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)

11/12/30 - 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 - 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)

12/05/30 - Baltimore, Maryland

E.C. Burghduff writes to Walter Clayton

about engine cowling for the autogiro

(Tom Heitzman Collection)

12/11/30 - 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)

12/17/30 - 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)

12/20/30 - Baltimore, Maryland

E.C. Burghduff writes to Walter Clayton

concerning propeller clearance

(Tom Heitzman Collection)

12/19/30 - Baltimore, Maryland

E.C. Burghduff writes to Walter Clayton

in regards to engine mounting brackets

(Tom Heitzman Collection)

12/29/30 - Baltimore, Maryland

Louis Chevrolet writes to E.T. Asplundh

about delay in shipment of new engine

(RR Auction Catalog)

Late 1930/Early 1931 - Baltimore, MD

Rare Factory Photograph

Louis Chevrolet's 333 Inverted Engine

(Mark Herdman Collection)

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)

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)