Vultee BT-13 Valiant

The Vultee BT-13 Valiant was a monoplane Basic Trainer with seating for an instructor and trainee, under a greenhouse canopy, and had fixed landing gear.   The base BT-13 and BT-13A variants were fitted with a 450 HP Pratt & Whitney R-985 radial engine, while a variant known as the BT-15 was fitted with a 450 HP Wright R-975 radial engine.  

Per reference [8] a prototype BT-13 took its first flight in March 1939 and entered service with the US armed forces in June 1940.  Eventually 9,525 of this type aircraft were built and it served as the main Basic Trainer for the USAAC during WWII.  A number of these aircraft were transferred to the US Navy to also serve as a Basic Trainer and were identified as the SNV in naval service.  In addition to service with the US Armed Forces it alsoeventually served with the air forces of Argentina, Bolivia, Brazil, Chile, China, Colombia, Cuba, the Dominican Republic, Ecuador, Egypt, El Salvador, France, Guatemala, Haiti, Honduras, Indonesia, Mexico, Nicaragua, Panama, Paraguay, Peru, the Philippines, the USSR, and Venezuela.

As shown in the images below distinguishing features of this aircraft including;

• radial engine
  
• inline cockpits for the instructor and trainee under a greenhouse canopy
• low mounted wing
• fixed landing gear
  

[Image Sources: US Government/Public Domain via Ref [8] - as annotated by this site]

        [Source: Ref [14a] - US Government/Public Domain]

[Source: Ref [14] - Scanned from a US Government Document - Believed to be in the Public Domain]

In order to try and better develop weight estimating relationships an effort has been made to estimate the length of the fuselage aft of the firewall, and the length of the engine section forward of the firewall based off scaled drawings.  Together these two distances add to a term called the "structural length" and do not consider any portion of the engine or propeller shaft the extend foward of the fuselage/cowling, or any empennage that extends aft of the fuselage structure.  The drawing below shows the current best estimate of these dimensions obtained from available drawings of the airplane and will be updated with any real world data that becomes available.  For any aircraft with an inclined firewall, an attempt has been made to locate an approximate center of this location.



The table below summarizes the current data collected on this type aircraft, identifying sources for the data

		BT-13	Secondary Sources	Notes
Primary Source		2
No of Crew		2
Engine:
Qty		1	5
Model		R-985-25	5
Displacement	(cu in)	985	5
Power
Military	(HP)
War Emergency	(HP)
Normal	(HP)	450	5
Take Off	(HP)	450	5
Eng Dims
Length	(ft)	3.53	5
Width/Dia	(ft)	3.81	5
Height	(ft)
Base Engine Wt	(lb)	665	5
Propeller
# Blades		2
Dia	(ft)	9
Manufacturer		Two-Speed
Type
Wing
Span	(ft)
Root Thickness	(%)
	(in)
Total Area	(sq ft)	239
Wing (less Ailerons & Flaps)	(sq ft)
Ailerons	(sq ft)
Flaps	(sq ft)
Tail Area	(sq ft)	71.7	3
V Tail Area	(sq ft)	18.62	3
Fin	(sq ft)
Rudder	(sq ft)
H Tail Area	(sq ft)	53.08	3
Stabilizer	(sq ft)
Elevator	(sq ft)
Total Control Surf Area	(sq ft)
Length
Overall	(ft)	27.8
Fuselage	(ft)	28.8
Body	(ft)	27.8
Body Depth	(ft)
Body Width	(ft)
Fuel Tank Volume	(gal)
Wing Tanks	(gal)
FuselageTanks	(gal)
Oil Tank Volume	(gal)
Water Injection Fluid Tank Volume	(gal)
Wetted Area (sqf)	(sq ft)
Pwr Ldng	(lb/HP)	9.36
Wing Ldng	(lb/sq ft)	17.62
Struct. Des. GW	(lb)
Ultimate Load Factor	(G's)
Design Speed	(mph)	180
Not to Exceed Speed	(mph)
Total Struct Weight		1630
Total Wing		710
Wing
Ailerons
Flaps
Fuselage Carry-Through
Tail		107
H Tail		82
Stabilizer
Elevator
V Tail		25
Fin
Rudder
Body + Eng Section + LG
Body + LG		813
Body		539
Fuselage
Engine Section
Landing Gear		274
Mn Landing Gr		236
Tail/Nose Aux LG		38
Tail Hook
Booms
Nacelles
Total Propulsion Weight		1018
Engine w/ Accessories		750
Engine(s) as Installed		689
Accessories		61
Turbocharger(s)
Controls		20
Propeller(s)		163
2-Blade		163
3-Blade
4-Blade
Starting System		39
Water Injection System
Tanks
Piping Etc
Cooling System
Lube System		21
Tanks
Piping Etc
Fuel System		25
Tanks
Piping Etc
Total Sys. & Eqpmt.		516
Instruments		69
Surface Controls		104
Hydraulics
Electrical Equip		192
Electronics (Purple means incl in Furn/Gray in Useful Ld)
Arm Prov/Equipment & Armor
Furnishings		151
Anti-Ice (If not in Furn)
Other /Misc
Hoisting Gear
Floatation Gear
Armor Plate
Empty Wt		3164
Basic Mission Useful Load		1048
Crew		400
Equipment
Oil		63
Fuel		552
Fuel & Oil Trapped in Systems
Water Solution for Engine Injection
Bombs/Torp Etc
Radio (if Not Included in Empty Wt)
Nav Equipment
Oxygen System
Armament
Guns & Ammo
Guns
Ammo
Pyrotechnics
Camera
Other
Other Useful Load		33
Basic Mission GW		4212

For the filming of the movie "Tora, Tora, Tora" in 1970 several BT-13 aircraft were converted to look like Japanese Aichi Val D3A dive bombers, some of which still appear in air shows.

Notes: This website has been developed with a number of low cost or free programs including Hot Metal Pro, KompoZer, MicroSoft Designer and Da Button Factory.com

Rev 3-22-26

Home