Dented Nose Truss

[markejackson02]

Took N201TK in for the annual.  The nose truss had a pretty healthy dent on the left side.  I pull the plane out of it's hangar and turn it left to get on the taxiway.  I use a Bogert 5' towbar.  As far as I know, it hasn't been towed this year.  That would mean that I have put a 1/8" dent in the steel tubing just by using a manual towbar.  Is that really likely or possible?

[orionflt]

It’s all about leverage. It is possible, but I would think you would have realized how much pressure you were putting on it 

[Boilermonkey]

5ft is a lot of leverage....I still put my bet on an FBO using a tug...that's what happened to me....but since it was caught at annual we couldn't prove which FBO...so out came the $$$$ from our pocket.

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[smccray]

If you have to replace it look at the Laser nose truss.  It adds stops to keep that problem from happening again.

[carusoam]

1) with a 5’ tow bar you can bend the thin tubes by hand...

2) as an owner you would know when the tubes crash, you feel a distinct pain in your left pocket...  

3) Using a powered tug, it is extra easy to bend tubes without knowing it...

Either way... the damage is done...

Time to get on to the solution...

Lasar has them.

To keep this from happening again, look for the structure that has the red limitations marks and pointer...

Best regards,

-a-

 

[RLCarter]

5 hours ago, smccray said:

It adds stops to keep that problem from happening again.

It can still be damaged, the line person just has to work harder at it....

[chrisk]

I have to admit to being some what paranoid about this.  Any time some one moves my plane, I check afterwards. 

[cliffy]

I've seen the LASAR stops broken off

[DonMuncy]

My hangar elf designed and installed a system on my plane which sounds a piezo alarm when the limits are reached. But better yet, it trips a relay with a light and substantially quieter alarm in the cabin. So if I am traveling somewhere and a lineman exceeds (or reaches) the limit, when I come back and open the door, the alarm will alert me to crawl down and check. It is a real pain to install and calibrate, and I keep it set so sensitive that many people with activate it without causing any damage. But I prefer to have to check often, rather than the alternative.

[cliffy]

I've given some thought to taking a piece of 4130 aircraft tubing (.032 wall) and cutting a piece into an oval shape to glue over the area of the denting. It would provide a little more defense against the dent. Maybe no fool proof but some help. Likewise it would cut the turning radius down a little. 

[Guitarmaster]

My hangar elf designed and installed a system on my plane which sounds a piezo alarm when the limits are reached. But better yet, it trips a relay with a light and substantially quieter alarm in the cabin. So if I am traveling somewhere and a lineman exceeds (or reaches) the limit, when I come back and open the door, the alarm will alert me to crawl down and check. It is a real pain to install and calibrate, and I keep it set so sensitive that many people with activate it without causing any damage. But I prefer to have to check often, rather than the alternative.

That is a genius idea!

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[Eight8Victor]

I’ve had my LASAR truss tab broken completely off by an FBO. Even though the tube was not bent, the break allowed moisture into the tube I’m assuming through micro tears in the metal. When my mechanic noticed what appeared to be rusty water forming at the break, we decided to replace it. I don't know how long it was broken. It must have been a while for moisture to form. 

[mooneyflyfast]

17 hours ago, smccray said:

If you have to replace it look at the Laser nose truss.  It adds stops to keep that problem from happening again.

It helps but I had an FBO break one of the stops off my Lasar truss.

FBOs seem to be training their linemen better these days. I havent had one damaged in a long time. When I caution them about towing they say " Oh we know about towing Mooneys"

[DonMuncy]

8 hours ago, cliffy said:

I've given some thought to taking a piece of 4130 aircraft tubing (.032 wall) and cutting a piece into an oval shape to glue over the area of the denting. It would provide a little more defense against the dent. Maybe no fool proof but some help. Likewise it would cut the turning radius down a little. 

You would be surprised how much it would restrict the turning radius. There is really very little space between the tubes to allow for turning.

[DonMuncy]

17 minutes ago, mooneyflyfast said:

 When I caution them about towing they say " Oh we know about towing Mooneys"

That is what they all say..... right before they tow it away in a tight turn.

[gsxrpilot]

It's really a judgement call every time I park on a ramp somewhere. Do I think the FBO will know enough, or is the FBO big enough to be able to easily compensate me for the damage? Should I tell them I'll drive it over to parking or should I let them tow it? Should I just ask if they know how to tow a Mooney or should I explain the damage that can happen and take them out to the airplane to show them the current pristine condition of my nose truss? It comes down to making a quick evaluation of the personnel, the FBO, the airport, each time. 

With right at 1000 hours across two different Mooneys, the method has worked out. So I'm pretty confident to continue. But with full knowledge that if I make the wrong call at some point, there is insurance to cover my mistaken judgement.

Checking the nose truss for damage is part of my preflight regimen anytime I'm departing from a ramp away from home. If an FBO does damage the truss, it's easier to get them to cover it if I'm still on their ramp.

[FloridaMan]

Always check before and afterwards. I like to demonstrate to the line guys how to inspect a Mooney nose truss and where the damage would occur that way I have a witness  I also usually throw the line guy $10 because I feel like it may be cheaper to do that every time than to have to deal with damage. 

[Bryan]

I check my truss, too, but I think mine has some stops built-in. 

Does anyone have some really good pictures that show where to check and what to look for? 

I check the two angled trusses going up to the point.  I still tell the line-guys that I have tow limits.  They (mostly) all shrug and indicate that they already know about it - but at least if there is damage, I feel better about going back to them.

[pwnel]

41 minutes ago, FloridaMan said:

Always check before and afterwards. I like to demonstrate to the line guys how to inspect a Mooney nose truss and where the damage would occur that way I have a witness  I also usually throw the line guy $10 because I feel like it may be cheaper to do that every time than to have to deal with damage. 

Alright here comes the dumb question (still in first year of ownership):   can someone here please post a photo of what this looks like when damaged. Where exactly should I look for?  Just had the Lasar solution installed on mine during annual based on AP recommendation, but I'm still somewhat clueless and forgot to ask them to show this to me.  Like @gsxrpilot explains I also do the FBO size-up and briefing each time so far - but I'd be honest to say I won't necessarily know where to look for damage.

Edited February 6, 2019 by pwnel

[DonMuncy]

I don't have a picture, but if you will take your tow bar and turn the nose wheel while laying on the ground next to it, it is easy to see where the two tubes bump. 

[FloridaMan]

2 minutes ago, pwnel said:

Alright here comes the dumb question (still in first year of ownership):   can someone here please post a photo of what this looks like when damaged. Where exactly should I look for?  Just had the Lasar solution installed on mine during annual based on AP recommendation, but I'm still somewhat clueless and forgot to ask them to show this to me.  Like @gsxrpilot explains I also do the FBO size-up and briefing each time so far - but I'd be honest to say I won't necessarily know where to look for damage.

[pwnel]

Thanks so much @FloridaMan

[gsxrpilot]

4 minutes ago, pwnel said:

Alright here comes the dumb question (still in first year of ownership):   can someone here please post a photo of what this looks like when damaged. Where exactly should I look for?  Just had the Lasar solution installed on mine during annual based on AP recommendation, but I'm still somewhat clueless and forgot to ask them to show this to me.  Like @gsxrpilot explains I also do the FBO size-up and briefing each time so far - but I'd be honest to say I won't necessarily know where to look for damage.

 

8 minutes ago, Bryan said:

Does anyone have some really good pictures that show where to check and what to look for? 

It's actually pretty easy.  One way is with your nose wheel turned all the way to the stop, get down and feel where the tubes are touching. That's the spot and it will be more likely on the tube attached to the wheel rather than the tube attached to the airframe. Another way is with the wheel straight ahead, get down and feel the back and inside of the nose truss assembly. You'll feel a gap between the tubes that is just about as wide as a finger. You can feel both tubes with the same finger. If there's damage, you'll feel an obvious dent in that tube.

It's easier to feel it than to see it or take a picture of it.

One other note, my cowl flap hides the tow limits mark, so I always have my cowl flap retracted when on the ground. This way the tow limit marks are easily seen.

Laura at SWTA keeps some bright red fingernail polish in her tool box just for painting on the tow limit marks every time a Mooney is in for annual in their shop. 

Every little bit helps...

[Bryan]

1 minute ago, gsxrpilot said:

Laura at SWTA keeps some bright red fingernail polish in her tool box just for painting on the tow limit marks every time a Mooney is in for annual in their shop. 

Every little bit helps...

Yes!  Just coming out of annual from SWTA, they replaced a couple of placards on the nose truss and highlighted with the red paint (fingernail polish) the tow limits.  They are very visible now, but like you say even better when the cowl flaps are closed on our 252s.

I will try to get a picture today.

[rbridges]

2 hours ago, bluehighwayflyer said:

I agree. I think the word is out now. FBO's are tired of having to pay for these things. It helps, too, that a lot of tugs nowadays lift the nose wheel up off the ground so no turning of the nosewheel is involved whatsoever.

I always ask, and every FBO seems to be aware of the mooney turn limits.  It doesn't mean they won't still mess up, but I figure it doesn't hurt to tell them.