Cub180 wrote:Replaced my right outer gear leg casting in October 04 .got part from Steve knopp he told me how to change it out the top.had no problems never bent anything. Took me 16 hrs looks original that was over. 2000 hrs .nothing lose yet . Did all my self needed a hand to buck 2 rivets

I have no idea how you get that bracket out the top without bending or cutting. One or the other has to happen to get it out.

ak49flyer wrote:Just for the record- there a lot of these airplanes that have had these brackets changed through the top and gone on to lead long happy lives. Thanks to Aeropod for the pics and description; that’s probably the “very best practices” way to do it and keep it 100% stock and not modify any structure at all. But like a lot of things, there can be more than one way to do it “right”. There are extremely well respected life long mechanics in Alaska that have changed tons of these things from the top- it’s a widely accepted practice. Does that make them “cobs”? Ask the 135 operators who’ve gone on to put thousands of hours on those airplanes after the repair…

I don't think I ever said it couldn't be done out the top. I just can't figure out why you would when it's not really that different effort-wise to do it out the bottom. You're right that there can be more than one way to do a job right. It is also true that some jobs there is one way to do it right, and a dozen ways to half ass it.

I can't say whether that would make them "cobs" or "hacks" as I think that is a mindset vs. performance on a single job. I don't see a problem pushing an airplane out with repairs you may consider temporary for reasons not associated with safety of the intended operation. If a job needs to get done, patch it and get to work until you get the right parts or the time to get it right. It's a problem when that attitude becomes your entire operational philosophy. At that point I think you graduate to "cob".

You acknowledge that this is probably "very best practices" and Cub180 says it took him 16 hrs to do it out the top. I've said several times I guesstimate this to be a 16-20 hr job doing it what I consider to be the right way. Is it really worth 4 hrs, assuming my higher number, to compromise the structure. Some guys might say yes. I've worked for them. Not my style, but your call.

limerick wrote:Amen ak49flyer!! -Bruce

I don't KNOW that any of these airplanes are going to fall apart from doing the repair this way. All I know is that my repairs are as good or better than Cessna's original assembly. I do know that my repairs aren't going to be the source of future problems. I've shown you evidence of your methods leading to problems. Not just the final failure because that may have been any number of things, but the cracks that were found 5 years after the repair and subsequently repaired.

As an A&P, you have to make the call. I just don't get why you'd do something that is so very clearly not as good, to save maybe 4 hrs on a piece of a equipment that, at today's prices, are hitting $250-350K fairly regularly.

This diagram may be a good complement for the thread.

Hello Aeropod,

Is there any chance for you to provide a wider Pic for the area of the crack so we can relate its position on the gearbox pls?

Thx for the great Pics of the disassembled gear box, very illustrative ones.

[email protected] wrote:Hello Aeropod,

Is there any chance for you to provide a wider Pic for the area of the crack so we can relate its position on the gearbox pls?

Thx for the great Pics of the disassembled gear box, very illustrative ones.

My buddy thought he might have the old bulkhead in the scrap pile. I'm still waiting to hear back. I'll ping him again.

Deleted

I've shown you evidence of your methods leading to problems. Not just the final failure because that may have been any number of things, but the cracks that were found 5 years after the repair and subsequently repaired.

As an A&P, you have to make the call. I just don't get why you'd do something that is so very clearly not as good, to save maybe 4 hrs.


AEROPOD, I'm not an A&P. Time was no factor, I posted I spent 2 months on this repair 15 years and 1200 hours ago. Why all the personal attacks? Drop the bone.

Nothing personal about it. The only argument that anyone has that coming out the top is okay is that a ton of people have done it. I guess if enough people do it wrong, it becomes okay.

It seems like this thread has devolved to this



When it should have gone this way.



You're right. I'm out.

I hope this is taken for what it is. A joke. Agree to disagree. Hope some other readers learned something. I sure did. If I'm looking over an airplane that has had a bracket replaced, I'll be checking out those angles with a fine tooth comb. Probably even worth getting out the dye-pen.

My buddy thought he might have the old bulkhead in the scrap pile. I'm still waiting to hear back. I'll ping him again.[/quote]

Thx. Would also be interesting to see the 5 year cracks you talked about.

I did it the easy way. I took it to Beegles.

Wayne

c180pilot wrote:I did it the easy way. I took it to Beegles.

Wayne

Is your aircraft one of the early ones that did not have the floor riveted to the offending 90 deg pressed angles that block the bracket from being able to lift up? (All pictures here are from riveted ones)

Would be interested to know what Beagles and other shops do on that while performing this job.... Be modified to riveted or left as is.
Guess the change was to provide more strength to the gearbox but wonder if there are other things to take into account. I am not a mechanic.

It would also be interesting to know if people who cut the small piece of the 90 deg bend have a different opinion because of doing it so.

-----

Have obtained some feedback outside this thread, all just over the top jobs.

All happy for the outcome of their repairs. Had I received some done from below they would have also been positive for sure.

Owner of one shop told me he just likes doing it from the top but not cutting anything. He loosens up the front reinforcement angle which goes back to back to the offending bend one, this in order to expand the area between the bulkheads and be able to rotate the bracket to lift it up.
Says some aircrafts are easy and some end up requiring loosening up more parts.

Different ways.... Respect them all and can't be more thankful to everyone.

datapoint

I saw that photo and thought the same thing. Hmmm. Wonder how he did it?

soyAnarchisto wrote:I saw that photo and thought the same thing. Hmmm. Wonder how he did it?

Wonder how he did what?

[email protected] wrote:

soyAnarchisto wrote:I saw that photo and thought the same thing. Hmmm. Wonder how he did it?

Wonder how he did what?

How he got that bracket out from the top without bending or cutting the aluminum and causing even more damage. I mean I guess the photos show us how it's done, but I know and trust IAs who are arguing both ways, so... I'm still not sure what the right way to do that job. All of us owners are 1 hard landing from being there at some point.

soyAnarchisto wrote:

[email protected] wrote:

soyAnarchisto wrote:I saw that photo and thought the same thing. Hmmm. Wonder how he did it?

Wonder how he did what?

" How he got that bracket out from the top without bending or cutting the aluminum and causing even more damage. I mean I guess the photos show us how it's done, but I know and trust IAs who are arguing both ways, so... I'm still not sure what the right way to do that job. All of us owners are 1 hard landing from being there at some point" .

To my understanding... Those brackets were originally extruded ones and can develop granular corrosion by themselves. Hard landings might not be a must to fall in the need for a change of them.

Yeah, different and acceptable ways for doing the change of brackets from what we have seen and researched.
One of the shops I contacted does them exactly like the last Pic.
I was able to get the opinion from a chief structural engineer in the USA for that method.
He said it was OK on the inner "angles". Outer angles untouchables. It was presented to him with putting a reinforcement underneath the cuts and bends.

Just sharing my valid or invalid research.

I was cleaning out the hangar and found this picture in a box. About 10 years ago a late 1960's or early 70's C180 was departing a down hill dog leg dirt strip in southern CA, and something went terribly wrong. Aircraft was substantially damaged and minor injuries to the sole occupant as I recall. Riverside (RAL FSDO) responded and took this digital image where the pilot side separated gear leg was found. The out-the-top guys will see the MLG outer bracket replacement work with angle cut and doubler protruding under the angle.

I see that gearbox had the ponk reinforcement kit.
Reminds me of the old generalization that in a bad going-sideways situation,
without the reinforcement kit, the gear leg rips out of the gear box--
but with the kit, the gearbox rips out of the plane.
Seems like the reinforcement kit is a good thing...until it isn't.

I read the entire thread and just couldn’t resist. I installed the inner pponk bracket in my wagon. The outer bracket was field replaced while in Africa so I don’t have to mess with it. I would prefer that one to also be pponk but not going to change it now. My outer saddle bracket was replaced through the top. Comments:
I have done metal work for 40 years and built 2 planes and maintained several vintage aluminum airframes. No, I’m not an expert but I do have lots of experience. I totally agree that an aluminum flange should never be un bent and re bent, especially if it is 2024T3. The radius always stretches when formed and it is not IF but WHEN it will crack if straightened and especially when re bent. By not cutting a small section of the flange off, the future crack will travel way past what needs to be removed in order to get the bracket out because it is straightened way father than where the bracket clears. All the photos I’ve seen either bend or removed more of the flange than the previous IA removed on mine. The small piece or missing flange was replaced by 1/8th inch thick 6061 T4 1” x1” angle bolted and riveted in place. I had it inspected by an IA who is also a structural aircraft engineer. He said not only was it legal but as strong as the original .

On the other side of the disagreement adding another access hole in the top skin of the box structure is allowed as long as repair procedures are followed by AN standard practices or Cessna’s specs outlined in the maintenance and repair manual. So no problem there. 3 main arguments against removing more belly skins than necessary. #1, more drilled out rivets means more chance to cause extra damage and the more things can shift.( it’s not in a fixture). #2, look at the picture on page 3 photo number 4. The bracket on top riveted to the casting is an absolute POS. 11 rivet holes and all but 4 are so out of round the part is unusable and I’d have to measure the other 4 to see if they are any good either.That bracket should have been trashed and replaced. #3, the plane you show has such crummy paint maybe the owner doesn’t care but for the rest of us that take pride in our planes the less rivets to touch up the better.
BTW loved the crutches!

Would appreciate vectors to the NTSB final investigation report for that S. Ca. accident.

Brgds.