I need a new skull cap spinner

[dstates]

I'm looking for a replacement skull cap spinner for my 1951 170A. Parts catalog says the part number is 0550101-3. I've been searching online with no luck finding one available anywhere. Does anyone have one for sale or do you know of a shop I can find one?

Thanks!
Doug
218-464-7340

[dstates]

I found this one on Aircraft Spruce, it mentions the 170, but doesn't have a part number. Does anyone know if it is a match?

https://www.aircraftspruce.com/catalog/ ... -21700.php

[Bruce Fenstermacher]

I can't say absolutely but can say with some certainty, that I ran one of these when I had my 170A 8 years ago. I had no trouble. I can not say if I used the screw and Tinnerman that cam with it or another from the our collection.

I'm pretty sure the AS Skull Cap is your only choice these days.

[dstates]

Thanks, Bruce

[gfeher]

Wicks also sells a 6” skull cap spinner, which is the size needed for the 170’s. (The actual size is 6 1/4”). https://www.wicksaircraft.com/shop/skull-cap-spinner/.

If i remember correctly, Univair used to sell a 6”, but they only sell a 5” now. I believe I bought mine from Spruce about 5 or 6 years ago.

[Bruce Fenstermacher]

5/31/26

Aircraft Spruce sells a Polished 6" Skull Cap assembly for $89.50
https://www.aircraftspruce.com/catalog/ ... sQQAvD_BwE

They also sell an unpolished 6" Skull Cap for $55.75 Note: this does not include the bracket and screw
https://www.aircraftspruce.com/catalog/ ... 6MQAvD_BwE

And just the bracket and hardware for $24.95
https://www.aircraftspruce.com/catalog/ ... llcap2.php

NOTE: if you don't buy an assembly, you might want to measure either the cap you have or the bracket you have to make sure the new part will work with what ever good part you have. This may require calling A.S. and asking. Over the years I've seen caps and brackets that would not work together depending on the maker if each part.

Wicks sells a 6" Polished Skull Cap assembly for $67.44. It looks identical to the Aircaft Spruce cap likely because the manufacturer is the same for both vendors but I don't know this to be true.

Personally if I was in the market, I'd buy from Wicks to help them survive as one of the last vendors competing against Aircraft Spruce. It's nice to have a choice.

[dstates]

Thanks to both of you for pointing out that Wicks had the skull cap spinner. It is drastically less expensive. They also had everything else I was going to order from Aircraft Spruce so I put in my order to Wicks this morning.

[n2582d]

It’s interesting that Spruce says that the 6” unpolished spinner is “for … Cessna 170s.” But in the Q&A section they say it is not FAA/PMA approved. Typing the p/n in the FAA’s DRS database shows that no one has a PMA for that p/n. I’d exchange the PK screw and tinnerman clip for a AN 525 machine screw and a nutplate and call the assembly an owner-produced part!

[gfeher]

Gary, your post reminded me that my skull cap spinner bracket came with a nut plate. So I checked my log book. My skull cap spinner, purchased in 2018, is from Aero Fabricators, Inc., p/n’s 1-808-000 (spinner) and 1-807-999 (bracket) with an AN525-10R14 spinner to bracket screw. Aero Fabricators was the manufacturing arm of Wag Aero, so I don’t know if they are around any more. I likely bought it from Wag Aero, not Spruce.

[Bruce Fenstermacher]

Aero Fabricators no longer exists as the assets were sold at auction to separate parties.

I've been aquatinted with the use of both a PK screw and Tinnerman and the use of a 10/32 (I think) and a clip nut. I prefer the machine screw and clipnut over a PK screw.

Gary used the term nutplate and a nutplate to me implies something that is riveted in place. Depending on the bracket width I'd think twice about drilling holes for nutplate rivets in the bracket. These holes would be just another place for the bracket to crack. I'd use a clip nut such as found here: https://www.aircraftspruce.com/catalog/ ... -01489.php

I agree, this product could be used after inspection, as an owner produced part. Fact is, I'd bet most every skull cap being flown today is not an original or PMA version and there is no paper trail for the installation

[n2582d]

Gary used the term nutplate and a nutplate to me implies something that is riveted in place. Depending on the bracket width I'd think twice about drilling holes for nutplate rivets in the bracket. These holes would be just another place for the bracket to crack. I'd use a clip nut such as found here: https://www.aircraftspruce.com/catalog/ ... -01489.php

Good thinking!