VFW Post Wooden Propeller Identification

[Charlie]

I started over a year ago to try and identify the following propeller. I am going to try again. Here is a set of pictures of the propeller. It is 96" long and was made by US Propeller.
http://www.flickr.com/photos/chukpik...7603786571375/

I thought it might be for a Stearman but would like help. I contacted the Smithsonian but they didn't know.

[MWP_Lamar]

Unfortunately I have very little information on US Propeller other than they made mostly wooden drone props although yours is most certainly an airplane prop. Wooden props for the Stearman N2S3 (the most likely candidate in my opinion) were 98 inches in diameter but did mount on the Continental and Jacobs 220 hp engine.

Lamar

[Charlie]

I will go back and make more careful measurements of the propeller length. I just held the tape up to it and eye balled it to a nice 96" or even 8ft length. To me props "all look alike" except, I can usually tell if one has more blades than another. (I guess in thinking about the # of blades, any prop with more than two blades would not be one piece)?

I will try to get dimensions on bolt mounting pattern, although maybe that is set in stone by engineering standards? Not single plane designers?

This prop belongs to a VFW Post and we no longer have a place to keep it on display. We are planning onselling it before it gets ruined, damaged, or lost in a garage.

[MWP_Lamar]

I guess in thinking about the # of blades, any prop with more than two blades would not be one piece)?

See these posts on this topic of more than two blades being in one peice or not: http://woodenpropeller.com/forum/viewtopic.php?t=1105

I will try to get dimensions on bolt mounting pattern, although maybe that is set in stone by engineering standards? Not single plane designers?

The bolt mounting pattern is determined by the engine standard.

Lamar

[Charlie]

Here is the answer I got last year from the Smithsonian:

"Dear Mr. Pritchard:

We received your e-mail communication of August 15, 2006, seeking assistance in establishing the provenance of a U.S. Propeller Co. Design 96LG98 prop that you have.

We have been utterly unable to identify this model number in any of the cross references that we have for U.S. Propeller Company designs, or any other cross reference. We do not believe it is a WW1 era prop, as most of those in production at that time are well established, and the power rating (220hp) indicates a late 1920s or 1930s era engine, such as the Wright J-4 or J-5 series. Admittedly, we do not hold a complete catalog of props produced by the U.S. Propeller Co., which would have been useful. However, the fact that it did not show up in any of the cross-references for U.S. military props indicates that it was probably intended for commercial/civil use. We also did not locate any references to such a prop in use in more than 40,000 pre-1946 U.S. civil registered aircraft that we have amassed to date. The serial number indicates that U.S. Propeller Co. may have produced as many as 11,788 propellers ahead of this one, so it is possible it was a "one-off" type that did not receive an Approved Type Certificate from the CAA, Department of Commerce (forerunner of the present FAA).

Sincerely,

Dan Hagedorn

Archives Research Team Leader and Adjunct Curator,

Latin American Aviation

Archives Division MRC 322, National Air and Space Museum"

I would like to point out that this propeller S/N 11789 would indicate some kind of usage. I thought it had a USN inspection stamp, but I think it is USP 1 inside a circle. The prop is very close to being 96" on a more careful measurement. Has an 8 bolt mounting pattern with a 7" diameter center to center. I guess the civilian application could be right.

It makes sense that the mounting hub would be more a product of the engine although it would be a small matter to make a hub for any motor to mate up.

Is it possible that they made a series of very large drones for Army Air Force pilots to practice on, while allowing the more proficent Navy pilots to use the very small drones?

[Dave]

Actually, Charlie, that propeller was in fact a production propeller with type certificate number 798. I have the dimensions for it, but I have no indication of what it might have been used on.

(Diameter 96", pitch 76"-99", bolt hole dia 7/16'", bolt circle 7", thickness 6", hub diameter 9 3/8" )