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Airframes Aluminum Strut Issue

Steve Pierce

BENEFACTOR
Graham, TX
Installed my first set of Airframes aluminum struts today and discovered an issue with the rear strut. Where the front of the strut attach block meets the wing strut attach fittings the joggle that is machined in the strut block hits the strut attach fitting. Called Airframes and talked to engineering and they have never seen this problem before. Called my buddy with these struts and he discovered he has the same issue. Curious if anyone else has run into this?
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That’s real cozy....and the fitting is riveted in so you can’t remove it to machine a relief...what are thinking Steve? Can you relieve the steel fitting on the wing a little bit with a saw blade? Or is that a no no? Looks like it wouldn’t take much. Or maybe a flat file would do it?
 
Piper Drawing 10096 shows 3/4" from hole center to bend on the strut. Drawing 14182 shows 5/8" from hole center to end of the attach bracket. I tried to paste in snip from each drawing, but it didn't work. I got the Dwgs from Christian's site - supercubproject.com
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Have you tried reversing them, the second pic it looks like they could be directionally challenged.
 
Waiting on this answer! Also, the bolts in the pictures are wrong, there are no threads.
 
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sure would be nice if they made that notch a little longer.
 

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There is a radius milled in the block of the rear strut where it changes angles. Problem is on the 4 airplanes I have gotten feedback and looked at personally that distance from the edge of the hole to where the radius starts is 3/8".
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From the edge of the hole to the end of the strut attach fitting on the wing is 1/2". That keeps the parts from laying flat against each other.
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So I have found 4 airplanes with this issue. Doug Keller who does the engineering for Airframes Alaska called and said he has not seen this issue, nothing has changed in manufacturing and it is not a structural issue. He will submit the paperwork to make the change but that will take a lot of time to approve the change from the FAA.
 
Piper wasn't always consistent, are there perhaps different lengths of Strut attach brackets in the world?
 
Why not take your choice of cutting tool and radius the strut fitting to address interference? It looks pretty minor.
 
Why not take your choice of cutting tool and radius the strut fitting to address interference? It looks pretty minor.

Looks like the programing on the CNC mill stopped the table just a little shy of design, or the fixture to hold the aluminum was either bolted just off of intended location or made a little short.
 
P stol flaps

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2 ex cubs in ft St. John with p stol flaps with no cut out notches for hangers. Can’t rig flaps all the way up . Anyone else with this problem. How to fix.
 

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Doug told me they were going to change the fitting. Talked to him quite a bit this past week and forgot to ask about it.

Correct, the fittings were changed shortly after we spoke in 2021 to move that cut back further to allow for variance in wing fittings. Haven't heard from anyone with the same issue since.

On those flaps, I have heard sporadic issues like what you picture there. Seems to be dependent on what experimental wing kit is used as to if the vane leading edge contacts the hangers or not. Unfortunately now that they're painted your options are limited but I would recommend trimming the leading edge out to go around the flap hangar. That's the only solution short of re-skinning the flaps or replacing them completely. The vanes in those pictures look close to level with the bottom of the wing so it may be you only need to rig the flap up to the vane element to get the rigging completed. Like Denny said feel free to give me a call and I can walk you through it.
 
Correct, the fittings were changed shortly after we spoke in 2021 to move that cut back further to allow for variance in wing fittings. Haven't heard from anyone with the same issue since.

On those flaps, I have heard sporadic issues like what you picture there. Seems to be dependent on what experimental wing kit is used as to if the vane leading edge contacts the hangers or not. Unfortunately now that they're painted your options are limited but I would recommend trimming the leading edge out to go around the flap hangar. That's the only solution short of re-skinning the flaps or replacing them completely. The vanes in those pictures look close to level with the bottom of the wing so it may be you only need to rig the flap up to the vane element to get the rigging completed. Like Denny said feel free to give me a call and I can walk you through it.
My son and I build javeron wing kits ang jay gave them the dimensions for the flaps .we fitted them with out knowing about cut outs. The white cub is smith wing fitted with p stol . See a set after for another cub ex had cut out they just forgot to put them in . They need to be in all
 
My son and I build javeron wing kits ang jay gave them the dimensions for the flaps .we fitted them with out knowing about cut outs. The white cub is smith wing fitted with p stol . See a set after for another cub ex had cut out they just forgot to put them in . They need to be in all

Had the same problem with a smith kit, got the flaps rigged almost level. Weird the certified flaps have cut outs at the hangars but not the exp ones. Seems like they all should have the cutouts at the hangars
 
Here is a picture of my shim.
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Steve, Since Airframes doesn't seem to want to rectify this, perhaps an advisory note to the FAA would be in order? You spotted this interference and provided a solution, others may not. What happens when the next mechanic removes and reinstalls this strut? Will he remember the shim? Or not see it when it falls on the floor? When that wing fitting is clamped down tight into the radius of the strut fitting, a stress rising location is created. In worse case scenario, a crack could get started with a possible strut separation. An alternate solution could be to relieve the radius further towards the strut. If I were Airframes, I would correct those parts immediately and at the very least notify all their customers of a fix.. A life could be saved. This could be more serious than it appears on the surface.
 
Steve, Since Airframes doesn't seem to want to rectify this, perhaps an advisory note to the FAA would be in order? You spotted this interference and provided a solution, others may not. What happens when the next mechanic removes and reinstalls this strut? Will he remember the shim? Or not see it when it falls on the floor? When that wing fitting is clamped down tight into the radius of the strut fitting, a stress rising location is created. In worse case scenario, a crack could get started with a possible strut separation. An alternate solution could be to relieve the radius further towards the strut. If I were Airframes, I would correct those parts immediately and at the very least notify all their customers of a fix.. A life could be saved. This could be more serious than it appears on the surface.


I have been talking with my fsdo about it, Seems as if airframes doesn't want to offer any fix, other than we have changed out new ones
 
We just had a bad experience with Airframes a few weeks ago concerning TWO sets of Pstol flaps. They had been offering a 20% discount on them at Oshkosh, we assumed
The discount was good for the experimental version, or certified version. The experimental version were advertised for $6600 per kit on their website. So my buddy who had spoke to them at show, conference called em to see what we could do on TWO sets. They fella that answered the phone told us, the 20% discount would only apply on the "New" price of experimental flaps, which was now $8600...... He then backed up like a crawdad, and said I am not sure where you saw that price but it must have been from years ago? I then told him we have a screenshot taken 15 mins ago. He then said it was the webmasters problem ........ I seriously doubt the owner of Airframes would wanted him to handle this way???? Couple other side notes, he also informed us there would be a $300 crating charge; and freight charges. We said "thought it was free shipping??? He said "Not on Flaps"...
He then added there was another $375 for the mounting kit that apparently is not included. So from what I heard experimental flaps that were on the website advertised at $6600 same day we called,see their listing below for two hanger flaps????? Apparently they had migrated to around $9300!!!! The moment we called for each set.???? I guess they are headed for the " multi millionaires" market only???
Good luck to them.
I hope you guys get your strut issue solved. I bet they will come up with a nice titanium shim for $1100 plus crating and shipping????
For what ever it's worth, it was NOT Gabe we spoke to.

PS. He refused to accept they were EVER $6600 until he looked back at sales and found that, the last set had indeed sold for that............. Screenshot_20220827-082705.png
 

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