Landing Gear Swing

[201er]

While my bird is still down for annual, I went in to get some video of the gear swing and to practice the manual gear extension. I don't practice it in the air but I try to do one every year while it is up on jacks. Here's a video with the whole process and detailed shots of electric and manual extension from different angles at the end.

 

I did screw something up some things and learned some. A more minor one was letting go of the gear override button before the gear was fully retracted. So I realized it's a "hold" button and not a "push" button. I think I knew this already but I wasn't sure so there was a moment I let it go and the gear stopped retracting and that confirmed to me that I'm not holding it for no reason the whole time.

Ran into a few issues during the manual gear extension. Certainly I followed the checklist and all but there was something the checklist would not help with. First one was just yanking the cord too hard. I remember from last time that it takes a bit of effort but my mechanic made a memorable comment to me, "you're not trying to start a lawn mower!" The bigger issue was how I did not go far enough to lock the gear down on the first try. I was staring at the mechanical indicator and kept going until the green lines lined up. I was using the indicator for cues for how much more to go but I also ignored the annunciator panel figuring one of the reasons for a manual gear extension is an electrical failure so this is how I would be doing it. When I thought I was done, the mechanic pointed to the annuciator and said it's not locked yet! Sure enough, the "Gear Down" light was not yet lit. One more pull and it was.

I learned a valuable lesson. Look for the light, feel for the click. Duh! I feel for the click every time I do a normal gear extension but for some reason I felt like manually moving it will be more subtle and smooth. No, the click is still there at the end. So even if the light doesn't illuminate and the indicator tells you you're down, feel for the click before assuming it's down and locked.

 

[N6758N]

Are you at AirMods Mike?

[201er]

10 minutes ago, N6758N said:

Are you at AirMods Mike?

Yup

[Marauder]

Hey! Post some more photos and do a video on your new interior. Saw in your video that you used a rug in between the seats. Like that idea. Wonder if there is more ideas I can steal.


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[kaba]

Thank you for sharing! Very informative!


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[Mooneymite]

Does Air Mods use the dreaded "Tied-down-Tail" method of jacking the plane?  

[Yetti]

I saw an engine hoist in one of the videos

[TonyK]

Neat video.  I liked the camera in the gear well shot.  

[carusoam]

Thanks for sharing the details, Mike.

Best regards,

-a-

[Yetti]

The newer E gear extension is interesting.   You always wonder what was going though the Engineers heads when they designed these things.   Just figuring out how all the tubes works is interesting to say the least.

 

[Andy95W]

Check out the manual gear sometime that has the "helper" pushrods and springs.  Even more impressive considering the balance when actuating the system.

[bonal]

Nice video, just a thought since I doubt you will be kneeling and half turned sideways while in flight. you might do it once again when the seats are back in and while doing what ever you would be normaly in actual flight. Body position will change your leverage also leaving your left on the yoke etc will be different. Just thinking while it's still on jacks. 

[201er]

1 hour ago, bonal said:

Nice video, just a thought since I doubt you will be kneeling and half turned sideways while in flight. you might do it once again when the seats are back in and while doing what ever you would be normaly in actual flight. Body position will change your leverage also leaving your left on the yoke etc will be different. Just thinking while it's still on jacks. 

Yeah, I've insisted on doing it that way on past years. 

[flyboy0681]

Until I saw the video from inside the well, I really had no idea how the whole mechanism worked. This was very informative.

Mike, you didn't mention anything about the light on the floor indicator, which is very important to look for in case the annunciator light fails to illuminate.

[201er]

7 minutes ago, flyboy0681 said:

Until I saw the video from inside the well, I really had no idea how the whole mechanism worked. This was very informative.

Mike, you didn't mention anything about the light on the floor indicator, which is very important to look for in case the annunciator light fails to illuminate.

I was looking at it and pointing to it the whole time. That's why I failed to have the gear locked the first extension because the lines lined up but the light didn't come on.

[RLCarter]

Several years ago when getting my E back in the air it was time for the gear swing for the A&P/IA. With him under the plane I was instructed to retract the gear, a few seconds later he was standing by the storm window asking if I could slow the swing (J-Bar) so he could actually see it go through the motion. He was amazed at how quick and smooth the gear worked, guess he was use to high wing Cessnas....lol

[kortopates]

Great write up and good for you practicing this. Very good points too about not yanking the cord too hard - we had one guy do this at a MAPA PPP years ago on the west coast and broke the cord! You don't want to see that happen One point of clarification though on the gear being down and locked when the light comes on since you bring up an excellent point of what will happen with a total electrical failure.

On 12/18/2017 at 8:38 AM, 201er said:

I was using the indicator for cues for how much more to go but I also ignored the annunciator panel figuring one of the reasons for a manual gear extension is an electrical failure so this is how I would be doing it. When I thought I was done, the mechanic pointed to the annuciator and said it's not locked yet! Sure enough, the "Gear Down" light was not yet lit. One more pull and it was.

I learned a valuable lesson. Look for the light, feel for the click. Duh! I feel for the click every time I do a normal gear extension but for some reason I felt like manually moving it will be more subtle and smooth. No, the click is still there at the end. So even if the light doesn't illuminate and the indicator tells you you're down, feel for the click before assuming it's down and locked.

Absolutely right about the light coming on to indicate the gear is fully down, but you have the light on the floor where the football; besides the lighted annunciator and afterall the floorboard football and light are the primary means of verifying the gear is down and locked rather than the annuciator. But its not really true the gear didn't lock down till the light came on. The gear actually locked down into place a good pull or more before the light actually came on. The Mooney light isn't triggered by a microswitch on the gear down link like some airframe are, but a single microswitch on one of the two the main gear tubes directly below the cockpit. After the gear is over center, its takes approximately another pull or more to compress the springs further to the desired pre-load. Its the pre-load on the springs that will prevent the gear from folding back up if it you side load the landing gear from imperfect cross wind landing technique or you take a turn off with too great of speed. The click you heard could only be the micro-switch clicking which was directly below you in the cockpit. But I doubt you could hear or feel this click in the air. So what does this all mean when lowering the gear with a total electrical failure? Without the light, you wouldn't be able to know precisely when you are at the proper pre-load setting. All we really have to rely on besides seeing the football centered is feeling the cord tension get much harder when the gear is down and we are compressing the springs with the final pull(s). But the springs aren't fully compressed when the gear is at the proper pre-loads either so its possible to keep going till the one of the springs reaches its limit first and is fully compressed or until the gear motor screw reaches it's limit. Which is beyond what you really want to do. So with no light to tell us (thankfully we have two bulbs) , be careful, go until the indicator shows the football is in place and stop after the pull that all of a sudden got real hard. Then land very gently being very careful not to side the load the gear any more than necessary till it can be properly inspected on jacks or at least re-cycled electrically on jacks to the proper pre-load. And there you have another reason of the importance of practicing this in the hangar on jacks to help get a sense of that last pull with the increased tension as the springs compress so you'll have an idea of what to expect should you have to do this for real with an electrical failure.

If you watch Mike's video of the gear extending by hand I think you'll be able to see the gear stop moving and then hear one more pull as the springs are compressed into the proper pre-load tension and close the microswitch.

Edited December 19, 2017 by kortopates

[Hank]

When I had a total electrical failure just after moving the gear switch on a VOR-A approach over hilly terrain (KGAS, Gallipolis, OH, on the WV border), everything shut off with the gear partially extended. I completed the manual extension from memory (engage lever, unfold handle and crank like an old car window) before digging out the Owners Manual for the CFII riding beside me.

No panel light to tell me when the gear was down, no radio to call ATC and report the problem, no transponder code for them to see my slow diversion home as I had just dropped off radar . . . So I turned the handle as far as possible without cranking down on it, maybe 20 turns (full extension is 52 turns). I landed gingerly, parked in the hangar and called  my friendly local A&P/IA.

[RobertGary1]

1 hour ago, Hank said:

When I had a total electrical failure just after moving the gear switch on a VOR-A approach over hilly terrain (KGAS, Gallipolis, OH, on the WV border), everything shut off with the gear partially extended. I completed the manual extension from memory (engage lever, unfold handle and crank like an old car window) before digging out the Owners Manual for the CFII riding beside me.

No panel light to tell me when the gear was down, no radio to call ATC and report the problem, no transponder code for them to see my slow diversion home as I had just dropped off radar . . . So I turned the handle as far as possible without cranking down on it, maybe 20 turns (full extension is 52 turns). I landed gingerly, parked in the hangar and called  my friendly local A&P/IA.

Did you have a flashlight to see the floor indicator? 

Maxwell wrote a report awhile back of emergency extensions not working in flight. He said that the splines on the manual cable at the gear box end will wear and will work well went not under load (gear swing) but not when the gear box has resistance (air load against the nose). So I've never felt 100% that my gear would extend in flight just because it does during a swing test.

-Robert 

[Hank]

55 minutes ago, RobertGary1 said:

Did you have a flashlight to see the floor indicator? 

Maxwell wrote a report awhile back of emergency extensions not working in flight. He said that the splines on the manual cable at the gear box end will wear and will work well went not under load (gear swing) but not when the gear box has resistance (air load against the nose). So I've never felt 100% that my gear would extend in flight just because it does during a swing test.

-Robert 

Negative on the flashlight; it was in my flightbag on the back seat, but we had popped out the bottom of the clouds 500-600' above the procedure turn, and it was daylight.

I've done two air extends in my plane, once during transition training and once for real above. The danger of wearing the spline comes from not disengaging the system before raising the gear electrically.

[RobertGary1]

3 minutes ago, Hank said:

Negative on the flashlight; it was in my flightbag on the back seat, but we had popped out the bottom of the clouds 500-600' above the procedure turn, and it was daylight.

I've done two air extends in my plane, once during transition training and once for real above. The danger of wearing the spline comes from not disengaging the system before raising the gear electrically.

Yea, or worse, the cable not fully disengaging and dragging on each electrical extension.

 

-Robert

[Yetti]

The splines you speak of. and the emergency disconnect.  It is actually a very well made unit.   Sits on the back of the gear motor