View Full Version : A330/340 speeds
Carnage Matey!
2nd Aug 2001, 01:41
Can anyone tell me the max IAS/Mach no for the A330/340 and typical cruise Mach No. Also, have Airbus managed to develop a decent A/THR system for these aircraft rather than the rubbish one on the A320 that leaves you nervously poisd to intervene whenever your at M0.80?
The Vmo/Mmo of A340 should be 330kts/0.86
For the second part of the question, I'm not quite sure what you are asking, but the A/Thr will be engaged during descent under normal circumstances. It will either keep it in a thrust mode, which it will maintain the same thrust and change the attitude of the aircraft to get the desired speed or in Speed mode, which it will keep the flight path constant and adjust thrust for speed.
;)
moleslayer
2nd Aug 2001, 14:32
CM - A/THR
Not quite sure what it is you're nervous about.Can you elucidate! :eek:
:) Even the A/THR on the old A300 was pretty darn good. What happenned on the Tupperware model then? :D
Open Climb
2nd Aug 2001, 20:51
The VMO/MMO on the A330 is 330/.86
The A/THR works well on the thing, except for maybe in turbulence. It tends to lag behind a bit and the result is a lot of 'pumping' between idle and climb thrust. The procedure is to disconnect A/THR and set thrust by N1.
The catch is to remember that you're not in A/THR anymore and keep an eye on your speed.... :D
Carnage Matey!
2nd Aug 2001, 21:21
The VMO/MMO on the A320 is 350/0.82, For those who don't fly the minibus, the problem is that during cruise with A/THR engaged it will tend to oscillate around the managed mach target by as much as 0.015M. Cruising at 0.80, this will take you frighteningly close to setting off the big scary red light and it makes your day far more stressful. Plus it will fly 10 knots above Vapp on the approach if you've used the speedbrakes!
[ 02 August 2001: Message edited by: Carnage Matey! ]
BEagle
3rd Aug 2001, 16:52
Hmmm - the RAF's Future Strategic Tanker Aircraft has to have a reliable full flight regime autothrust system. Not much help if large thrust changes occur when someone has just made contact on a hose, the reduced drag is sensed by the autothrust and the throttles snap shut! Seems like this is an area where some development might perhaps be needed?
[ 03 August 2001: Message edited by: BEagle ]
Bearcat
4th Aug 2001, 01:05
when the 330 first came out the a/thr was the pits. A change from a high to a low pressure system or even light turbulance would cause the a/thr to saw up and down and it was very uncomfortable to watch the racket it made. It would have the a/thr sawing form max power to trying to come back to idle! For the pax when they heard the pwr come off they though the engs had quit as when the pwr reduced the changes to the bleed sysytem and subsequently the air flow to the cabin was frightening. Airbus got on the case as people were flying the machine with no a/thr due its poor management. Today it is a different fish. Can you believe the a330 is around since late 93? I am sure sensible will have his own twist to the issue.
Capt Bearcat :D