by sea to Karachi, Pakistan in
the second half of 1943, wearing US markings. There they were
re-assembled and ferried on to Chengtu, China, finally receiving
their Chinese nonsequential registration in the P-13002 to P-26886
range. However, of the destined 129 only 79 actually arrived at
Chengtu, some crashed while flight-tested at Karachi, some were lost
en route. The Vanguard served only briefly with the Chinese forces,
being far from a success.