7WP, the Enigmatic Spartan

by Jim Savage

When construction on what evolved into the 7WP-1 began, it was the second of 36 airframes that would ultimately be built.  The completion of this airframe actually occurred in two steps. The first was in September 1936 and the second was in June 1937. The airplane is different than the 7X prototype and it is different than the 34 production 7W’s that were built. To fully understand this unique model, we need to first understand some of the history behind the 7X prototype model

When Spartan decided to reenter the aircraft production business in 1935, they decided to move from the typical rag and tube construction techniques and materials that had been employed in the past to a futuristic, all metal monoplane. Designer James Ford’s initial design was quickly turned into a flyable prototype designated as the 7X.  The airplane was hand built and was initially powered by a 260 HP Jacobs engine with a Hamilton Standard ground adjustable propeller.  The airplane had 4 seats, it held 75 gallons of fuel and the gross weight was 3500 pounds.  The engine cowling and tail section can best be described as unconventional. For comparison, production model 7W’s had 5 seats, held 112 gallons of fuel and the gross weight was 4400 pounds. 

The first flights of the 7X were in March 1936 and it was quickly determined that major changes needed to be made. The airplane was underpowered, unstable and had a difficult to use landing gear.  By May 1936, the engine had been moved forward and upgraded to a 285 HP Jacobs. At the same time, the cowling was modified to a more traditional configuration that was similar to what would ultimately be used on the production 7W’s.  

At around this time, it appears Spartan realized that with the extensive modifications already made to the 7X, as well as ones that would need to be made in the coming months, it would be impractical (or perhaps impossible) to have the 7X conform to the anticipated configuration that would be specified in a production type certificate. From May through August 1936, additional modifications were made to the 7X that included noticeable changes like a conventional tail assembly, similar to what would be used on the production 7W’s. The propeller was also changed from a Hamilton Standard ground adjustable to a Curtiss-Reed fixed pitch model. After August 1936, no additional modifications were ever made to the 7X prototype.  Though the final version of the 7X looked externally similar to the production 7W, it was actually quite different.

At some point in time in 1936, a second airframe was begun.  Although this second airframe would ultimately evolve into the 7WP, at this point it is best described as the second prototype. This airframe incorporated changes either already made or anticipated to be made to the 7X, as well as other changes that would ultimately be part of the production 7W’s. The most notable change was an upgrade from the Jacobs 285 HP Jacobs engine to a 450 HP Pratt & Whitney Wasp Junior engine.  From photographic evidence, we know this second prototype retained the unique landing gear arrangement used on the 7X, but had the engine, cowling and tail section of the 7W production models. 

In August 1936, Spartan had a flyable 7X with a 285 HP engine and a nearly finished second prototype airframe with a 450 HP engine.  At this point in time, it looks like the marketing folks got a bit ahead of themselves.  An article was written that appeared in the September 1936 issue of Aero Digest describing the two Spartan models as the Standard Seven and the Super Seven.  The article had performance specifications for the Super Seven even though the 450 HP airplane had not yet flown.  The cover of that September magazine shows two Spartans, the 7X prototype with registration number X13984 on the ground and a second airplane in flight wearing registration number X13986. Although never stated as such, the cover picture and the related article leads the reader of the magazine to believe these are two different airplanes, with the one on the ground apparently the Standard Seven and the one in the air the Super Seven.

Unfortunately, that article and more specifically the picture have created a level of confusion around the specifics of the initial version of the second prototype airframe. That confusion remains today. The airplane shown in flight it a doctored version of the 7X with a fictitious registration number. The registration number chosen was also problematic since it was in use by another non-Spartan aircraft at that time.  To understand the second prototype airframe that ultimately became the 7WP, you need to completely ignore the altered magazine cover.

By September 1936 when the second prototype was initially completed, Spartan was already starting to build additional airframes that would be completed as 7W production models. Those new airframes incorporated features that were different than some features of the second prototype.  To obtain a type certificate for the ultimate 7W, Spartan would need an airplane that had all of the features associated with that type certificate.  Hindsight tells us Spartan had two choices, either modify the second prototype or use one of the production models that were in the process of being built for certification purposes.

We know from existing FAA files that S/N’s 1 and 2 initially obtained Experimental licenses and were used to earn Type Certificate 628 that was issued February 15, 1937. 

Shifting back to the second prototype, photographic evidence shows an airplane that looks identical to a production 7W except for the propeller, the landing gear and the smaller wheels.  It also is shown with no trim paint.  There is no evidence this second prototype ever had a registration number and it is not known if the airplane was ever flown in this configuration.  The following pictures shows what it looked like with those telltale preproduction features.

What we do know is this airplane would be extensively modified, it would be awarded a second type certificate that was different than the one used for the production 7W’s and the airplane would ultimately be sold to the Chinese. The new type certificate numbered 646 was issued June 28, 1939. The model designation on the type certificate is 7WP, with the 7 representing the 7th basic model produced by Spartan, the W indicating the Wasp Junior engine and the P indicating if was a photoreconnaissances model.

Photographs taken while the airplane was being disassembled for shipment to China show the airplane had been modified with the landing gear and larger wheels used on the 7W models. Vol. 7 of the Joseph P. Juptner series U.S. Civil Aircraftindicates the technical description published by the CAA (predecessor to today’s FAA) as a 3-place cabin monoplane.  Other sources indicate the center section of the airframe was significantly modified from what is seen in a standard 7W to accommodate photographic equipment, thus the need for a different type certificate.  Only one aircraft was produced under the authority of type certificate 646, and it was assigned serial number 7WP-1

The 7WP was sent to China under Export C of A E2740 dated July 16, 1937, where it was delivered to China Airmotive of Shanghai for the Chinese government, marked “1309.” 

Carrying Nationalist Chinese markings, the 7WP was ultimately shot down or simply crashed into a river, bringing an end to its flying career.  

It was apparently recovered from the river, as a later photo shows the 7WP looking fairly battered but upright and on its landing gear near other similarly worn combat aircraft, in front of what appears to be a baseball stadium.  The eventual fate of the 7WP is unknown.

Photos from the Kevin Gray collection.