Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Spoiler Deployment  
User currently offlineHighFlyer9790 From United States of America, joined Jul 2005, 1241 posts, RR: 0
Posted (7 years 6 months 5 days ago) and read 3023 times:

Hey everyone-

Im just wondering about the connection from the spoiler handle in the cockpit to the actual spoilers. On a boeing aircraft, the spoilers have some kind of a mechanical connection to the handle where as airbus is completely electrical? if thats the case, then if a pilot moves the handle to the full flight detent position very fast in a boeing, will the spoilers go up just as fast? could the be damaging to the spoilers? With airbus, ive noticed the deployment seems a lot smoother than boeing's- becasue they always come up at the same speed regardless of the speed of the handle? (not talking about auto deployment on landing- just about the manual deployment on descent)

thanks a bunch!

highflyer


121
5 replies: All unread, jump to last
 
User currently offlineValkyrie01 From United States of America, joined Mar 2007, 72 posts, RR: 0
Reply 1, posted (7 years 6 months 4 days 16 hours ago) and read 2948 times:

Quoting HighFlyer9790 (Thread starter):
Im just wondering about the connection from the spoiler handle in the cockpit to the actual spoilers. On a boeing aircraft, the spoilers have some kind of a mechanical connection to the handle where as airbus is completely electrical?

I hope this does not turn into an A vs B, personally i get tired of those.
As for A/C you did not specify which ones. 757/767 spoilers are electonically controlled and hydraulic operated. The 777 operates the same way and they called it FBW. As far as mechanical control to the speed brake lever/spoiler handle there is a control rod that is attach to the speed brake mechanism which includes lvdt(757/767) rvdt(777) etc etc.As for AB i am sure there as to be a control rod or some other mechanical connection on the speed brake lever,but i could be wrong.

Quoting HighFlyer9790 (Thread starter):
if thats the case, then if a pilot moves the handle to the full flight detent position very fast in a boeing, will the spoilers go up just as fast? could the be damaging to the spoilers?

The spoilers increase drag and decrease the amount of lift the wing supply,yeah the spoilers will go up just as fast on the A/C i mention above.

Quoting HighFlyer9790 (Thread starter):
With airbus, ive noticed the deployment seems a lot smoother than boeing's- becasue they always come up at the same speed regardless of the speed of the handle?

When i ops chk spoilers they seem to deploy at the same speed unless an actuator is not working properly



The best there is the best there was the best there ever will be
User currently offline411A From United States of America, joined Nov 2001, 1826 posts, RR: 8
Reply 2, posted (7 years 6 months 3 days 22 hours ago) and read 2867 times:

L1011.

Pull the spoiler handle up rapidly, the spoilers extend radidly.

Pull the spoiler handle up slowly, spoilers extend slowly.

No specific speed limit for spoiler use on this type, and indeed little if any pitch change is noted with spoiler use.


User currently offline474218 From United States of America, joined Oct 2005, 6340 posts, RR: 9
Reply 3, posted (7 years 6 months 3 days 19 hours ago) and read 2828 times:

Quoting 411A (Reply 2):
L1011.

Pull the spoiler handle up rapidly, the spoilers extend radidly.

Pull the spoiler handle up slowly, spoilers extend slowly.

No specific speed limit for spoiler use on this type, and indeed little if any pitch change is noted with spoiler use.

411A,

The spoilers on the L-1011 will actually blow down, not all the way down but to a specific point for each individual spoiler panel, if the the spoilers are deployed at too high a speed.


User currently offline411A From United States of America, joined Nov 2001, 1826 posts, RR: 8
Reply 4, posted (7 years 6 months 3 days 16 hours ago) and read 2773 times:

Indeed so, 474218...quite a nice design, unlike some early Boeing designs that I have flown...especially in the no pitch change arena.
Lockheed did it right.


User currently offlineJetlagged From United Kingdom, joined Jan 2005, 2556 posts, RR: 24
Reply 5, posted (7 years 6 months 3 days 14 hours ago) and read 2760 times:

Quoting HighFlyer9790 (Thread starter):
On a boeing aircraft, the spoilers have some kind of a mechanical connection to the handle where as airbus is completely electrical? if thats the case, then if a pilot moves the handle to the full flight detent position very fast in a boeing, will the spoilers go up just as fast? could the be damaging to the spoilers?

In older Boeings it's a mechanical connection to a speedbrake/spoiler mixer system to a hydraulic actuator on each panel. This will be rate limited to an extent, so even if you snap the speedbrake lever back quickly the spoilers can only move at their maximum rate, which can be modified at the design stage with flow restrictors. As for damaging them, all spoiler systems I know of are designed to blowdown so at high speeds they will deflect less. In "mechanical" systems this is usually achieved with pressure relief valves in the hydraulics. Clearly at higher speeds the spoiler rate will be reduced as well as the maximum deflection.

With FBW aircraft things are more complex. For example, on the A320 spoiler rate is affected by whether the autopilot is engaged or not. Maximum spoiler deflection is also limited if the autopilot is engaged. Even so, if you move the Airbus speedbrake lever slowly, the spoilers will only deflect slowly. The pilot still has the opportunity to use finesse at the controls.



The glass isn't half empty, or half full, it's twice as big as it needs to be.
Top Of Page
Forum Index

Reply To This Topic Spoiler Deployment
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Asymetric Flap Deployment posted Thu Mar 8 2007 09:38:41 by StealthZ
Landing Gear Deployment posted Tue May 2 2006 06:42:33 by Slovacek747
Thrust Reverse Deployment posted Sat Aug 6 2005 19:50:56 by ANITIX87
A340-500 Thrust Reverser Deployment posted Sun Apr 3 2005 05:56:02 by Videns
757 Wing,flaps, And Spoiler Diagram posted Wed Mar 30 2005 21:14:12 by Jerplane
Reverser Deployment During Preflight posted Sat Jul 17 2004 23:43:26 by Doug_or
Spoiler / Airbrake Use 737-300 During Approach posted Mon Jan 12 2004 18:48:14 by Klm-md11
B737Classic Ground Spoiler Actuator posted Wed Sep 17 2003 07:54:35 by HAWK21M
Landing Gear Deployment posted Fri Sep 12 2003 10:14:04 by Ted747
L1011 Take Off With Spoiler Panel Up. posted Sat Aug 30 2003 10:31:13 by Cx flyboy

Sponsor Message:
Printer friendly format