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kimon
Topic Author
Posts: 252
Joined: Mon Nov 23, 2009 2:37 pm

Questions about spoilers.

Tue Mar 02, 2010 4:43 pm

I thought the spoilers deployed with idle, not reverse thrust.
What is the deal?
Many thanks!
 
vikkyvik
Posts: 12679
Joined: Thu Jul 31, 2003 1:58 pm

Questions about spoilers.

Tue Mar 02, 2010 5:00 pm

Quoting kimon (Thread starter):
I thought the spoilers deployed with idle, not reverse thrust.
What is the deal?

Far as I know on typical airliners, when set to auto-spoilers, they automatically deploy on touchdown (through weight-on-wheels sensors or something).

Where did you hear that they deployed on thrust reverser activation?
 
AutothrustBlue
Posts: 47
Joined: Mon Feb 15, 2010 2:37 am

Questions about spoilers.

Tue Mar 02, 2010 5:11 pm

On the 737NG, the spoilers will deploy if the following conditions are met:

SPEED BRAKE lever is in the ARMED position
•SPEED BRAKE ARMED light is illuminated
•Radio altitude is less than 10 feet
Landing gear strut compresses on touchdown
Note: Compression of any landing gear strut enables the flight spoilers to
deploy. Compression of the right main landing gear strut enables the
ground spoilers to deploy.
•Both thrust levers are retarded to IDLE
•Main landing gear wheels spin up (more than 60 kts).

For the A320/30/40:

Which can be read as: If ((Ground spoilers armed AND TLs at idle) OR (One TL in idle AND (Other TL in rev OR idle)) AND (MLG wheel sped > 72 kts OR Fligh to ground transition memorized)), then spoilers will deploy.  faint   Smile

To answer your question, spoilers can deploy with thrust levers at idle, provided other conditions are met.

Regards

[Edited 2010-03-02 09:24:23]
 
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Jetlagged
Posts: 2564
Joined: Sun Jan 23, 2005 3:00 pm

Questions about spoilers.

Tue Mar 02, 2010 7:25 pm

On many airliners deploying the thrust reversers will automatically deploy the ground spoilers, whether they are armed or not. Thus it is a backup in case the crew do not arm the spoilers before touchdown, or if auto spoiler does not work. Moving the thrust levers significantly forward of idle will automatically stow the ground spoilers. This is to cater for the go-around case.
 
flymatt2bermud
Posts: 551
Joined: Tue Jan 31, 2006 11:58 am

Questions about spoilers.

Tue Mar 02, 2010 7:41 pm

Quoting jetlagged (Reply 3):
Moving the thrust levers significantly forward of idle will automatically stow the ground spoilers. This is to cater for the go-around case.

An aborted landing attempt (unplanned go around following touchdown) after the Thrust Reversers have been deployed, yikes. I am not saying they can't happen, it would require a great amount of justification. Our SOP prohibits an attempted takeoff after touchdown (if T/R's have been deployed). However, the PIC can always declare an emergency and deviate as necessary to the extent to meet the safety requirements of the situation. But from a practical aspect, I hope there are thousands of feet of runway remaining or odds are the aborted landing will end up written up as an attempt.
 
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Jetlagged
Posts: 2564
Joined: Sun Jan 23, 2005 3:00 pm

Questions about spoilers.

Tue Mar 02, 2010 8:51 pm

Quoting flymatt2bermud (Reply 4):
An aborted landing attempt (unplanned go around following touchdown) after the Thrust Reversers have been deployed, yikes. I am not saying they can't happen, it would require a great amount of justification. Our SOP prohibits an attempted takeoff after touchdown (if T/R's have been deployed). However, the PIC can always declare an emergency and deviate as necessary to the extent to meet the safety requirements of the situation. But from a practical aspect, I hope there are thousands of feet of runway remaining or odds are the aborted landing will end up written up as an attempt.

I didn't mean to suggest you might go around after T/R deployment. But after touchdown, with spoilers extended, advancing the throttles will stow the spoilers automatically.
 
flymatt2bermud
Posts: 551
Joined: Tue Jan 31, 2006 11:58 am

Questions about spoilers.

Tue Mar 02, 2010 9:02 pm

Quoting jetlagged (Reply 5):

I didn't mean to suggest you might go around after T/R deployment

Well if I wouldn't have been jet lagged when I read it I would not have responded. Sorry about that!  
 
boeingfixer
Posts: 573
Joined: Fri Jul 29, 2005 2:02 am

Questions about spoilers.

Tue Mar 02, 2010 10:43 pm

There's also RTO (Refused Take Off) auto spoiler deployment. On the Boeings I've worked on, the B727and B737, this is armed with wheel speeds above 60 knots and the reverse levers placed in idle reverse. This manually moves the spoiler lever into the Armed position allowing the auto spoiler system to deploy full flight and ground spoilers.

This is slightly different on the B757 and B767 which rely on bogey tilt for ground sensing to allow the RTO system to function.

Cheers,

John
 
kimon
Topic Author
Posts: 252
Joined: Mon Nov 23, 2009 2:37 pm

Questions about spoilers.

Wed Mar 03, 2010 6:08 pm

http://www.youtube.com/watch?v=EgeT-F9-1KI

Quoting vikkyvik (Reply 1):
Quoting vikkyvik (Reply 1):
Where did you hear that they deployed on thrust reverser activation?
 
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Web500sjc
Posts: 893
Joined: Tue Sep 15, 2009 4:23 am

Questions about spoilers.

Wed Mar 03, 2010 6:19 pm

Spoilers can also be deployed manually or in flight.
 
David L
Posts: 8551
Joined: Tue May 18, 1999 2:26 am

Questions about spoilers.

Wed Mar 03, 2010 8:36 pm

Quoting kimon (Reply 8):

What are we looking/listening for in that clip?
 
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Jetlagged
Posts: 2564
Joined: Sun Jan 23, 2005 3:00 pm

Questions about spoilers.

Thu Mar 04, 2010 8:26 pm

Quoting David L (Reply 10):
What are we looking/listening for in that clip?

It's the comments posted with the clip I think kimon is referring too. Tech/Ops it isn't.  
 
David L
Posts: 8551
Joined: Tue May 18, 1999 2:26 am

Questions about spoilers.

Thu Mar 04, 2010 8:30 pm

Quoting jetlagged (Reply 11):
It's the comments posted with the clip I think kimon is referring too. Tech/Ops it isn't.

Ah... right. Well, that's 5 minutes of my life I'm not getting back!
 
mandala499
Posts: 6600
Joined: Wed Aug 29, 2001 8:47 pm

Questions about spoilers.

Fri Mar 05, 2010 7:43 am

Quoting AutothrustBlue (Reply 2):
For the A320/30/40:

I'm just going to be picky for the fun of it...   "you missed some parts!!!!" (just pulling your leg!!!!)



Need to add on the 737NG... reverse thrust at wheelspin speed >60kts also deploys the ground spoilers even when not armed. Plus when armed, no wheelspin is detected, the ground spoilers will deploy when your right MLG is compressed.

Quoting kimon (Thread starter):
thought the spoilers deployed with%uFEFF idle, not reverse thrust.

As jetlagged said, activation on the ground through reverse thrust at high speed is just and added safety feature. This is to cover for the unlikely case of the groundspoiler entering a disarmed condition at anytime during arming and touchdowm (with all other conditions met).

I think on the E170/190, one does not need to arm the ground spoilers... Speed above X knots ground speed and throttles idle and wheels on the ground = those walls come up... plus the same reverse thrust for deployment backup method too.

Quoting kimon (Reply 8):
http://www.youtube.com/watch?v=EgeT-F9-1KI

0:25 Groundcontact/touchdown
Armed speedbrake lever moves to the up position, confirmed by:
0:27 "Speedbrakes up"
0:30 nosewheel contact/derotation complete.
I only heard the audible signs of the reverse being deployed at about 0:31 onwards or so.

Mandala499
 
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HAWK21M
Posts: 30175
Joined: Fri Jan 05, 2001 10:05 pm

Questions about spoilers.

Fri Mar 05, 2010 10:17 am

The B732/B752 has the option during Rejected T/O,in case the speed brake lever is not armed,movement of the thrust reverser can mechanically lift the speed brake lever off the down detent & electrically operate the lever aft.

regds
MEL.
 
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Starlionblue
Posts: 20861
Joined: Fri Feb 27, 2004 9:54 pm

Questions about spoilers.

Fri Mar 05, 2010 10:32 am

Quoting David L (Reply 12):
Ah... right. Well, that's 5 minutes of my life I'm not getting back!

Never EVER read youtube comments. EVER!!!!

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