What is the Pratt & Whitney R-1340 Wasp & List of R-1340 Powered Aircraft

The Pratt & Whitney R-1340 Wasp was a 9 cylinder, single-row, air-cooled radial engine with horsepower ranging from 410 hp to 600 hp, depending on the model and configuration. It was used in a range of aircraft that included the North American AT-6, Boeing P-26, and Boeing 247. Jimmy Doolittle used the Wasp to set records in his Gee Bee Racer and Amelia Earhart made history using the Wasp in her Electra L-10.

In the mid 1930s, Pratt & Whitney produced five basic engines:
The single-row   Wasp Junior.
The single-row   Wasp.
The single-row   Hornet.
The double-row Twin Wasp.
The double-row Twin Wasp Junior.


The Wasp was the first engine produced by Pratt & Whitney and it was completed December 24, 1925 at the new Pratt & Whitney Company, formed by Frederick Brant Rentschler. Pratt & Whitney had formerly been a longtime machine tool manufacturer.

Rentschler had a background in internal combustion engines and more specifically aero engines since 1917. He graduated from Princeton and afterwards, he worked in his father’s machine company as a molder and machinist. When World War I started, he enlisted in the Army and was assigned to the aviation section for Aero Engine Production and Inspection. His main duties were involved with the inspection and production of the Hispano-Suiza engines then being built under license by Wright-Martin.

In 1919, Rentschler played a leading role in the formation of Wright Aeronautical Corporation and became president of the company. Frustrated with Wright Aeronautical, he resigned in 1924 with idea of producing his own engine. He was looking to build bigger and more powerful engines to be used in military and commercial applications. Rotary engines were now obsolete and liquid-cooled engines were still too heavy for the amount of horsepower they produced. The best American engines available at the time were the Curtis OX-5, the Liberty L-12 and the Curtiss D-12. What looked promising was the new Wright R-790 Whirlwind that Rentschler was involved with when he was president at Wright Aeronautical. This engine would eventually power Charles Lindbergh’s famous Spirit of St Louis. England had also been working on developing radial engines since 1919 and the US Navy had been seeking a 200 hp air-cooled radial since 1921. Rentschler saw the future to be the lighter air-cooled radial engines in the 400-500 hp range.

What Aircraft are Powered by the R-1340?

Here is a list of most of the R-1340 Powered Aircraft (If we are missing any, let us know and we’ll add it!):

  • Curtiss Falcon
  • Curtiss F7C Seahawk
  • Curtiss O-52
  • Curtiss P-6S Hawk
  • Curtiss SOC Seagull
  • de Havilland Canada DHC-3 Otter
  • Douglas Dolphin
  • Fairchild FB-3
  • Fokker F.10
  • Fokker F.32
  • Ford Trimotor
  • Gee Bee R-1
  • Gee Bee R-2 Super Sportster
  • Gee Bee R 1/2 Super Sportster
  • Gee Bee Z
  • Gee Bee QED
  • Grumman Mallard
  • Grumman Ag Cat
  • Howard DGA-6
  • Ireland N-2C Neptune
  • Junkers W 34
  • Junkers Ju 52
  • Knoll Aircraft Company KN-3[4]
  • Kaman HH-43 Huskie
  • Lockheed Vega 5
  • Lockheed Model 8 Sirius
  • Lockheed Model 9 Orion
  • Lockheed Model 10-C & 10-E Electra
  • Lockheed XC-35
  • Loening OL-8
  • Noorduyn Norseman
  • North American BC-1
  • North American T-6/SNJ Texan/Harvard
  • Northrop Alpha
  • Northrop C-19 Alpha
  • Scottish Aviation Twin Pioneer
  • Sikorsky H-19
  • Sikorsky S-38
  • Thomas-Morse XP-13A Viper
  • Vought O2U Corsair
  • Wedell-Williams Model 45
  • Westland Whirlwind (helicopter)

Read the rest of the post at Aviation History.

5 thoughts on “What is the Pratt & Whitney R-1340 Wasp & List of R-1340 Powered Aircraft

  1. You misspelled Amelia Earhart’s name, and also Charles Lindbergh’s name (a common error). I normally don’t gig anyone for misspelling, unless it’s someone’s name – I don’t like to see mine misspelled!

  2. The Air Tractor AT-301 and AT-401 both still fly with the 1340 as does the S2R Thrush and numerous other early Snow designs.

  3. Commonwealth Aircraft Corporation (CAC) in Australia built over 750 “Wirraway” trainer and general purpose aircraft through WW2 and they remained in service into the 1960s. These used the geared version of the engine with a 3-blade propeller. Superficially similar to the T-6 and Harvard types, but developed prior to those entering service. A number of restored examples fly today. Kermit Weeks has two.

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