Big problem found during Annual Inspection

[Flybeech21]

So, on a recent trip, I was decending at close to redline in smoth air when I hit Moderate to Severe turbulence.  No warning at all!  Not even a ripple of chop.  It stayed really bumpy the remainder of the flight. 

The next flight, I noticed a tail wag, similar to the yawing that some pilots report from V tail Bonanzas.  I wrote it off as the PC control system probablly needs to be adjusted since it had been taking all of the roll left adjustment to stay level. 

Well folks, I was wrong.  Really wrong!  We just started the annual yesterday and upon inspection of the empennage noticed sheered rivets just aft of the upper attach point extending down ward and aft beneath the horizontal stabilizer.  This is allowing the tail to move horizontally about 1" at the tips of the horizontal stab. 

I normally check the tail by grabbing it and giving it a push or two to check security.  After someone on the feild commented that I was going to cause dammage by doing that so much, I didnt check it for two flights (The two flights prior to the annual).  One of the flights was the turbulence encounter.  Little did I know, the tail of my airplane was working loose and starting down the path of catastrophy!  My wife and kids were on the last flight.  Unreal!

Moral of the story is, dont let anyone talk you out of your pre-flight routine and watch out for turbulence when operating in the yellow arc. 

I will post pictures of the damage once I get the tail torn apart and completely inspected.

[scottfromiowa]

Kevin,

 

Glad you found at annual!  Thanks for sharing.  I would definitely like to see photos of this damage.  I have never heard of this type of failure in a Mooney.  Again, glad story has happy ending.

[flight2000]

Yikes, that is bad. Glad nothing happen to you and your family.

I agree, why would you not check the tail and wings with a small tug.  Sure, yanking on it as hard as possible might be bad, but looking for new wiggles should help identify this type of problem early on. 

Brian

[Piloto]

This is indeed a rare event. Was there corrosion in the area?. Sounds like there may has been some prior corrosion and the rivets just gave up when subjected to stress. Glad you caught it on time 

José

[N6784N]

really interesting you brought this up. my last few flights i have had to move my pc control all the way to the left even with full fuel. has anybody ever had this problem before or should i have a mechanic look at my plane?

 

thnx

[Mooney65E]

Quote: N6784N

really interesting you brought this up. my last few flights i have had to move my pc control all the way to the left even with full fuel. has anybody ever had this problem before or should i have a mechanic look at my plane?

 

thnx

[PTK]

Ouch!!  Made my hair stand up!  Very happy you found it on the ground.  Very interested in some pics.

[rbridges]

thanks for sharing.  were the damaged rivets pretty obvious?  I usually glance over the sheetmetal during preflight but don't take time to examine every square inch fo the plane.

[Sabremech]

Hi Guys,

 I bought this Mooney from Kevin in June of this year. I did see it apart and what was required to fix it and make it solid. Learning from Kevin, I grab the horizontal stab on both sides during my preflight and check for movement. It is rock solid now. It made enough of an impression on me that it is standard practice to check this before every flight.

 If you find any movement, check the line of rivets under the forward edge of the horizontal stab which is where the bracket for the tail pivot bolts is mounted.

 

[rbridges]

lol.  I didn't notice that it was a resurrected thread.

[Sabremech]

Next time I'm out by the Mooney, I'll snap a few pictures of the area in question. I saw the hardware which included the pulled rivets and a bent pivot fitting bolt. Definitely worth looking at if you routinely fly your airplane in the yellow arc and in turbulence.

[Sabremech]

Here's the area on the tail to watch for rivets loosening up and the horizontal stab gettting play in it.

 There's three new rivets that identify the area to inspect.

[acrotex]

There is a steel bracket inside that those rivets attach to.  That bracket cracks.  It does no good to put in new rivets without replacing the bracket (pair of them).  There might be some cases where the rivets were working and the bracket is still OK, but I bet most are broken.  Someone that had this happen bought two more tails, thinking he could remove the brackets to use on his.  It turns out the brackets were cracked in all 3 tails. 

[Sabremech]

You are correct. There is a steel bracket and it wasn't cracked on this one. I will be doing a dye penetrant on the brackets in the tail during my annual. Cheap and easy to do.

 

[jpusser]

I checked my tail.  I don't see any cracks in the brackets but there is a little play when you move the tail forward and reverse.  There is none up and down.  I would say there is between 1/4 and 1/2 inch.  Sounds and feels like maybe a bushing.  Is this normal?  Would anyone be willing to check theirs for me.  Thanks

[takair]

Quote: jpusser

I checked my tail.  I don't see any cracks in the brackets but there is a little play when you move the tail forward and reverse.  There is none up and down.  I would say there is between 1/4 and 1/2 inch.  Sounds and feels like maybe a bushing.  Is this normal?  Would anyone be willing to check theirs for me.  Thanks