Tail boom issues

[ianboag]

One of my tail booms cracked and almost broke. The other one had started to go. The gyro is a 15 year old Xenon with 400-odd hours. I suspect my habit of leaning on the tail and wheeling it around - nose wheel off the ground - was not helpful. I spoke to two of the three previous owners and they did it too. When you do that it is obvious that there is a lot of load on the bolt hole that cracked. And of course in 15 years there has no doubt been the odd hard landing ..... :-(

The story is all there at https://avmet.nz/nzfi/xenon_defect.pdf. Make of it what you will.

I have passed the link to Trendak and Celier. I bought two new booms from Trendak for about E600 including air freight to NZ. Fitting them was not all that hard.

IB

 

[BEN S]

That's some scary shit right there! And you think that was from ground handling and not vibration?
I know your going to keep an eye on that, but not that you wont be handling it the same if you develop craks again be sure to let every know as well!
Thank you for finding those, I enjoyed my time in a Xenon what there was of it.

 

[ultracruiser41]

Yeah..... trying to pick up the front end by using the tail is not a good plan. Too much weight up there. Cavalons would have the same issue.

 

[okikuma]

Old habits carried over from pushing down on the horizontal stabilizer spar on Cessna C-150/152/172s to lift the nose wheel off the ground and then swing the airplane around.

Wayne

 

[ianboag]

There is one other Xenon in NZ - has done about 300 hours, one careful owner, never wheeled by pushing the tail down.

A borescope check has revealed a crack in the same place as mine. Rear upper bolt hole.

When my new booms arrived, there was a 300mm or so sleeve that fitted inside. I ignored it as there had been no such sleeve in my Xenon (or the other one). It is a reinforcer to be placed roughly where the attachment bolts are. There was no documentation with the booms, so I didn't think as hard as I should have. The boom also has a 12mm wide slot so the top of the rear bolt so the bolt does not touch the actual boom.

So I assume that at some time in the past, there were cracks found in Xenon booms and the reinforcing sleeve is a fix that presumably is now standard. Our 15 year old ones did not have it .....

 

[gyrojockey]

There is one other Xenon in NZ - has done about 300 hours, one careful owner, never wheeled by pushing the tail down.

A borescope check has revealed a crack in the same place as mine. Rear upper bolt hole.

When my new booms arrived, there was a 300mm or so sleeve that fitted inside. I ignored it as there had been no such sleeve in my Xenon (or the other one). It is a reinforcer to be placed roughly where the attachment bolts are. There was no documentation with the booms, so I didn't think as hard as I should have. The boom also has a 12mm wide slot so the top of the rear bolt so the bolt does not touch the actual boom.

So I assume that at some time in the past, there were cracks found in Xenon booms and the reinforcing sleeve is a fix that presumably is now standard. Our 15 year old ones did not have it .....

we are going to check ours this weekend - I'm hoping for a clean inspection

 

[All_In]

We are flying an ARGON and asked about the tail boom cracking on them. I had no idea.
Will inspect them often.
Been training at Adventure Air and they have 4 Cavalons, MTO, and a Caladuis.
This explains why Henry trained me to turn her with one of the rudders and to never try and lift the nose to pivot tighter turn.
It's only a slight pain. With wide turns, I have to back up twice to position her in between the other gyros.

That is the only way we have moved the ARGON too but by luck, as it's straight in and out of my hangar with a wide turn to the center of the taxi line. And only had her out a few times.

 

[ianboag]

we are going to check ours this weekend - I'm hoping for a clean inspection

Have a look at avmet.nz/nzfi/XJE.pdf and avmet.nz/nzfi/ZMY.pdf. Just a domain I own that gave me a place to park the info.

Repeating myself a bit here . If you find a problem, there's no point trying to deal with Celier. Trendak will sell you all the stuff. If you need two new booms, the cost is about E600 including DHL delivery (I am in NZ) and it takes about 4 weeks from order to delivery.

If your booms do not have a reinforcing sleeve, I would think about replacing them anyway. It is not a huge job. The two Xenons here are 14 years old. Interestingly there never seems to have been an SB about the sleeves.

 

[gyrojockey]

Have a look at avmet.nz/nzfi/XJE.pdf and avmet.nz/nzfi/ZMY.pdf. Just a domain I own that gave me a place to park the info.

Repeating myself a bit here . If you find a problem, there's no point trying to deal with Celier. Trendak will sell you all the stuff. If you need two new booms, the cost is about E600 including DHL delivery (I am in NZ) and it takes about 4 weeks from order to delivery.

If your booms do not have a reinforcing sleeve, I would think about replacing them anyway. It is not a huge job. The two Xenons here are 14 years old. Interestingly there never seems to have been an SB about the sleeves.

thanks for the info. I'm surprised there was no SB issued for this problem

Hoping to get away with just buying the sleeves IF we find don't find any cracks.

We already have an issue with the tail booms bent downwards slightly as the previous owner admitted he pushed down on the tail because that's the way he was told to do it when doing maneuvering the aircraft.

This brings me to my next question: will the bent down tail effect the fore & aft trim of the aircraft when flying in any way? because when I fly I have max trim and still have to hold some back pressure on the stick to maintain level flight?

 

[ianboag]

thanks for the info. I'm surprised there was no SB issued for this problem

Hoping to get away with just buying the sleeves IF we find don't find any cracks.

We already have an issue with the tail booms bent downwards slightly as the previous owner admitted he pushed down on the tail because that's the way he was told to do it when doing maneuvering the aircraft.

This brings me to my next question: will the bent down tail effect the fore & aft trim of the aircraft when flying in any way? because when I fly I have max trim and still have to hold some back pressure on the stick to maintain level flight?

 

[ianboag]

Hoping to get away with just buying the sleeves IF we find don't find any cracks.

Fair enough. To install the sleeves you will have to pull out the booms so you can feed the sleeves in from the cockpit end. You will have to debur the bolt holes in the booms and open out the top rear bolt hole to 12mm so the bolt does not touch the boom (which is where it cracks).

If you want to feed the sleeves in from the other end (booms not removed) you will have to take off all the tail surfaces and debur all the pop rivet holes ....

As far as the trim thing is concerned, just move the seat back a notch ....

 

[Tyger]

We are flying an ARGON and asked about the tail boom cracking on them. I had no idea.
Will inspect them often.

Don't you have to remove them to inspect them?

 

[All_In]

Hi Tyger
Yes, we will remove them and the main landing gear which is part of the attachment system in order to inspect it.
IIRC It took less than an hour to install them. Would have to disconnect the rudder cables to slide them off.

 

[Tyger]

You had said you will inspect them often... I am just curious how often you plan to do that, since doing so seems non-trivial.

 

[All_In]

Every 100 hours is often to me or annual inspections, whichever occurs first.
Ron and I will be flying her to all lower 48 states so anticipate every 100 hours.

The first inspection will be right after the 40 hours are flown off.

 

[ianboag]

Hi Tyger
Yes, we will remove them and the main landing gear which is part of the attachment system in order to inspect it.
IIRC It took less than an hour to install them. Would have to disconnect the rudder cables to slide them off.

If you have the reinforcing sleeves I wouldn't bother with a more detailed inspection. The sleeves are about 300mm long and hang out the rear of the fuse by about 75mm or so, The Argon is much newer than mine. Assuming you can get at the front end of the booms, you can just look through a borescope camera - see avmet.nz/nzfi/ZMY.pdf ... But as you note, getting them in and out is not all that hard. We have trick with a bit of wood and a tiedown ratchet strap for getting them out if you are interested.

 

[All_In]

If you have the reinforcing sleeves I wouldn't bother with a more detailed inspection. The sleeves are about 300mm long and hang out the rear of the fuse by about 75mm or so, The Argon is much newer than mine. Assuming you can get at the front end of the booms, you can just look through a borescope camera - see avmet.nz/nzfi/ZMY.pdf ... But as you note, getting them in and out is not all that hard. We have trick with a bit of wood and a tiedown ratchet strap for getting them out if you are interested.

I forgot the tail booms come all the way through on the Argon with a plastic beauty ring on the inside of the cabin. I can use my new borescope cellphone camera attachment. Hope to go to the hangar today and will check it out. Thank You, Ian, U-ROCK.

 

[Greg Vos]

Hoping to get away with just buying the sleeves IF we find don't find any cracks.

Fair enough. To install the sleeves you will have to pull out the booms so you can feed the sleeves in from the cockpit end. You will have to debur the bolt holes in the booms and open out the top rear bolt hole to 12mm so the bolt does not touch the boom (which is where it cracks).

If you want to feed the sleeves in from the other end (booms not removed) you will have to take off all the tail surfaces and debur all the pop rivet holes ....

As far as the trim thing is concerned, just move the seat back a notch ....

Or lose a bit of weight…. I fly the same gyro and have to have 10kg of ballast in the nose no trim….just saying gyrojocky

 

[Andino]

I would hope that the "reinforcing sleeves" solve the problem, and not transfer the bending point elsewhere on the booms to fatigue there. Many "fixes" actually relocate the problem vs. solve it.