Fleetwings XBT-12 "Sophomore"

[marine air]

We have started working on the sole surviving Fleetwings BT-12, actually the 1940 XBT-12 . Desperately need any maintenance manuals, parts manuals or even a Flight Manual. Would appreciate any help towards sourcing any of these and glad to purchase a copy of any material. Thanks.

[mike furline]

https://www.flight-manuals-online.com/p ... ngs-bt-12/

[marine air]

Thanks! They have the flight manual and that helps a bit.

[Dan K]

You may have already seen this, but here's the intro to that October '43 article in Aviation:

Another of AVIATION's important "Design Analyses" appears on page 119, with the Fleetwings BT-12 basic trainer the object of a complete part-by-part breakdown. Crammed with fundamental design information, weights, measurements, and structural details, the article is rounded out as an invaluable reference work by numerous perspective sketches and photos of the important components.

https://archive.aviationweek.com/issue/ ... #!&pid=118

[Dan K]

Possible source with the Grundy Archive?

https://archindex.grundylibrary.org/rep ... esources/7

Check out the description for Box 5.2, Folder 6:

https://archindex.grundylibrary.org/rep ... tainers/18

[mike furline]

https://www.aerialvisuals.ca/AirframeDo ... rial=59111

https://www.airhistory.net/photo/408674/39-719

[Dan K]

Marine Air: I'm curious if you're having any luck securing engineering info from NARA. PM if you prefer.

And don't hesitate to submit a parts list for scrounging help. So many folks have helped me with similar over the years that I enjoy returning the favor when able.

Wishing much success.

[marine air]

Haven't found any more manuals other than a flight manual. Will try your recommendations. Thanks.

[Mark Allen M]

Neat airplane.

https://edan.si.edu/slideshow/viewer/?e ... 56_ref1282

https://edan.si.edu/slideshow/viewer/?e ... 356_ref780

[Michel Lemieux]

Great news!

Was this a plane that was in Soplata collection?

Cheers and best of luck.

[Noha307]

You should reach out to Ester Aube of AirCorps Library. Every once and a while, she has included requests for documentation from a member to her weekly update emails. An example is below:

What's New on AirCorps Library - Aug 18th (Excerpt).png (160.31 KiB) Viewed 6425 times

(Source: Email)

You should be looking for T.O. 01-130BA and T.O. 01-130BB:

(Source: AirCorps Library)

Was this a plane that was in Soplata collection?

Yes, marine air purchased it back in 2019.

[marine air]

You guys are amazing! So, the thought is we will have to reverse engineer quite a bit as we tackle areas that are missing and no manual exists. This is the ex-Soplata prototype and the only one that escaped the smelter in 1945. The Hayes 27'' wheels are dated 1937 and 1937. However, they are the same that North American was putting on their designs of the time. Because, FLeetwings was such a small company, by necessity they would have borrowed ideas and purchased items from other manufacturers.
In 1939, many manufacturers were not yet pursuing ( or having much success) with the military contracts. The seats look straight out of a PT-19, for example.
We have started cleaning the sixty plus years of tree sap off the airframe and getting it where it can roll. Soon we will be rolling it to the new shop. The Timken wheel bearings #18200 and 19150 are still in production after 100 years! The prices ranged new from $1,100 to $35. depending on how much one enjoys paying for the exact same item.
Will try to post pictures in the future.

[Cvairwerks]

marine: Anything that has a commercial part number, search far and wide for it, to located the best price. On the L-5's, the hinge bearings for the elevator and rudder are still in production and I've found them ranging from a couple bucks each to over 20$ each. The control column pivot bearings are the same as some bicycle headset bearings and range in price in an even greater spread. One of the harder things to find will be the Heim joints used on lots of the controls. Prices are crazy on them, and availability can be very spotty. I'd also suggest that you start looking for things like nuts, washers and cotter keys in bulk. I get mine from various sources and sometimes in huge quantities. For example, I lucked out and picked up almost 9000 AN960-10L and -10 washers for less than buying 500 from most of my usual sources. I managed to pick up a few thousand cotter keys in the three main sizes I need, for under 5$ total. Pays to shop around on hardware.

[Randy Haskin]

You guys are amazing! So, the thought is we will have to reverse engineer quite a bit as we tackle areas that are missing and no manual exists. This is the ex-Soplata prototype and the only one that escaped the smelter in 1945. The Hayes 27'' wheels are dated 1937 and 1937. However, they are the same that North American was putting on their designs of the time. Because, FLeetwings was such a small company, by necessity they would have borrowed ideas and purchased items from other manufacturers.
In 1939, many manufacturers were not yet pursuing ( or having much success) with the military contracts. The seats look straight out of a PT-19, for example.
We have started cleaning the sixty plus years of tree sap off the airframe and getting it where it can roll. Soon we will be rolling it to the new shop. The Timken wheel bearings #18200 and 19150 are still in production after 100 years! The prices ranged new from $1,100 to $35. depending on how much one enjoys paying for the exact same item.
Will try to post pictures in the future.

Quite a project -- hoping you'll keep WIX updated on the progress.

Good luck and thanks!

[Noha307]

The William Harry Engle page on the Pitcairn Field website includes an image of his logbook with entries that indicate he flew your airframe, 39-719. The image is sourced to his family, so maybe there's a chance they still have some manuals or other papers related to the aircraft?

Did NACA ever test any BT-12s? If so, there might be some reports in the NASA Technical Reports Server. For example, there are ones involving other Fleetwings aircraft such as the Model 33 and XA-39.

EDIT: A few results from Google Books gave me another idea for an avenue of research. Since the BT-12 was a novelty in terms of construction, it would have likely been covered heavily in trade journals and other literature dedicated to materials science or the stainless steel industry. For example, the Manual of Aircraft Materials, Steel Aircraft Materials and Applications or Electromet Review. There is also reportedly a cutaway drawing in the Aviation Sketch Book of Design Detail published by Aviation.