Re: comment on possible upside down elevator.

Not possible on a 55, it is symmetrical. L and R are same. Unless it is an elevator from later model, in those the bolt holes in the torque tube bracket (don't remember actual part name) are offset. So if you use those you get wrong angle of incidence.

Unless the rivets were previously drilled out, rotated, drilled, re-riveted, making Swiss cheese... Ask me how I know.

'55, I feel your pain bro. Today I conquered a whole bag of gummy bears,(swallowed most of them whole, but who's counting...) a personal victory! Felt so good I went out and flew a few loads Then proceeded to wrench my back out of shape... man it sucks getting old

Back at your issue... I am beginning to think there may not be one glaring issue, but a multitude of smaller pain in the @$$ es ... Don't get too down on her yet, that airplane has a lot of good in her, you just need to get her into shape.

Good luck man!

Skydive206:
That's what I meant to say, slower on short final means less down lift in the tail even though the larger wing is still happy. Interesting your report on VGs not helping, I had heard that they do (on tail that is). Not to hijack the thread...

55wagon wrote:just got off the phone with john efinger up at hicks in dallas. supposed to be a cessna rigging expert. he can see me in about 2 months!!

Not to quibble... but Hicks is a long way from Dallas..... it is on the north side of Fort Worth. If you went to Dallas you'd never find it. We have a saying here in Fort Worth... 'Life is too short to live in Dallas"....

gunny

Meant Dallas area I guess gunny. You heard of the guy? Any good?

Ya well get her rob. Just gotta get over getting my eyes poked and just spending a bucks of $ on it. Especially with no rain in sight

Zzz wrote:

akavidflyer wrote:Check you engine mounts. Is it possible that the mount is tweaked, or broken allowing a variable thrust line? It does not take much movement in the engine to really hose up the thrust line and make trimming impossible as your chasing it with trim and various power settings. Just a WAG since you seem so certain that the trim is getting full range of movement.

This is a good lead. You'd think enough movement/displacement to affect thrustline would be obvious, as the crack would have to be pretty bad; there'd be vibration like mad. Maybe not with a crumbled/collapsed Lord mount. Maybe it's not a failure at all, but a poor installation on the "new" motor mount.

The reason I tossed this out there (other than trying to think outside the "box" ) is because I have dealt with loose engine mount bolts, on one the engine mount looked like it was firm against the firewall when doing a preflight / checking oil etc, however, the nyloc nut was worn out and you could spin the nut by hand. The bottom nuts had backed off and the engine under power would pull the mount away from the firewall 1/8"-3/16". That was plenty to make me think the trim was screwed up and I landed to tighten the spring on the trim cables (piper set up). It took me a bit to figure out what the real issue was. This was after flying ~10 hrs on a fresh engine overhaul and I never thought of the mount being the issue as the IA had just done the overhaul and install.

Another one was the lord rubber mounts failing but they looked like they were good just glancing at them. in both cases I never felt any vibrations or nothing seemed to grab my attention other than chasing trim and at times running out of trim. If the engine is at full power, and the lower mounts are pulling out your getting upthrust in the engine and thereby needing more down trim to force the nose down.. If all else seems to check out on the tail end of the plane, I would be looking at the other end of it instead of fixating on one thing (such as the weight on the tail wheel). Chances are I am all wet, but I would grab the prop hub and pick it up and down and see if you get any movement.

Avid. I'm new firewall forward. Including all hardware. I was hands on in this process. Not saying its not possible but have gone back over the areas. Also the problem existed b4 the swap as well so.... Hoping to get an actual legit weight and balance done today. If it happens I'll report back then. Have quit beating my head against this wall till then. If that checks out then all I know to do is find a good rigging guy. Looked at a service manual yesterday and could find surprisingly little about factory settings, measuremts, etc. Was pretty shocked at how little was in there. It was at a mechanic friends shop who mostly works on king airs but let me use his computer with all the updated info.
Even on setting the eccentrics the instructions where start at the 12oclock position, fly it, move to 6oclock if one wing heavy. Fly it. Not much more than that!

Wing eccentrics angle change will not create that much pitch issues that you state.

I don't think so either skydive. Wish I could find some measurements to check angles and symmetry in tail. I get about 10degrees of horizontal movement w a smart level. About 5"s total travel. On 29's w an xp 10" tail wheel it reads about 3.7-13.7 degrees from full up to full down position. Just in case anyone has an idea if that's close or not by some crazy chance.

'55,
I didn't mention Steve before because he's not in south TX, and Cessna's aren't really his specialty. Although he does have one of the most diverse mechanical backgrounds you'll find.
Having said that, he is the kind of guy that knows how to make things fly 'right' and he is pretty meticulous when it comes to things like rigging. He's pretty busy, but it may be worth your time to give him a call. Then keep his # handy for when you get a cub, he is an exceptional cub guy.

http://www.pierceaero.net/

The travel is: Up 0° 45' +- 15' and down 8° 45' +- 15', although my manual only goes back to 61. The elevator is up 25° +-1° down 23° +- 1°. So your in the ballpark.

Again, you may have issues with the brackets and their attaches. You kind of need to do the Polish Blueprint method: find a know straight aircraft and use it as a template for measurements. You can pull lines from points on the wing to the tailplane. Use non-streach string and compare left to right and the pattern aircraft.

Exactly how much of the tailbone was re-skinned? The weight really wouldn't come from that, even if the doubled the skin thickness it wouldn't add up to 30#. I'd be leaning to the mis-placed bracket attach points, primarily the rear pivot. Couple that with a slightly different bracket, from lets say a later model 180 and it could add up. The STOL kit may have been done poorly and it just changed enough to make the make the center of lift move forward.

Yeah you have a real mystery on your hands. Rigging one of these is not rocket science. First you get the two yokes to be level with each other and clamp them that way. The adjustment is on the turnbuckles on the T. Then you get the flaps set to the best up position, not so much they rub, but as close in as you can. You can check this with a yardstick and ensure that the flaps are level with the bottom of the wing. Then you get the ailerons cables tensioned and adjust the rods to get the inner corners of the ailerons to match with the flaps. Some times you need to relive one side of the cables to let the center move a bit so you have enough rod adjustment to get the ailerons to match. Elevators and rudders are tension and stop adjustments. The jackscrews on the stab are the most convoluted. But essentially, you get them timed to be the same height. Get the chain in the middle when they are about in the middle of their range. The stops are the bottom of the mount and there is an upper stop that adjusts, a bit. Again, not rocket science.

This is a gross over-simplification of the process, but a decent mechanic can do this in a few hours a true expert is not needed, unless your plane is bent. Then the wizardry starts, a tweak here and there can make it fly better (straighter). An investment in a PDF manual would be in order for your year model so you have actual numbers and procedures.

Hopefully skalywag will be here next week and we can compare planes and measurements.

Marty. I checked your measurements and mine are exactly the same as yours.

Dogpilit. Thanks for the info. Not quite sure I follow the first part of that clearly but I do have 10 degrees movement in horizontal and 23-24 degrees movement in elevators. Ailerons and flaps seem to be real close to your description. Don't know if it means anything but wo the load it flies perfectly straight and level. Ailerons even and no adverse characteristics. Also the repairs where done with the right size skin for what its worth. Appears to be excellent repairs.

Looks like you have checked about everything. Have your elevators been rebuilt, Might check to see if the forward part of the hinge line where counter weight is symmetrical top to bottom, lay a straight edge on the rear portion measure down to center of weight do the same for the bottom I'm sure that distance should be the same, 180 experts am I correct? How is your elevator trailing edges, sometimes they are bent in a manor which can act as a trim tab working against the jack screw trim system. Might also check the elevator balance, would have to be way out to cause this problem but should be checked anyway. Good luck.

55,

Last year I had work done that required rerigging of the trim. My mechanic read the limits "# up", and "# down". He was confused as to whether that meant actual trim tab up and down, or the up and down adjustment of the wheel. He got it backwards. First trip around the pattern was exhausting. I couldn't get enough trim in to let pressure off the controls. We had words, corrected it, and all was well with him next to me on the next takeoff.

I didn't have a stabilator like you, but this smells of a rigging problem to me.

Brett

Bushmaster. I actually even changed my elevators. My old ones were in better condition than the ones on it. So I had them stripped and painted. And the problem existed before that so...
Looking at my old bird which is very disassembled, I can't see anything g different. Have looked and measured till I'm blue in the face. It appears everything in the tail is working properly and correct. Which I was hoping was where the problem was.
Getting really nervous now because it doesn't seem simple.
Weather blew in today and couldn't get to the scales. I've quit looking(not thinking) till the w&b and my buddy shows up with a good plane to check more measurements against.

Brett. Thanks but absolutely no way possible its backwards.

Jason,

I sent you a PM but it's not showing in my out folder nor my sent folder, did you get it?

I didn't Phil. Ill try and pm you.

I dont have enough up trim and called Beegles and he said my eccentrics on the wing where set for best cruise speed and thats why I ran out of trim at 70 mph. He also said one set up the other direction would cause not enough forward trim. Just a thought. If they are changed all the cable tensions would have to be done again.

bcd. I had thought about that and wondered if that could be the case. Hard to imagine that little of movement could cause that drastic of an effect... Mine are set about 4 oclock which would be close to the slowest side. Thought about changing and seeing if it makes a difference. Some further test flying empty(nothing but me, not back seat or anything at all in plane) now paying closer attention after realizing the severity, it flies an inch or two further nose down than it should at cruise and lands just back of take off trim with 3/4 tanks and just me at 215lbs. That leaves me about 7 full rolls back to full nose up trim. Definetly way out.

correction. therye closest to the fast side. 6 oclock being least angle of attack. so again,, not good..