N1702B, 1942 Boeing PT-13D 'Ruthies Doll' Plus More! Rev.2.

The basic Stearman Model 70 open-cockpit two-place tandem biplane first flew in December, 1933, winning a competition for a military primary trainer in 1934. The Boeing Model 75 Stearman biplane first flew in 1935, the year after the Boeing Airplane Company of Seattle acquired Stearman Aircraft of Wichita, Kansas. The aircraft was used by both the US Army and the US Navy as their main primary trainers. Most of them were made by Stearman after it was acquired by Boeing in models ranging from the 70 to the Model 76. Eight thousand, five hundred and eighty-four complete aircraft were built in all models, and another 1,762 sets of components as spares were built mainly after Boeing acquired Stearman.

See my photos below near and at bottom in three views of N61JP as example of a very late 1973 build from the spares with extremely low airframe and engine hours. The custom cowling of this showplane (never a cropduster) is from a Convair (Vultee 54) BT-13 Valiant and the engine upgrade is a Pratt & Whitney R-985 450 horsepower radial shown with chromed prop and nose cone.

Power for the Stearman production models were radial engines by Wright, Lycoming, Continental and  Jacobs, mostly between 215-225 horsepower, but some were built with early 420 horsepower Pratt & Whitney R-985 radials for The Philippines. Inclusive factory production ran from 1934 to 1945.

Many of the aircraft have been re-engined with the Pratt & Whitney R-985 Wasp Junior 450 horsepower radial and used as an aerial applicator, or cropdusters after World War II. Some of these have had the fabric covered fuselages metallized. Special high-lift wings for STOL work were available; the front cockpit can be faired over and many are registered Restricted category. They have also been used as airshow display aircraft in aerobatics, ribbon-cutting and wing-walker acts or for aerial display banner towing or smoke writing commercial advertising with as much engine as the Pratt & Whitney R-1340 Wasp  600 horsepower radial.  I remember seeing them in late Summer, 1939 writing 7UP (the soft drink) with smoke high in the skies over Minneapolis, Minnesota, so not all were early used by the military.

The aircraft's model nomenclature  history can be confusing because the Model 75 alone had eight different factory numbers and nine basic military service designations. The US Army flew PT-1s, PT-3s, PT-11s, PT-13s, PT-17s and  PT-18s. Canada got lend-leased PT-27s. The US Navy first flew the Model 73 NS-1 in 1935 with a surplus older Wright J-5 (R-790-8) engine and then later A75N-1s and N2S-2 Kaydet versions. All these basic models had suffixes-leading to nomenclature confusion. The factory Model E75 was called the PT-13D by the US Army and called the N2S-5 by the US Navy from 1942 on. Probably most are commonly known on sight as just Stearmans. The service moniker "washing machine" in World War II referred to the fact these trainers washed out many students who failed to master a powerful taildragger with stiff, strong main landing gear. Stearman's finished in all yellow have been mistakenly referred to as "Yellow Perils", which moniker actually rightly belongs to the similar contemporary Naval Aircraft Factory N3N-3 biplane trainer. See N44879 for a true N3N-3 "Yellow Peril" example photographed by me also at SZP, but that one is now in all-silver finish, except yellow on top of top wing only which my latest photos show, which perhaps is just as confusing. No one said this was easy!

I will turn the discussion to the illustrated N1702D "Ruthies Doll", the feature aircraft of this article designated PT-13D which originally was a primary trainer believed delivered with a 220 horsepower Lycoming R-680-17 7 cylinder air-cooled radial engine. Somewhere along the way, its was re-engined with a Continental W670 7 cylinder radial of 220 horsepower, probably more supportable. I first photographed this beautiful example  in 2005 at a military airshow at NAWS Point Mugu NTD, where I worked for 29 years before retirement.. I have subsequently photographed "Ruthies Doll" at Santa Paula Airport SZP where it is hangared. Some of these aircraft have retained their various Army or Navy military all yellow, blue and yellow or silver coloration in restorations, but N1702B has been finished uniquely personalized. The lower two photos of "Ruthies Doll" were taken by me at SZP on takeoff and climb from runway 22.

Please CLICK on either top photo to see the N1702B aircraft profile page with more aircraft photos. See lower photo for Dean Heald's fine photo of a 1943 US Navy restored N2S-1 N5580M. Thank you, Dean! And for a special treat, see the 'Spirit of OPEC' below right, thanks to the Mason family at SZP, and N61JP, a late build (1973) custom Stearman at bottom group of photos.

Specifications: Boeing Stearman E75 N2S-5 (PT-13D)                   N1702B            

Stearman Aircraft Division

Boeing Aircraft Company

Wichita, Kansas 

Type: Two seat tandem primary trainer

Engine: one Lycoming R-680-17 air-cooled radial 220 Hp

Wingspan upper: 32' 2" staggered over lower

Wingspan lower: 31' 2"

Wing total area: 297 sq. ft.

Length: 25' 1/4"

Height 9' 2"

Empty weight: 1,936 lbs.

Loaded weight: 2,717 lbs.

Performance:                                                                                  N1702B

Max speed: 124 mph at sea level

Cruise speed: 106 mph at sea level

Wing loading: 9.15 lbs./sq.ft.

Power loading: 12.35 lbs./hp

Initial climb rate: 840 ft./min.

Service ceiling: 11,200 ft.

Max range 505 statute miles

Contract prices FAF varied from $7,713 to $10,412 during

the war including all Stearman military versions. 

                                                                                                      N5580M

I thank Dean Heald for a fine inflight photo of N5580M, a 1943 Boeing Stearman B75N1 as a US Navy N2S-1 showing authentic military colors of this restored  primary trainer. See aditional photos taken at several locations by several members on the N5580M aircraft profile page. This stunning aircraft gets around!

                                                                                                        N65124

This article would not be complete without showing an example of a working SZP Boeing Stearman with high horsepower engine. N65124 is the Mason's 1943 A75N1 (PT-17) "Spirit of OPEC" workhorse equipped with Jacobs-built  P&W R-985 450 horsepower engine, Experimental classed used for glider towing and banner towing. Note the squared-tip wings. Thank you Rowena, Pete and Sammy!

                                                                                                        N61JP
Example of a stunning 1941 late build (1973) from spares and customized with larger engine, added cowl, custom panels and other refinements. Multiple FAA certification.

                                                                                                        N61JP
 

 N61JP

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