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Pitcairn Autogiro Letters
1930 - 1935
1931 Pitcairn Aircraft Corp
Model PAA-2 Autogiro
equipped with Chevrolet 333 Inverted Engine (Tail # X10756).
The autogiro was the first aircraft to successfully employ rotary lift technology. It was developed in Spain during the early 1920’s by a talented aviator named Juan de la Cierva. The vehicle was similar to fixed wing aircraft in many respects, and used a conventional engine to provide forward thrust. The rotor blades on the autogiro were not mechanically powered, but as the name suggests, rotated autonomously as airflow rushed over the surface of the blades. The faster the aircraft moved forward, the more momentum built up in the rotor assembly, eventually providing lift for the vehicle. The autogiro was a revolutionary aircraft, and was the forerunner of the modern day helicopter.
Harold Pitcairn purchased the American manufacturing rights to the autogiro in the late 1920’s, and started the Autogiro Company of America. The company spent a great deal of time and money improving the autogiro, and was credited with a number of important patents that would eventually be used in helicopter design. In the fall of 1930 the company engaged in a contract to purchase engines from the Chevrolet Aircraft Corporation. Below are some interesting documents that relate to Louis Chevrolet’s participation in the Pitcairn PAA-2 autogiro project.
1930 Letters
10/28/30 - Willow Grove, Pennsylvania
Walter Clayton writes Louis Chevrolet
concerning coupling & starter flange
(Tom Heitzman Collection)
11/04/30 - Baltimore, Maryland
Louis Chevrolet writes to J.S. Pecker
concerning starter jaw for 333 engine
(RR Auction Catalog)
11/05/30 - Philadelphia, Pennsylvania
J.S. Pecker writes to Louis Chevrolet
about starter requirements for autogiro
(Billy Dunbar Collection)
11/06/30 - Baltimore, Maryland
Louis Chevrolet writes to J.S. Pecker
about starter motor for 333 engine.
(John Reznikoff Collection)
11/12/30 - Baltimore, Maryland
Louis Chevrolet writes to J.S. Pecker
regarding oil supply to starter motor
(Billy Dunbar Collection)
11/14/30 - Willow Grove, Pennsylvania
Walter Clayton writes Louis Chevrolet
about engineering issues with 333 mill
(Tom Heitzman Collection)
11/14/30 - Philadelphia, Pennsylvania
J.S. Pecker writes to Louis Chevrolet
concerning starter motor requirements
(Billy Dunbar Collection)
11/18/30 - Baltimore, Maryland
Louis Chevrolet writes to J.S. Pecker
regarding mounting flange for starter
(Dr. Harlan Hunter Collection)
11/18/30 - Baltimore, Maryland
Louis Chevrolet writes to Walter Clayton
about gas tank, carbs, & starter mount
(Gallery of History Collection)
12/04/30 - Baltimore, Maryland
E.C. Burghduff writes to E.T. Asplundh
concerning modifications to 333 engine
(Tom Heitzman Collection)
12/05/30 - Baltimore, Maryland
E.C. Burghduff writes to Walter Clayton
about engine cowling for the autogiro
(Tom Heitzman Collection)
12/05/30 - Willow Grove, Pennsylvania
Walter Clayton writes to Louis Chevrolet
regarding engineering details
(Tom Heitzman Collection)
12/05/30 - Baltimore, Maryland
E.C. Burghduff writes to J.S. Pecker
regarding fastener requirements
(David M. Beach Collection)
Dec 1930 - Baltimore, Maryland
Louis Chevrolet sends Harold Pitcairn
Christmas Greetings
(Tom Heitzman Collection)
12/11/30 - Baltimore, Maryland
E.C. Burghduff writes to J.S. Pecker
regarding fastener requirements
(David M. Beach Collection)
12/17/30 - Baltimore, Maryland
E.C. Burghduff writes to Walter Clayton
about proximity of propeller to engine
(Tom Heitzman Collection)
12/19/30 - Baltimore, Maryland
E,C. Burghduff writes to Walter Clayton
about engine mounting brackets
(Tom Heitzman Collection)
12/19/30 - Baltimore, Maryland
E.C. Burghduff writes to Walter Clayton
in regards to engine mounting brackets
(Tom Heitzman Collection)
12/20/30 - Baltimore, Maryland
E.C. Burghduff writes to Walter Clayton
concerning propeller clearance
(Tom Heitzman Collection)
Late 1930/Early 1931 - Baltimore, MD
Rare Factory Photograph
Louis Chevrolet's 333 Inverted Engine
(Mark Herdman Collection)
12/29/30 - Baltimore, Maryland
Louis Chevrolet writes to E.T. Asplundh
about delay in shipment of new engine
(RR Auction Catalog)
1931 Letters
1/19/31 - Baltimore, Maryland
Louis Chevrolet writes to Walter Clayton
regarding new intake manifold design
(RR Auction Catalog)
1/20/31 - Baltimore, Maryland
Louis Chevrolet writes to Walter Clayton
about carburetor support brackets
(RR Auction Catalog)
2/16/31 - Baltimore, Maryland
Louis Chevrolet writes to Walter Clayton
concerning propeller hub wrench
(Catherine Barnes Collection)
2/23/31 - Baltimore, Maryland
Louis Chevrolet writes to J.S. Pecker
about blue prints (signed by secretary)
(David M. Beach Collection)
3/12/31 - Baltimore, Maryland
Louis Chevrolet writes to Walter Clayton
about carburetor set up of 333 engine
(RR Auction Catalog)
3/14/31 - Baltimore, Maryland
Warren Baker writes to J.S. Pecker
concerning allocation of 333 engines
(David M. Beach Collection)
10/09/31 - Baltimore, Maryland
Louis Chevrolet writes to Mr. Clayton
about new reduction gears & crankcase
(Gallery of History Collection)
Circa 1930's - Baltimore, Maryland
Glenn L. Martin Factory
(Postcard Image)
Later Letters
7/14/32 - Baltimore, Maryland
Glenn L. Martin writes to E.T. Asplundh
about development of 6-cylinder engine
(ebay Auction)
11/03/32 - Baltimore, Maryland
Glenn L. Martin writes to E.T. Asplundh
about 6-cylinider engine performance
(RR Auction Catalog)
7/15/35 - Detroit, Michigan
Walter Chrysler writes to Mr. Pitcairn,
and responds to inquiry about engines
(David M. Beach Collection)