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n797mx
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Uneven Reverser Deployment, Is It Normal?

Mon Aug 27, 2012 8:05 pm

Today I was watching this video of an MD-11 landing and noticed that the reversers did not deploy simultaneously as normally seen on airliners. Is this a commonality in some cases, was the pilot doing this to correct for not being on center, or was he just clumsy and did not pull the reverser handles evenly?

The second landing is the one I am referring to:
http://www.youtube.com/watch?v=-KB9bDUKFJY
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XFSUgimpLB41X
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RE: Uneven Reverser Deployment, Is It Normal?

Mon Aug 27, 2012 10:23 pm

That looked pretty even to me... within a second of each other.
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wingscrubber
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RE: Uneven Reverser Deployment, Is It Normal?

Mon Aug 27, 2012 11:49 pm

Yep #3 reverser seems to deploy a couple of seconds before #1, with #2 out of camera shot.
My theory: either the reversers were manually activated out of sequence (most likely) or, because each thrust reverser is powered by a separate hydraulic system, if engine RPM was higher on engine #3, it would have higher available flow from the hydraulic pumps, which could have opened the right hand TR more quickly.
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CosmicCruiser
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RE: Uneven Reverser Deployment, Is It Normal?

Tue Aug 28, 2012 12:36 am

I think y'all are getting way too technical. I would say if you think about it or if you've ever held the reverse levers in your hand that it's very easy for the little fingers on no.3 to lift slightly before your other fingers pull #1 & #2. not a big deal. Also if the rpm were higher as one post suggests then the throttle would not be in idle and the reverser would not deploy. Sometime they can be a little more difficult than others in moving the levers.
 
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longhauler
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RE: Uneven Reverser Deployment, Is It Normal?

Tue Aug 28, 2012 1:47 am

Exactly, it's just a mechanical lever, and some are easier than others ... making one deploy quicker than the other. It is not normally a big deal. Heck, when you are dispatched with one reverser inop, you still use the other on landing or rejected take-off.
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mandala499
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RE: Uneven Reverser Deployment, Is It Normal?

Tue Aug 28, 2012 2:24 am

Hey, you can land without reversers (it's not included in the dispatch landing calculations)... so, what's the big deal? And these guys were just pulling idle reverse, which is a "just in case" you need the reversers at full if something goes wrong.

Nothing to see here... move along...   
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tb727
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RE: Uneven Reverser Deployment, Is It Normal?

Wed Aug 29, 2012 1:57 pm

That's also why we wait until you have all the deployed lights illuminated before you pull anything more than idle thrust in reverse.
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HAWK21M
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RE: Uneven Reverser Deployment, Is It Normal?

Thu Aug 30, 2012 8:24 pm

Quoting longhauler (Reply 4):
It is not normally a big deal. Heck, when you are dispatched with one reverser inop, you still use the other on landing or rejected take-off.

Exactly what I was thinking..............but a no go in rain though....out here.A monsoon SOP.

[Edited 2012-08-30 13:25:02]
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CosmicCruiser
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RE: Uneven Reverser Deployment, Is It Normal?

Fri Aug 31, 2012 12:49 pm

We can go with one inop AND on a contaminated runway but with a big weight penalty.

I landed the other night with no. 2 inop. F/O was flying, had no problems.
 
B777LRF
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RE: Uneven Reverser Deployment, Is It Normal?

Sat Sep 01, 2012 8:22 am

Sticky lever.

If memory serves me right the reverser on no. 2 is delayed until NLG touch-down. She can be a tricky bird to land, and comes in a bit on the fast side. Not that I'd say no to having a go, of course.
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