Johnson bar fails and gear collapses in my Mooney 78934 at landing in KLZU

[Alan Fox]

If the bar was not in the locked in position , its not preload , let this be a lesson to all the manual gear guys , If you don't know the thumbnail trick , you should learn it to save some grief....The agreed upon value in the policy is the value , no matter what you do to it , If you remove parts from the airplane , they can deny the claim.....

[RobertGary1]

I had one claim, a truck hit me in Mexico. The insurance co had lots of opportunities to try to save money but never complained about paying for top service. New parts, Mooney Service Center etc. never felt that they were trying to be cheap. This is AIG (Chartis).

-Robert

[Andy95W]

according to my wife, it was in the middle position when she exited the plane. It was in gear down when collapse started to develop

If the bar was not in the locked in position , its not preload , let this be a lesson to all the manual gear guys , If you don't know the thumbnail trick , you should learn it to save some grief.

I'm with Alan, and if the JB was "in the middle position" when she exited, then it wasn't securely latched, for whatever reason. Sounds like either they didn't know the thumbnail trick or the thumb latch was worn to the point of being noneffective.

[kommers]

Forgive me for asking, but what is called "thumbnail trick"? I never heard this term. When my mechanic replaced the bracket with new one that has j-hook, I was instructed to move JB into gear down position, push the handle up while twisting slightly its head  counter- and clockwise until I hear that it "snaps" into place. I used this ever since the bracket replacement for about 15 flights and never had any issues. I pretty much passed the same info to my wife and her CFI. Quite frankly, I saw nothing else that could be done there to ensure that JB is securly latched

[Andy95W]

After extending the gear, and making sure it is latched all the way up, you shouldn't be able to get your right thumbnail into the small space between the Johnson Bar and the latch. After that, try to shove the handle back down without pushing the j-hook release. The Johnson Bar shouldn't budge out of the latch.

I'm curious about your rigging issues. It really shouldn't be that difficult for a shop with the right tools to rig the gear if they follow the manual exactly to the letter. The gear should swing freely until about the last inch of movement. That last inch should by stiffer but still smooth.

Good luck.

[carusoam]

Adding to your challenge...

Airspeed makes a huge difference in the challenge of putting the gear up or down.

When you say it got easier and easier, it could be interpreted that you were going faster while putting it down.

If it is easy going up, you were going slow.

There are two speeds that make it near effortless to put the gear up and down.

Don't use this judgement to tell anything about how well the gear is rigged. The book procedure is the only way I know it is done correctly.

Get the book. Get the tools. Have your mechanic follow the procedure for proper rigging...

Also take a picture of the down lock block, while the gear is up. It should be perfectly round. They wear over time. When it is egg shaped it causes problems.

From my M20C experience,

-a-

[MyNameIsNobody]

You have to pull down on the bar collar. If it is locked it will not unlock without pushing the thumb detent. I used to pull toward me, but this is not as effective as pulling down. Sorry to hear about your GUP. She will be better when back in the air. Hope your insurance gets sorted OK for you too.

[kommers]

Whatever is the outcome, we will not be flying this plane again. At this point I am not sure if my wife will overcome the shock and if she does there will be no 20C in my possession again.I will let the dust settle, count my financial and emotional losses then we decide if we are buying another plane or explore other ways of keeping ourselves busy in this life. And if it is another plane it is likely to be 20J

[DXB]

If the bar was not in the locked in position , its not preload , let this be a lesson to all the manual gear guys , If you don't know the thumbnail trick , you should learn it to save some grief....The agreed upon value in the policy is the value , no matter what you do to it , If you remove parts from the airplane , they can deny the claim.....

Sounds like something else important i don't know- what's the thumbnail trick?

[DXB]

Sounds like something else important i don't know- what's the thumbnail trick?

Never mind.  Mr. Maxwell has now educated me.  Guess I need to grow my right thumbnail out a bit??

http://www.donmaxwell.com/publications/MAPA_TEXT/Manual%20Gear%20Operation/LANDING_GEAR)OPERATION.HTM

[Parker_Woodruff]

And if it is another plane it is likely to be 20J

Even if it is an electric gear Mooney, the rigging and preloads should be properly handled IAW the maintenance manual or this event could still happen.

[Marauder]

Even if it is an electric gear Mooney, the rigging and preloads should be properly handled IAW the maintenance manual or this event could still happen.

I have a friend with a J that had a gear collapse for the preload issue. Whether electric or manual, they both need to be maintained correctly.

Sent from my iPad using Tapatalk

[Shadrach]

Gents,

 

I think it's going to be a J because his wife wants nothing to do with a manual gear airplane after the "gear failure", not because he thinks the electric gear is maintenance free.                                                                                                                                           

[kommers]

Here is an update: initially, my understanding was that FAA was going to finish its investigation today and it was a job for one investigator; at least I got that notion last Sunday. However, this incident apparently sparked quite an interest as today a whole FAA team of five  people was observed around the plane and they were inspecting the plane again, reviewing plane logs and interviewing CFI and mechanic. There were some FAA guys inspecting the plane yesterday as well. Something that doesn't look to me like  a thing that would draw such attention if it was an ordinaryJB pilot error overlooked by CFI...

[Shadrach]

Here is an update: initially, my understanding was that FAA was going to finish its investigation today and it was a job for one investigator; at least I got that notion last Sunday. However, this incident apparently sparked quite an interest as today a whole FAA team of five  people was observed around the plane and they were inspecting the plane again, reviewing plane logs and interviewing CFI and mechanic. There were some FAA guys inspecting the plane yesterday as well. Something that doesn't look to me like  a thing that would draw such attention if it was an ordinaryJB pilot error overlooked by CFI...

 

Never underestimate the FAA's ability to make a simple situation complex...

It's a shame it was reported at all, but it happened in the Delta and closed a runway.  At a smaller field it's likely they wouldn't have been called. I do not believe this incident meets the requirements for notification as written in CFR 49 part 830 and there was no legal reason to involve them. Even if there was a reporting requirement the NTSB would have jurisdiction which they could choose to cede to the FAA.

 

If the Johnson bar came out of its socket, the thumb latch was either not properly secured or the socket was so badly worn that it should have been deemed unairworthy.  I don't see any other way for this to go, responsibility lies with either the CFI or the last person who signed off the annual.

 

Perhaps the FAA will come come up with an alternate narrative like "design flaw in the system precludes some pilots form operating the gear" or maybe an SB/AD for the sockets.

[MyNameIsNobody]

Didn't the down socket just get replaced? Isn't this his plane? Can't you ask questions? Five...FIVE FAA on site for a GUP incident? Good grief, what a waste of resources. Was runway made of gold?

[MyNameIsNobody]

When will this country and in this case the GA flying public say "stop the waste of resources"!

No outrage ever from a unanimous voice saying "Ridiculous"!

[MyNameIsNobody]

Yep, I thought the same way. Well, I guess I have to bite the bullet and lose my new radio... the bad thing about the whole situation is that my mechanic just replaced JB socket a month ago because he found old one elongated. He just followed AD and installed that new fancy socket with J-hook. The reason for gear collapse seems to be in preload. I noticed that JB was lighter and lighter to operate with every flight but I thought it is   because JB was brand new and it was going through break-in. In reality, it was probably just worn-out bearings that my mechanic was going to replace in August during the annual, I just didn't survive to that point...

What is your planes total airframe time?

[kommers]

5600

[rbridges]

If it's a gear preload issue the Johnson bar would have remained locked. It's easy to put the Johnson bar in the gear down position without moving the collar up fully enough to truly lock the bar.

 

my gear up alarm saved me some potential embarrassment last Sunday.  I always engage the Johnson Bar and jiggle it to make sure it's seated; sometimes it won't do that last click without rocking it a little.  Anyway, I thought it was in 100%, and then I heard the alarm on base.  I don't know if the JB would have popped out or not, but I don't want to test it.  This thread actually came to mind after I landed.

[MyNameIsNobody]

my gear up alarm saved me some potential embarrassment last Sunday.  I always engage the Johnson Bar and jiggle it to make sure it's seated; sometimes it won't do that last click without rocking it a little.  Anyway, I thought it was in 100%, and then I heard the alarm on base.  I don't know if the JB would have popped out or not, but I don't want to test it.  This thread actually came to mind after I landed.

Pull done hard on the collar. If it is locked it is locked if not...re-lock

I too have gotten my gear warning on final. Not since doing collar pull down

[gsxrpilot]

Pull done hard on the collar. If it is locked it is locked if not...re-lock

I too have gotten my gear warning on final. Not since doing collar pull down

Damn! twice in one day.  I agree.

 

I've had the gear horn come on twice on me, both times a quick downward tug on the bar released it. Now I don't let go of the bar until I've given a couple of sharp downward pulls to ensure it's seated.  

 

If it's locked, it's locked.

[Shadrach]

I don't get it.  I can get my head around how one might get distracted miss the gear. I don't understand how pilot who is experienced with manual gear Mooneys doesn't seat the the J-bar in the recepticle until it's locked.  To me it is all part of the same motion the final click signals that the motion is compleat. It's not like there is no tactile signal that something is amiss...the thumb lock is very distinguishable.  I had it not catch on one occasion when a piece of carpet wedged in front of the J-bar. the bar went into the socket but without the familiar click. Gear came up, my copilot rectified the situation, gear down and the familiar click was heard and felt as always.

[Jerry 5TJ]

I have the two Mooney gear tools, and a calibrated torque wrench, and I've checked preloads a dozen times or more and still I find it a highly subjective test. Your finger must detect "first motion" of the over-center link. I can imagine a non MSC technician puzzling over the procedure.

If the preload values are not in the annual inspection notes I'd be wary.

PS. Replaced the downlock block in the "C" several years ago--4000 hours and it was worn to a grooved, oval mess.

[KSMooniac]

It could be that it was a nice weather day and the FAA office used the "investigation" as an excuse to get out of the office, too.    Or perhaps their manager made them get out into the field for some more experience.  

 

Hopefully everything concludes without undue drama.