Airbus Flysmart TO Perf EO Acceleration
Thread Starter
Joined: Jul 2009
Aviation Qualifications: Spotter
Posts: 241
Likes: 50
From: Coast to Coast...
Airbus Flysmart TO Perf EO Acceleration
The Flysmart Takeoff performance calculated Engine Out Acceleration Altitude for most airports with no terrain considerations is 800ft AGL. What happened to the days of 1500 AGL as a rule? I keep on telling guys that this is simply a minimum and I can adjust it to a higher value (limited by TOGA time limit) if I wanted to. Seems we have a lot of monkey say, monkey do going on. I'm being asked "where is it written that you can change it?" It's common sense that you probably don't want to be accelerating at 800ft AGL out of LGW given 3 GA airfields in close proximity. Thoughts?
Joined: Jun 2007
Posts: 3,443
Likes: 39
From: Wanderlust
The Flysmart Takeoff performance calculated Engine Out Acceleration Altitude for most airports with no terrain considerations is 800ft AGL. What happened to the days of 1500 AGL as a rule? I keep on telling guys that this is simply a minimum and I can adjust it to a higher value (limited by TOGA time limit) if I wanted to. Seems we have a lot of monkey say, monkey do going on. I'm being asked "where is it written that you can change it?" It's common sense that you probably don't want to be accelerating at 800ft AGL out of LGW given 3 GA airfields in close proximity. Thoughts?
Joined: Jan 2004
Posts: 3,246
Likes: 202
From: Here and there
OP is talking about the EO ACC so fuel savings and noise abatement are irrelevant. Our EO ACC is 1500 minimum with 800 only applying to the all engines operating case.
Personally I think it best to enter the Flysmart EO ACC in the perf page. That way you have a readily accessible reminder of the minimum value. If you suffer an engine failure, there’s nothing stopping you from delaying the acceleration until you’re comfortable. There’s nothing saying you MUST level off at the EO acceleration altitude, you have to secure the engine and complete any turns anyway, but there’s also no good reason to actually change it to a higher value preemptively. Unlike the all engines operating case, the EO ACC altitude has no effect on anything in the cockpit , it doesn’t automatically increase the speed for example.
Personally I think it best to enter the Flysmart EO ACC in the perf page. That way you have a readily accessible reminder of the minimum value. If you suffer an engine failure, there’s nothing stopping you from delaying the acceleration until you’re comfortable. There’s nothing saying you MUST level off at the EO acceleration altitude, you have to secure the engine and complete any turns anyway, but there’s also no good reason to actually change it to a higher value preemptively. Unlike the all engines operating case, the EO ACC altitude has no effect on anything in the cockpit , it doesn’t automatically increase the speed for example.
Joined: Jul 2018
Posts: 202
Likes: 69
From: on the edge.
From Airbus FCTM, FMGES PREPARATION:
The engine-out acceleration altitude must:
There are generally a minimum and a maximum one-engine-out altitude values.
Any value between those two may be retained.
The one-engine-out acceleration altitude is usually defaulted to 1500ft AGL, and may be updated as required.
The engine-out acceleration altitude must:
- Be at least 400ft above airport altitude;
- Ensure that the net flight path is 35ft above obstacles;
- Ensure that maximum time for takeoff thrust is not exceeded.
There are generally a minimum and a maximum one-engine-out altitude values.
The minimum value satisfies the first two criteria. The maximum value satisfies the last one.
The one-engine-out acceleration altitude is usually defaulted to 1500ft AGL, and may be updated as required.
Last edited by TheEdge; 4th July 2023 at 10:24.
Joined: Feb 2003
Posts: 543
Likes: 337
From: Blue sky
Seems more like a false sense of security. It’s not because you’ve been doing it for all this time’ all this time it was the safest option. We should learn from the past.
Joined: Jan 2004
Posts: 3,246
Likes: 202
From: Here and there
Joined: Apr 2010
Posts: 1,320
Likes: 102
From: IRS NAV ONLY
FWIW, at a Boeing operator I work for, we don't have an option to select a different EO acceleration altitude, so we're stuck with what we have - default is 1000ft AAL, unless higher required to maximise payload.
Joined: Sep 2008
Aviation Qualifications: ATPL
Posts: 940
Likes: 57
From: Scotland
Ask your technical department or fleet technical pilot. There are a vast range of configurable options under the hood in Flysmart+ which will have been evaluated and set by your Technical Managers of which this is one.
We set it to 1000’ agl minimum.
We set it to 1000’ agl minimum.
Joined: Sep 2021
Posts: 29
Likes: 3
From: Hong Kong
I don’t see the completion of a turn or being “comfortable” as a valid reason to delay EO acceleration.
