View Full Version : Help in identifying propeller

04-06-2017, 12:26 AM
Hi there-
I'm trying to identify a propeller my grandfather gave me about 40 years ago. It's a beautiful wood propeller with what appears to be copper sheathing. Here's what I have for markings on the propeller below. I believe I know what some markings signify, but not all numbers.

Signal Corps clover leaf inspection stamp.
SC11066 (which I know is the Signal Corps serial number).
OX5 (which I believe is a Curtis engine it was used on).
8-4" (length I believe)
1 (stamped under the clover stamp)

It looks sort of like the Hartzell Liberty propeller or the Star Piano Co. propeller on this site, however, the tips of my propeller are more rounded in shape like the Curtiss R4, but not as large. I would appreciate if somebody could help let me know what all the marking mean, perhaps the make of the propeller and the value too. Thank you!

04-06-2017, 09:21 AM
You won't know for sure what aircraft it was used on, but you are correct that it was for an 0X5 5 engine, which was used on a lot of different airplanes. The Signal Corps number doesn't identify its usage. The other numbers are a serial number and blade numbers (1 and 2). The 8'4" is its diameter and there would be a number after the 5 which would complete the figure for pitch in feet (usually a decimal but occasionally expressed in feet and inches).

The manufacturer name was probably lost with decals removed during refinishing. There are, however, "witness marks" on the hub that indicate that the prop was mounted and used before being removed from the engine.

By far the most likely aircraft for that design was the Curtiss JN4 "Jenny". The so-called "toothpick" shape was adopted as a more economical substitute for the scimitar shaped props, as props were frequently damaged in landing and taxiing mishaps.

04-07-2017, 02:24 PM
Thank you for the information. Much appreciated. :D