Legalitys of one dot low during visual approaches?
PPRuNeaholic
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Permanent THR displacement can occur for reasons other than the existence of a (new) obstacle. In my part of the world, the most common reason for it is pavement failure and lack of money to effect repairs. That is the case at Momote airport, on Manus Island, where the remaining length isn't especially critical.
It was also the case at Daru for many years and continues to be the case at Port Moresby, for RWY 14R/32L, which now has a very restricted length and limited to aircraft with MTOW below 5700 Kgs. In this latter case, the T-VASIS was decommissioned (Daru has never had VASIS or PAPI) while, at Momote, the T-VASIS was relocated at the 34 THR end and subsequently replaced by PAPI.
Before escaping from Port Morbid, I put the question to our Air Nav Services people ... What is the procedure in the event that a permanently displaced THR was needed at a place served by an ILS? Their answer was to turn off the GP and VASIS/PAPI and issue a Notam. I suspect that this answer was based on the known fact that money would not be rapidly forthcoming to enable resiting of those facilities.
It was also the case at Daru for many years and continues to be the case at Port Moresby, for RWY 14R/32L, which now has a very restricted length and limited to aircraft with MTOW below 5700 Kgs. In this latter case, the T-VASIS was decommissioned (Daru has never had VASIS or PAPI) while, at Momote, the T-VASIS was relocated at the 34 THR end and subsequently replaced by PAPI.
Before escaping from Port Morbid, I put the question to our Air Nav Services people ... What is the procedure in the event that a permanently displaced THR was needed at a place served by an ILS? Their answer was to turn off the GP and VASIS/PAPI and issue a Notam. I suspect that this answer was based on the known fact that money would not be rapidly forthcoming to enable resiting of those facilities.
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I am with earthmover in that many displaced TZR are there to improve runway utilization, I know the one in Madrid is. Making up your own "System" only messes the whole thing up as well as open you to be hanged out to dry if anything goes wrong.
Another thought is that if you are flying your one dot low app you might, due to windshear for example, sink to two dots low. Will you then automatically go around? in the end you are just eating into your safety margins.
Does the 60% (with no reverse) landing distance rule not provide a sufficient landing distance in all cases?
Another thought is that if you are flying your one dot low app you might, due to windshear for example, sink to two dots low. Will you then automatically go around? in the end you are just eating into your safety margins.
Does the 60% (with no reverse) landing distance rule not provide a sufficient landing distance in all cases?
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As I pointed out on another thread, if you fly an approach one dot low you should actually touch down at the same point.
You will, however, have arrived having flown a shallower-angle approach. If you did this at the correct speed for your weight, you will have flown a higher-energy approach than the writer of the performance charts calculated. Your engine power will be higher (to maintain a shallower descent) and therefore will be slower to spool down when you chop the power. With a slower rate of descent you will spend longer in ground effect before touchdown, so you will be at a higher risk of tailstrike OR you will actually land longer or with a longer run-out.
All-in-all, not desirable. The physics of flying one-dot-low approaches do not help you. In fact, it makes your landing longer than it should be according to the book, all other factors being equal.
You will, however, have arrived having flown a shallower-angle approach. If you did this at the correct speed for your weight, you will have flown a higher-energy approach than the writer of the performance charts calculated. Your engine power will be higher (to maintain a shallower descent) and therefore will be slower to spool down when you chop the power. With a slower rate of descent you will spend longer in ground effect before touchdown, so you will be at a higher risk of tailstrike OR you will actually land longer or with a longer run-out.
All-in-all, not desirable. The physics of flying one-dot-low approaches do not help you. In fact, it makes your landing longer than it should be according to the book, all other factors being equal.
still learning....
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West Coast-
Sure, we've all done it. But the original post dealt with the "legality".
I've gotten many "winks" and opinions from ACIs and even my POI over the years, but I'll bet they won't put that in writing.
Sure, we've all done it. But the original post dealt with the "legality".
I've gotten many "winks" and opinions from ACIs and even my POI over the years, but I'll bet they won't put that in writing.
Moderator
quid,
That's all fine .. but legality is determined by the jurisdictions's legal system and appeals processes ...
Tell me, on those occasions when things have been a little tight and you don't have the benefit of prescribed rules or even ops manual recommended procedures to give you comfort and a measure of protection ..... how comfortable do you find the seat buttons ?
That's all fine .. but legality is determined by the jurisdictions's legal system and appeals processes ...
Tell me, on those occasions when things have been a little tight and you don't have the benefit of prescribed rules or even ops manual recommended procedures to give you comfort and a measure of protection ..... how comfortable do you find the seat buttons ?
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jt-
Quite comfortable. Thank you for asking.
When I'm wearing my "legal" hat (as a DE), I'm likely to give the "legal" answer. When asked my personal opinion, it's likely to be somewhat different.
I'm dead against the "only by the rules, no matter what" position that many take today. See my comments on the "Takeoff Briefing" thread on Questions to get some idea where I'm coming from.
Like you, I've spent many years instructing and checking. We both know that you can't make a rule or an SOP to cover any and every eventuality. In fact, the FARs empower (require?) the PIC to deviate to any extent necessary to insure safety. I'm seeing less and less "thinking" as the years go by. Sad.
Do you agree?
Quite comfortable. Thank you for asking.
When I'm wearing my "legal" hat (as a DE), I'm likely to give the "legal" answer. When asked my personal opinion, it's likely to be somewhat different.
I'm dead against the "only by the rules, no matter what" position that many take today. See my comments on the "Takeoff Briefing" thread on Questions to get some idea where I'm coming from.
Like you, I've spent many years instructing and checking. We both know that you can't make a rule or an SOP to cover any and every eventuality. In fact, the FARs empower (require?) the PIC to deviate to any extent necessary to insure safety. I'm seeing less and less "thinking" as the years go by. Sad.
Do you agree?
Moderator
I'm with you good sir ... the present button-pressing PacMan brigade presents its own set of management and training problems.. and I can recall, many years ago, a wise greybeard checkie making the observation that the OM etc generally omitted to include the most important statement on the front page .. "to be used with a modicum of commonsense".
I only question the wisdom of innovative pilot initiative if there is not a reasonable need for it in the circumstances ... much along the old lines of "the superior pilot using his superior knowledge to avoid having to demonstrate his superior skill to get out of the superior quality hole he dug himself into ....... " (apologies to a BA article if my recollection is correct).
The need for thinking pilots is not likely to change ... but there is also the problem of overconfidence begetting unnecessary exposure to hazard in operations.
Having seen the legal system up close, I prefer to run a course which is generally conservative .. with a desire to avoid a repeat of the exercise. While my exposure was comfortable, I have seen the disastrous effects of unfortunate outcomes on the lives of responsible chaps who tried to do the right thing at the time ... but were called to account for their actions before the bench. It is unfortunate that the legal community has this need to put things in shades of black and white rather than real world greys ...
And it is not even the case where one's actions would be called into question by the most critical of one's professional peers ... I can recall several colleagues (in different disciplines) over the years who have found themselves at the wrong end of a skilful advocate's venom in the wonderful legal sport of trying to expand the available set of deep pockets prior the final attempt to seek damages ....
I guess it depends on just how much excitement a chap might like to have in his life ... I recall a colleague once suggesting that excitement in an aircraft was uncalled for and that one ought to keep excitement where it belongs .. on overnights ...
Perhaps I am just becoming insufferably boring in my old age ... as opposed to just plain boring in my younger years ?
I only question the wisdom of innovative pilot initiative if there is not a reasonable need for it in the circumstances ... much along the old lines of "the superior pilot using his superior knowledge to avoid having to demonstrate his superior skill to get out of the superior quality hole he dug himself into ....... " (apologies to a BA article if my recollection is correct).
The need for thinking pilots is not likely to change ... but there is also the problem of overconfidence begetting unnecessary exposure to hazard in operations.
Having seen the legal system up close, I prefer to run a course which is generally conservative .. with a desire to avoid a repeat of the exercise. While my exposure was comfortable, I have seen the disastrous effects of unfortunate outcomes on the lives of responsible chaps who tried to do the right thing at the time ... but were called to account for their actions before the bench. It is unfortunate that the legal community has this need to put things in shades of black and white rather than real world greys ...
And it is not even the case where one's actions would be called into question by the most critical of one's professional peers ... I can recall several colleagues (in different disciplines) over the years who have found themselves at the wrong end of a skilful advocate's venom in the wonderful legal sport of trying to expand the available set of deep pockets prior the final attempt to seek damages ....
I guess it depends on just how much excitement a chap might like to have in his life ... I recall a colleague once suggesting that excitement in an aircraft was uncalled for and that one ought to keep excitement where it belongs .. on overnights ...
Perhaps I am just becoming insufferably boring in my old age ... as opposed to just plain boring in my younger years ?
Last edited by john_tullamarine; 16th Dec 2002 at 01:03.
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I'm with West Coast on this one...
If you follow the GS all the way down at MDW or SNA you may well wet your pants toward the end of the rollout.
My manual says that if the runway is in sight at the MM, you may descend to one dot below the GS. If the GS isn't available, fly the VASI and if that's not up, well, just do the best you can(paraphrased, of course
)TC
My manual says that if the runway is in sight at the MM, you may descend to one dot below the GS. If the GS isn't available, fly the VASI and if that's not up, well, just do the best you can(paraphrased, of course
)TC
