Empennage vertical "play"?

[skeptic]

I recently looked at a nice Mooney 231, and I noticed that when pushing up on the rudder and/or horizontal stab, there was some slight vertical "free play" around the the tail hinge points.  Not the elevator hinges, but rather the hinge that allows the entire tail to move for trim purposes.  Is this small amount of free play normal, or does it perhaps indicate some worn bearings?

 

The airplane in question was in above average condition, and appeared to be very well maintained, so I feel sure that this would have been addressed if the owners had been told that it was a problem.  It was obvious that they had not knowingly cut any corners on maintenance.

[M016576]

Not sure what's normal, but my 1980 J has no "free play" at all in the tail trim

[Seth]

As part or the pre flight I lift the bottom of the tail. I have never had any play in any Mooney I have flown. This play could indicate worn bolts/bushings. Get it checked out by a Mooney knowledgable A&P and fixed or deemed safe prior to flight.

-Seth

[skeptic]

I just found a reference to this in an M20J service manual......max vertical free play at the rudder is 0.08 inches for a 201.  Not sure if the 231 has the same limits.

[Jeev]

Part of my preflight as well and my J has no play if it ever does I'm not flying until I I find the cause and have it repaired. I would investigate the cause further but if it can be fixed properly by the seller before the purchase I would not let it stop the purchase.

[flight2000]

I just found a reference to this in an M20J service manual......max vertical free play at the rudder is 0.08 inches for a 201. Not sure if the 231 has the same limits.

Beat me to it... the maintenance manual is where you'll find the acceptable tolerance. Wouldn't go with any other information except what is published by Mooney for those tolerances.

Brian

[Alan Fox]

The play is from the link between the end of the trim jack screw , and the mounting eye on the articulating emp.....The part was around 80 $ last time i purchased one , It is not a major concern , as the wind pushing on the vertical stab will not allow any play in flight.....Very common  for this play to be evident....

[N601RX]

I have not saw one that did not have at least some free play.  For those who think yours don't you may not be picking up hard enough. Below is a quote from Maxell about free play and how he measures it .

Empennage free play is not a big concern. We tie the tail down and lift at
the trailing egde of the rudder near the tail nav lite. We measure from the
ground to the bottom screw that holds the nav lite lens on. 3/16" is our
number. Bill Wheat in his certification flights flew a Mooney with no
bushings installed in the tail. It would move around several inches in every
direction, he then did an FAA witnessed, from afar, dive test  to 250 mph
and recovered with only a minor brown spot in the pilot seat. I asked him
how they came by the limits in the SM and he said , "they, the feds, wanted
a number, we gave them some". I once flew a C model that was pitchy in rough
air. On inspection , someone had installed a 1/4 inch bolt instead of a 5/16
in the trim link. Forward movement at the tip is common and is usually
remedied by retorquing the two top attach bolts.
Don

[flight2000]

I will say that Bill Wheat was a very brave man....and very confident in Al Mooney's design...   

 

There would be more than a brown spot in my pilot seat if i did that dive....

 

Brian

[Marauder]

Speaking of Bill Wheat, anyone hear an update on him?

[skeptic]

The play is from the link between the end of the trim jack screw , and the mounting eye on the articulating emp.....The part was around 80 $ last time i purchased one , It is not a major concern , as the wind pushing on the vertical stab will not allow any play in flight.....Very common  for this play to be evident....

 

Which part in the trim linkage normally has to be replaced?

[skeptic]

 

I have not saw one that did not have at least some free play.  For those who think yours don't you may not be picking up hard enough. Below is a quote from Maxell about free play and how he measures it .

Empennage free play is not a big concern. We tie the tail down and lift at
the trailing egde of the rudder near the tail nav lite. We measure from the
ground to the bottom screw that holds the nav lite lens on. 3/16" is our
number. Bill Wheat in his certification flights flew a Mooney with no
bushings installed in the tail. It would move around several inches in every
direction, he then did an FAA witnessed, from afar, dive test  to 250 mph
and recovered with only a minor brown spot in the pilot seat. I asked him
how they came by the limits in the SM and he said , "they, the feds, wanted
a number, we gave them some". I once flew a C model that was pitchy in rough
air. On inspection , someone had installed a 1/4 inch bolt instead of a 5/16
in the trim link. Forward movement at the tip is common and is usually
remedied by retorquing the two top attach bolts.
Don

 

It would need to be checked by a mechanic, but I doubt that the vertical free play exceeded Maxwell's limit of 3/16".

[kerry]

Just start off by replacing the two bolts that hold the tail on and the one bolt that attaches to the trim jack screw.  In my case just doing that "tightened my tail" to the point that there is now no discernable movement, either vertically or laterally.  While you're back there see how much slop there is in your rudder (with the nose wheel on the ground, of course).  Mine had something over 2 1/2" of play when measured at the trailing edge, which is a sign that it is time to have LASAR overhaul your nose gear steering horn and linkage.  I also experienced a little nose wheel shimmer once under relatively heavy braking, which is what made me start looking for a cause.  After the nose gear steering horn overhaul my rudder free play is now around 3/4", maybe less.

 

Jim       

Jim,  After replacing the hardware in the tail did make any difference when flying e.g.(Did you find any difference in trim).

[Alan Fox]

Which part in the trim linkage normally has to be replaced?

When you pull the two side fairings that go on the fuse and float over the emp , you will see a link that is about 3/4 inch wide , by 2 inches long , with two 5/16 bolts going through it , that is the one...

[BigTex]

I have not saw one that did not have at least some free play. For those who think yours don't you may not be picking up hard enough. Below is a quote from Maxell about free play and how he measures it . Empennage free play is not a big concern. We tie the tail down and lift at the trailing egde of the rudder near the tail nav lite. We measure from the ground to the bottom screw that holds the nav lite lens on. 3/16" is our number. Bill Wheat in his certification flights flew a Mooney with no bushings installed in the tail. It would move around several inches in every direction, he then did an FAA witnessed, from afar, dive test to 250 mph and recovered with only a minor brown spot in the pilot seat. I asked him how they came by the limits in the SM and he said , "they, the feds, wanted a number, we gave them some". I once flew a C model that was pitchy in rough air. On inspection , someone had installed a 1/4 inch bolt instead of a 5/16 in the trim link. Forward movement at the tip is common and is usually remedied by retorquing the two top attach bolts. Don It would need to be checked by a mechanic, but I doubt that the vertical free play exceeded Maxwell's limit of 3/16".

Just had my annual over at Don's place. Not sure how much I have on mine but it's definitely more than 3/16". Wasn't even discussed so must not be a big concern.

[fantom]

Just had my annual over at Don's place. Not sure how much I have on mine but it's definitely more than 3/16". Wasn't even discussed so must not be a big concern.

 

Don has always liked his tails to move some....

[BigTex]

Who doesn't!

[thinwing]

about 1/8in on mine