Eric will correct if me if I’m wrong, but I’m pretty sure the 340 is the same as the 320 in this regard: thrust is electronically set by the FMS. And as long as trim is set in a takeoff off range, the takeoff configuration won’t yell at you.
Thrust levers are set in the “flex /MCT†detent.
How not to take-off in an A340
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Eric Janson
- Posts: 412
- Joined: Tue Jul 14, 2015 10:31 am
[quote author=TundraTire link=topic=9060.msg24933#msg24933 date=1538107812]
Any chance the takeoff was attempted with insufficient thrust (incorrect reduction) or an incorrect CG/stab trim setting?
[/quote]
Nark is correct regarding the stab trim.
It’s quite normal to rotate close to the end of the runway - nothing unusual about that in the video. Incorrect thrust setting is possible but unlikely imho.
At 150 knots a slow rotation eats up a lot of runway which is compounded by a pitch attitude that is too low.
Hard to be certain but it looks like a Conf 1+F take-off. I always use Conf 2 as the aircraft doesn’t want to fly with Conf 1+F.
Any chance the takeoff was attempted with insufficient thrust (incorrect reduction) or an incorrect CG/stab trim setting?
[/quote]
Nark is correct regarding the stab trim.
It’s quite normal to rotate close to the end of the runway - nothing unusual about that in the video. Incorrect thrust setting is possible but unlikely imho.
At 150 knots a slow rotation eats up a lot of runway which is compounded by a pitch attitude that is too low.
Hard to be certain but it looks like a Conf 1+F take-off. I always use Conf 2 as the aircraft doesn’t want to fly with Conf 1+F.
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TundraTire
- Posts: 70
- Joined: Mon Jul 25, 2016 3:42 am
Incorrect/insufficient thrust could lead one to a shallow deck angle on climbout, otherwise wouldn't the airspeed begin to get excessive?
On the 340 can you be within takeoff range for stab trim, but not have sufficient pitch authority to rotate properly? For example if you had a forward C of G and the stab was trimmed a little too forward, it could be difficult to rotate.
On the 340 can you be within takeoff range for stab trim, but not have sufficient pitch authority to rotate properly? For example if you had a forward C of G and the stab was trimmed a little too forward, it could be difficult to rotate.
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Eric Janson
- Posts: 412
- Joined: Tue Jul 14, 2015 10:31 am
[quote author=TundraTire link=topic=9060.msg24952#msg24952 date=1538159530]
Incorrect/insufficient thrust could lead one to a shallow deck angle on climbout, otherwise wouldn't the airspeed begin to get excessive?
On the 340 can you be within takeoff range for stab trim, but not have sufficient pitch authority to rotate properly? For example if you had a forward C of G and the stab was trimmed a little too forward, it could be difficult to rotate.
[/quote]
A340 is quite under powered - this particular aircraft has the 31.2k engines. Slightly more thrust than a 767 but 80,000kg heavier. A340 accelerates slowly at high weights.
Never had a severe mistrim situation - just going by what the books say. As long as the trim is in the green band you can take-off safely. The newer versions of the A340 will set the trim to the value entered for take-off automatically - that surprised me the first time I saw it.
If there is some kind of thrust issue all you need to do is push the thrust levers all the way forward to get maximum thrust - it's so intuitive even I can understand it! ;)
Don't forget the sidestick is not connected directly to the elevator and the feedback is simply a spring.
Incorrect/insufficient thrust could lead one to a shallow deck angle on climbout, otherwise wouldn't the airspeed begin to get excessive?
On the 340 can you be within takeoff range for stab trim, but not have sufficient pitch authority to rotate properly? For example if you had a forward C of G and the stab was trimmed a little too forward, it could be difficult to rotate.
[/quote]
A340 is quite under powered - this particular aircraft has the 31.2k engines. Slightly more thrust than a 767 but 80,000kg heavier. A340 accelerates slowly at high weights.
Never had a severe mistrim situation - just going by what the books say. As long as the trim is in the green band you can take-off safely. The newer versions of the A340 will set the trim to the value entered for take-off automatically - that surprised me the first time I saw it.
If there is some kind of thrust issue all you need to do is push the thrust levers all the way forward to get maximum thrust - it's so intuitive even I can understand it! ;)
Don't forget the sidestick is not connected directly to the elevator and the feedback is simply a spring.
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