Wooden Propeller Forum  

Go Back   Wooden Propeller Forum > Wooden Propeller Identification > "Modern" Wooden Propellers

Reply
 
Thread Tools Display Modes
Old 10-03-2015, 12:46 PM   #1
Larryh86GT
 
Join Date: Sep 2015
Posts: 12
Default Sensenich Bros D102 Crash Propeller

I recently purchased this old Sensenich Bros propeller. While I know I will probably never know it's story it looks great with nice patina. It was owned by a 92 year old pilot who was a barnstormer in his younger days and had survived 9 crashes over time. I am thinking if he saved it it must have held a good story for him. I cannot find much information on the propeller. It is stamped with:
D.102.
No.850.
A.T.C.450.
and also stamped with the number 850 and the number 1
There is still some cloth left on one blade.
I assume the D102 means it was 102" long. Right now it measures 80" from one broken end to the other.
The hub is 4" thick.
The center hole diameter is 2 3/4"
The bolt hole circle is 5 1/2"
The bolt hole diameters are 3/8"
It's going to look great mounted on my wall.
Larryh86GT is offline   Reply With Quote
Old 10-03-2015, 12:48 PM   #2
Larryh86GT
 
Join Date: Sep 2015
Posts: 12
Thumbs down

Some more photos:
Larryh86GT is offline   Reply With Quote
Old 10-04-2015, 09:14 AM   #3
Dbahnson
Administrator
Site Admin
 
Join Date: Nov 2008
Posts: 522
Default

The "ATC" refers to the Type Certificate, but I can't find that listed for any Sensenich propeller, or for any other manufacturer for that matter. Looking closely at the photo it looks as if the "5" may actually be a "6". (You might check it with a magnifying glass or other enlarging technique.) The only Type Certificate number of 460 that I can find was listed for Hartzell. (See attached scans.) Note that the hub thickness, bolt hole diameter and bolt circle diameter are all consistent with the numbers on your list, and correspond to Hartzell model number 706 (E,EI, and I) which had a diameter of 83" or 82" and was designed for use with a 145 HP engine.

If you look up Hartzell number 706 on this page you'll see the propeller listed for various Fairchild aircraft with the Warner 145 HP engine.

Sometimes one manufacturer (in this case Sensenich) would manufacture props using the Type Certificate from another (in this case Hartzell) under agreement. I think the scimitar shape of yours is also consistent with a Hartzell design, so it all fits.

It's VERY likely that your measurement of 80" is consistent with an original size of 83". It just doesn't look as if 22 inches of prop are missing on that photo.

So all in all I'm 95% certain that prop was designed for a Fairchild airplane with the 145 Warner Scarab engine and was manufactured by Sensenich under Hartzell's type certificate. The type certificate expired in 1954, but I suspect you prop was manufactured in the 30s or 40s.
Attached Images
File Type: jpg Hartzell 1.jpg (95.2 KB, 8 views)
File Type: jpg Hartzell 2.jpg (76.6 KB, 7 views)
Dbahnson is offline   Reply With Quote
Old 10-06-2015, 09:39 AM   #4
Larryh86GT
 
Join Date: Sep 2015
Posts: 12
Default

Thanks for the quick reply and information. The ATC number is definitely 850. I have posted a clearer picture.

A couple of questions:

1. Normally isn't a "D" on a propeller indicative of it's length?

2. One of the blades is 42 1/2" long to center with 24" of brass. The other blade is 37 1/2" long with 18 1/2" of brass. There is 6" of cloth showing on the longer blade and no cloth showing on the shorter blade. Normally wasn't
the tip enclosed in brass also on these types of propellers? So the propeller
was at least 86" long and probably longer with the amount of damage
showing.

3. According to the characteristics of an "Earlier Wooden Propeller" on this site they are generally 8 bolt holes, darker woods, often scimitar, and fabric covered tips.

4. From the looks of the age of this propeller might it be a propeller made by Sensenich before they kept records?

Just curious.
Thanks,
Larry
Attached Images
File Type: jpg D102 Propeller px 10 6 15 006.JPG (45.6 KB, 5 views)
Larryh86GT is offline   Reply With Quote
Old 10-06-2015, 07:42 PM   #5
Larryh86GT
 
Join Date: Sep 2015
Posts: 12
Default

A better photo of the propeller:
Attached Images
File Type: jpg D102 Sensenich propeller 10 6 15 002.jpg (52.8 KB, 8 views)
Larryh86GT is offline   Reply With Quote
Old 10-06-2015, 10:35 PM   #6
Dbahnson
Administrator
Site Admin
 
Join Date: Nov 2008
Posts: 522
Default

Quote:
Originally Posted by Larryh86GT View Post
Thanks for the quick reply and information. The ATC number is definitely 850. I have posted a clearer picture.

A couple of questions:

1. Normally isn't a "D" on a propeller indicative of it's length?

In British props that is common, but not so much on U.S. propellers.

2. One of the blades is 42 1/2" long to center with 24" of brass. The other blade is 37 1/2" long with 18 1/2" of brass. There is 6" of cloth showing on the longer blade and no cloth showing on the shorter blade. Normally wasn't
the tip enclosed in brass also on these types of propellers? So the propeller
was at least 86" long and probably longer with the amount of damage
showing.

Usually there was curvature around the tip, so I agree that it was likely longer than 86", but I'm still skeptical that it was 102"

3. According to the characteristics of an "Earlier Wooden Propeller" on this site they are generally 8 bolt holes, darker woods, often scimitar, and fabric covered tips.

That's only a very general guideline, probably more applicable in reverse, i.e. most early propellers had 8 bolt holes. Modern propellers are usually 6 bolt holes but 8 holes are still very common.

4. From the looks of the age of this propeller might it be a propeller made by Sensenich before they kept records?

But the reason they start the listing as 1932 is that's the year the business started.

Just curious.
Thanks,
Larry
I think the next step in your quest is to see if you can find a record of the Type Certificate #450. It will likely take some some footwork.
Dbahnson is offline   Reply With Quote
Old 10-06-2015, 11:05 PM   #7
Larryh86GT
 
Join Date: Sep 2015
Posts: 12
Default

Would this match up?

ATC450 American Eagle B-31
Larryh86GT is offline   Reply With Quote
Old 10-07-2015, 12:26 PM   #8
Dbahnson
Administrator
Site Admin
 
Join Date: Nov 2008
Posts: 522
Default

I don't think so. I think that Type Certificate is for the Eaglet airplane, not the propeller, and as near as I can tell that airplane used a 45 to 50 HP engine, which would not likely be using a prop of that length, although I suppose it's possible.
Dbahnson is offline   Reply With Quote
Old 10-07-2015, 12:49 PM   #9
Larryh86GT
 
Join Date: Sep 2015
Posts: 12
Default

Thanks for trying to identify it. I guess it is a mystery propeller. It is still very cool looking and I will be mounting it on the wall shortly. Here is a better picture of one blade of the propeller. I finally figured out how to attach better pictures.
Larry
Attached Images
File Type: jpg Sensenich D102 propeller 10 7 15 001.jpg (103.4 KB, 7 views)
Larryh86GT is offline   Reply With Quote
Old 10-07-2015, 01:19 PM   #10
Dbahnson
Administrator
Site Admin
 
Join Date: Nov 2008
Posts: 522
Default

Maybe try contacting Sensenich and ask them about TC450. They list a number of props with TC numbers in the 400s, including 449 and 452, so it may just be that it's not included in the listing I have, which is from a 1983 FAA publication.
Dbahnson is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 10:56 AM.


Powered by vBulletin® Version 3.8.9 Beta 3
Copyright ©2000 - 2017, vBulletin Solutions, Inc.