Stone Propeller Company

[John]

I have an old prop made by Stone when they were in Witchita the markings ar as follows

ENG R-755-9
HP 225
RPM 2000
AT 17
DWG NO.
43K15605
S6585

I am thinking that it may be off of an old Cessna AT-17 AKA bamboo Bomber but all of the info that I have found on that A/C shows the higher HP engine. the 225 HP seems to be the earlier LM-4 engine fond on the original civilian versions and the earlier Canadian version.

I am just trying to figure out if what I am assuing is correct. I get questions on it all the time.

TIA

[dbahnvt]

Any chance that the drawing number is 43K13605, rather than 15605?

[John]

You are correct the Drawing number is 43K13605 My bad I needed to get up close with a flashlight to read it properly

[dbahnvt]

In that case, it looks as if your assumptions are all correct. On Lamar Bevil's site if you follow the link to Sensenich propellers you'll find a reference to the military drawing numbers (click on this link), which shows it as an equivalent of the model number 90 JA81. You'll see that number listed on this page referenced to the AT17 with the engine you mentioned.

Stone most likely built the propeller under an agreement with Sensenich to use their type certificate. The "43K" in the drawing number indicates that the contract to produce the propeller was issued in 1943. Quite a few props for that airplane have shown up that were built by S&S Propellers in Winnipeg.