Landing Gear bolt

[TimHicks]

Attached is a photo of the two landing gear bolts that I replaced on 96872 (1946 BC-12) this past weekend. Their location is at the bottom of the gear leg. They pin the gear leg to the bungee strut (I don't know their real names). That's not parallax from the photo, those bolts are bent!

I don't ever remember landing this airplane hard enough to cause this kind of deformation, but my passengers may. I just thought that others might want to check theirs when the opportunity presents itself.

Tim

[Dan Mahalak]

Re: Landing Gear bolt

Fat boy? hard to believe since your flying a T'...

I suggest you lay off the donuts...

[mhorowit]

Re: Landing Gear bolt

Tim - could you be referring to the 'undercarriage strut" bobm is refering to? - Mike

[Guest]

Re: Landing Gear bolt

Attached is a photo of the two landing gear bolts that I replaced on 96872 (1946 BC-12) this past weekend. Their location is at the bottom of the gear leg. They pin the gear leg to the bungee strut (I don't know their real names). That's not parallax from the photo, those bolts are bent!

I don't ever remember landing this airplane hard enough to cause this kind of deformation, but my passengers may. I just thought that others might want to check theirs when the opportunity presents itself.

Tim

Hi Tim,

I am curious from your picture, good tip by the way. Thanks.

Do you use and extar bungee cord (3 instead of 2)?

Or perhaps some non standard cord?

Dave

[TimHicks]

Re: Landing Gear bolt

I do indeed use 11104 shock cords (2 per side). I believe that these are L-2 shock cords that are stiffer than the usual 9010HD.

I went to the 11104's after going through about 3 sets of 9010HDs over 3 months (years ago). They would start sagging just after installation or after just a couple of landings. Aircraft Spruce kept saying that there was a bad batch of them and kept sending me new 9010HD's. But I couldn't keep swapping them out every time I wanted to fly, so I changed to 11104's. I've been completely happy with the 11104's.

I caution anyone from making a cause/effect assumption between the bungee selection and the bent bolts, however, until we have more info.

I'm 6'5" weight 240#. Not exactly made for a Taylorcraft, but we get along fine. The ship is fairly heavy also.

[mhorowit]

Re: Landing Gear bolt

I'm 6'5" ....

I'm 6'2" with long legs. What did you do with your seat? - Mike

[TimHicks]

Re: Landing Gear bolt

I sit on it. ;-)

[mhorowit]

Re: Landing Gear bolt

I sit on it. ;-)

TimHIcks is reallly Henny Youngman

[Goneflyin]

Re: Landing Gear bolt

I changed a bolt that was bowed like yous on the passenger side last year, I have the standard 9010hd cords on the gear. Must have been the previous owner that bent it.

Bill

[Guest]

Re: Landing Gear bolt

I do indeed use 11104 shock cords (2 per side). I believe that these are L-2 shock cords that are stiffer than the usual 9010HD.

I went to the 11104's after going through about 3 sets of 9010HDs over 3 months (years ago). They would start sagging just after installation or after just a couple of landings. Aircraft Spruce kept saying that there was a bad batch of them and kept sending me new 9010HD's. But I couldn't keep swapping them out every time I wanted to fly, so I changed to 11104's. I've been completely happy with the 11104's.

I caution anyone from making a cause/effect assumption between the bungee selection and the bent bolts, however, until we have more info.

I'm 6'5" weight 240#. Not exactly made for a Taylorcraft, but we get along fine. The ship is fairly heavy also.

Hi Tim, thanks

I agree with you, don't jump to conclusions about the bolts.

Who knows, maybe at some point in history some one may have replaced the bungees with ropes, cables... for road towing (hopefully not for flying) and that could have effected the bolts.

I also wonder about the case where the bungees break and you go down on the snare cable that has to shock those bolts too. But having both bent by that scheme may be unlikely, I guess they don't have to get bent at the same time though. Over 60 years maybe each side dropped once. Then if the a/c was flown back to a place to get the cords installed it would get a to TO and landing on the snare. That might bend a bolt.

Landing gear bolts take a good load and should be checked. I recall that AC43.13-1B has a section on inspecting them.

I had a similar issue with 9010's they would last a year or less. Went thru 2 or 3 sets before I realized what was happening to me.

I was my fault. I had not noticed that the safety wire for the snare cable was under the bungee. It was put orginall so that it was supposed to be over the bungee so when it was under the safety wire had a little tension on it and was pulling into the shock cord. As the wires pulled into the cord it weakened and lasted a very short time.

As I said, it was my mistake.

Dave.

[Richard Boyer]

Re: Landing Gear bolt

On the way to Oshkosh last year, the Piper Clipper flying with me departed the runway abruptly and "skipped" over a ditch hitting the slope on the other side. They though they had damaged the airplane because they heard something snap. It turnes out that the only damage (luckily) was that the saftey cable snapped. It kept the plane from prop striking but sacrificed itself instead.

We all felt it should not have broken, but were grateful that there was no (more) damage.

That was one hell of a trip!

Richard Boyer
N95791

[crispy critter]

Re: Landing Gear bolt

Tim,
I've never had a problem with the 9010HD's if installed correctly,if they are not then they will certainly wear out fast. Of course IMHO the bungees should be inspected every year and replace every 3 years(5 if hangered and not treated rough). Think about it this way,these bungees are your shocks,they are made to flex and take the jolts,hard hits,and general loads off of the airframe. If they don't flex the way they were designed then what do you think takes the abuse.....that's correct,the airframe,especailly the bungee strut bolts and the gear attach bolts.However,if these were the original bolts then the fact that they are 60 years old and have been treated really rough may have been part of the problem,but I know Crispy had the originals in it and the looked perfectly new when they came out....I replaced them anyway.

[alwaysoar]

Re: Landing Gear bolt

Following the post about landing gear bolts, and currently in the middle of my annual, I hoisted off the ground and checked them all;lots of clunking, so I changed them all. Found slight bowing, but mostly wear. I was afraid of bolt hole elongation as they must have had all that play for a long time. However, replacing all bolts eliminated all play. Thanks Tim for the heads up!
Replacing bungees is a mixed deal. Our field is pretty rough, and before I replaced the bungees last year it rode like a '64 Caddy. Now, it rides like a John Deere B. I won't be so quick to change them next time.

Ed@BTV VT
TF 527

[Richard Boyer]

Re: Landing Gear bolt

So everyone is changing their bolts. Thats cool, but would anyone share what the bolt size is?

It would be nice to have extras laying around just in case.....I would hate to take them off someday and have to WAIT to fly for another set to arrive in Santa's Brown Truck.

Richard Boyer
N95791

[Dusty]

Re: Landing Gear bolt

I do a lot of ski flying, so my gear bolts get beat up pretty bad. I've bent several in the Champ (T-cart has MUCH better suspension for skis). They're cheap - really cheap, when compared to a night or two of unplanned winter camping followed by, at best, getting someone to fly me a new prop in. I make a habit of changing them every year or two.

I like the bungees a little soft and generally replace them one (per side) at a time to keep them "just right."