Reggaebird
Topic Author
Posts: 886
Joined: Tue Nov 02, 1999 7:43 am

Boeing 747-400 Wing Variances?

Sun May 12, 2013 7:15 am

Hello,

I was out plane spotting and saw a BA 744 landing, immediately followed by an AF 744. I made videos of both landings and, upon review, noticed that the flaps look different on the two birds. So I thought I would ask the following. Other than engine type-related variances, are there any major mechanical variances in the wings/flaps of the BA and AF fleets? I thought that all 744s were pretty much the same, with the possible exception of the 744ER.

The visual difference in flaps that I am referring to can be seen at 0:24 (BA) and 2:24 (AF) in the video link below.

http://www.youtube.com/watch?v=ojsnpUnh2Qw

Any insight would be appreciated.

Thank you

[Edited 2013-05-12 00:19:10]
 
User avatar
747classic
Posts: 1948
Joined: Sat Aug 15, 2009 9:13 am

RE: Boeing 747-400 Wing Variances?

Sun May 12, 2013 8:09 am

Probably BA performed a flaps 25 landing
Seen the increased spacing between the TE flap segments, AF performed a flaps 30 landing.

On all 744 series, incl. the 744ER, the TE flaps are identical.

[Edited 2013-05-12 01:32:16]
Operating a twin over the ocean, you're always one engine failure from a total emergency.
 
Reggaebird
Topic Author
Posts: 886
Joined: Tue Nov 02, 1999 7:43 am

RE: Boeing 747-400 Wing Variances?

Sun May 12, 2013 10:51 am

Quoting 747classic (Reply 1):
Probably BA performed a flaps 25 landing
Seen the increased spacing between the TE flap segments, AF performed a flaps 30 landing.

Thank you for the information. That begs the question why the different flap configurations for the same flying conditions? However, I suspect I will need to go to flight school to learn that answer.  
 
Ronaldo747
Posts: 272
Joined: Sat Feb 14, 2009 4:58 pm

RE: Boeing 747-400 Wing Variances?

Sun May 12, 2013 10:55 am

Quoting Reggaebird (Reply 2):
That begs the question why the different flap configurations for the same flying conditions?

IIRC for saving fuel the approach with flaps 25 is quite common with BA 747s at Heathrow.
 
User avatar
747classic
Posts: 1948
Joined: Sat Aug 15, 2009 9:13 am

RE: Boeing 747-400 Wing Variances?

Sun May 12, 2013 11:24 am

A lot a variables can influence the decision for a flaps 25 or flaps 30 landing :

- Landing weight
- Runway length
- Local noise regulations (idle reverse, upon landing))
- OAT
- Field elevation
- Autoland
- Aircraft defects (one brake U/S, reverser U/S )
- Company policy (fuel saving - noise avoidance)
- Maintenance costs (flap tracks - brake wear)

But, in the end it's always the captain's decision.

[Edited 2013-05-12 04:29:02]
Operating a twin over the ocean, you're always one engine failure from a total emergency.
 
User avatar
jetmech
Posts: 2316
Joined: Wed Mar 29, 2006 2:14 am

RE: Boeing 747-400 Wing Variances?

Mon May 13, 2013 4:28 am

Quoting Reggaebird (Reply 2):
That begs the question why the different flap configurations for the same flying conditions?

As stated by 747classic, and amongst other reasons, the particular procedure for each airline has a lot to do with landing flap choice.

One airline made the choice to do flap 25 landings as a standard procedure, to reduce noise fees as well as TR and flap maintenance. Page 125 of the following also states that flap 25 landings were chosen to put more energy into the brakes, which actually decreased wear rates.

http://www.atsb.gov.au/media/24447/aair199904538_001.pdf

Regards, JetMech
JetMech split the back of his pants. He can feel the wind in his hair :shock: .
 
Max Q
Posts: 5629
Joined: Wed May 09, 2001 12:40 pm

RE: Boeing 747-400 Wing Variances?

Mon May 13, 2013 5:45 am

F25 is also preferable in strong, gusty wind conditions.
The best contribution to safety is a competent Pilot.
 
User avatar
Aaron747
Posts: 8529
Joined: Thu Aug 07, 2003 2:07 am

RE: Boeing 747-400 Wing Variances?

Mon May 13, 2013 6:40 am

Quoting Reggaebird (Thread starter):
I thought that all 744s were pretty much the same, with the possible exception of the 744ER.

There are only four major variances you will ever find on 747-400 wings, and two of them are cosmetic:

1. The engine pylons differ significantly in size and shape depending on whether PW, GE, or RR are installed.

2. No winglets are installed on the -400D.

3. Some operators have a painted stripe on the 2nd and 3rd flap slots, while others are solid colored.

4. Some operators have a darkened area running the length of the center skin panel on tops and bottoms of the wings (the areas covering the fuel tanks)
If you need someone to blame / throw a rock in the air / you'll hit someone guilty
 
User avatar
Scooter01
Posts: 1183
Joined: Tue Nov 28, 2006 11:06 pm

RE: Boeing 747-400 Wing Variances?

Mon May 13, 2013 8:25 am

The Airliners.net Photo Search Engine is an amasing place to look up all sorts of things,
and truly amasing what one can learn.

By searching through "Aircraft Window Views" on the Boeing 747 flaps , you can see all kinds of landing-configurations,
from this:

View Large View Medium
Click here for bigger photo!

Photo © Fyodor Borisov - Russian AviaPhoto Team



to this:

View Large View Medium
Click here for bigger photo!

Photo © Hayk Martirosyan



ending up with:

View Large View Medium
Click here for bigger photo!

Photo © Andries Waardenburg




All series Boeing 747 featured triple slotted flaps, ECEPT the -SP which had a double pivot, single slot flap:

View Large View Medium
Click here for bigger photo!

Photo © Sam Chui



Scooter01   
There is always a good reason to watch airplanes
 
User avatar
Starlionblue
Posts: 17056
Joined: Fri Feb 27, 2004 9:54 pm

RE: Boeing 747-400 Wing Variances?

Mon May 13, 2013 8:37 am

Quoting Scooter01 (Reply 8):
All series Boeing 747 featured triple slotted flaps, ECEPT the -SP which had a double pivot, single slot flap:

The -8 has single-slotted outboard flaps and double-slotted inboard flaps.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
User avatar
Scooter01
Posts: 1183
Joined: Tue Nov 28, 2006 11:06 pm

RE: Boeing 747-400 Wing Variances?

Mon May 13, 2013 8:53 am

Quoting Starlionblue (Reply 9):
The -8 has single-slotted outboard flaps and double-slotted inboard flaps.

Sorry, forgot about that one. (It's too new for me, haven't flown on one yet)

Scooter01   
There is always a good reason to watch airplanes
 
User avatar
Starlionblue
Posts: 17056
Joined: Fri Feb 27, 2004 9:54 pm

RE: Boeing 747-400 Wing Variances?

Mon May 13, 2013 8:59 am

Quoting Scooter01 (Reply 10):

Quoting Starlionblue (Reply 9):
The -8 has single-slotted outboard flaps and double-slotted inboard flaps.

Sorry, forgot about that one. (It's too new for me, haven't flown on one yet)

Scooter01   

No worries. The -8 throws people off. 

[Edited 2013-05-13 01:59:54]
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
Viscount724
Posts: 18850
Joined: Thu Oct 12, 2006 7:32 pm

RE: Boeing 747-400 Wing Variances?

Mon May 13, 2013 6:47 pm

Quoting aaron747 (Reply 7):
No winglets are installed on the -400D.

-400D also lacks the wingtip extensions of other -400s to which the winglets are attached. It thus has the same wingspan as all earlier 747s.
 
Reggaebird
Topic Author
Posts: 886
Joined: Tue Nov 02, 1999 7:43 am

RE: Boeing 747-400 Wing Variances?

Mon May 13, 2013 9:01 pm

Quoting Starlionblue (Reply 9):
All series Boeing 747 featured triple slotted flaps

Are there any other large airliners that had/have triple-slotted flaps? Also, any thoughts on why the new -8 has discarded the triple-slotted design?
 
User avatar
Starlionblue
Posts: 17056
Joined: Fri Feb 27, 2004 9:54 pm

RE: Boeing 747-400 Wing Variances?

Mon May 13, 2013 11:40 pm

Quoting Reggaebird (Reply 13):
Quoting Starlionblue (Reply 9):
All series Boeing 747 featured triple slotted flaps

Are there any other large airliners that had/have triple-slotted flaps?

727. Ok so it isn't a widebody but definitely large.

Quoting Reggaebird (Reply 13):
Also, any thoughts on why the new -8 has discarded the triple-slotted design?

Complexity costs both in construction and maintenance. With more modern aerodynamics Boeing could achieve the same performance without the triple-slotted design.

Same reason the 787 has offset hinge flaps and does away with flap tracks. Simpler and cheaper.

[Edited 2013-05-13 16:41:21]

[Edited 2013-05-13 16:43:01]
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
User avatar
jetmech
Posts: 2316
Joined: Wed Mar 29, 2006 2:14 am

RE: Boeing 747-400 Wing Variances?

Tue May 14, 2013 12:27 am

Quoting Starlionblue (Reply 14):
Same reason the 787 has offset hinge flaps and does away with flap tracks. Simpler and cheaper.

A great picture illustrating this;

http://upload.wikimedia.org/wikipedia/commons/5/51/Flaps_Mechanism_B787_A320.png

http://upload.wikimedia.org/wikipedi...5/51/Flaps_Mechanism_B787_A320.png

Regards, JetMech
JetMech split the back of his pants. He can feel the wind in his hair :shock: .
 
User avatar
Aaron747
Posts: 8529
Joined: Thu Aug 07, 2003 2:07 am

RE: Boeing 747-400 Wing Variances?

Tue May 14, 2013 1:16 am

Quoting Scooter01 (Reply 8):
By searching through "Aircraft Window Views" on the Boeing 747 flaps , you can see all kinds of landing-configurations,

  

You can also find the cosmetic differences in the flap markings and wing skin panels I mentioned above  
If you need someone to blame / throw a rock in the air / you'll hit someone guilty
 
User avatar
Starlionblue
Posts: 17056
Joined: Fri Feb 27, 2004 9:54 pm

RE: Boeing 747-400 Wing Variances?

Tue May 14, 2013 2:46 am

Quoting Jetmech (Reply 15):
Quoting Starlionblue (Reply 14):
Same reason the 787 has offset hinge flaps and does away with flap tracks. Simpler and cheaper.

A great picture illustrating this;

Great pic indeed. Another neat feature on the 787 flaps is that the spoiler panels droop to cover some of the gap when the flaps extend.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
dynamicsguy
Posts: 442
Joined: Tue Jul 08, 2008 9:24 am

RE: Boeing 747-400 Wing Variances?

Tue May 14, 2013 10:39 am

Quoting Jetmech (Reply 15):
A great picture illustrating this

Good picture. I've never seen anything similar in the public domain. The 787 angle is wrong though.

Quoting Starlionblue (Reply 17):
Another neat feature on the 787 flaps is that the spoiler panels droop to cover some of the gap when the flaps extend.

It came from the C-17, and is also a feature of the A350. The width of the slot is very tightly controlled on the 787.

Who is online

Users browsing this forum: zaphod42 and 26 guests