Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
A B744 LE Flaps While Braking, Again  
User currently offlineAvi From Israel, joined Sep 2001, 939 posts, RR: 6
Posted (12 years 2 weeks 4 days 2 hours ago) and read 4164 times:

A few weeks ago there was a discussion in here about the B744 Leading Edge (LE) flaps.
It was said that when the thrust reversers are active the inboard Kruger flaps (slats) and the midspan Variable Camber flaps are retracted as seen in the KLM picture.

View Large View Medium
Click here for bigger photo!

Photo © Peter Unmuth - Vienna Aviation Photography
View Large View Medium
Click here for bigger photo!

Photo © Lee Archer


Now here is a picture of a PIA B744 and as you can see the thrust reversers are active and ALL of the LE flaps (including the outboard Variable Camber flaps) are retracted. My questions are:

1) Is that an airline specific item (the outboard LE flaps)?
2) Does it have anything to do with the engines type?
3) Did the KLM picture was photo before the outboard LE flaps were retracted?
4) What does actually happen when the pilot activate the thrust reverser?

Thanks



Long live the B747
17 replies: All unread, jump to last
 
User currently offlineAamd11 From UK - Wales, joined Nov 2001, 1059 posts, RR: 1
Reply 1, posted (12 years 2 weeks 4 days 1 hour ago) and read 4074 times:

That is NO PIA 744! Cos afterall PIA dont have any 744s.
It is a 747-300 that they recently bought from Cathay Pacific.

Aside, i think that maybe the classic 747s have retracting LE flaps the whole length of the wing, my guess is Boeing decided it wasnt necessary for all of them to retract (or it was better that they didnt all retract), and so made it so only the inboard and midspans retracted.

A^A MD-11


User currently offlineJETPILOT From United States of America, joined May 1999, 3130 posts, RR: 29
Reply 2, posted (12 years 2 weeks 3 days 20 hours ago) and read 3982 times:

Your killing me here.....

Inboard Krueger.... FLAPS
Midspan.... SLATS

JET


User currently offlineHkgspotter1 From Hong Kong, joined Nov 2005, 0 posts, RR: 0
Reply 3, posted (12 years 2 weeks 3 days 19 hours ago) and read 3946 times:

Flaps / Slats,

They are just metal things that move about on the wing  Smile/happy/getting dizzy


User currently offlineJETPILOT From United States of America, joined May 1999, 3130 posts, RR: 29
Reply 4, posted (12 years 2 weeks 3 days 18 hours ago) and read 3920 times:

Not true... but if you want to be ignorant.... enjoy.

JET


User currently offlineMartinKoschel From Germany, joined Jun 2002, 14 posts, RR: 0
Reply 5, posted (12 years 2 weeks 3 days 13 hours ago) and read 3786 times:

JET: I agree......

Hkgspotter1: hope you're kidding on this. Here at High-Lift Systems Integration at Airbus we take our Job serious. Very serious. Thus, I have some difficulties with that kind of humor, sorry.
DOn't know if you're a technical person, but anyways: I recommend reading the Book "Aircraft Flight Control Actuation System Design" by E.T. Raymond and C.C. Chenoweth. Will give you some more insight. It's a nice overview.

-martin


User currently offlineShaun3000 From United States of America, joined Mar 2002, 445 posts, RR: 0
Reply 6, posted (12 years 2 weeks 3 days 12 hours ago) and read 3776 times:

I didn't think the 747s had slats, rather that they had Kreugers down the entire LE. They all fold out from under the LE. Do the outboard ones have a slot, thus making them a slat? I know that Kreugers don't have a slot between the flap and the LE.

User currently offlineFredT From United Kingdom, joined Feb 2002, 2185 posts, RR: 26
Reply 7, posted (12 years 2 weeks 3 days 10 hours ago) and read 3765 times:

The terminology in this area is messed up. Slats, slots, flaps... you'd get your head chewed off in some places for even daring to mention flaps as being among the LE devices. So I'd tread lightly on this one...

Cheers,
Fred



I thought I was doing good trying to avoid those airport hotels... and look at me now.
User currently offlineVC-10 From United Kingdom, joined Oct 1999, 3700 posts, RR: 34
Reply 8, posted (12 years 2 weeks 2 days 23 hours ago) and read 3721 times:
Support Airliners.net - become a First Class Member!

A -300 is a 200 with a stretched upper deck.

747 Classic leading edge devices do not retract on reverser selection. They did in the early days when the engines had turbine reversers but when they went so the LED retraction.


User currently offlineShaun3000 From United States of America, joined Mar 2002, 445 posts, RR: 0
Reply 9, posted (12 years 2 weeks 2 days 21 hours ago) and read 3699 times:

Clarification on my post:

When I say "they all fold out from under the LE" I'm referring to the LE devices on the 747s, not LE devices, in general.

Anyway, what do 747s have? I always thought they were Kreugers and I took an airframe class where the teacher agreed with me, but others said they were something different...


User currently offlineVC-10 From United Kingdom, joined Oct 1999, 3700 posts, RR: 34
Reply 10, posted (12 years 2 weeks 2 days 20 hours ago) and read 3688 times:
Support Airliners.net - become a First Class Member!

Ind of the inbd engines they are Krugar's

All the rest are Variable Camber Flaps


User currently offlineShaun3000 From United States of America, joined Mar 2002, 445 posts, RR: 0
Reply 11, posted (12 years 2 weeks 2 days 14 hours ago) and read 3641 times:

I am not familiar with variable camber flaps. Can you please explain to me what those are and briefly how they work? I have an idea of what they are from the name but I don't know how that would work.... haha

Thanks!  Smile


User currently offlineVC-10 From United Kingdom, joined Oct 1999, 3700 posts, RR: 34
Reply 12, posted (12 years 2 weeks 2 days 7 hours ago) and read 3624 times:
Support Airliners.net - become a First Class Member!

A Krugar Flap remains flat at all times

A VC Flap is flat when it is stowed but a camber is induced in it during deployment to provide more efficient low speed lift.

You will also notice a slot is formed between the flap and the wing LE to increase the aero' efficiency.






When the TE & LE flaps are fully deployed on a 747, lift is increased by 80% compared to the clean wing.


User currently offlineShaun3000 From United States of America, joined Mar 2002, 445 posts, RR: 0
Reply 13, posted (12 years 2 weeks 1 day 22 hours ago) and read 3581 times:

Ok, that's cool. So it actually bends the aluminum (or whatever material it uses) on the surface? Doesn't this lead to increased wear?

User currently offlineAJ From Australia, joined Nov 1999, 2386 posts, RR: 24
Reply 14, posted (12 years 2 weeks 1 day 13 hours ago) and read 3558 times:

I believe the B747-400 VC flap is composite. I've observed them being extended in the hanger with only pneumatic power to the flaps (TE weren't being run) and they groan as they extend. Fortunately engine noise normally masks this noise!
JETPILOT: My -400 manual describes all the leading edge devices as flaps, inboard, midspan and outboard!


User currently offlineB747skipper From , joined Dec 1969, posts, RR:
Reply 15, posted (12 years 2 weeks 1 day 13 hours ago) and read 3561 times:

Dear VC-10
Our 747 classics "more recent" retract LE during reverser operation, but some older airplanes we have leased, did not... you got me confused there...
Apparently, Mr. Boeing decided to "retract the LE" during reversers to prevent that foreign objects or... ice located itself under the LE devices due to the reverser thrust... that feature was also common with the 707s I flew, and was the explanation I was given back then...
I remember "slats" from my DC-8 flying days, never heard that word in the 747 and we dont care, they are for us "leading edge devices"...
Cheers, dont insult each other...  Wink/being sarcastic
(s) Skipper


User currently offlineVC-10 From United Kingdom, joined Oct 1999, 3700 posts, RR: 34
Reply 16, posted (12 years 2 weeks 1 day 11 hours ago) and read 3542 times:
Support Airliners.net - become a First Class Member!

B747skipper,

dont insult each other... - Who did I insult ?


User currently offlineAvi From Israel, joined Sep 2001, 939 posts, RR: 6
Reply 17, posted (12 years 2 weeks 1 day 6 hours ago) and read 3537 times:

Thanks to the replies guys.

I didn’t notice that the PIA aircraft is not 400.

VC-10, great illustrations. Can you post illustrations for the TE flaps (not SP) and the gears (all 3 types  Smile ) please?

Thanks again.




Long live the B747
Top Of Page
Forum Index

Reply To This Topic A B744 LE Flaps While Braking, Again
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...
Setting Flaps For Takeoff While Taxiing? posted Tue Aug 1 2006 23:46:34 by Jfrworld
B744 Landing Gears And TE Flaps Illustrations posted Mon Jul 29 2002 15:07:44 by Avi
Flaps Failure While Extending posted Wed Jul 3 2002 15:49:34 by Popee
Stored/Parked Aircraft With Flaps Extended? posted Mon Nov 13 2006 04:59:56 by Warreng24
No Flaps Landings... posted Wed Nov 1 2006 20:19:13 by UsAirways16bwi
Braking/Spoilers On BAe-146 posted Tue Oct 17 2006 13:55:24 by Smoose
Split Flaps posted Sun Oct 15 2006 12:01:43 by Speedracer1407
B-52 Flaps posted Sun Oct 15 2006 09:06:45 by Speedracer1407
Air Scanner While Inflight. posted Sat Sep 30 2006 18:24:04 by COEWR737
B744 Wx Radar posted Tue Sep 26 2006 05:03:56 by Onetogo

Sponsor Message:
Printer friendly format