practice emergency gear extensions

[Hank]

2 hours ago, Mooney Dog said:

I remember doing demonstration in a travel air and I want to say it was like 48 cranks to get the gear down. It worked, sure, but dam was it a pain. 

To lower the gear in my C, it's 52 cranks of the handle by my left knee . . . Did it once in the air during transition,  and finished lowering the gear once in the air after electrical failure on approach in actual (only about a dozen cranks until it wouldn't go any further). May have done it once on jacks at annual, but won't swear to it. This covers the period from June 2007 to now.

Know how your system works. You don't want your first time to be in the clouds near the ground, and by God you want to know that the gear is down and locked!

[WheelPantsOff]

Bumping this to the top, and asking specific to the J model:  is there any damaging effects to demonstrating an emergency gear extension or any required maintenance actions afterward to return to service?  The POH makes me think twice before wanting to attempt it and I am getting plenty of conflicting opinions from other (non-Mooney) pilots.

[Jerry 5TJ]

17 minutes ago, WheelPantsOff said:

asking specific to the J model:  is there any damaging effects to demonstrating an emergency gear extension or any required maintenance actions afterward to return to service?

There should not be, no. 

That said, the mechanism is not beefy and most of us prefer to demonstrate the procedure only with the plane up on jacks.   

[Fly Boomer]

1 hour ago, WheelPantsOff said:

Bumping this to the top, and asking specific to the J model:  is there any damaging effects to demonstrating an emergency gear extension or any required maintenance actions afterward to return to service?  The POH makes me think twice before wanting to attempt it and I am getting plenty of conflicting opinions from other (non-Mooney) pilots.

Different models have different procedures.  Unless you have a real emergency, I wouldn't do it in the air.  Practice once a year at annual.  Here is my checklist from my 252.  Emphasis is mine:

- If you are flying, slow down.

- Pull landing gear circuit breakers.

- Move gear switch down.

- Move manual gear extension latch forward, and move lever back to engage manual extension mechanism.

- Slowly pull "T" handle 1 to 2 inches to rotate clutch mechanism and allow it to engage drive shaft.

- Pull "T" handle 12 to 20 times and allow it to return until landing gear is down and locked as indicated by gear-down light.

- Stop when resistance is felt.

- Verify visual gear-down indicator (on floor) by viewing from directly above the indicator.

- Return manual gear extension lever to stowed and latched position.

- Before activating the electric gear actuator, pull belly panel, and verify that clutch mechanism has fully disengaged from drive shaft.

- If it was a real emergency, find out why gear failed, and fix it.
 

[Schllc]

Emergency gear extension is absolutely 1,000% something everyone should do at least once. 

I did mine during an annual and I am very glad because the procedure doesn’t really reflect well what is written in the poh, and had I had to do it under duress, I would have been confused and much less confident. 

[kortopates]

Different models have different procedures.  Unless you have a real emergency, I wouldn't do it in the air.  Practice once a year at annual.  Here is my checklist from my 252.  Emphasis is mine:
- If you are flying, slow down.
- Pull landing gear circuit breakers.
- Move gear switch down.
- Move manual gear extension latch forward, and move lever back to engage manual extension mechanism.
- Slowly pull "T" handle 1 to 2 inches to rotate clutch mechanism and allow it to engage drive shaft.
- Pull "T" handle 12 to 20 times and allow it to return until landing gear is down and locked as indicated by gear-down light.
- Stop when resistance is felt.
- Verify visual gear-down indicator (on floor) by viewing from directly above the indicator.
- Return manual gear extension lever to stowed and latched position.
- Before activating the electric gear actuator, pull belly panel, and verify that clutch mechanism has fully disengaged from drive shaft.
- If it was a real emergency, find out why gear failed, and fix it.
 

When pulling the handle to extend the gear it’s not actually correct to stop pulling when you feel resistance. Resistance increases at the end; especially when the gear is down and you are compressing the springs. So what is more correct is to slow down and watch the floor light indicator carefully to pull no further than causing the gear down light to illuminate. Pulling beyond this point can damage the gear extension tubes and pulling less than this wouldn’t provide the necessary pre-load on the springs to keep the gear down; especially if you side load it.


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[Fly Boomer]

36 minutes ago, kortopates said:

When pulling the handle to extend the gear it’s not actually correct to stop pulling when you feel resistance. Resistance increases at the end; especially when the gear is down and you are compressing the springs. So what is more correct is to slow down and watch the floor light indicator carefully to pull no further than causing the gear down light to illuminate. Pulling beyond this point can damage the gear extension tubes and pulling less than this would provide the necessary pre-load on the springs to keep the gear down; especially if you side load it.


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I have not done it in flight, so that may be different, but when extending the gear at annual, I could feel when it was coming up against resistance just like my POH predicted.

[RoundTwo]

1 hour ago, Fly Boomer said:

I have not done it in flight, so that may be different, but when extending the gear at annual, I could feel when it was coming up against resistance just like my POH predicted.

This topic was just discussed with Don Maxwell during a Mooney panel discussion. Don’s recommendation is to test emergency extension on jacks and never in flight. His reasoning is because it is a delicate mechanism, designed for use in emergencies, it is not designed for lots of use. Don’t take a chance of binding it extended because it can only be unbound on the ground. It’s just not worth the risk.

And as was stated above, stop as soon as the lights illuminate, not when resistance is felt.

[WheelPantsOff]

I'm glad this spurred discussion, but is there anything which states that there is a maintenance action required after its use for a non-gear emergency/just demonstrating the extension procedure?

[RoundTwo]

1 minute ago, WheelPantsOff said:

I'm glad this spurred discussion, but is there anything which states that there is a maintenance action required after its use for a non-gear emergency/just demonstrating the extension procedure?

I don’t believe so. The concern is binding caused by over extending. If done properly, meaning stopping at the correct point, it should be fine. 

[A64Pilot]

My opinion is if your doing it in flight, slow to into the white arc especially if you have lower gear doors on, pull cb of course place gear switch down, shouldn’t matter with cb pulled, unlock the handle and slowly pull the slack out then pull up not particularly fast, repeat but take slack out at first every time just like you do when starting a weed eater, but do not snatch of course like you do the weed eater.

I won’t check it in flight myself, just don’t see the upside, parts for this thing I believe are pretty much non existent.

The gear actuator is the one part that worries me about the airplane, what’s the plan when one breaks? Is there anywhere that can overhaul one?

I’m speaking Eaton actuator on the J

[Fly Boomer]

30 minutes ago, WheelPantsOff said:

I'm glad this spurred discussion, but is there anything which states that there is a maintenance action required after its use for a non-gear emergency/just demonstrating the extension procedure?

Check with DMAX — he will know.

[Hank]

6 hours ago, Schllc said:

Emergency gear extension is absolutely 1,000% something everyone should do at least once. 

I did mine during an annual and I am very glad because the procedure doesn’t really reflect well what is written in the poh, and had I had to do it under duress, I would have been confused and much less confident. 

My C has the hand crank on the sidewall rather than the lawnmower pull cord. I did one extension in the air during initial transition, and a partial extension after total electrical failure in the air during VOR-A approach in the mountains several years later. It was not a big deal, but the CFII beside me thought it was.

I cranked the gear down the rest of the way, only about the last 10 turns of the 50 required, checked the floor indicator, then dug the Owners Manual out for both of us to check.

The moral of the story:  do it at least once. No special inspection or maintenance is required afterwards. If you need it for real, having done it before will take the edge off of your worry, as it's pretty simple.

[EricJ]

On 6/24/2023 at 3:58 PM, WheelPantsOff said:

I'm glad this spurred discussion, but is there anything which states that there is a maintenance action required after its use for a non-gear emergency/just demonstrating the extension procedure?

No, the M20J SMM covers this in section 32-31-05, which covers testing the emergency system for both the pull and crank type systems.

[kortopates]

I'm glad this spurred discussion, but is there anything which states that there is a maintenance action required after its use for a non-gear emergency/just demonstrating the extension procedure?

The key point and reason for Don’s statement is that doing in the air demonstrations of the manual gear extension procedure is a fools errand.
Years ago the Mooney PPP’s used to do these but learned the hard way that occasionally it would reveal a Mooney with deferred maintenance on the gear and problems would arise with the gear getting stuck partially extended with the only choice to land gear up or partially extended. After the third such incident at a PPP a policy of no manual gear extension demonstrations was adopted.
It’s a big risk that is totally avoidable by doing the procedure on ground at every annual.


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[A64Pilot]

On 6/24/2023 at 5:24 PM, Fly Boomer said:

I have not done it in flight, so that may be different, but when extending the gear at annual, I could feel when it was coming up against resistance just like my POH predicted.

I did it in flight a couple of times, but almost 30 years ago. but the lower gear doors were removed for some reason (trainer aircraft, but prohibited from grass)

Just looking at the lower gear doors it’s my belief that in flight they are going to be pulling down quite hard, how hard being airspeed dependent of course, if that’s correct then maybe the opening pull may override at least partially the over center springs?

If I’m right then lower gear doors would make retraction of a J bar airplane really tough.

[PT20J]

Also, keep in mind that the system  manually rotates the motor so it only protects against electrical component failures. It won’t help if the failure is mechanical.