Jump to content

1978J Nosegear truss turning radius stop tab broken


wiseng

Recommended Posts

My FBO tug driver (Signature-go figure) exceeded the turning radius of the nose gear stop tabs and broke the right one off.  Does anyone have an opinion if this makes the airplane un airworthy.   I suspect not since there is probably a lot of Mooneys flying out there that have this condition.  

Anyone have any thoughts.

 

DW

 

Link to comment
Share on other sites

17 minutes ago, wiseng said:

My FBO tug driver (Signature-go figure) exceeded the turning radius of the nose gear stop tabs and broke the right one off.  Does anyone have an opinion if this makes the airplane un airworthy.   I suspect not since there is probably a lot of Mooneys flying out there that have this condition.  

Anyone have any thoughts.

 

DW

 

The Mooney Service Manual for a J has specific guidance on this. While their wording does not include the word "un-airworthy", the phrasing would make me take pause as, I believe,  the result of exceeding the damage limit has in the past been identified as the cause of a nose gear collapse on landing and all of the resulting damage to the plane.

Not a mechanic, but a voracious reader of manuals.

image.png.4ae863885aad12727941499fe0ff5631.png

Link to comment
Share on other sites

9 minutes ago, Oldguy said:

And I am not sure this is a valid statement. Wishful thinking or observation?

concur, I am sure the OP can get a ferry permit to fly it (VFR, required crew only) to where it can be repaired if he doesn't want to do it on the field - that is if it does have a dent exceeding 1/32 since that make it un-airworthy (assuming not too bad). No dent, just broken off tab without damage to the tube exceeding 1/32 in depth where it broke off shouldn't be a problem.

But I don't think you'll find the word "un-airworthy" anywhere in the maintenance manual - that's a FAA term to mean unconforming to the TC. Exceeding any "max allowable" limit is unconforming. 

Edited by kortopates
  • Like 1
Link to comment
Share on other sites

Thanks guys.  Oldguy I have never seen the 1/32" tube damage limitation.  Its not In my old POH.  As far as the statement being wishful.   I flew for probably a half year on a previous  broken tab incident and did nor find out until annual.  My bad.  After this incident when pulling the plane out I check the tab limits by swinging the nose gear.  

 

OK if the plane is airworthy what is the opposite.  Not or un. 

 

Signature did fess up when they they broke it.  I do admire that. And I am having to go through my insurance for subrogation to Signature.  What a pain..

 

DW 

  • Like 1
Link to comment
Share on other sites

The key thing to be aware of is tube damage...

When the two tubes collide from over torqueing and exceeding the turn limits... the result is a slight depression, to a full on 1/4” dent...

The guidance shows a measurable dent....

Visually inspect where the tubes run into each other... to see if a dent or even a scuffed paint mark exists...

The damage is usually right at that spot... as a point to point contact... of two lines interfering with each other...

PP thoughts only...

Best regards,

-a-

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

If the nose gear was over steered enough to break the stop tab off, I would have the entire rudder control system inspected.  The rudder travel stops in the tail may have been shifted.

Clarence

Link to comment
Share on other sites

1 hour ago, wiseng said:

Thanks guys.  Oldguy I have never seen the 1/32" tube damage limitation.  Its not In my old POH.  As far as the statement being wishful.   I flew for probably a half year on a previous  broken tab incident and did nor find out until annual.  My bad.  After this incident when pulling the plane out I check the tab limits by swinging the nose gear.  

 

OK if the plane is airworthy what is the opposite.  Not or un. 

 

Signature did fess up when they they broke it.  I do admire that. And I am having to go through my insurance for subrogation to Signature.  What a pain..

 

DW 

I assume by "swinging the nose gear" you mean turning it left and right to its stops (as opposed to putting it up on jacks and retracting/extending it)?

A plane is not airworthy if the pilot has reason to think it is not in safe condition to fly.  After what @M20Doc said above, as a pilot I'd have reason to believe it might not be in safe condition to fly.

Link to comment
Share on other sites

I had a tab broken off at some point and didn't find it till annual. My mechanic and I were replacing a bad steering horn and I was going to have the truss powder coated. After glass beading the truss, I noticed that moisture would form at the break where the tab was. I showed my mechanic and we determined it was coming from inside the truss tube. Even though the tabs prevent the truss tube from being dented, the break in the metal allows micro tears in the metal and moisture into the tube. I would have it replaced.

Link to comment
Share on other sites

15 hours ago, wiseng said:

Oldguy I have never seen the 1/32" tube damage limitation.  Its not In my old POH.

You are correct; it is not in the POH, but is on page 13 of the Mooney Service Manual Section 5-20-06 titled "100 HOUR INSPECTION (or ANNUAL)". The revision I have is as of December 1998, and I bought it and the Illustrated Parts Catalog from Mooney in 2013 when I bought my J. They have both been incredibly helpful in chasing down parts and seeing the specifics on how to do the minor maintenance as a pilot I am allowed to perform on my own. Highly recommended if you don't have them.

Link to comment
Share on other sites

 

Does anyone know if Mooney factory trusses have the stop tabs? My original nose truss did not have the stop tabs.  When I replaced it with a rebuilt one from Lasar,  it had the tabs.  One tab got broken so I replaced it with the current one which does not have the tabs.  I believe the tabs may be a Lasar modification.  If the tubes are not bent, I don't see why you couldn't cut the tabs off. You would then have a truss identical to the factory ones.

Edited by mooneyflyfast
Link to comment
Share on other sites

Several years ago, a friend of mine told me his story about his J nose truss getting dented because of an FBO employee exceeding the limits while tugging it around.  He was without his Mooney for over a year (no parts) and got wrapped up in a legal battle with the FBO over cost of repairs.  What a headache from every angle.

Moral to the story?  I let no one move my Mooney by tug...by hand with tow bar only.  Yes, some FBOs roll their eyes.  I don’t really care...

So, for your situation, if it were me, I’d ferry it my MSC and let them fix it properly and, hopefully, the FBO would pick up the tab.

  • Like 1
Link to comment
Share on other sites

Coming back to inspect the nose truss prior to departure is always on my mind any time I leave the Mooney unattended while on a trip.

I've thought about fabricating a lock for the nose truss "handling hole" to keep anyone from hooking up to it. Maybe that would be overkill?

  • Like 1
Link to comment
Share on other sites

11 hours ago, DAVIDWH said:

Probably best to replace, although I flew for about three years with no issues. The second law of thermodynamics may apply here. It simply states,

Disorder always increases with time and the process is irreversible.

Just saying

I've always liked Ginsberg's Theorem (after poet Alan Ginsberg) paraphrasing the three laws and including the zeroth.   I've always found them easy to remember this way.

The three, actually four, laws of thermodynamics:

0.  The game exists. (Thermal Equilibrium)

1.  You can't win.   (Conservation of Energy)

2.  You can't break even.  (Entropy)

3.  You can't get out of the game. (Ultimate Equilibrium)

  • Like 3
Link to comment
Share on other sites

On 2/22/2019 at 11:43 AM, Jsavage3 said:

Several years ago, a friend of mine told me his story about his J nose truss getting dented because of an FBO employee exceeding the limits while tugging it around.  He was without his Mooney for over a year (no parts) and got wrapped up in a legal battle with the FBO over cost of repairs.  What a headache from every angle.

Moral to the story?  I let no one move my Mooney by tug...by hand with tow bar only.  Yes, some FBOs roll their eyes.  I don’t really care...

So, for your situation, if it were me, I’d ferry it my MSC and let them fix it properly and, hopefully, the FBO would pick up the tab.

I would love to be able to do that but what if the line crew has to move it any appreciable distance? I always caution them about no more then a 20 deg turn radius or it will damage the nose gear and most assure me they know about the Mooneys. Still makes me nervous.

Link to comment
Share on other sites

I have my turn limits brightly marked (Laura at SWTA keeps some bright red nail polish on hand just for this purpose). They get touched up every annual or more often if needed. I keep my cowl flap retracted while on the ground so the markings on the nose gear are easily seen. I notify both the ground crew and the FBO office about the limitations of towing my Mooney. If the ground crew is there, they will see me checking the nose gear truss before walking away and will let them know what I'm doing.

The rest is what insurance is for. Today parts are readily available and there are numerous shops that will rebuild the nose gear if parts can't be sourced.

This allows me to comfortably travel in my Mooney and park it on whatever ramp I happen to land on, and sleep easy.

  • Like 3
Link to comment
Share on other sites

2 hours ago, ArtVandelay said:

Mooney can’t be the only plane to have this limitation?


Tom

Piper Comanche series also have the same issue with over steer.  Our nose parts are forged aluminum with limited supply and few repair shops.  Many Piper owners will disconnect the nose gear torque links to avoid damage.

Clarence 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.