Johnson Bar latching problem

[dcrogers11]

Either I have grown decreasingly weak in the last few weeks or my Johnson Bar is getting harder to latch back into the gear down position.  My plan is to raise the plane on jacks and see what is going on and have the A&P check things out.  It has just started in the last few flights. Can the adjustment change that quickly.  We installed new disks on the two main gear in April and had done a fairly extensive check on the gear then.  I have no problem retracting the gear and is as easy as it always has been.  Any ideas or suggestions?

[MooneyMitch]

Hi Don.

I suggest that yes, put the plane on jacks and check the pre-load settings on both the main gear and the nose gear per the parameters in the manual for your specific Mooney. 

It is certainly possible something has changed, including the eccentric bushings on the nose gear.  Those little devils can cause all sorts of issues if not properly set, including making it more difficult to lock the bar in place due to excessive pre-load.

Of course, lubrication can affect things as well but I'm sure you've covered that with regular maint.

Let us know please as we are always wanting to know more about our beloved Mooney's.

 

[Hank]

Don't forget the [aluminum] dock that your handle locks into. Wear in that piece can be hard to notice but result in unlocking under load, something you don't want to experience.

[Seth]

Don-

When I had my Johnson Bar F model, I replaced one spring/bungie in the gear system and the aluminum block/dock where the handle locks gear down during my first annual.  It made a HUGE difference in the ease of working the gear.  And this is coming from someone who had shoulder surgery about a year and a half ago (I was worried I was going to have to sell my plane if my shoulder didn't like working the gear anymore - ended up not being a problem at all).

As it turns out, the block was pretty worn, but the bungie is what made the largest difference according to the MSC.

It should be an easy fluid motion.  If it's not, something is wrong - it should not be binding and you shouldn't be struggling at landing or take off speeds - if you are talking about retracting during a missed approach on an IFR flight plan or putting the gear down just before setup for the ILS, well, that's a different story and always needs a little more muscle.

Take care,

-Seth

[fantom]

So, the clain that a johnson bar is bulletproof is just another one of those:

I suspected it all the time :-)))

[carusoam]

Has the rug been changed or moved?  Anything (shell casings, lead balls, gunpoweder) caught between the rug and J-Bar?

The simple act of rug modernization can effect how easily the JBar goes to the floor....

Best regards,

-a-

[Seth]

Quote: fantom

So, the clain that a johnson bar is bulletproof is just another one of those:

I suspected it all the time :-)))

[carusoam]

"Has anyone ever heard of a Johnson Bar failure to extend? " - Seth

Seth,

You probably have a better chance of your right arm falling off inflight.

Best regards,

-a-

[Seth]

Well said

[Shadrach]

Quote: fantom

So, the clain that a johnson bar is bulletproof is just another one of those:

I suspected it all the time :-)))

[fantom]

Quote: Shadrach

[MooneyMitch]

For me, and just my opinion only, based on my experience with both for electric and manual for over 25 year, I like both and both have served us well.  Neither have ever failed for us.

With that said, I feel more confident in the manual system.  Simply because it is indeed more simple than the electric.

Just my 2 cents.

[knute]

Quote:

Has anyone ever heard of a Johnson Bar failure to extend?  Not that it failed on landing because it wasn't excatly locked in place with a worn block, but a Johnson Bar Mooney with the gear jammed up that could not even partially extend.  I have never heard of that.

[triple8s]

I think I read somewhere (maybe on Mooneyspace) that someone had misplaced a flashlight which was found when it had gotten into a place that interfered with the J-bar. (Maybe it was a screwdriver) Not sure but needless to say keep the area clear of things that could get in the way of the lever. Worst experience I ever had with the Johnson bar was when I was right seat with my friend/CFI, we were inbound to land and he was about to lower the gear, when I asked "Need a little nose down?" he said "yep" so I put my hand on the trim wheel right as he was coming up with the Johnson bar...................take my advice Dont do that! IT HURTS LIKE H _ LL!

[carusoam]

"I put my hand on the trim wheel right as he was..."  888

This doesn't happen on the 'lectric ones.  Cuz the trim is on the left yoke and the gear down switch is way up on the instrument panel......!

I'm with Mitch.  Both systems work well.  It seems how we use them is the bigger challenge.

Best regards,

-a-

[Shadrach]

Quote: fantom

[fantom]

....if you had the beginings of an issue with preload or a link out of adjustment, which system do you think would give you earlier warning?

[pinerunner]

In one case I remember reading of the handle of the Johnson flew off while retracting the gear.  My understanding (I haven't been able to find that post or site again) was that the head of the handle had worn away to the point that it broke loose and the spring-loaded mechanism shot it over the pilots shoulder.  I believe that with the help of the passenger the broken handle was located, stuck in place, the gear extended and latched, and decent gear down landing made. It made sense to me that that could happen sense its hard to be gentle with it when bringing the gear up and there would be metal on metal rubbing. With someone in the right seat it wouldn't be hard to inspect the head of that handle. I wish I knew where to get a replacement for it if it looks very worn out.

 

I think the Johnson bar is simple and easier to keep reliable than electric. But the word foolproof shouldn't be in our vocabulary, except as a dark joke.

[mooniac15u]

Nothing is completely foolproof.  The Johnson bar is still attached to a mechanical system and anything mechanical can fail.