Flap Track Replacement

[hilltop170]

Most guys just go ahead and cut it, you can’t really tell once it’s back together. Lots easier than all that riveting unless you need to remove that piece for some other reason.

[redacted]

Any updates or pics on how it went? Mine is in annual now and the LH outboard track failed the no go gauge. Tracks and rollers ordered from McFarlane. Got all the paperwork to study. Seems straightforward enough, just time consuming. Is that the consensus?

Cheers

[Bruce Fenstermacher]

I'm finishing replacing both tracks on the left side of 185 now. On this airplane the C cover skin had been slit at the track next to the existing rivet and a new one drilled on the side now without a rivet to hold it. I only removed the rivets from the top trailing edge and this was workable. Certainly better than drilling the lower rivets and replacing them.

All for of the Z brackets needed replacing. We ended up using more Cherry Max than I wanted because unless you do this job every day you just won't have the specialty bucking bars (or the skill) to get most of the C skin rivets bucked. We ended up oversizing most of the top rivets to -4 on the top as this was the second time they'd all been drilled and replaced. We also had to patch some skin on the trailing edge of the top skin due to cracks at the rivet holes. We also put new rivets between those rivets that the holes had cracks from them duplicating work that someone else previously had done. If this was a restoration the top skin would have been replaced adding much much more time to the project.

As is we are right about the 15 man hour mark. It could easily be more.

We had recently had a ''65 172 in the shop and all 4 tracks replaced by the A&P owner. This was his first big sheet metal experience and there was time spent thinking, gathering tools and of course a learning curve. He was also mostly working alone. He totally removed the C skin as his was not slit and it could not be "just pulled down". it took him every bit of 40 hrs.

[redacted]

Hopefully my mechanic I work with will be fine splitting the skin so as to not remove the whole flap well skin then. Won’t know about the z brackets until we get in there so hopefully good and won’t have to wait on more parts. Thanks for the info. Will keep this thread updated as we get into it.