Flight, August 1934

AN AMERICAN "SPORT" MONOPLANE
The Ryan S-T With Menasco B.4 or C.4 Engine

   A COMPLETELY new type of two-seater ' Sport'' monoplane has recently made its first test flights and has been approved by the American Department of Commerce. The machine is known as the Ryan S-T, and for a comparatively low-powered type has an excellent performance.
   The fuselage is a metal monocoque structure of 17 S.T. aluminium alloy and 17 S.T. alclad skin. A luggage compartment is situated between the two tandem cockpits. If desired a sliding type enclosure for the cockpits may be supplied.
   Solid spruce spars are used for the wings, which are of high aspect ratio and braced with streamlined tie rods. All other structural parts are of metal. The ribs are stamped from aluminium alloy 17 S.T. sheet, and the covering of the wing from the leading edge to the rear of the front spar is also of this material. The rest of the wing and the control surfaces are covered with fabric. The ailerons are of the modified Frise type and are differentially operated. Flaps extend over half the wing span and are operated by a small crank. It has been proved that these flaps decrease the landing speed by 8 m.p.h. and permit a steep angle of approach.
   The stub wings are of tubular steel construction, and are removable.
   Steel tube is employed for the engine mounting, which is supported on rubber mountings at the fuselage. The engine is also carried on large rubber mountings on the bearers, with resultant damping of vibration at all speeds.
   The neat undercarriage may be seen in the accompanying general arrangement drawings, for which we are indebted to Aero Digest. It is of racing type, incorporating long-throw vertical oleo shock-absorbers and full Goodyear air wheels and brakes. Landing stresses are distributed to the fuselage by a pair of inclined struts between the wing panels and the body.
   Arrangements, it may be noted, have been made for the Goodyear air wheels to be completely removed without disturbing the fairings which enclose them. An 8in. pneumatic tyre of the full swivelling type is fitted beneath the tail.
   As in most of these American low wing monoplanes "tabs" are provided on the trailing edges of the elevators for trimming. Dual controls are fitted, those in the front cockpit being quickly removable.
   Either the 95 h.p. Menasco B.4 or 125 h.p. Menasco C.4 in-line air-cooled inverted engines may be used. It is claimed that with the Menasco B.4 fuel consumption is about 20 m.p.g.
   It is expected that an improved airscrew will increase the top speed figure of the machine given in the accompanying table.

RYAN S-T
Menasco B.4 95 h.p. engine.

DIMENSIONS
   Span 30ft. (9,14 m)
   Length 21ft. 5in. {6,6 m)
   Wing area 124 ft. (11,5 m2)
   Height 6 ft. 11 in. (2,1m)

WEIGHTS
   Weight empty 1,022 lb. (464,5 kg)
   Gross weight 1,550 lb. (70.3 kg)

PERFORMANCE
   Top speed 142 m.p.h. (228.5 km/hr)
   Cruising speed 122 m.p.h. (7.96 km/hr)
   Service ceiling 16,500ft. (5 029 m)
   Absolute ceiling 17,650 ft. (.5 3S0 m)
   Landing speed 38 m.p.h. (61 km/hr)
   Cruising range 403 miles (649 km)

Flight, February 1941

TWO AMERICAN TRAINERS
The Ryan ST-3 and Howard DGA-125 Make Their Appearance

  THE new Ryan low-wing open cockpit trainer for 1941, known as the ST-3, has the familiar Ryan appearance but is an entirely new aeroplane, designed and built to take advantage of production experience. The new Ryan ST-3 is the commercial trainer version of the trainers being produced for the U.S. Army Corps. One of the ST-3 models is powered with the radial Kinner B-54 five-cylinder air-cooled engine; another has the in-line Menasco.
  Many other important changes have been incorporated. The fuselage is wider by 3in. and longer by 14in., assuring roomy cockpits for student and instructor. The entire treadle-type landing gear has been changed and allows for several wheel and brake combinations. Tread has been increased by more than a foot to 78 3/4 in., and the wheels are now set farther forward. The familiar Ryan streamlined wire-braced wings are used, but they are now swept back. The ST-3 fuselage is of semi-monocoque stressed-skin all-metal construction.

Competition Winner

  Ryan now holds orders for $7,425,000 from the Air Corps for trainers to be built for Army and Navy pilot training. Confident in the belief that the ideal primary trainer should be a low-wing monoplane, the Ryan Aeronautical Company, in 1934, produced the first Ryan ST. Since then Ryan has been the pioneer in the low-wing trainer field, retaining the basic ST design, but constantly making numerous refinements.
  It was a Ryan which last year was the winner of an Air Corps competition for primary trainers. Then the Ryan ST became the Army's first low-wing primary trainer, thus breaking away from a 30-year precedent of biplanes for initial instruction.
  As far as possible, machined castings and forgings and built-up light alloy structures have replaced welded steel tubular units. The stub wings are of riveted aluminium alloy construction, while the outer wing panels incorporate spruce spars and ribs stamped from Alclad sheet. The stub wings are metal-covered, while the outer panels and the ailerons, flaps and tail surfaces are covered with fabric which is attached by sheet-metal screws instead of orthodox rib stitching. The entire pleading edge of the wing is covered with Alclad sheet. The flaps are operated by direct-action lever from the left side of the cockpit. The maximum lowered angle is 30 deg., but the flaps can locked in any intermediate position. Hinges of the flaps and all control surfaces are fitted with ball bearings.
  The Alclad skin of the fuselage has the robust thickness of 0.032 in., and none of the panels require any forming, so making them simple to replace. Brakes may be either mechanical or hydraulic, and the tail wheel is steerable. Elevator tabs are provided for trimming and are operated by hand wheel. Dual control, with dual brakes, are standard. Four engine installations are available, the Kinner B-54 (125 h.p. at 1,925 r.p.m.), the Kinner R-54 (160 h.p. at 1,850 r.p.m.), the Menasco D-4 (125 h.p.), and Menasco C4-S (150 h.p.), the two latter being four-cylinder in-line air-cooled engines.

Weights and Performance

  Weights of the ST-3 with the Kinner B-54 engine installed are as follows: Weight empty, 1,228lb.; oil, 23lb. ; petrol (24 U.S. gals.), 144lb. ; instructor, 190lb. ; student, 190lb. ; other load, 547lb. ; total loaded weight, 1,775lb. The power loading is 14.2 lb./h.p., and wing loading 13.2 lb./sq. ft.
  The span is 30ft. 1in. and length 22ft. 5in. Height is 7ft. 2in. Various surface areas in square feet are: wing, 134; tail plane, 14.5; elevator, 11; fin, 4.6; rudder, 7.8; aileron, 11.1 ; and flap, 12.5. Other interesting quantities are: Wing dihedral, 4 1/2 deg. ; sweepback, 4 deg. 10 min. ; airscrew diameter, 7ft. 6in.; airscrew clearance with thrust line level, 9in. ; ground angle, 11 3/4 deg. ; type of flaps, plain.; wing aerofoil section, NACA 2412.
  The makers' performance figures, subject to limits of plus or minus 5 per cent., are set out hereunder:
Kinner B-54 Menasco C4-S
125 h.p. 150 h.p.
Maximum speed at sea level 120 m.p.h. 136 m.p.h.
Cruising speed 108 m.p.h. 122 m.p.h.
Rate of climb at full power and full load at sea level 635 ft./min. 830 ft./min.
Time to climb to 6,562ft. (2,000 m.) 13.5 min. 8.8 min.
Service ceiling, full load 12,900ft. 18,000ft.
Take off run, 5 m.p.h. wind, sea level 610ft. 520ft.
Landing speed, sea level 57 m.p.h. 57 m.p.h.
Endurance at operating speed 2.86 hr. 2.4 hr.