Diversion/alternate question
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Diversion/alternate question
For example, if a commercial flight was to depart an airport say in the UK and fly towards it's destination airport lets say in Europe, what would be the course of action, if the crew calculated during the flight, that they would end up using some of their fuel reserves to get to the original destination? ie Stronger than forecast headwinds or ATC delays/restrictions, hence more fuel used than planned.
Would they fly to their first or second alternate or would they continue to the planned destination using some of their fuel reserves and contingency fuel?
I'll apologise in advance if it appears to be a silly question. However, with commercial pressure being what it is, I just wondered if it would be normal to carry on to the originally planned destination.
Many thanks,
Would they fly to their first or second alternate or would they continue to the planned destination using some of their fuel reserves and contingency fuel?
I'll apologise in advance if it appears to be a silly question. However, with commercial pressure being what it is, I just wondered if it would be normal to carry on to the originally planned destination.
Many thanks,
Not daft at all !
Don't forget that alternates may be located beyond the original destination anyway which would preclude somewhat the reason for the diversion. In the normal course of events planned 'contingency' fuel should cover unexpected headwinds, lower than planned flight-levels etc - however, on the day it is possible that things totally conspire against the crew in question. In such event an analysis of weather at destination, anticipated delays, possibility of short-cuts and an expeditious approach may help the crew out of the mire - an appreciation of weather and similar factors at the planned alternates will also come into the equation.
As the crew will be monitoring their fuel situation (I hope) during the cruise they will also have time to weigh up the reaction of their management to a. landing at destination with less than normal reserves or b. diverting en-route to refuel because they cannot justify continuing to their destination - either way they will be criticised or worse !
Some aircraft and indeed some airlines are more likely to encounter this particular problem than others. Personally I weigh up all the things may might go wrong and come up with what I believe is a sensible fuel figure which strikes a compromise between the plog (computer flight plan) fuel requirement and the cost of carrying fuel that I probably will not require on the day. Fortunately my aircraft allows me the luxury of taking as much fuel as I wish 99% of the time - other aircraft types are however much more performance limited and may operate schedules in which the likelihood of an en-route diversion are much higher. Dare I say that since the introduction of computer flight plans the carriage of unnecessary fuel has reduced dramatically - which is not to say that the figures don't have to be carefully examined against met-winds etc - rubbish in, rubbish out !
There are of course additional factors regarding long-haul operations which are probably outside the remit of your question.
Don't forget that alternates may be located beyond the original destination anyway which would preclude somewhat the reason for the diversion. In the normal course of events planned 'contingency' fuel should cover unexpected headwinds, lower than planned flight-levels etc - however, on the day it is possible that things totally conspire against the crew in question. In such event an analysis of weather at destination, anticipated delays, possibility of short-cuts and an expeditious approach may help the crew out of the mire - an appreciation of weather and similar factors at the planned alternates will also come into the equation.
As the crew will be monitoring their fuel situation (I hope) during the cruise they will also have time to weigh up the reaction of their management to a. landing at destination with less than normal reserves or b. diverting en-route to refuel because they cannot justify continuing to their destination - either way they will be criticised or worse !
Some aircraft and indeed some airlines are more likely to encounter this particular problem than others. Personally I weigh up all the things may might go wrong and come up with what I believe is a sensible fuel figure which strikes a compromise between the plog (computer flight plan) fuel requirement and the cost of carrying fuel that I probably will not require on the day. Fortunately my aircraft allows me the luxury of taking as much fuel as I wish 99% of the time - other aircraft types are however much more performance limited and may operate schedules in which the likelihood of an en-route diversion are much higher. Dare I say that since the introduction of computer flight plans the carriage of unnecessary fuel has reduced dramatically - which is not to say that the figures don't have to be carefully examined against met-winds etc - rubbish in, rubbish out !
There are of course additional factors regarding long-haul operations which are probably outside the remit of your question.
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Beamer,
Thanks for taking the time to explain the question. I think my concern would be the 'worst case scenario' dilemma! ie. no short cuts, no expeditious routing, no improved flight levels etc. then what do you do? Continue, to the destination eating in to the reserves, or divert to the closer alternate and causing major expense and inconvenience to all and sundry?
What do you now do with the flight plan? If, diverting amend the flight plan or what exactly?
I apologise for taking it to the extreme, but I've heard that this is a typical interview question, and you go through the obvious answers, but the interviewer continues to say' you cannot do this or that ' so now what are you going to do? That kind of thing!
Many thanks,
Thanks for taking the time to explain the question. I think my concern would be the 'worst case scenario' dilemma! ie. no short cuts, no expeditious routing, no improved flight levels etc. then what do you do? Continue, to the destination eating in to the reserves, or divert to the closer alternate and causing major expense and inconvenience to all and sundry?
What do you now do with the flight plan? If, diverting amend the flight plan or what exactly?
I apologise for taking it to the extreme, but I've heard that this is a typical interview question, and you go through the obvious answers, but the interviewer continues to say' you cannot do this or that ' so now what are you going to do? That kind of thing!
Many thanks,
Assuming that all your calculations show that landing at your destination will put you below normal arrival minimum fuel - you should nonetheless be able to continue to that destination provided that you are able to be assured of a landing - in other words you now need everything going for you - good weather, choice of runways ideally, an ATC environment that will assist your potential predictament etc. As I mentioned earlier, it may be that you will have to overfly your destination to reach your nominated alternate, example inbound UK from Spain, destination Birmingham with Manchester as alternate. By definition of course you would normally land with even less fuel having diverted from overhead your destination prior to deciding to divert. If on the other hand you had to overfly your alternate prior to reaching your destination you may have to make an earlier decision - example inbound UK from Spain - destination East Midlands with Gatwick nominated as alternate.
At the end of the day you make a decision at the planning stage as to the suitability of declared alternates and the fuel you intend to carry. Normal fuel planning will give a range of requirements to calculate the fuel required including contingency, diversion and holding - you then decide how much you will actually take based upon your knowledge and experience of the flight you are about to depart upon. Flying is not an exact science so on the day you may find that you should have taken that little bit more and are now concerned as to whether you can achieve a safe landing at destination. If you find yourself in the overhead or hold with delays you will know how much fuel you need to divert with BUT there may be proviso in your company's procedures for you to elect to land at your destination with less than normal reserves IF you are certain that a landing is imminent based upon prevailing circumstances. No-one is going to get too excited if you shutdown with a little less than normal - management tend to get more concerned when you flame out taxying onto stand because you are down to fumes !
On longer sectors there are concepts of Critical Points, Last Point of Diversion, Point of No Return etc which perhaps you will encounter later in your career.
At the end of the day you make a decision at the planning stage as to the suitability of declared alternates and the fuel you intend to carry. Normal fuel planning will give a range of requirements to calculate the fuel required including contingency, diversion and holding - you then decide how much you will actually take based upon your knowledge and experience of the flight you are about to depart upon. Flying is not an exact science so on the day you may find that you should have taken that little bit more and are now concerned as to whether you can achieve a safe landing at destination. If you find yourself in the overhead or hold with delays you will know how much fuel you need to divert with BUT there may be proviso in your company's procedures for you to elect to land at your destination with less than normal reserves IF you are certain that a landing is imminent based upon prevailing circumstances. No-one is going to get too excited if you shutdown with a little less than normal - management tend to get more concerned when you flame out taxying onto stand because you are down to fumes !
On longer sectors there are concepts of Critical Points, Last Point of Diversion, Point of No Return etc which perhaps you will encounter later in your career.
Refering to an interview question:
Perhaps you may mention during the interview that a quick word to the helpful folks at ATC would be in order.
No need to declare " min fuel" or anything drastic but mention you are a bit tight on fuel and sometimes they can give you a hand.
Not so great an idea in a high traffic enviroment but usefull when headed for the boonies.
Of course if you are actually at min fuel do not be shy about confessing.
I do believe there was a case in New york when a 707 was flown to exhaustion and they never actually CLEARLY told ATC that they had an emergency.
Take this with a grain of salt because:
Remember, I am a helicopter pilot and we always seem to be short of fuel from start up when IFR. Our low cruise speeds mean we are effected by any headwind and burn fuel at a high rate VS total on board. ( 600 LBS/ hr 1850 lbs on start - 135 KTS TAS 0 wind ) We also operate in the boonies and the alternate is often our departure airport.
Airline interviewers may be looking for an entirely different answer.
Best of luck.
Perhaps you may mention during the interview that a quick word to the helpful folks at ATC would be in order.
No need to declare " min fuel" or anything drastic but mention you are a bit tight on fuel and sometimes they can give you a hand.
Not so great an idea in a high traffic enviroment but usefull when headed for the boonies.
Of course if you are actually at min fuel do not be shy about confessing.
I do believe there was a case in New york when a 707 was flown to exhaustion and they never actually CLEARLY told ATC that they had an emergency.
Take this with a grain of salt because:
Remember, I am a helicopter pilot and we always seem to be short of fuel from start up when IFR. Our low cruise speeds mean we are effected by any headwind and burn fuel at a high rate VS total on board. ( 600 LBS/ hr 1850 lbs on start - 135 KTS TAS 0 wind ) We also operate in the boonies and the alternate is often our departure airport.
Airline interviewers may be looking for an entirely different answer.
Best of luck.
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As an airline pilot you should always put safety first,so you should always consider the worst scenario possible.Every take-off may be a reject,every landing may be a go-around,...
This way you'll be prepared no matter what.
And you should not put yourself in a corner.
One ex: at an airport,heavy snow,rwy closed ,a/c holding for rwy to be opened.Some arrived at fuel reserve and divert.One cpt asks the controller when he estimates the rwy will be open,then decides to wait a little longer,consuming his final reserve.The ground staff couldn't open the rwy as said,so later on ,a mayday declared,and the cpt had to land on a very contaminated rwy,in heavy snow..not a nice thing to do.He put himself in a corner,not many choices of what to do.
So,my answer to you is,divert.If you decide that you'll reach your destination with less than final reserve you'll better land at a route alternate,and get some more fuel.
It's also your licence involved.Imagine something will go wrong,you'll have to declare emergency,and the CAA will be all over you.And your company will not back you up with such a decision,i can assure you.
Fly safe , the cowboys era is gone...
Brgds
Alex
This way you'll be prepared no matter what.
And you should not put yourself in a corner.
One ex: at an airport,heavy snow,rwy closed ,a/c holding for rwy to be opened.Some arrived at fuel reserve and divert.One cpt asks the controller when he estimates the rwy will be open,then decides to wait a little longer,consuming his final reserve.The ground staff couldn't open the rwy as said,so later on ,a mayday declared,and the cpt had to land on a very contaminated rwy,in heavy snow..not a nice thing to do.He put himself in a corner,not many choices of what to do.
So,my answer to you is,divert.If you decide that you'll reach your destination with less than final reserve you'll better land at a route alternate,and get some more fuel.
It's also your licence involved.Imagine something will go wrong,you'll have to declare emergency,and the CAA will be all over you.And your company will not back you up with such a decision,i can assure you.
Fly safe , the cowboys era is gone...
Brgds
Alex
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I've heard that this is a typical interview question, and you go through the obvious answers, but the interviewer continues to say' you cannot do this or that ' so now what are you going to do? That kind of thing!
Always give double answers. "If that happens then I will do x and if I can't do that then I will do y".
If they jump ahead and deny you option y you go back a step and say "well when option _x_ closed I would check option y was still available and plan option z just in case.
If they keep denying you options it may well be that the right answer is to crash. Don't forget to prepare for that!
