It could have ended differently---a lot differently

[donkaye, MCFI]

27 minutes ago, LANCECASPER said:

@Amelia 2016

 

Some people have great memories.  I just reread that thread.  I even had posted in it.  This issue has been around long time.  I think it should have been an AD to get it fixed, then everyone would have known about it.  It is easy to Monday morning quarterback.  And it's often helpful.  I'm going to check it out on my airplane, but the manual was not clear to me that disabling ESP with the AP on also disables it with the AP off.   Had I tried it before, I don't think I would have turned it off, and the issue would have resolved itself with an immediate down trim.  But that would have just masked the problem.  The fact is that a servo can cause the trim jackscrew to lock up if the SB has not been implemented and that is a major issue that should be addressed before an accident happens.  Even knowing the issue was discussed 9 years ago here didn't help because I had forgotten about it.

Regarding other solutions such as bank angles;  We were configured for slow flight with gear and full flaps.  I'd be a little reluctant to go into a bank of greater than about 20° due to stall speed increase.  That being the case 20° is not going to help much because the wing isn't loaded enough.  At 45° where it would help, the plane would already have gone into a spin, having stalled earlier.

[Marc_B]

I might have missed it but what changed to have some year models have the service bulletin and others not?  What did Mooney changed in ~1990 that changed this behavior??

Was it just incorporation of a stepped stop nut around 1990?  Any pictures of original vs stepped?

[Will.iam]

Probably a shorter jack screw. Boeing fixed theirs with the same problem by using a shorter travel jackscrew as they didn’t need that much up trim. 

[PT20J]

The original service instruction, SIM20-88, was issued in 1990, so the change would have probably been incorporated in production airplanes around that time. My 1994 MSE came from the factory with the stepped nuts.

We often hear that service bulletins (mandatory or otherwise) need not be complied with for part 91 operations, and this is true. But, sometimes complying is the smart and safe thing to do. The owner/operator is primarily responsible for maintaining the aircraft in a safe and airworthy condition. It's not difficult to search Mooney's website for all the SIs and SBs that apply to your airplane and check the logbooks to see which have been complied with. 

[Slick Nick]

30 minutes ago, PT20J said:

The original service instruction, SIM20-88, was issued in 1990, so the change would have probably been incorporated in production airplanes around that time. My 1994 MSE came from the factory with the stepped nuts.

We often hear that service bulletins (mandatory or otherwise) need not be complied with for part 91 operations, and this is true. But, sometimes complying is the smart and safe thing to do. The owner/operator is primarily responsible for maintaining the aircraft in a safe and airworthy condition. It's not difficult to search Mooney's website for all the SIs and SBs that apply to your airplane and check the logbooks to see which have been complied with. 

My 1991 MSE came with the stepped nuts also. They probably implemented the fix pretty quickly on the assembly line. 

[Fritz1]

Don, Thank you for posting this, got my attention, immediately checked my serial # which is 27/0280, out of the SB range.

[PT20J]

I tried a little experiment today in my M20J MSE. Climbed to 5000'. Put gear down and flaps full down and set power to maintain 75 KIAS. Put the gear up and held altitude and the airspeed stabilized at 80 KIAS. Put the gear down and stabilized again at 75 KIAS. Raised the flaps to TO position (15 deg). Airspeed stabilized at 80 KIAS. So the drag from the gear and full flaps is the same. With gear up and full flaps and only me and half tanks, the airplane would climb at greater than 500 fpm with full power. So, I agree with @donkaye, MCFI: The simplest procedure for going around is gear then flaps.

 

[201guy]

Just checked the price and availability on this SI Kit.    $2400+.   Yes, over 2400 dollars for a couple of nuts!

[kortopates]

8 minutes ago, 201guy said:

Just checked the price and availability on this SI Kit.    $2400+.   Yes, over 2400 dollars for a couple of nuts!

Looking at it as the cost of a couple of machined nuts is one perspective. Although I did this many years ago, I looked at it as the cost to avoid a locked up full nose up (or down) situation that can and has lead to an accident with injuries that also totaled the aircraft. It was a an easy safety decision for me for a plane I share with my wife.

[Fly Boomer]

1 hour ago, 201guy said:

Just checked the price and availability on this SI Kit.    $2400+.   Yes, over 2400 dollars for a couple of nuts!

Whatever the cost, it should be mandatory.  Go around with trim locked full up (typical in the flare or at touchdown) and a big-bore engine can kill you.

[N201MKTurbo]

23 hours ago, Fly Boomer said:

Whatever the cost, it should be mandatory.  Go around with trim locked full up (typical in the flare or at touchdown) and a big-bore engine can kill you.

If you give it full power. About 100 HP will stop your descent. Just give it enough power to get a positive rate of climb. It won’t be hard to hold your pitch attitude. 

[Fly Boomer]

1 hour ago, N201MKTurbo said:

If you give it full power. About 100 HP will stop your descent. Just give it enough power to get a positive rate of climb. It won’t be hard to hold your pitch attitude. 

I agree.  That's the argument for:
- power/trim
- gear
- flaps/trim
- more power/trim
- more flaps/trim

Or one of the many variations of that sequence.

 

[N201MKTurbo]

5 minutes ago, Fly Boomer said:

I agree.  That's the argument for:
- power/trim
- gear
- flaps/trim
- more power/trim
- more flaps/trim

Or one of the many variations of that sequence.

 

That’s exactly how I do it. It looks like a lot, but it only takes a few seconds to do all that and get established in a climb.