One of the cheapest and easiest to replace part broke part on my plane that absolutely grounded me.

Gary Ward

Gary Ward

Pattern Altitude
PoA Supporter
Joined
Jan 16, 2020
Messages
2,327
Location
Cincinnati, Ohio
Display Name
Display name:
Challenger1
Last week while using the tug to pull the plane out of the hangar and I hear a crack while in a turn. What was that? Unclamp the tug and the nut, bolt and washers fall on the ground. Oh oh ! Can’t fly it like that and I will be lucky to get it back into the hangar by myself and make a 90 degree turn. I was able to do it with just one nub sticking out of the front strut. Using a tug puts a little more stress on that part but not my back.

Ain’t gonna find a bolt like that local so I ordered online from my friend's at ACS. They have it in stock.
I am not paying big bucks for over night shipping for a 16 dollar bolt and nut. So I go for priority mail for 8 bucks.
First tracking says Tuesday delivery and then it says Monday delivery.
So I don’t look again until today and it was delivered Saturday at 11am! Oh well I missed a great day yesterday flying.

Not the first time I have received a part in under 48 hours from ACS.
Don’t you wish all aircraft repairs were so simple and inexpensive?
I ordered 2, one for next time. Or let me know if you need one in a hurry.
IMG_4375.jpegI already had the valve cover gasket in stock, it goes on next oil change.
 
Last edited:
Gary Ward said:
Last week while using the tug to pull the plane out of the hangar and I hear a crack while in a turn. What was that? Unclamp the tug and the nut, bolt and washers fall on the ground. Oh oh ! Can’t fly it like that and I will be lucky to get it back into the hangar by myself and make a 90 degree turn. I was able to do it with just one nub sticking out of the front strut. Using a tug puts a little more stress on that part but not my back.

Ain’t gonna find a bolt like that local so I call my friend's at ACS. They have it in stock. I am not paying big bucks for over night shipping for a 16 dollar bolt and nut. So I go for priority mail for 8 bucks.
First tracking says Tuesday delivery and then it says Monday delivery.
So I don’t look again until today and it was delivered Saturday at 11am! Oh well I missed a great day yesterday flying.

Not the first time I have received a part in under 48 hours from ACS.
Don’t you wish all aircraft repairs were so simple and inexpensive?
I ordered 2, one for next time. Or let me know if you need one in a hurry.
View attachment 128513I already had the valve cover gasket in stock, it goes on next oil change.
Click to expand...
That bolt also holds the plug in the bottom of the strut, and has oil under pressure against it. You did release the pressure first, right?

Now, an edit: some of those had a hollow pin retaining the plug. Yours might. Lucky, maybe. The bolt went through the pin.
 
Dan Thomas said:
That bolt also holds the plug in the bottom of the strut, and has oil under pressure against it. You did release the pressure first, right?

Now, an edit: some of those had a hollow pin retaining the plug. Yours might. Lucky, maybe. The bolt went through the pin.
Click to expand...
I am aware of that but no I didn’t. The old one slide out by hand and the new one slide in and I didn’t touch the plane in between. Knew the weight of the plane was holding it together. I have had the fairing on and off pretty many times. I top off the nitrogen about every 16-18 months. It must have the hollow pin in it.
If it didn’t come out by hand then that would have been the first thing I did relieve the pressure.

I learn something every time I read one of your posts. Thanks
 
Last edited:
Gary Ward said:
Knew the weight of the plane was holding it together.
Click to expand...
The weight will keep the strut from blowing out of the oleo cylinder if the torque links are disconnected, but it won't keep that bottom plug in the strut. Only the hollow pin is doing that.
 
Skyrys62 said:
I'm guessing,
Hollow pin meaning #23?
Which slides through 13, 21, and 22?
Click to expand...
That's it.

#18 is a metering rod. It moves up and down through a hole in #8. As #13 goes up and down, it pumps fluid through that hole, in and out of #8. The thickened sections at each end of the pin restrict the flow at each end of #13's travel, damping the ends of the travel so as to avoid hard hits at each end of the travel.

The bottom end of #8 has a diameter only slightly smaller than the bore in #13, so as to force the fluid to mostly move through that metering hole.
 
Some interesting engineering which seems to work pretty well.

And highly shimmy proof apparently. Ask me how I know lol..
 
If I understand this; it is the bolt( unidentified in pic) that goes through bushing (23) and holds spacers ( 27) that broke?

A common reason for some failures is over- extension of the
nose strut. This essentially locks the strut by means of a
“ Centering Cam “ on the Upper Torque Link. This usually causes the Torque Link Bolts to break when using a tug. Even a momentary bounce when under tug load can cause a failure .

What is the reason for your bolt breaking?
 
Magman said:
What is the reason for your bolt breaking?
Click to expand...

Magman said:
If I understand this; it is the bolt( unidentified in pic) that goes through bushing (23) and holds spacers ( 27) that broke?

A common reason for some failures is over- extension of the
nose strut. This essentially locks the strut by means of a
“ Centering Cam “ on the Upper Torque Link. This usually causes the Torque Link Bolts to break when using a tug. Even a momentary bounce when under tug load can cause a failure .

What is the reason for your bolt breaking?
Click to expand...
I think it broke because it got loose.
 
Gary Ward said:
I think it broke because it got loose.
Click to expand...
That's it. A loose bolt will bend under towing forces, and while AN bolts are a ductile nickel-steel alloy that resists cracking, eventually they give up.

Turning too tightly with the tug, especially a tractor tug, forces the steering collar up against its stop, and puts a lot of stress on that bolt. One can bust the collar or stop, too. Expensive.
 
Skyrys62 said:
Some interesting engineering which seems to work pretty well.

And highly shimmy proof apparently. Ask me how I know lol..
Click to expand...
That mechanism has nothing to do with shimmy. It's to handle and damp landing loads. The shimmy stuff involves the shimmy damper, torque links, steering collar, all of which get owrn when shimmy is allowed to continue. Replacing it is expensive, and if the shimmy is not addressed, the new stuff is soon shot, too.

Shimmy is due to a dynamically imbalanced nosewheel and tire. Static balancing will not cure it, but that's all most airplanes get. Cars have been getting their wheels dynamically balanced for more than 50 years, while airplanes are far, far behind. We still use bias-ply, tube-type tires on wheels that use felt grease seals. Cars abandoned bias-ply tires in the early '70s, and felt wheel bearing seals went out in the 1930s, at least. Leather replaced them, then nitrile replaced leather, a very long time ago.
 
Some airport employ folks with minimal trading as the Line Crew.

Steering Stops may not be In Syllabus.

Many places do not allow “ backing” light aircraft with tugs.

Heavy aircraft usually have better trained people.

Some people blame the kids when the fault is with management!
 
I sympathize with your plight, but disagree with your characterization. This is about the cheapest part that can break and ground you:

1715099021963.png​

Snapped off in my baggage compartment door and would have certainly grounded me if I hadn't had a spare in the plane.
 
Dan Thomas said:
That's it. A loose bolt will bend under towing forces, and while AN bolts are a ductile nickel-steel alloy that resists cracking, eventually they give up.

Turning too tightly with the tug, especially a tractor tug, forces the steering collar up against its stop, and puts a lot of stress on that bolt. One can bust the collar or stop, too. Expensive.
Click to expand...
A lot of those bolts capture the nose wheel fairing and can't be tightened much without crushing the fiberglass/plastic.
 
bnt83 said:
A lot of those bolts capture the nose wheel fairing and can't be tightened much without crushing the fiberglass/plastic.
Click to expand...
That is true. But the torque spec for an AN5 bolt in shear is low enough that crush damage is unlikely. I have seen the fairings all torn up around the bolt holes from the bolt being too loose; nosewheel shimmy then wrecks the fiberglass.
 
I have been using the tug since 2018 and I fly a lot 3-7 days a week so it get's used a lot. I pull the plane the same every time so I don't think it was too sharp of a turn. The Best tug is A3 so I am using it by hand and subconsciously I try not to turn it on a dime. I knew for a while it was a bit loose but never remembered to tighten it. Was planning taking the tire off someday to improve a slight shimmy I get sometimes when I have passenger and try to stop too fast. But I haven't made time for that yet as I fly alone most times and have learned to keep it from shimmying when by myself.
OT
A couple times recently I took my A3 home and used it to move 2 trailers around, that works real nice and I wish I had another one for at home. I also used it to tow a big block 1970 dodge challenger around my backyard. It was very useful for that also. My wife gave me the thumbs up because she didn't have help push. She just manned the wheels chocks.
IMG_3516.JPG

IMG_3525.JPG
 
Last edited:
Dan Thomas said:
That mechanism has nothing to do with shimmy. It's to handle and damp landing loads. The shimmy stuff involves the shimmy damper, torque links, steering collar, all of which get owrn when shimmy is allowed to continue. Replacing it is expensive, and if the shimmy is not addressed, the new stuff is soon shot, too.

Shimmy is due to a dynamically imbalanced nosewheel and tire. Static balancing will not cure it, but that's all most airplanes get. Cars have been getting their wheels dynamically balanced for more than 50 years, while airplanes are far, far behind. We still use bias-ply, tube-type tires on wheels that use felt grease seals. Cars abandoned bias-ply tires in the early '70s, and felt wheel bearing seals went out in the 1930s, at least. Leather replaced them, then nitrile replaced leather, a very long time ago.
Click to expand...

Yeah, just saying with the ridiculous amount of shimmy I've seen on some of the rental 172's, and mine on occasion, those strut parts are well engineered enough to take it all without frequent failure.
Plus the wheelbarrowing, porpoising, and nose landings. (don't ask me how I know) :lol:
 
Half Fast said:
I sympathize with your plight, but disagree with your characterization. This is about the cheapest part that can break and ground you:


Snapped off in my baggage compartment door and would have certainly grounded me if I hadn't had a spare in the plane.
Click to expand...
Can ground you more ways than one:


 
You must log in or register to reply here.
Back
Top