Couple of Q's!

[P2T2]

Couple of quick q's for you guys. Any help would be greatly appreciated.

1. Why is there no winglets on the B777 but there is on the BBJ-737, A330 (all short / medium haul)?

2. How many aircon' packs are on the 747-400?

3. How which is the most important, trailing or leading edge flaps ie which one would cause the most dramas if it became U/S?

4. What happens on the A340 if you lose 1 hydraulic system? What about 3?

5. What are the indications on both the A340 ECAM screens, and the B747-400 EICAS screens? And why the difference?

Thanks guys!

tis the season to be jolly...

[Skunkworks]

A quick A:

1. Move your cursor to the upper right corner of your screen. Hold it over "search" and press the left mouse-button.


(No offense intended, good luck with the rest of the q's)

/skunks

[static]

2- : 3 packs

3- : imho the leading edge devices are most critical. For instance, the flaps 1 selection on a 744 gives you only leading edge devices and this gives you about 20 kts lower minimum manouvering speed.

[SixDemonBag]

1, The 777 has a super-critical wing (i.e the wings thickest section is further back from the leading edge than normal.) This delays the onset of drag caused by the formation of shockwaves. Then exact answer..i dont know. I guess the weight saving from the lack of tips (even the cost saving) is more of saving then having them on. Plus, being a large wing there may have been a constraint on the span for parking at gates, etc.

2, 3 i think. Same as a classic? Pressurisation can still me maintained with one operating though.

3, Well looking at the overall picture, the loss of the trailing edge flaps would be the most limiting. These devices create a greater amount of lift than the leading edge ones. This reduced lift leads to higher speeds required, which leads to longer landing rolls.

4, A340? well in any plane i think the loss of one Hyd. System will cause no great dramas. Depends's on the level of redundency built into the aircraft. Boeings are great in that respect...dont know about the buses. Loss of 3 of the 4 systems would leave you with primary controls and items that were run from the existing system.

5, I think they are both fundamentaly the same. But i dont know.

[Skyjob]

3) Leading edge devices are more critical. These autoslats can provide a significant safety feature when approaching a stall (not that you should). The autoslat system is designed to enhance airplane stall characteristics at high angles of attack (733). Trailing edge flaps provide lift or a lift/drag combination, usefull for landing or taking off, especially when using shorter fileds. Leading edge devices such as autoslats provide a vital safety backup.

[P2T2]

Thanks for the info guys!

Always nice to see guys out there willing to pass off stuff like that.

Cheers