A.T.C. #640 (5-26-37) STINSON "RELIANT", SR-9F

This fabulous "Reliant", the thundering SR-9F, more or less had to be developed because of insistent demands by buyers of national prominence. Then too, it was 1931 since the last Pratt & Whitney powered Stinson (a "Junior" model W) had been built. With times getting better and better some of the moneyed customers were getting anxious to enjoy the extras their money could buy in a more powerful Stinson. As introduced early in 1937 the "Reliant" SR-9F was a shade smaller than the old "Model W", but it was over 600 lbs. heavier when empty, some 850 Ibs, heavier at loaded gross weight, about 50 m.p.h. faster (with 100 hp. more, of course), and cost exactly twice as much! This perhaps pictures the kind of progress that had taken place at Stinson Aircraft in the 6 years since. Stinson was rightfully proud of the new SR-9F, saying "this is the greatest airplane we have ever built," and you almost have to agree with that. It was indeed a superb airplane with "class" written all over it, an airplane surely designed for the executive and gentleman-pilot. But, was it only that. The husky SR-9F was actually an airplane with a many-faceted personality. When dressed up and polished to a fine shine it could "put on the dog" with the best of them, but it didn't mind getting its face dirty either and would pitch in to get the job done no matter what. Actually the SR-9F was at ease on most any job, and it seemed to be happy doing it. Some have said it seemed to radiate with a kind of eagerness and a happy hum, they also said this radiance was contagious upon frequent exposure to it. The roster of owners read like a "Who's Who" of wealth and big business, but that's understandable-the SR-9F "Reliant" was a special kind of airplane, and it wasn't cheap.

The Stinson "Reliant" model SR-9F was a hefty high-winged cabin monoplane with seating arranged for 5. In the optional "Deluxe" version it was elegant, very plush, and usually adorned with all the extras that one could possibly buy for an airplane. Most often used in the pursuit of business matters as an executive-transport, the talented SR-9F offered speed and utility with an intimate type of comfort; this "Reliant" was an impressive airplane and had the habit of making its presence felt, and this was good for business. The massive-looking wing on the "Reliant" created plenty of lift, which translated into short-field performance and a sizable payload. It is logical that the SR-9F with all its power would also be offered as a multi-purpose plane (SR9FM) for freight or charter. The "M" (Multi-Purpose) version was usually fitted with a metal-clad interior and extra doors to allow the loading of kegs, boxes, and stuff, it was also available as a seaplane on Edo twin-float gear, or on skis. The Bureau of Air Commerce (BAG) needed an airplane such as this in Alaska, so they outfitted their hard-working SR-9F as the seasons permitted with wheels, skis, pontoons, and a two-way radio for inspection and regulatory service "in the bush." As powered with the 9 cyl. Pratt & Whitney "Wasp Jr." SB engine rated 400 hp. plus, the SR-9F "Reliant" was a lively brute that reveled noisily in its high performance. Pilots practically worshipped its ability to get off quick, they loved its terrific climb-out, and when leveled off "on the step" they knew they were hard to catch. With all of this power surging through its bones the SR-9F was inclined to be a bit of a brute at times, but it was inherently amiable and responded well to firm handling. The type certificate for the "Reliant" model SR-9F was issued 5-26-37 and the Stinson Aircraft Corp. at Wayne, Mich., manufactured some 25 or more examples. Cy Younglove was Stinson's roving sales mgr. at this time, and he had no trouble selling the "Reliant;" in fact, he had a waiting list.

Listed below are specifications and performance data for the "Reliant" model SR-9F as powered with "Wasp Jr." SB engine rated 400 hp. at 2200 r.p.m. at 5000 ft. (450 h.p. at 2300 r.p.m. for takeoff)-(TB engine also available); length overall 27'11"; height overall 8'6"; wingspan 41'11"; max. wing chord 96". wing chord at tip 38"; total wing area 258.5 sq. ft.; airfoil mod. Clark Y; wt. empty 2990 lbs.; useful load 1510 lbs.; payload with 102 gal. fuel 668 lbs. (3 pass. & 150 lbs. bag.); Payload with 78 gal. fuel 698 lbs. (4 pass. & 18 lbs. bag.); gross wt. 4500 lbs.; max. speed 173; cruising speed (.75 power) 165 at 7000 ft.; landing speed (with flaps) 63; climb 1510 ft. first min. at sea level; ser. ceiling 21,000 ft.; gas cap. 102 gal.; oil cap. 8 gal.; cruising range (.75 power) at 24 gal, per hour 500 miles; price $18,000 at factory field. Model SR9FM was utility version with extra doors and interior fitted for freight and charter; takeoff run (loaded) was normally 545 It, and landing run (using brakes) was normally 375 It.

The fuselage framework, beefed-up considerably to handle 450 hp., was built up of welded 4130 plate and steel tubing, faired to shape with wooden formers and fairing strips, then fabric covered. A large door on each side provided an easy step-up into the large cabin. The big, formed windshield offered a clear, panoramic view and all windows were of shatterproof glass. The adjustable front seats were individual, and the rear seat was wide enough to seat 3 across. The cabin area was insulated, sound-proofed, and upholstered in a variety of rich fabrics. Cabin trim in real leather was optional. The main baggage compartment with outside door and an allowance for 100 lbs. was behind the rear seat; 50 lbs. of baggage was also allowed under the rear seat. The unusual tapered wing was built up around an alloy steel main spar beam, a formed dural rear spar, and built-up dural wing ribs; completed frame work was covered in fabric. Three tanks (of 39-39-24 gal.) in the wing stored the 102 gal. fuel supply; an extra 24 gal. tank in the wing was optional. The cantilever landing gear of 9'8" tread was fitted with internally-housed spring-oil shock struts; 7.50x10 wheels were fitted with 8.50x10 tires and hydraulic brakes. Streamlined metal wheel pants were optional. The SR-9F was also eligible as a seaplane on Edo WB-5030 twin-float gear at 5030 lbs. gross wt.; the seaplane was about 478 lbs. heavier than the landplane version. The large fabric-covered tail group was built up of welded 4130 steel sheet and tubing; the horizontal stabilizer was adjustable for trim. A metal trim tab on the rudder was adjustable on the ground only. All movable control surfaces had aerodynamic balance. The swiveling tail wheel was fitted with a 10.5 in, streamlined tire. A Hamilton-Standard controllable prop, Eclipse electric engine starter, a generator, Exide battery, navigation lights, cabin lights, cabin heater, carburetor heater, cabin vents, dual control wheels, fire extinguisher, roll-down windows, plated hardware, map pockets, ash trays, assist ropes, seat belts, and first-aid kit were standard equipment. Bonding & shielding, radio gear, landing lights, para-flares, oil cooler, multipurpose cargo interior, extra 19-24-50 gal. fuel tanks, and skis were optional. The next "Reliant" development was the model SR-10 series as described here in the chapter for ATC # 678.

Listed below are SR-9F entries as gleaned from registration records:

NC-2215; SR-9FD (# 5700) Wasp Jr. 400

; SR-9F (# 5701) Wasp Jr. 400

; SR-9F (# 5702) Wasp Jr. 400

; SR-9F (# 5703) Wasp Jr. 400

; SR-9F (# 5704) Wasp Jr. 400

; SR-9F (# 5705) Wasp Jr. 400

-17191; SR-9F (# 5706) Wasp Jr. 400

-17194; SR-9F (# 5707) Wasp Jr. 400

-18426; SR-9F (# 5708) Wasp Jr. 400

-18400; SR-9F (# 5709) Wasp Jr. 400

-18411; SR-9F (# 5710) Wasp Jr. 400

-18412; SR-9F (# 5711) Wasp Jr. 400

-18414; SR-9F (# 5712) Wasp Jr. 400

; SR-9F (# 5713) Wasp Jr. 400

-18422; SR-9F (# 5714) Wasp Jr. 400

-18425; SR-9F (# 5715) Wasp Jr. 400

-2085; SR-9F (# 5716) Wasp Jr. 400

-18429; SR-9F (# 5717) Wasp Jr. 400

; SR-9F (# 5718) Wasp Jr. 400

-18450; SR-9F (# 5719) Wasp Jr. 400

-18446: SR-9F (# 5720) Wasp Jr. 400

-18418; SR-9F (# 5721) Wasp Jr. 400

-18483; SR-9F (# 5722) Wasp Jr. 400

NC-89; SR-9FM (# 5723) Wasp Jr. 400

; SR-9FM (# 5724) Wasp Jr. 400

; SR-9FM (# 5725) Wasp Jr. 400

-18451; SR-9FM (# 5726) Wasp Jr. 400

This approval for ser. # 5700 and up: no listing available thru 1938 records for ser. # 5701-05, 5713-14. 5716, 5718, 5720, 5722, 5724-25; some SR-9F were exported, number not known; 4 of SR-9F in USAAF as UC-81E; approval expired 10-25-40.

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Last modified: March 23, 2004