Close-in obstacles limiting takeoff
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john_tullamarine, ok i think i got your point. I indeed shouldn't have used the term balanced field. I thought about optimizing V1/Vr & V2/Vs for different Flap settings and as consequence possible usage of the full TODA with lower flap settings. I have associated it with BFL because the MAX TOW would be achieved with optimum Flap setting, optimum Speeds using the full length, rather then using higher flap setting and not the full length, if the take off is obstacle limited.
I hope i have regained some of your credit.
Cheers.
I hope i have regained some of your credit.
Cheers.
Moderator
Bro' .. we all on the same side .. no sheep stations at stake here.
What you are doing is a normal performance analysis for a given runway .. ie juggle about with the numbers until you get a combination of weight, flap, and overspeed which fits in with the runway and obstacle data and gives you the maximum RTOW ("optimise the RTOW" in ops engineering speak).
Almost invariably, this means an unbalanced field length takeoff.
Well done, good sir. Pass "GO" and collect $200.
What you are doing is a normal performance analysis for a given runway .. ie juggle about with the numbers until you get a combination of weight, flap, and overspeed which fits in with the runway and obstacle data and gives you the maximum RTOW ("optimise the RTOW" in ops engineering speak).
Almost invariably, this means an unbalanced field length takeoff.
Well done, good sir. Pass "GO" and collect $200.
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Somebody in this post mentioned the Required Navigational Accuracy as defined in AMC-OPS 1.495.
As anyone looked into it in any detail. It is my understanding that today, no aircraft meets the requirements (IMC).
Comments plz
As anyone looked into it in any detail. It is my understanding that today, no aircraft meets the requirements (IMC).
Comments plz
Thread Starter
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RNP
Seems they're getting tired of going around from 3000' AGL.....
http://www.flightinternational.com/A...or+A320s+.html
http://www.flightinternational.com/A...or+A320s+.html
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Contrary to what's been stated here, unless you're turing before the endo of the TODA, the splay does not change for changes in TOD. It is assessed only from the TODA.
JAR-OPS 1.495(a)
An operator shall ensure that the net take-off flight path clears all obstacles by a vertical distance of 35 ft or by a horizontal distance of at leat 90 m plus 0.125 x D, where D is the horizontal distance the aeroplane has travelled from the end of the take-off distance available or the end of the take-off distance if a turn is scheduled before the end of the take-off distance available.
I wouldn't want to have to re-compute the splay for every takeoff.
JAR-OPS 1.495(a)
An operator shall ensure that the net take-off flight path clears all obstacles by a vertical distance of 35 ft or by a horizontal distance of at leat 90 m plus 0.125 x D, where D is the horizontal distance the aeroplane has travelled from the end of the take-off distance available or the end of the take-off distance if a turn is scheduled before the end of the take-off distance available.
I wouldn't want to have to re-compute the splay for every takeoff.
Moderator
... one of the head scratching inconsistencies in the system ... it presupposes that one can track the centreline for a low vis takeoff until the splay commences .. which can be a bit difficult in older (non FMS) jets with significant deck angles. So far as turns are concerned, it would be very unusual to schedule a turn before runway head.
In practice, a sensible ops engineer will look at this problem and figure out a way to reduce the off centreline tracking risk in the case of a long runway with significant obstacles for a takeoff by a smaller aircraft .... this might well be a matter of generating a more conservative trapezoid from a convenient mid runway position if the case dictates.
Above all, blind compliance with the rules is not always a good thing ... one should consider that the rules give a baseline for commonsense to be applied .. same thing applies for the design standards. That is to say, there are occasions where the rules should be seen to be inadequate for the requirements of reasonable risk management and should be modified conservatively to reduce risk ....
In practice, a sensible ops engineer will look at this problem and figure out a way to reduce the off centreline tracking risk in the case of a long runway with significant obstacles for a takeoff by a smaller aircraft .... this might well be a matter of generating a more conservative trapezoid from a convenient mid runway position if the case dictates.
Above all, blind compliance with the rules is not always a good thing ... one should consider that the rules give a baseline for commonsense to be applied .. same thing applies for the design standards. That is to say, there are occasions where the rules should be seen to be inadequate for the requirements of reasonable risk management and should be modified conservatively to reduce risk ....
Popay- I know a pilot who might have worked for your (previous) company. He will probably get laid-off again, along with almost 400 other pilots who were recalled here just last winter. He flew a smaller Airbus.
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donstim, to cover the problem with the turn, there's a min. turn alt. 400 ft for the BUS. Om stipulates the height for turn as well e.g. MSA for IFR or 500 ft VMC.
Ignition Override, yea man not the best time in the industry right now i guess. PM me the guys name please.
Cheers
Ignition Override, yea man not the best time in the industry right now i guess. PM me the guys name please.
Cheers
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JT -- I was just trying to correct an erroneous statement. Didn't mean to imply that "blind compliance" with the rules is always the prudent thing to do. On the other hand, if you can't follow a track within a 200 foot half-width until the end of the TODA, maybe piloting isn't your strong suit. 
Popay and JT -- I wasn't trying to point out any kind of a problem with turns -- just being complete as far as what the rules require. Certainly turns before the runway end are rare, but they may be appropriate (especially over clearway) in certain circumstances.
Popay and JT -- I wasn't trying to point out any kind of a problem with turns -- just being complete as far as what the rules require. Certainly turns before the runway end are rare, but they may be appropriate (especially over clearway) in certain circumstances.
Moderator
.. from more than a few sessions in back of the sim, give a chap an IMC failure with a little bit of crosswind and no track guidance ... and centreline tracking becomes more than a little problematic ...
No sheep stations at stake in these discussions .. so please don't think I am being critical of your comments.
No sheep stations at stake in these discussions .. so please don't think I am being critical of your comments.
Last edited by john_tullamarine; 30th Oct 2005 at 09:38.
