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747FOCAL
1st Aug 2001, 02:37
Do any Airbus pilots or anybody else know of any Airbus planes that use one engine rating at takeoff brake release that gets reduced to another rating after liftoff? This would not be initiated by the pilot. The FMC or the FADEC controls would handle it.

ie. you set power at brake release at 60k and at V35 max engine thrust is 55k.

Thanks. Also if this is so which airplanes.

Christopher James
1st Aug 2001, 22:05
Do A340s in fact have thrust? :D :D

GustyOrange
1st Aug 2001, 23:42
As someone with only a lose grip on the subject, could somebody please explain the jokes about the lack of thrust on the A340. And also please why they are selling ? As I understand it the 777 is the airplane most pax prefer.
Cheers
:)

Carnage Matey!
2nd Aug 2001, 02:25
The A320 range doesn't have the feature you mention 747. We just apply derated TO thrust at brake release and maintain it until AA at which point we throttle back to calculated climb thrust.

Gusty: as I understand the A340 is a remarkably fuel efficient aircraft but grossly underpowered resulting in very poor climb performance when heavy. As it's also designed for optimum fuel efficiency it cruises around Mach.76, whilst the Boeings I think can cruise around M0.86. That said, with 4 engines the A340 is unaffected by ETOPS regulations which restrict the 777 on some routes. Also the A340 can be flown on a virtually common type rating with the A330 and A320 series, saving a vast amount in airline training costs. Id like to see someone current on the 737, 757, 777 and 747 simultaneously! As for the 777 being the aircraft pax prefer, well I suppose that depends on which pax you ask! I think most of them don't care as long as the seats are comfy and they can get a drink! :)

126.9
2nd Aug 2001, 04:12
:) Check your speeds :)

Airbus (depending on model) cruising at around M0.80
B747 (depending on model) cruising at around M0.83

Calculated between Johannesburg and London; thats around 20 minutes difference! :D

Carnage Matey!
2nd Aug 2001, 04:25
I'll be b*ggered if I'm cruising at 0.80 in an A320! My nerves can't take that and I may even have to put down the Daily Telegraph! I'll go at 0.79 and tell you it's 0.80!

Still think optimum cruise in A340 is about 0.76.

flaps
2nd Aug 2001, 19:16
I'll do .80 in the 319/320 but not in the descent. Also in the 319's fuel flow at .80 @FL390 isn't much worse than .78 @FL350 so it gets me home quicker.

Open Climb
2nd Aug 2001, 21:38
We cruise at M.82-.83 in the A330, I do believe the 744 is faster, M.85 or something.

The A330 will do M.85, but the fuelconsumption gets pretty insane at those speeds. No idea what the A340 does, but M.76 sounds real slow...

[ 02 August 2001: Message edited by: Open Climb ]

northern boy
3rd Aug 2001, 00:23
The current A340 model cruises at 0.82.
The new 500/600 series with the Trent Engines should cruise at 0.83-0.84 and hopefully climb a bit better. (Airbus figures).
The new 380 is supposed to do 0.86 or greater,Airbus figures again.
The A320 manages 0.78 econ cruise and will do 0.8 with increased fuel burn.(only recommended in smooth air!).
Dont know where the 0.76 comes from.Apart from being high altitude turbulence penetration speed in the 320.


The A340 sells because it burns around 6-7 tons per hour as compared with 12-13 tons per hour for a 747 classic and 10-11 tons (I think)per hour for the 747-400.It also has an enourmous cargo capacity.This along with mixed fleet flying endear them to accountants even if some pilots seem to hate the sight of them.