Flap Skin Source

How to keep the Cessna 170 flying and airworthy.

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bagarre
Posts: 2615
Joined: Thu Sep 30, 2010 11:35 pm

Re: Flap Skin Source

Post by bagarre »

Thanks for the info.
I need to pay closer attention when looking at 170's for now on. I've never noticed one with spot welds.
bagarre
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Joined: Thu Sep 30, 2010 11:35 pm

Re: Flap Skin Source

Post by bagarre »

Next question:
While masking off the rudder, I noticed the ribbed diamonds were cut back on the skin leading edge by bout 45 degrees.
That one is an original skin - best I can tell.

Did the flaps have the same taper originally or were they just straight cut? Odd that the rudder would be that way but the others dont but I dont have any originals to compare to.
tks
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Ryan Smith
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Joined: Tue Nov 25, 2008 4:26 am

Re: Flap Skin Source

Post by Ryan Smith »

bagarre wrote:Thanks for the info.
I need to pay closer attention when looking at 170's for now on. I've never noticed one with spot welds.
I can confidently say that I have never seen any 170 model with spot welded flap trailing edges.
c170b53
Posts: 2560
Joined: Mon Apr 22, 2002 8:01 pm

Re: Flap Skin Source

Post by c170b53 »

Sorry David, I gave bad Intel; the T/E has 3 rivets, the third smack in the middle... Loss of grey matter traction there :D
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
Metal Master
Posts: 526
Joined: Thu Dec 02, 2004 1:52 am

Re: Flap Skin Source

Post by Metal Master »

Ryan Smith wrote:
bagarre wrote:Thanks for the info.
I need to pay closer attention when looking at 170's for now on. I've never noticed one with spot welds.
I can confidently say that I have never seen any 170 model with spot welded flap trailing edges.
Never let it be said you have never seen spot welded trailing edges from this point forward. For your viewing pleasure:
In these pictures you will see spot welded Ailerons, Flaps, Rudder and re-riveted elevators. On the rudder you will see where the spot welds have Corroded and started to break loose. They will need to be riveted to repair. Note that the spot welds are not evenly spaced in edge distance or spacing. The posting here is not letting me post more then three pictures so I will make another post with a couple of more pictures.
Broken spot welds on rudder trailing edge RS..jpg
Larger View Spot Welded Flap Trailing Edge RS.jpg
Left Aileron Outboard End Spot Welded RS.jpg
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Last edited by Metal Master on Sun Jul 10, 2016 1:18 pm, edited 1 time in total.
A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
Metal Master
Posts: 526
Joined: Thu Dec 02, 2004 1:52 am

Re: Flap Skin Source

Post by Metal Master »

A few more pictures of Trailing edges.
Left Elevator Riveted Trailing Edge RS.jpg
In this first picture of the elevator trailing edge the spot welds were breaking out when I first started rebuilding this airplane so I cut to the chase and riveted the whole trailing edge to prevent any further issue.
Riveted Elevator Trailing Edge RS.jpg
I have new skins to make a new trim tab but have not gotten around to it yet. When I riveted the trailing edge of the elevators I did not pay attention to where the spot welds were at as most of them had not broken yet. So I just placed the rivets with normal edge distance and spacing using three rivets between each corrugation four where required. You may also note that these skins show fila-from corrosion at the corrugations. It mostly polishes out when I have polished it. It has not been polished in a year and a half. These skins are 66 years old.
Regards,'
Jim
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A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
bagarre
Posts: 2615
Joined: Thu Sep 30, 2010 11:35 pm

Re: Flap Skin Source

Post by bagarre »

Thanks for the photos!

Back riveting a flush head like the RV builders do on their control surfaces would give a similar look to spot welds.

The backing plate would need to allow of the corrugation.

A bit more work and no real advantage other than trying to look like a spot weld.
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