Johnson Bar Stuck!

[MBDiagMan]

I had quite a takeoff at a towered field today!

i got off the runway and I couldn't get the bar down out of its socket.  I pushed the button while pulling down and wrestled with it a number of times.  As if that weren't bad enough, a wasp appeared flying around the windshield area and dive bombed me a few times.  I told the tower a wasp is in the cockpit and I am coming back around.  Very little traffic so they were good about it.  I came back, gear down, and got the wasp out and took off again.

i got up again and wrestled trying to get the Johnson bar out of the socket.  I finally got it out and the handle went to the floor easily.  I don't understand what is up that the bar would not go straight down.  I pushed and pulled on it with the button depressed trying to relieve side pressure. 

Dont know what to make of it.

[1964-M20E]

was something jammed between the bar and the wheel well with the gear in the down position?

 

You might want to get it up on the jacks and double check it and make sure everything is well greased.

 

 

[RLCarter]

Maybe some motion lotion is in order?

[Hank]

When was the aluminum socket it locks into the panel in replaced? Look in the logs. Does it look new or 50 years old? LASAR makes replacements, they usually release on the ground when they get worn . . . .

[DAVIDWH]

Don't understand Johnson bars and they are considerable above my pay grade, I just move a small wheel like switch and task is finished.

However, I can be of some help with those pesky burning wasp stings. Wasp venom is a three carbon propionic acid. (I didn't always sleep in class)

As everyone remembers those equations from organic chemistry, an acid plus a base yields a salt plus water.

Hence, propionic acid plus baking soda yields, you got it no more burning and problem solved.

Best,

[BDPetersen]

Get it up on jacks. Check the down lock pressure settings with the special tools and torque wrench. They may be too high. Then unlock the bar and inspect the inside of the latch receptical for a groove worn into the aft portion. Replacement latch available from LASAR.  Both issues will make unlatch into unpleasant.

[gsxrpilot]

It's sounds like the block might be out of round. They get that way after 30 years of use or so. It's not really easy to look at it while on the ground as the Jbar is in the block. But it would be worth it to stick your head under there and take a look at the fit. You can also use your phone to take a picture of it while in flight. If it's in the budget you might just go ahead and replace it.

[Bob_Belville]

3 hours ago, MBDiagMan said:

I had quite a takeoff at a towered field today!

i got off the runway and I couldn't get the bar down out of its socket.  I pushed the button while pulling down and wrestled with it a number of times.  As if that weren't bad enough, a wasp appeared flying around the windshield area and dive bombed me a few times.  I told the tower a wasp is in the cockpit and I am coming back around.  Very little traffic so they were good about it.  I came back, gear down, and got the wasp out and took off again.

i got up again and wrestled trying to get the Johnson bar out of the socket.  I finally got it out and the handle went to the floor easily.  I don't understand what is up that the bar would not go straight down.  I pushed and pulled on it with the button depressed trying to relieve side pressure. 

Dont know what to make of it.

Unlike Hank, I've been yanking on J'Bars for many years and more than 2500 flight hours. 

•  My first thought is that the capture pin is not being released. The thumb button is a little awkward and it must be pressed in completely to free the sleeve. Try pushing in on the handle as you push the pin to allow the pin to move without friction. If you can get the plane on jacks you can play with it until you figure out exactly what's happening.
• I work pretty closely with my A&P who is a MSC. The Mooneys that have J'Bars are all about 50 years old and probably half of them have lock down blocks that are worn enough they should be replaced. 

[Guitarmaster]

15 minutes ago, DAVIDWH said:

Don't understand Johnson bars and they are considerable above my pay grade, I just move a small wheel like switch and task is finished.

However, I can be of some help with those pesky burning wasp stings. Wasp venom is a three carbon propionic acid. (I didn't always sleep in class)

As everyone remembers those equations from organic chemistry, an acid plus a base yields a salt plus water.

Hence, propionic acid plus baking soda yields, you got it no more burning and problem solved.

Best,

Are you speaking Latin?

[HRM]

I replaced the block for mine (after 50 years) last annual. Tight and smooth as a ... now.

<...> fill in to your comfort level with cockpit humor.

[HRM]

Just now, Guitarmaster said:

Are you speaking Latin?

He is just showing off. After getting a D in organic I decided to go electrical engineering...so much easier.

[takair]

Mine can be a little tight.  If someone else flies the plane they seem to have the problem described. What I find myself doing is first applying slight forward pressure to the bar, then pushing the thumb release, then pulling down on the slide (while still applying slight forward pressure), and then swinging the gear.  I notice that those unfamiliar try to start swinging the gear too early, thus making it tough to unlock.  The more frustrated you are, the harder to get it unlatched.  My block shows some signs of wear and is on the list for this years annual.

[DonMuncy]

9 minutes ago, HRM said:

He is just showing off. After getting a D in organic I decided to go electrical engineering...so much easier.

If you think organic was bad, try biochemistry.

[1964-M20E]

20 minutes ago, HRM said:

He is just showing off. After getting a D in organic I decided to go electrical engineering...so much easier.

skipped organic chemistry, biology and went straight to electrical engineering but ultimately took the scenic route through college I was having too much fun AFROTC and getting my pilot license.  In the end not pilot slot in the USAF .  Chemistry 1 and 2 were enough though we did make aspirin in one of the labs but it still didn't get rid of the headaches.

 

 

[DAVIDWH]

Not sure about you electrical engineering majors.

That E=IR Ohms law formula sort of flummoxed me.

I think the Brits say Gobsmaked??

[Hank]

32 minutes ago, 1964-M20E said:

skipped organic chemistry, biology and went straight to electrical engineering but ultimately took the scenic route through college I was having too much fun AFROTC and getting my pilot license.  In the end not pilot slot in the USAF .  Chemistry 1 and 2 were enough though we did make aspirin in one of the labs but it still didn't get rid of the headaches.

 

 

Freshman chemistry kicked my tail, but just like Circuits I and Electromagnetic Physics, I made an A in the lab. The work is very doable, it's just the theory and paperwork that twist my pointy little mindy into strange shapes. Mechanical is where it's at . . . Hand me a pile of parts and I can usually finesse them together the right way, even without knowing what it's supposed to be. Maybe that's part of why I've been getting paid to take things apart, fix them  and put them back together for so long . . . . Really makes my annuals pretty easy and great learning experiences, and I know the shape the plane is in.

[carusoam]

Happy Friday everybody!  

Summary:

1) Lots of wear can effect how well the lock down block works.

2) Oval shaped holes are bad.

3) Replacement blocks are low cost and readily available. Check in with Lasar...

4) it's probably not as bad as it seems, proper cleaning and lube may help.

5) Shooting a selfie of the hole while in flight is a great idea.

6) A good way to know it is working properly, and a good way to get practice, and a good way of inspecting the whole thing is done while the plane is on jacks.

7) There is one reported problem that you don't want to have...  This is the one where the chrome handle falls off in flight.

8) the important nut holding the assembly together is visible through a hole in the J-bar itself, just a few inches below the chrome handle. Probably want to get a picture of that too...

9) The challenge of testing this on the ground, is it can be expensive...

10) The challenge of failed testing in flight, is it can be more expensive...

11) Organic chemistry... I asked the professor about one of the standard organic reactions, his reply... 'you have read the Bible, and still you don't know who Jesus Christ is...'. Very funny, Dr. Manhas, I'm poking fun at you now...  

12) Two semesters of O chemistry, followed by P chem, just to get a look-see at polymer chemistry.

13) Pilot slots available to AFROTC students, very few.  Everybody in the class competing for a couple of slots. If you don't get a slot... have a look at Missile Command... Movies get made about the guys who fly planes, on carriers, close to a famous city... not so much for the two guys, underground, with a pair of keys, in middle America.

14) there is an odd thing that some people have missed along the way...  make sure the J-Bar is locked in place for landing...

15) The locked down test is something called the thumbnail test.  Believe it or not, you use your thumbnail to perform the test.

16) Having difficulty sleeping thinking about this issue... read up on the light cycle, dark cycle, light converted to sugar, and Kreb cycle ADP converted to ATP and back with the release of energy. Bio chemistry is hard, but really good for sleeping!

Aaaah, the memories.  Let me know if I missed anything.

PP thoughts only, not a Scientist or mechanic...

Thanks for sharing,

-a-

 

[mike20papa]

I would suspect the gear preload is TOO high - if all other inspections do not reveal a worn part or loose fastener.  When you lower the gear, does it get stiff just before it goes into the socket and lock, or does it swing down and engage the locking socket easily?  It should not have to be forced the last degree of swing into the socket.  Put the AC up on jacks and check the preload. 

[jdawg]

Had mine release from retracted in air, you never forget that whack in the elbow......

[mooniac15u]

I took organic chemistry and liked it so much I got a Ph.D. 

Wasp and bee venoms are somewhat more complex than simple organic acids. In fact wasp venom is slightly alkaline so baking soda probably won't have the desired effect. 

[MBDiagMan]

Thanks for all the feedback.

Once I manage to get the bar to release from the block and get it to go down shorter, the gear actuates beautifully.  The problem is all in the lock block.  I did indeed push, pull, shake and everything else trying to get it unlatched.  

I have a plan.  After I learned that both planes would not fit in my hangar, my Cessna 140 was out in the weather for a few days before I managed to get a hangar at the field where my Mooney mechanic is located.  I put the 140 in that hangar.  At first opportunity I will swap hangars and put the Mooney on field with the Mooney mechanic.  He can jack I t up in my hangar and we can get to the bottom of it.  I think once the gear is safely extended I will see what the problem is, and of course my Mooney guy will have a handle on it.  He has flown and worked on Mooneys many years.

If there is even a remote need for a new block or anything else I will replace it.

BTW, I have flown the Mooney about 15 hours or so now, and am getting quite comfortable with it.  From where I sit, it is just not the quirky handling, impossible to land without being trained by someone with a PhD in Mooney flying, as some people seem to believe.  The wasp and the gear problem of yesterday have been the worst things I have dealt with.  I am even getting comfortable with the 430 now.

Thanks again for all the information.  I will report back what I come up with.

[Chocks]

From where I sit, it is just not the quirky handling, impossible to land without being trained by someone with a PhD in Mooney flying, as some people wanted me to believe.

Agree 100%. Got the same bad info when I started. Good luck with your big Johnson.


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[Nokomis449]

Don't know if this has been mentioned yet but make sure no one has stuck a stick uf Beeman's gum up in the lock block.

[Marauder]

Thanks for all the feedback.
Once I manage to get the bar to release from the block and get it to go down shorter, the gear actuates beautifully.  The problem is all in the lock block.  I did indeed push, pull, shake and everything else trying to get it unlatched.  
I have a plan.  After I learned that both planes would not fit in my hangar, my Cessna 140 was out in the weather for a few days before I managed to get a hangar at the field where my Mooney mechanic is located.  I put the 140 in that hangar.  At first opportunity I will swap hangars and put the Mooney on field with the Mooney mechanic.  He can jack I t up in my hangar and we can get to the bottom of it.  I think once the gear is safely extended I will see what the problem is, and of course my Mooney guy will have a handle on it.  He has flown and worked on Mooneys many years.
If there is even a remote need for a new block or anything else I will replace it.
BTW, I have flown the Mooney about 15 hours or so now, and am getting quite comfortable with it.  From where I sit, it is just not the quirky handling, impossible to land without being trained by someone with a PhD in Mooney flying, as some people seem to believe.  The wasp and the gear problem of yesterday have been the worst things I have dealt with.  I am even getting comfortable with the 430 now.
Thanks again for all the information.  I will report back what I come up with.

Agree 100%. Got the same bad info when I started. Good luck with your big Johnson.


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I'm not sure what advice or what bad info you guys were given. I've owned my Mooney for 26 years and it is predictable until it isn't.

When it isn't, it is usually a self inflicted event. Taking off without the plane trimmed correctly, getting behind the power curve or landing too fast are the things that can make things interesting. I don't think there is a long time Mooney owner out there who doesn't have a story about "there was one time when...".

My worse experience early in my ownership, was getting behind the power curve while landing. I built a healthy respect after that event.


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[gsxrpilot]

20 minutes ago, Marauder said:

I'm not sure what advice or what bad info you guys were given. I've owned my Mooney for 26 years and it is predictable until it isn't.

When it isn't, it is usually a self inflicted event. Taking off without the plane trimmed correctly, getting behind the power curve or landing too fast are the things that can make things interesting. I don't think there is a long time Mooney owner out there who doesn't have a story about "there was one time when...".

My worse experience early in my ownership, was getting behind the power curve while landing. I built a healthy respect after that event.

 

 

But these things apply to any airplane. In any airplane, it's important to stay ahead of the airplane, be an active participant, fly the plane, don't just ride along, etc, etc, etc. Mooney's certainly require more attention than a C172 or a Cherokee, but no more so than say a Bonanza, Cirrus, or Columbia. I've taken off in my Mooney completely out of trim, I've landed at 90kts, I've gone around with full up trim, gear out, flaps down, it's a non-event. Granted, I have no Long body experience, but in my short body C and the mid-body K, it was the same. 

Pay attention and fly the airplane... works in the Mooney just like every other piston single I've flown.