Warbird Information Exchange

I just recieved copies of '43 HS drawings of the"cuff" for P-51B/C/D. These are great, showing sections and and dimensions (the shanks are "square" under there!). Does anyone know of a source for the blade itself? I have surveyed a blade(with slightly different cuff) and will use it if I have to, but would verymuch like to have better docs, if possible.

Also have aquired HS "square tip blade" drawing and is exactly the type of drawing I need for the other. Very complete from a historical point of view!

TIA
Charlie

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Charles Neely

In the UK in 2002 I had the privilege of seeing a 4th FG prop blade from a P-51 crash. A picture of the actual crashed plane is in Garry Fry's The Debden Eagles. They uncovered many bits of the plane, including shell casings and actual wooden baffles from the 108-gallon drop tanks. The farmer said I could have a few pieces, and some of the shell casings are in my studio on display today.

The kite had gone through the fence and the farmer found the pieces relatively recently while digging deep on his land to remove a stump or something. The rubber cuff had largely disintegrated, revealing part (not all) of the "shank" underneath. Charlie, according to your information, was it the shank arm itself that was square? That would make sense to help "hold" the cuff in place, but the lower part was definitely "rounded" ...

I'll have another look at the original photo, but for now scroll down this page to see me and the farmer holding up the blade:
http://wademeyersart.tripod.com/id36.html

Wade

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Website: http://www.wademeyersart.com
Facebook: http://www.facebook.com/Wade.Meyers.Studios

Wade,

Thanks for the reply. I first learned about the "square shank" about a year or so ago from Glenn Wegman, in our discussion re: "cuffless propellers" over at the MustangsMustangs forum. His is the only aircraft that I know of to have actually flown with the cuffs removed. This is not to be confused with HS 6547A-6 "square tipped" blade, which never had them. It has been my experience (your milage may vary) that reports of Mustangs being flown without cuffs USUALLY means some sort of blade other than a J-or K-6523A-24 HS blade fitted to the 24D50-65/-105 hub.

A quick glance at the drawing shows you are correct, in that the shank is definitely round as it leaves the hub, but quickly transition to four hard edges before it leaves the spinner (the section is more rectangular than square) and transitions back to airfoilshape just before it leaves the cuff covered area. I was surprised to learn how far into the spinner (3"+/- at c/l axis) the rubber cuff actually covers. I believe i have referenced your site re: photo of blade you mention. Now if only I understood how the fluid was stored for the anti-icing feature!
thanks again
Charlie

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Charles Neely

Hello Charlie,

Glad to see you back on the air!

I saw your request for a blade comparison on the MM board but can't remember my top secret password so I thought I'd answer here!

Anyway, you might try a propeller overhaul facility that has authorization to do the larger HS props as they have all of the various thickness and width dimensions at various blade stations for each type of blade as the blades must be inspected for and meet certain dimensional requirements to be certified. Possibly they could send you copies of the specifics so you could compare profiles.

Glenn

Thanks Glenn
great idea! Things go so much better when other minds can suggest another angle.
Say, do you know of anone that has actually put a tape on a "square tipped HS to check its diameter? New HS data I have indicates this prop dia. is 11'-0". Most refs. (including 01-60-J2) allude to it's diam. as 11'-2". Could there be a slight difference in hub diameters???!! may be another question for the repair shop.
Thanks again,
Charlie

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Charles Neely

Aero Products is 11.0', Ham Std is 11'2"

http://www.airweb.faa.gov/Regulatory_an ... L-11-3.pdf

The blade part numbers are all listed.

bdk-

the problem is not what is historically listed as the "correct" or even proper prop diam. At this point, I'm not ready to say that 11'-2' is not THE proper dimension. The problem arises from the manufacturer's detail drawing (dated 4-15-44 and ?-14-45), which show 12 stations, with detailed ordinates, for each. and a diam of 11ft for the 6547A-6 blade. In all there apears to be 12 different propeller model variants based upon a single basic "blank", varying in given diameters: 8'-11" up to 13'-9" . The drawing is titled: Blade Assemby 6547A. So my question is, which is right?
It is quite possible this blade was originally invisioned for a different, perhaps smaller dia. hub (3 bladed?). In which case the drawing wouldn't be wrong. Another possiblity is that the Mustang 01-60-J2 manual is wrong. In a quick review, I'm thinking the wording can be construed as vague on that particular prop's dia. In reality, we are only talking about a blade that may only be 1" shorter all away around and well within the AAF's penchant for rounding up to the nearest inch, when it comes to basic /rough dimensions.
thanks
Charlie

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Charles Neely

Charlie,

The airplane called "Dam Yankee" is one that I have personally seen using a cuff bladed prop with the cuffs knocked off. Why-- don't know, other than at that time there may not have been a shop around capable of reinstalling them correctly. Also, FYI, 11'2" is the correct number for a full length standard blade prop for the Mustang. As you are finding, that same blade blank could be used for many differant applications as only makes sense.

Sparrow

there is a guy here in vt that i will be seeing this weekend. He is a expert on props.........esp HS. He does not care about engines or airframes, just props. He has hords of Props and blades in his basement.............looks like the ham standard factory. One of his props was on the Kee Bird!

His latest find was 3 NOS blades for a B-25. Still sealed in the crate. I dont think he is online so send me your number and what you are looking for and I will pass it on to him.

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Long Live the N3N-3 "The Last US Military Bi-Plane" 1940-1959
Badmouthing Stearmans on WIX since 2005

N3Njeff,

Would very much like to correspond with your friend!

I am spefically looking to acertain the reason for the apparent 2" discrepancy between the HS drawing I have of 6547A blade (11'0") and the call out diameter found in AN 01-60JE-2 (11'-2").

I'm also wondering if the 6547A blade has the same exact sections/thickness as the J/K-6523A-24 blades (11'-2")? I have heard that they do.

Thanks for the offer,

Charles Neely
visaliaaviation@sbcglobal.net
phone: 559-786-3863 or 559-625-3011

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Charles Neely

Thanks to all for their input!

Upon re-checking my manuals will defer to the very specific statement found on page 175 of AN 01-60JE-3,

"blades J-6523A-24, K-6523A-24, or 6547A-6 have a diameter of 11 feet 2 inches."

According to AN 01-60-3, page 424, cuffs on HS props will,

"be attacked slowly by hot solvent degreasers and laquer thinners."

60+ years and there can't be many usable original cuffs left. Prior to Glenn's enlightening statements and photos, myself and some other interested Mustang students were getting a bit frustrated at trying to locate an actual photo of a 6523A blade with the cuffs removed. All to that point invariably showed a non 6523A shank profile where the cuff was supposed to have been ( didn't know about the "square section then), leading us to surmise that there wer'nt no animal. We was wrong.

That being said, I still strongly suggest being wary of any so-called reference work or expert pointing to an image purporting to show a "Hamilton Standard prop with its cuffs removed". IMHO- things to look for are asemetry of the shank profile (front view) and the squared off edges where the cuff is supposed to go.

Charlie

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Charles Neely

You probably know that the 6101 T-6 blade starts off as a blank much longer and is cut down for the T-6 application. Other applications do use a longer blade, and shorter blades can be used on other aircraft. My point is that the blank only determines the maximum diameter possible, not what was used by the airframe manufacturer or is certified on the aircraft.

The HS drawing only defines the blank and not necessarily the final diameter.

Question: Is the diameter with the exact same blades different between 3 and 4 bladed hubs?

Bdk,

No, I wasn't aware of the extent of HS's multiple prop blank manufacturing practice until I came accross the drawing above. It make sense though.

One of the things I really enjoy as a died in the wool Mustang buff is the variety of interests surrounding my favorite aircraft. Another is the "spin off" leading to new and just as exciting areas of interest/subjects to explore.

Thanks'

Charlie

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Charles Neely

There is always something to learn here! That's what I like about this place.

Hello Charlie,

Look what I ran accross today...........

Looks like 11' 2.050" is the real number!

This is from one of Ed Horkey's Performance Reports using a K6523A-24 blade propeller.