A380 Take-Off Flaps

[Wombat_VC]

I notice the A380 has 4 levels of flap settings, and it takes off with 3rd. level, which is almost full-flap (not much difference between level 3 and 4). I don't recall other heavies needing that much flap on take-off.

[Rezabrya]

Well have you seen the size of that thing!!?! Obviously it's gonna need lots and lots of lift. :jump:

[JT8D-9A]

Takeoff:
http://www.youtube.com/watch?v=EgjgLQF3N8A&fmt=22

http://www.youtube.com/watch?v=zKichQnoKGM&fmt=22

Landing:
http://www.youtube.com/watch?v=-zc0wbvSbx8&fmt=22

http://www.youtube.com/watch?v=9gu7Y4DeK74&fmt=22

[deathfromafar]

In the first video, the setting was Flaps 2 which is nominal for most weights and field ops conditions. If you're at an airport at higher altitude(altitude density ops) and have significant obstructions, you're likely going to use only Flaps 1 to make the climb gradient.

Question, on your 380 model does Flaps 1 only have the slats out or both the slats and flaps?

[Wombat_VC]

In the first video, the setting was Flaps 2 which is nominal for most weights and field ops conditions. If you're at an airport at higher altitude(altitude density ops) and have significant obstructions, you're likely going to use only Flaps 1 to make the climb gradient.

Question, on your 380 model does Flaps 1 only have the slats out or both the slats and flaps?

Actually, the first video does show it to be F3, which was identical to what I had observed. I was sitting next to it and there were clear markings on the wing that showed 0, 1, 2, 3 positions. The plane I was in was taking off from Hong Kong Chek Lap Kok, so it was at sea level.

Unlike 747's, I couldn't see the slats (may be blocked from my view) even when landing. The flap gradient was only slightly steeper (position 4, not marked) than when take-off.

[tigisfat]

I've seen plenty of 747 takeoffs with 20 degrees of flaps.

[deathfromafar]

Actually, the first video does show it to be F3, which was identical to what I had observed. I was sitting next to it and there were clear markings on the wing that showed 0, 1, 2, 3 positions. The plane I was in was taking off from Hong Kong Chek Lap Kok, so it was at sea level.

Unlike 747's, I couldn't see the slats (may be blocked from my view) even when landing. The flap gradient was only slightly steeper (position 4, not marked) than when take-off.

Urrrrrrrrg. My Mistake(Sorry). Yes, flaps 3. Flaps 1 being slats only on the Bus. Some of my friends who have flown the A320 to places like Bogota(SKBO) told me that they use Flaps 1 (slats only) out of there to be able to make the climb gradient. FHASL is around 8300 feet. I suspect that an A380 at weight would go Flaps 2 there and 3 at lower FHASL fields. It's my guess as I haven't cracked open the manual in 3 years! I have the real A320 PDF manual here beside me.

Also, Buses use Flaps positions, Boeings are in degrees on gauge.

[fliger747]

Four engine aircraft are usually runway rather than climb limited. At full weight the 747-400 has a V2 of 181 knots.... My personal opinion is that the tires are the weakest part of the system, blow a tire or two and all of the distance calcs go out the window, so I do all heavy weight takeoffs at flaps 20. Even at Bogota and Quito in the 400 the higher flap selection is worth consideration in a four engine aircraft due to the high groundspeed associated with high altitude takeoffs. A two engine aircraft is much more critical for high altitude climb. In the 737's we used what was called improved climb, which accelerated more on the runway to slingshot the plane into the air.

I have watched the other large aircraft you mentioned above takeoff on a number of ocassions. I believe that they have had to make a number of operational compromises to achieve acceptable takeoff speeds for runway and tire requirements.

Cheers: T.

[Wing_Z]

Pretty quiet engines...
Pretty LOUD flapjacks!

[Wombat_VC]

Four engine aircraft are usually runway rather than climb limited. At full weight the 747-400 has a V2 of 181 knots.... My personal opinion is that the tires are the weakest part of the system, blow a tire or two and all of the distance calcs go out the window, so I do all heavy weight takeoffs at flaps 20. Even at Bogota and Quito in the 400 the higher flap selection is worth consideration in a four engine aircraft due to the high groundspeed associated with high altitude takeoffs. A two engine aircraft is much more critical for high altitude climb. In the 737's we used what was called improved climb, which accelerated more on the runway to slingshot the plane into the air.

I have watched the other large aircraft you mentioned above takeoff on a number of ocassions. I believe that they have had to make a number of operational compromises to achieve acceptable takeoff speeds for runway and tire requirements.

Cheers: T.

Very interesting. Thanks for the explanation. :wavey: