Although somewhat forgotten
among the ranks of war bird enthusiasts
today, the Vultee BT-13, played a vital role in
training many USAAC and USAAF pilots.
This is manifested in a total production run of
11,537 aircraft in five variants.
(Let me just insert something here... Now,
the 11,537 is actually unverified. I am
conducting research on all serial numbers from
the Air Force in Georgia and other resources.
As of today I have three conflicting numbers.
11,537 +1 prototype serial # 200 which was
converted later in 1943 to a BT-13A. However,
other resources claim, 13,740 or 13,100 or
10,375. I am trying to dig and find out total
production.)
In fact the BT-13 production run outnumbers all
other Basic Trainer (BT) types produced.
It was back in 1938 that Vultee Aircraft's chief
designer, Richard Palmer, began the design of a
fighter.
At this time the USAAC issued a requirement and
design contest
for an advanced trainer for which substantial
orders had been promised to the victor.
Palmer began to adapt his design concept from a
fighter to that of an advanced trainer and
the result of this was the V-51 prototype.
The aircraft made its maiden flight sometime
during March of 1939
as a cantilever low-wing monoplane of all-metal
construction.
Despite the use of metal throughout the design
the control surfaces remained fabric-covered.
The prototype was powered by a Pratt & Whitney
R-1340-S3H1-G
Wasp radial rated at 600 hp (447 kW) driving a
two-blade variable pitch metal propeller.
Other features included an enclosed cockpit for
the crew of two,
integral fuel tanks in the wings, and a
hydraulic system for the operation of the flaps
and retractable main landing gear.
The V-51 was entered into the USAAC competition
as the BC-51 during May 1939.
The USAAC instead chose the North American BC-2,
but purchased the BC-51 prototype anyway.
Despite the disappointment, Palmer was not
finished yet. He continued to refine the design
of the VF-51 into the VF-54 in an attempt to
meet the expectation of an export market for
just such a trainer.
The VF-54 used the same basic airframe as the
VF-51,but was fitted with a lower powered
engine.
No export sales were made.
From this design, evolved the VF-54A.
Instead of retractable gear, it had fixed gear
very nicely faired and a revised power plant of
a
Pratt & Whitney R-985-T3B Wasp Jr. radial rated
at 450 hp (335.5 kW) and the Vultee BT-13
Valiant was born.
The USAAC was made aware of the improvements
made to the aircraft and in August 1939
the type was ordered as the BT-13. The initial
order was for 300 aircraft with a
Pratt & Whitney R-985-25 radial and the first of
these was accepted by the USAAC in June of 1940.
The BT-13A was produced to the extent of 7,037
aircraft and differed only in the use of a
P&W R-985-AN-1 radial engine and lack of landing
gear fairings.
There were 1,125 BT-13B's produced and differed
from the A model in having a 24-volt,
rather than the original 12-volt electrical
system.
The next variant was actually designated BT-15
due to the fact that Pratt & Whitney
found it impossible to keep up production of the
R-985 engine. Instead a Wright R-975-11
radial was substituted into the 1,263 aircraft
produced.
The US Navy began to show an interest in the
aircraft as well and ordered 1,150 BT-13A models
as
the SNV-1. In addition, the Navy ordered some
650 aircraft designated as SNV-2 roughly
equivalent to the BT-13B.
Once in service, the aircraft quickly got it's
nickname of "Vibrator" due to the fact that it
had a tendency to shake quite violently as it
approached it's stall speed.
The BT-13 served it's intended purpose well. It
and its successors were unforgiving aircraft
to fly, but were also extremely agile.
Thus the BT-13 made a good aircraft to help
transition many hundreds of pilots toward their
advance trainers and fighters yet to to be
mastered.
1932: When Lockheed-Detroit fails, Gerard
"Jerry" Vultee forms the Airplane Development
Corp.
financed by E.L. Cord.
1934: Reformed as the Airplane Manufacturing
Corp. owned by AVCO
(of which Cord is a partner).
1936: Renamed the Vultee Aircraft Division of
the Airplane Manufacturing Corp.
1940: AVCO merges Stinson with Vultee to form
Vultee Aircraft Inc.
1943: Vultee acquires Consolidated to form
Consolidated-Vultee (Convair).
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