Johnson bar landing gear

[drifter001]

Hello

Sorry if this is a duplicate post. I tried using the search function to filter out options but had no luck finding what i was looking for so here it goes. You guys with the Johnson bar, what or how do you confirm that your gear is down since the light on the panel just detects the position of the bar itself. So far ive been relying on thoughts and prayers but was curious if you guys are using other methods. Thanks in advance

[Rwsavory]

Pull down on the bar and make sure it’s locked in place. 

[Shadrach]

On 7/15/2022 at 11:10 AM, drifter001 said:

Hello

Sorry if this is a duplicate post. I tried using the search function to filter out options but had no luck finding what i was looking for so here it goes. You guys with the Johnson bar, what or how do you confirm that your gear is down since the light on the panel just detects the position of the bar itself. So far ive been relying on thoughts and prayers but was curious if you guys are using other methods. Thanks in advance

The bar is physically coupled to the gear. If it's in the down position, then the gear is as down as it is going to get. The real question is whether it is locked down.  Jbars have inherent tactile feedback with regard to the locking mechanism. The knurled handle telescopes, first contracting when it contacts the block and then expanding into the down lock causing the side button to depress and the snap back into the locked position. Kind of like opening an umbrella with a spring loaded pin. The umbrella can be open but not locked, the runner must be pushed until the user feels that satisfyingly click of the spring button hitting home.

[drifter001]

17 minutes ago, Shadrach said:

The bar is physically coupled to the gear. If it's in the down position, then the gear is as down as it is going to get. The real question is whether it is locked down.  Jbars have inherent tactile feedback with regard to the locking mechanism. The knurled bar telescopes, first contracting when it contacts the block and then expands into the down lock causing the side button to depress and the snap back into the locked position. Kind of like opening an umbrella with a spring loaded pin. The umbrella can be open but not locked, the runner must be pushed until the user feels that satisfyingly click of the spring button hitting home.

yup. one mental checklist i always do when extending the gear is pulling down on the handle to make sure it properly locks into place. i was just curious if theres anything else as a safety precaution in case say a link or something breaks where it would place the gear in an unsafe position

[hammdo]

Thumbnail check also

-Don

[Jerry 5TJ]

15 minutes ago, drifter001 said:

i was just curious if theres anything else as a safety precaution in case say a link or something breaks where it would place the gear in an unsafe position

If the various pushrods or couplings or the Johnson bar fail there’s no backup method to lock the gear down.  

[drifter001]

12 minutes ago, Jerry 5TJ said:

If the various pushrods or couplings or the Johnson bar fail there’s no backup method to lock the gear down.  

Right. But there’s no way of knowing that until you actually touch down and the gear collapses, right?

[EricJ]

1 hour ago, drifter001 said:

Right. But there’s no way of knowing that until you actually touch down and the gear collapses, right?

If the bar is properly locked in the block, the only way that will happen is if there is a serious, unusual mechanical failure in the gear, and, yes, you won't know until it actually happens.   This is true with electric gear, too, which just has a single down indicator light and a mechanical indicator in the floor that is the equivalent of indicating the position of the Johnson bar.

That type of failure is unlikely to happen with properly maintained gear.   It is a pretty rare occurance.

[steingar]

The electric gear is the exact same as the J-bar, there's just a motor instead of a stout right arm.  There are far greater things to worry about.

[ShuRugal]

2 hours ago, drifter001 said:

Right. But there’s no way of knowing that until you actually touch down and the gear collapses, right?

you would know, immediately, if any of those linkages failed while operating the gear.  It would make very loud "banging" noises, the feel of the resistance on the J-bar would change dramatically, and you would probably also experience trim issues.

Those linkages are not small components.  The way the gear extension mechanism is designed, those linkages bear the load of the weight of the airplane and are under significant load when cornering while taxiing (or if you land not in nose-to-tail trim).  They are beefy, would require tremendous force to break, and would release considerable energy upon breaking.

[ncflyer]

If I was looking to buy a single engine aircraft what would I buy ? I have owned several single and multi engine aircraft and I have learned a lot  about cost of ownership . I have lots of flight time and type ratings and I have learned many systems . The aircraft I would buy would be a mooney with a Johnson bar . The Mooneys are the most  efficient aircraft on the market and the Johnson bar is bulletproof . M20 c e f  with a Johnson bar would be my choice .

[ncflyer]

The c I owned the first thing I did to airplane was install new down lock . I would twist and shack the bar. this  would confirm down and locked. Old down locks wear and become egg shaped and this  will lead to trouble.

[Browncbr1]

Watch the thumb button click into place when you push the bar into the block.   Then verify by pulling down on the handle to make sure it doesn’t come unlatched.      I don’t pay much attention to the light, although my light did burn out one time and it was a no brainer to look at the bar.   I also unscrewed the red gear up light and put it into the gear down socket just to verify it was just the bulb before landing.  
 

consider a new block if the plane has higher total time with the original block.  

[Shadrach]

Just as a data point, I replaced my block ~3200hrs. I have no idea how many cycles that was but probably on the high side for the hours. We do a fair amount short trips and or pattern work in between long XCs. My up block was in better shape than the down block. Both were ready to be replaced but were nowhere near failure. 

 

[BlueMooneyOverKentucky]

I don’t know shoes from Shinola, but those blocks look fine to me. I’d guess the lost metal is no thicker than a coat of paint. Certainly no harm in replacing them, of course. 

[Shadrach]

19 minutes ago, BlueMooneyOverKentucky said:

I don’t know shoes from Shinola, but those blocks look fine to me. I’d guess the lost metal is no thicker than a coat of paint. Certainly no harm in replacing them, of course. 

If you zoom in on the down block (1st image) you can see the wear is off set and while not yet significant, is certainly worn .

[DXB]

On 7/15/2022 at 11:10 AM, drifter001 said:

Hello

Sorry if this is a duplicate post. I tried using the search function to filter out options but had no luck finding what i was looking for so here it goes. You guys with the Johnson bar, what or how do you confirm that your gear is down since the light on the panel just detects the position of the bar itself. So far ive been relying on thoughts and prayers but was curious if you guys are using other methods. Thanks in advance

Tugging on your Johnson repeatedly on base and final to relieve nervousness related to gearing up is a tried and true tradition among vintage Mooney pilots .   Unless the gear position sensing switch in the down lock block is perfectly adjusted (mine isn't), it can show green without the Johnson bar sleeve being fully locked in receptacle.  It's not a priority for me to fix - the gear position lights are a regulatory necessity but kinda stupid on these planes in my view.  The position of the bar itself along with manually ensuring it is fully locked down is all you need on these planes.  

[Utah20Gflyer]

Tug down on the locking sleeve to verify it's locked in position.  

[carusoam]

On 7/16/2022 at 11:33 AM, BlueMooneyOverKentucky said:

I don’t know shoes from Shinola, but those blocks look fine to me. I’d guess the lost metal is no thicker than a coat of paint. Certainly no harm in replacing them, of course. 

What we aren’t seeing in the pic of the down-lock block…..

There are two parts to the wear issue…

1) It’s nice oval egg shape….

2) A step that gets created down inside…

The egg and step interfere with the bar going in place…

Unfortunately, it feels normal… but it’s not locked…

 

If you see a new block… the hole is a perfect cylinder…

The worn shape and step, look like they are supposed to be there… don’t be fooled by the appearance…

Take a pic next time you are flying… 

 

Changing to a new block is pretty easy and low cost….

Thumbnail test works

Green light works 

Pulling down on the handle works

Use Mr. Reagan’s advice… trust, but verify…

 

As far as knowing if one wheel has left the team…. This has only happened a couple of times….

There are tools and procedures to follow to keep the gear rigged properly….

 

If you find yourself worrying about all three gear not being down and locked….

How do you feel about both flaps working together?

Both airlerons?

Proper maintenance and proper parts keep these working as expected…. With huge margins of safety….

The biggest gear issue MSers have… pilots not putting the gear down… electric or manual!

 

Gumps checks are important don’t skip them!

Best regards,

-a- 

[rrodriguzzi1]

Probably the first thing I will do to a manual gear system. Up and down lock blocks. It makes a world of difference and way safer. 

[carusoam]

Great pic of the down lock block!

the egg shaped hole with the ridge step in it is what causes the gear to go down, and NOT lock, on some occasions…

Best regards,

-a-

[rrodriguzzi1]

Operating the Johnson bar with old blocks is also extremely hard. With new blocks and properly rigged landing gear is way easier and safer. 

Edited August 22, 2022 by rrodriguzzi1