Fairchild Trainer for 1940

With the attitude of the Air Corps apparently drifting towards the low-wing primary trainer it is important when a new model of this type of ship has been accepted. The Fairchild M-62 has been designated by the Army as the PT-19 and at present is in quantity production at the Fairchild plant in Hagerstown.

Built to have a strength factor of 10 the new trainer has the ATC #724. Aerodynamically the wing has been designed so that the wing tip should remain unstalled even after the wing root has passed the stalling point. Ease of servicing has also been a prominent feature of the design and in addition to the regular inspection holes large inspection panels have been placed at important points on the ship and can be easily removed.

The fuselage is of welded 4130 chrome-molybdenum steel tubular structure. Wood fairing and fabric covering are employed except that the top of the fuselage aft of the cockpit is metal covered. Army type seat are adjustable vertically 7½" and are designed to accommodate seat-pack parachutes. Rudder pedals are adjustable in three positions, and a parking lock is supplied to lock the rudder bar in neutral position and the stickl in forward center position.

The wing construction consists of a center section and two outer panels with conventional two-spar construction, both spars being at 90° to the plane of symmetry. Ribs are Warren truss type with spruce cap strings and bracing, and end ribs, landing gear ribs and those at the fuselage attachment are chrome-molybdenum. Split flaps, manually controlled, extend from fuselage to outer wing panel. Ailerons are statically and aerodynamically balanced fabric-covered aluminun alloy structures and are differentially controlled.

The plywood-covered wing was chosen for its structural characteristics of lightness and large tortional rigidity. The improved type of plywood used for the wing cover is of the phenolic-glue-bonded type which has been developed from plywood used previously in aircraft construction. Phenolic resin gives a glue line which is stronger than wood in shear; is insoluble in warm or cold water, in dilute alkalis, acids and such organic solvents as alcohol, benzine and ether. Dry or humid conditions do not affect it; it is repellent to living organisms; and it is not attacked by mold or fungi. When properly set by heat, phenolic resin glue is a hard inert solid which does not deteriorate with time or exposure. The plywood cover is prepared by its manufacturer so that a single piece covers the whole top of a wing panel and extends around the leading edge back to the bottom of the front spar. This means that there are no joints or seams in the covering in the main part of the upper wing surface.

The tail surfaces are cantilever with fixed surfaces being mahogany plywood-covered units treated in a similar manner to the wings, built up from spruce spars and ribs. Movable surfaces are a composite steel and aluminum alloy structure, fabric-covered and are dynamically balanced. Cockpit-controlled tabs for longitudinal balance are provided in the elevators. All controls, bellcranks, etc, are mounted on ball bearings, and elevators are interchangeable right and left for easier replacement of spares.

The landing gear is of the cantilever type, having vertical motion of 8" equipped with 6.50” × 10" low-pressure tires, having a tread of 9' 4". The tailwheel is steerable through full range of rudder travel and automatically disconnects to become full-swiveling for spot turns and hangar handling. Hydraulic brakes of the expander tube type are provide and also a parking brake controllable from both cockpits is supplied.

Two tanks of 22½ gallons capacity each designed with expansion space are provided, one in each wing, giving the ship four hours’ range. The fuel system is of the pump-feed type, and an auxiliary wobble pump is provide which can be operated from either cockpit.

A Ranger 6-440 C-2 engine is used. It develops 175 hp and can be run on 65-octane fuel. Engine is of conventional Ranger design being 6-cylinder air-cooled inverted inline type The metal propeller is standard equipment of the McCauley steel type having detachable and adjustable blade and a diameter of 7' 2". A direct-drive hand-turning Eclipse starter is provided with the handle located on the lefthand side of the ship just forward of the wing.

Open cockpit arrangement is standard equipment with a suitable brace to protect the crew in the event of turnover. Cockpit enclosures are provided as extra equipment. These are of the sliding type, covered with Plexiglas and fully enclosing both cockpits. Each cockpit is equipped with a shock-mounted panel offering space for instruments. All instruments are recessed in a rubber crash pad, and fuel gauges are located one in each wing visible from either cockpit.

Performance, based on 175 hp (65-octane fuel)
High Speed at sea level135 mph216 kph
Operating speed at sea level (75% power)120 mph192 kph
Cruising range4 hours
Service ceiling16,000 feet4880 m
Rate of climb sea level835 ft/min250 mpm
Landing speed sea level48 mp77 kph
Specifications
Gross weight2450 lb1110 kg
Weight empty1749 lb790 kg
Useful load701 lb320 kg
Overall span35' 11-3/16"11 m
Overall length27' 8-3/8"8.5 m
Height93"2.3 m

This article was originally published in the "Maintenance Note Book" section of the May, 1940, issue of Aviation magazine, vol 39, no 5, pp 54, 126.
The original article includes one photo and two captioned drawings.
Photo is not credited.

Illustrations: