T/O Engine failure acceleration altitude
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T/O Engine failure acceleration altitude
Hi folks!
Wondering what is the acceleration altitude in case of engine failure at take off (no contingency procedure due to obstacles) according to your AFM or/and company SOP.
I'd appreciate a brief comment on the pros and cons of different options, especially low altitude (ca. 400 ft) versus high altitude (ca. 1500 ft).
Thanks so much for your kind help, happy landings!!
Wondering what is the acceleration altitude in case of engine failure at take off (no contingency procedure due to obstacles) according to your AFM or/and company SOP.
I'd appreciate a brief comment on the pros and cons of different options, especially low altitude (ca. 400 ft) versus high altitude (ca. 1500 ft).
Thanks so much for your kind help, happy landings!!
...no contingency procedure due to obstacles...
I would caution that just because there is no contingency procedure, it doesn't mean that there aren't any obstacles - just that following your SOPs will give you the required terrain clearance. It is not a licence to invent a novel OEI procedure and see if it works! (Or not... )
As far as the effects go, an early clean up might compromise the second and third segment obstacle clearance (compared with normal). A later clean up will probably give better clearance initially but there's the possibility of going below the net flight path later on if it's tight.
If you're taking off over the sea, then I suppose it doesn't matter (tall ships excepted!) but I'd be very wary of doing anything non-standard under limiting conditions as it's sometimes not obvious where the critical performance limitation is: could be just off the end of the runway, could be 10 miles away round a corner...
We use 1,000'AAL unless otherwise specified.
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Thank you guys!
FullWings: it means the general rule, when you have obstacle clearance with the 2.4° certification gradient; to distingush from special airports where a higher gradient is required (and you might have to delay the acceleration)...
FullWings: it means the general rule, when you have obstacle clearance with the 2.4° certification gradient; to distingush from special airports where a higher gradient is required (and you might have to delay the acceleration)...
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800 agl minimum for acceleration.
Note, fire drills are not accomplished (except bell silence) until the flaps are fully retracted, unless engine severe damage or separation are confirmed/suspected.
Type, L1011.
Note, fire drills are not accomplished (except bell silence) until the flaps are fully retracted, unless engine severe damage or separation are confirmed/suspected.
Type, L1011.
I guess 400'/1500' are the reference for most. Of course, these are minimum heights, not mandatory!
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Some thoughts ..
(a) AEO ... the aim is to fly the aircraft so that the flight path stays above the calculated OEI flight path so that there is no particular concern in the normal takeoff case .. however, one needs to watch IAS critically if there are turns in the procedure as the turn radius varies with speed.
(b) while AEO routine cleanup procedures vary, typical protocols see a gentle acceleration (ie reduced ROC) from heights varying from 800 ft. Generally with twin jets, the AEO performance is such that, by the time the initial climb is established etc., the aircraft is going to be at a reasonable height arp anyway ... we all understand that this doesn't apply to some of the wonderful old girls .. Fokker, Argosy, 748 etc. etc ...
(c) minimum (OEI) third segment (acceleration) is 400ft arp
(d) maximum third segment is only limited by the AFM and commonsense .. so, for instance, Dart powered machines I have played with have a 600 ft maximum due to feather pump limits. Many jets can be pushed up to 800ft or more as necessary and considered appropriate. The general limit is that height which results in the END of the third segment occurring within the time limit for engine operation at takeoff thrust (generally either 5 or 10 minutes)
(e) often an operator will adopt a standard height based on a critical runway for standardisation (the Australian domestic airlines did this years ago for the jets using 800ft based on Canberra departures which were critical for the DC9.
(f) your particular operator's SOP for a given runway should prescribe the third segment height, either specifically or as a generic level for that operation ... he who doesn't follow that procedure exposes the aircraft to potential problems .. obstacle clearance in particular .. the pilot generally has NO idea what sums went into the procedure or what obstacle(s) are critical and under what circumstances .. be aware that the critical obstacle may well change depending on OAT or W/V
(a) AEO ... the aim is to fly the aircraft so that the flight path stays above the calculated OEI flight path so that there is no particular concern in the normal takeoff case .. however, one needs to watch IAS critically if there are turns in the procedure as the turn radius varies with speed.
(b) while AEO routine cleanup procedures vary, typical protocols see a gentle acceleration (ie reduced ROC) from heights varying from 800 ft. Generally with twin jets, the AEO performance is such that, by the time the initial climb is established etc., the aircraft is going to be at a reasonable height arp anyway ... we all understand that this doesn't apply to some of the wonderful old girls .. Fokker, Argosy, 748 etc. etc ...
(c) minimum (OEI) third segment (acceleration) is 400ft arp
(d) maximum third segment is only limited by the AFM and commonsense .. so, for instance, Dart powered machines I have played with have a 600 ft maximum due to feather pump limits. Many jets can be pushed up to 800ft or more as necessary and considered appropriate. The general limit is that height which results in the END of the third segment occurring within the time limit for engine operation at takeoff thrust (generally either 5 or 10 minutes)
(e) often an operator will adopt a standard height based on a critical runway for standardisation (the Australian domestic airlines did this years ago for the jets using 800ft based on Canberra departures which were critical for the DC9.
(f) your particular operator's SOP for a given runway should prescribe the third segment height, either specifically or as a generic level for that operation ... he who doesn't follow that procedure exposes the aircraft to potential problems .. obstacle clearance in particular .. the pilot generally has NO idea what sums went into the procedure or what obstacle(s) are critical and under what circumstances .. be aware that the critical obstacle may well change depending on OAT or W/V