ENGINE KINNE» B-5 125 KP
came before (he PAA-1. Pitcairn's three-view drawing of the PAA-2 is dated a few days ahead of the PAA-2 drawing. Larsen, Pitcairn's Chief Engineer, said that the PAA-2 was tried and lacked performance.
The landing gear had the characteristic wide tread. The long oleo struts were attached at their upper ends to a cabane structure that in turn attached to the fuselage and the front wing spar. A lail skid, using a rubber cord shock absorber was installed similarly to thePCA-2. Mechanical brakes, controlled by pedals in the cockpit, aided in ground handling. A small nose wheel could be added to protect the propeller in case of a nose-up which could be caused by a rebounding of the tail shock absorber.
The rotor system had been referred to as a scaled-down model of the PCA-2 rotor. The same system of support and interblade cables, dampers and hinges were used. The rotor blade spar tubes were the same hand-polished, hand-straightened 4130 heat-treated steel, but the tubes were of a smaller diameter.
The Kinner engine was started with the same kind of compressed air starter as was used to start the Wright Whirlwind on the PCA-2, The propeller installation was optional: wood, fixed-
pitch aluminum or ground-adjustable alum: num.
The pilot flew from the rear cockpit and a the instruments necessary to operate the autc giro were in the rear cockpit except the rote tachometer which was mounted on the bottor of the rotor mast so it could be seen from eithe cockpit. Some autogiros had air speed indice tors and altimeters in the front cockpit alsc Enclosures were installed over the rear cockp on a few PAA-ls. They may have been cor sidered PA-24s.
There was no standard color, but black wa found on most of the autogiros.
After the PAA-ls were put into use they, toe were found to lack takeoff performance. Som PAA-ls were designated PA-20, most of bot models were modified toPA-24s. This modifies tion consisted of adding an R-5 Kinner engine c 160 hp in place of the B-5 and the rotor diamete was increased from 37 to 40 feet.
To keep the PAA-1 in longitudinal trim wit or without a passenger in the front, a 16-poun lead slug was installed just ahead of the tail po: without a passenger, and it was removed an installed in a pocket alongside the front seat (o the center of gravity) when the front seat w£ occupied.
P¡¡cairn PAA-2 with Martin-Chevrolet 120 hp air-cooled in-line engine. Note "Training Wheel" no vertical auxiliary surfaces yet
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