How much fuel do you carry ?
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How much fuel do you carry ?
Another thread touched upon a recent case at LHR , where some problems were possibly caused to some inbound pilots due to a runway closure, leading to holding. The basic question raised was, "Why should a few minutes' holding cause distress ?"
My usual fuel load (max 1000nm, usually much less) :
Taxi
Departure take-off to destination landing
5% of departure t/o to destination l/d, with a minimum cut-off
30 mins holding at destination holding waypoint, low level
Destination go-around to alternate landing
30 mins holding at alternate holding waypoint, low level
Extra added on for all the usual reasons -- notams, weather, icing, lower levels, serviceability, airmanship, common sense, past experience etc. etc. etc. etc. etc. .
Anyone agree/disagree. I never stop learning, or wanting to.
Would also be interested in the long-haul side of things, of which I've no experience, asuming there's any difference (apart from more zeros at the end of the figures).
My usual fuel load (max 1000nm, usually much less) :
Taxi
Departure take-off to destination landing
5% of departure t/o to destination l/d, with a minimum cut-off
30 mins holding at destination holding waypoint, low level
Destination go-around to alternate landing
30 mins holding at alternate holding waypoint, low level
Extra added on for all the usual reasons -- notams, weather, icing, lower levels, serviceability, airmanship, common sense, past experience etc. etc. etc. etc. etc. .
Anyone agree/disagree. I never stop learning, or wanting to.
Would also be interested in the long-haul side of things, of which I've no experience, asuming there's any difference (apart from more zeros at the end of the figures).
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You misread my other post. I did not say pilots were having problems, I said they were in discussion with the company about possible diversion.
You carry 30 mins more fuel than I do, as I usually plan;
Route burn
Contingency (% or ERA)
Diversion
Reserve (30mins)
Taxi
Now, as the reserve is the legal minimum, then the only fuel carried "spare" is the contingency, planned remaining is therefore the reserve plus unused contingency. Reserve fuel is not considered "holding fuel at alternate" or anything else other than what *must* be in the tanks on landing.
There is no problem adding extra fuel if the ETA is a busy time at the destination and vectoring/holding can reasonably be expected, or CAT3 conditions are forecast or any one of a number or reasons left to the pilot's discretion but we don't regularly carry holding fuel we don't use, that's one of the things the contigency fuel is for.
Arriving at destination holding fix with all the contigency and (commercial alternate) diversion fuel available, it makes sense to talk to the company and see where they might like us to go when ATC announce, without notice, a runway closure that indicates landing with the contigency all used up in a 25 minute hold.
To always carry another 30 minutes of fuel around is commercial madness, it is surely better to suffer the odd (rare) fuel diversion than to burn fuel carrying the stuff around?
You carry 30 mins more fuel than I do, as I usually plan;
Route burn
Contingency (% or ERA)
Diversion
Reserve (30mins)
Taxi
Now, as the reserve is the legal minimum, then the only fuel carried "spare" is the contingency, planned remaining is therefore the reserve plus unused contingency. Reserve fuel is not considered "holding fuel at alternate" or anything else other than what *must* be in the tanks on landing.
There is no problem adding extra fuel if the ETA is a busy time at the destination and vectoring/holding can reasonably be expected, or CAT3 conditions are forecast or any one of a number or reasons left to the pilot's discretion but we don't regularly carry holding fuel we don't use, that's one of the things the contigency fuel is for.
Arriving at destination holding fix with all the contigency and (commercial alternate) diversion fuel available, it makes sense to talk to the company and see where they might like us to go when ATC announce, without notice, a runway closure that indicates landing with the contigency all used up in a 25 minute hold.
To always carry another 30 minutes of fuel around is commercial madness, it is surely better to suffer the odd (rare) fuel diversion than to burn fuel carrying the stuff around?
Enough!
The trick is always to be comfortable with your decisions. I fully accept that simply adding an arbitary amount "for the wife & kids" on each and every sector is commercial madness, but when the situation requires extra then, by all means, take it.
As an example: Winter weather blankets Western Europe. Fog and snow almost everywhere. Flight planned fuel from MAN to AMS was 7000kg using Boeing 737-200 equipment. I actually took over 15 tonnes as my evaluation was that it was unlikely we would get in either at AMS or the alternate DUS. Ops were insistant that as we were CAT 3 we should depart on schedule so off we went. A few hours later back at MAN we landed with under 3000kg left having been all around the Netherlands and Germany as visibilities dropped to 50m. The only two major airports were left MAN & PWK.
Throught all this I was able to take my time making decisions as fuel was not a problem and things were working out much as I presumed. An extreme example I know but as they say "I learned about flying that day"
As an example: Winter weather blankets Western Europe. Fog and snow almost everywhere. Flight planned fuel from MAN to AMS was 7000kg using Boeing 737-200 equipment. I actually took over 15 tonnes as my evaluation was that it was unlikely we would get in either at AMS or the alternate DUS. Ops were insistant that as we were CAT 3 we should depart on schedule so off we went. A few hours later back at MAN we landed with under 3000kg left having been all around the Netherlands and Germany as visibilities dropped to 50m. The only two major airports were left MAN & PWK.
Throught all this I was able to take my time making decisions as fuel was not a problem and things were working out much as I presumed. An extreme example I know but as they say "I learned about flying that day"
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Apologies to the Moderators for posting in RP. Good job I had enough diversion bytes in my tanks to make it to TL !
EDDNR -- was referring to BOAC's post, not that it matters -- it simply sparked of the idea of this separate thread which might be of interest.
Thanks for your comments, though. In my case, contingency, even if I had all of it unburnt at start of destination hold, would typically be, say, 150 kg. That's 4mins 30secs of destination holding at the stipulated 1500ft ; not a lot, then. I frequently get "10mins holding" estimates into LHR, which often work out that way, so I'd frequently be off to my alternate !
In addition, when everyone else is diverting from LHR, the alternates can fill up and/or become congested very quickly ; I've been in that scenario! I remember diverting to LTN one time and parking virtually where I'd turned off the runway -- chocka ! Alternate holding becomes highly likely in those cases, too. If you divert on min fuel and have to hold at alternate, then you're declaring an emergency, are'nt you ? (less than final reserve on landing).
EDDNR -- was referring to BOAC's post, not that it matters -- it simply sparked of the idea of this separate thread which might be of interest.
Thanks for your comments, though. In my case, contingency, even if I had all of it unburnt at start of destination hold, would typically be, say, 150 kg. That's 4mins 30secs of destination holding at the stipulated 1500ft ; not a lot, then. I frequently get "10mins holding" estimates into LHR, which often work out that way, so I'd frequently be off to my alternate !
In addition, when everyone else is diverting from LHR, the alternates can fill up and/or become congested very quickly ; I've been in that scenario! I remember diverting to LTN one time and parking virtually where I'd turned off the runway -- chocka ! Alternate holding becomes highly likely in those cases, too. If you divert on min fuel and have to hold at alternate, then you're declaring an emergency, are'nt you ? (less than final reserve on landing).
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AC - for me, and I think, most, the '30 mins holding at destination' (planned as a matter of course) is an expensive luxury!
"EDDNR -- was referring to BOAC's post, not that it matters"
I'm not hurt, really
. My point was that there should be no cries of 'foul' if you have to hold for 20 minutes inbound LON major airfields. That indeed is the required fuel planning the CAA ask for/expect? If you reduce below that holding fuel at LON you do it at your own risk and will suffer more 'stress' eg if a runway closure happens. The CAA recommendation is, as I recall, to build EXPECTED holding into route fuel. Then 'contingency' that. Then comes fuel for mum and the kids if you wish it/have them.
In 37 years of aviation I have been SERIOUSLY let down by the Met (world-wide) service at least 4 times, landing (non commercial) with empty tanks once, getting past PNR (commercial light twin) with destination wx well below minima once, finding the whole of the south of UK's airfields bar one in unforecast freezing fog (commercial - thank you Manston!) and almost having to either land a Harrier in Stavanger high street - or eject - once. I have grey hairs. I do not want any more (grey ones!).
"EDDNR -- was referring to BOAC's post, not that it matters"
I'm not hurt, really
. My point was that there should be no cries of 'foul' if you have to hold for 20 minutes inbound LON major airfields. That indeed is the required fuel planning the CAA ask for/expect? If you reduce below that holding fuel at LON you do it at your own risk and will suffer more 'stress' eg if a runway closure happens. The CAA recommendation is, as I recall, to build EXPECTED holding into route fuel. Then 'contingency' that. Then comes fuel for mum and the kids if you wish it/have them.In 37 years of aviation I have been SERIOUSLY let down by the Met (world-wide) service at least 4 times, landing (non commercial) with empty tanks once, getting past PNR (commercial light twin) with destination wx well below minima once, finding the whole of the south of UK's airfields bar one in unforecast freezing fog (commercial - thank you Manston!) and almost having to either land a Harrier in Stavanger high street - or eject - once. I have grey hairs. I do not want any more (grey ones!).
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Which all goes back to my original point about long hauls being caught out yesterday. Weather forecast CAVOK or pretty close to, nothing in the NOTAMS, middle of the afternoon lull at LHR (which is probably why they decided to carry out the de-ice/pre-ice then).
ATC only learn about delays at our TOD and the situation builds as we are the last 100 miles into LAM.
If there are sudden holds announced with 10, then 20 then 25 mins being quoted, isn't it sensible to discuss options before you use up the contigency?
Wish I worked for a company where it was considered OK to carry an hours holding fuel on every flight.
Your decision on your MAN 737 day was correct with all the information you had to hand. Yesterday was an exception.
ATC only learn about delays at our TOD and the situation builds as we are the last 100 miles into LAM.
If there are sudden holds announced with 10, then 20 then 25 mins being quoted, isn't it sensible to discuss options before you use up the contigency?
Wish I worked for a company where it was considered OK to carry an hours holding fuel on every flight.
Your decision on your MAN 737 day was correct with all the information you had to hand. Yesterday was an exception.
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Many long-haul flights operate on re-dispatch, where the company has this procedure.
Have only had a problem at LHR one time....holding at LOGAN for 20 minutes, suspected a rat when told to hold for another twenty (ATIS all the while reporting 4000 metres), asked the F/E to monitor LHR ground and he reported that the airfield was going to low vis procedures and the RVR was now 800 metres....ATIS still reporting 4000.
Quick dash to LGW, first one in with others following close behind.
Three tons remaining at shutdown (TriStar), slim but workable.
ATC very accomodating that day...
Have only had a problem at LHR one time....holding at LOGAN for 20 minutes, suspected a rat when told to hold for another twenty (ATIS all the while reporting 4000 metres), asked the F/E to monitor LHR ground and he reported that the airfield was going to low vis procedures and the RVR was now 800 metres....ATIS still reporting 4000.
Quick dash to LGW, first one in with others following close behind.
Three tons remaining at shutdown (TriStar), slim but workable.
ATC very accomodating that day...
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To always carry another 30 minutes of fuel around is commercial madness, it is surely better to suffer the odd (rare) fuel diversion than to burn fuel carrying the stuff around?"
Really ? How much does it really cost to carry that extra 30 mins of fuel compared to the odd (rare) diversion. Our quotes are aprox. 50 kilo's extra burn per extra 1000 K carried per hour. 50 kilo's is around 62 litre's, last I heard Jet A1 was around 15p per litre, ( don't know the latest figure though ). So, total cost for carrying an extra ton per hour = £9.30. Our average flight is about 1 hour 30 mins so aprox. £14 per flight.
Now this may not sound allot but to be fair you have to multiply by the total flights per year - for me at the most = 450. Total cost per year = Aprox. £6300
Anyone care to work out how much a divert cost ? It's not just the extra financial cost of going to another airport and either doing an extra flight to final destination or coaching pax. from one to another, it's also the delay it incurs and the damage to customer relations - particularly when the competition has got in because they can hold at destination. The problem is the accountants can not easily put a price on that, unlike adding up the cost of carrying fuel.
I may be wrong but I'll stick with my 'commercial madness' and do what I always do - take at least an extra 20 mins fuel if I can get it on, it keeps me young if nothing else.
Really ? How much does it really cost to carry that extra 30 mins of fuel compared to the odd (rare) diversion. Our quotes are aprox. 50 kilo's extra burn per extra 1000 K carried per hour. 50 kilo's is around 62 litre's, last I heard Jet A1 was around 15p per litre, ( don't know the latest figure though ). So, total cost for carrying an extra ton per hour = £9.30. Our average flight is about 1 hour 30 mins so aprox. £14 per flight.
Now this may not sound allot but to be fair you have to multiply by the total flights per year - for me at the most = 450. Total cost per year = Aprox. £6300
Anyone care to work out how much a divert cost ? It's not just the extra financial cost of going to another airport and either doing an extra flight to final destination or coaching pax. from one to another, it's also the delay it incurs and the damage to customer relations - particularly when the competition has got in because they can hold at destination. The problem is the accountants can not easily put a price on that, unlike adding up the cost of carrying fuel.
I may be wrong but I'll stick with my 'commercial madness' and do what I always do - take at least an extra 20 mins fuel if I can get it on, it keeps me young if nothing else.
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My original post referred to long haul flying. Over the sectors I fly, half the extra fuel would be burnt carrying it, meaning having to load say 10 tonnes extra to arrive with 5,000kg (lasting 30 mins on my type).
With many long haul departures up to MTOW, that means we'd need to leave 100 pax or 10 tonnes of freight behind just to carry fuel "just in case". Commercial madness, as I said.
With many long haul departures up to MTOW, that means we'd need to leave 100 pax or 10 tonnes of freight behind just to carry fuel "just in case". Commercial madness, as I said.
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There are two distinct types of operation being discussed in parallel here, which is causing some of the disagreement.
1 -- Long haul. Carrying extra fuel creates a vicious circle. To carry fuel increases fuel burn to the extent that it becomes necessary to carry even more fuel to compensate and restricts pax/cargo loads. Cost escalates rapidly.
2 -- Short haul. Carrying extra fuel is usually a relatively minor problem with respect to pax/cargo and cost. Frequent sectors and business style pax demand low diversion frequencies as a high priority.
Make sense ?
PS. -- BOAC, no offence intended. I did'nt mean that your post did'nt matter, I meant that it did'nt matter that EDDNR thought that I was referring to his post ........ if you see what I mean.
1 -- Long haul. Carrying extra fuel creates a vicious circle. To carry fuel increases fuel burn to the extent that it becomes necessary to carry even more fuel to compensate and restricts pax/cargo loads. Cost escalates rapidly.
2 -- Short haul. Carrying extra fuel is usually a relatively minor problem with respect to pax/cargo and cost. Frequent sectors and business style pax demand low diversion frequencies as a high priority.
Make sense ?
PS. -- BOAC, no offence intended. I did'nt mean that your post did'nt matter, I meant that it did'nt matter that EDDNR thought that I was referring to his post ........ if you see what I mean.
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"2 -- Short haul. Carrying extra fuel is usually a relatively minor problem with respect to pax/cargo and cost. Frequent sectors and business style pax demand low diversion frequencies as a high priority."
I could not agree more. Try costing the goodwill of the pax who have missed their connections/meetings/etc. and are now sitting somewhere else, unable to get off and waiting for the 'plan' to come together to get them to where they paid to go in the first place! Sometimes though, as has been said already, it is better to scoot off early and refuel 'first in the queue' if you cannot wait.
PS AC - No offence taken - all in "the best POSSIBLE taste" as KE? used to say. I was only 'joshing'!
I could not agree more. Try costing the goodwill of the pax who have missed their connections/meetings/etc. and are now sitting somewhere else, unable to get off and waiting for the 'plan' to come together to get them to where they paid to go in the first place! Sometimes though, as has been said already, it is better to scoot off early and refuel 'first in the queue' if you cannot wait.
PS AC - No offence taken - all in "the best POSSIBLE taste" as KE? used to say. I was only 'joshing'!
JAR-OPS Fuel Policy
For interest and as a reference, you might like to read/revisit the CAA's report on UK air operators' fuel planning policies. This report, which was based upon information obtained in the Summer of 2000, describes JAR-OPS 1 fuel policy and how various operators specified these requirements for the aeroplanes they operated. In particular, the report addresses reserve fuel.
The report can be accessed through www.chirp.co.uk>>confidential reports>>library.
The report can be accessed through www.chirp.co.uk>>confidential reports>>library.
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FlpasOne,
I`d be interested in your AIC.
At our company we typically depart for LHR with trip fuel, altn fuel (EGSS mostly), final reserve(30 min), and a statistical amount of contingency fuel, which has a minimum of 5 min.
Now, this contingency fuel will in some cases be more than 20 min (as it is statistical), but more often it is closer to 10 min.
Regards.
I`d be interested in your AIC.
At our company we typically depart for LHR with trip fuel, altn fuel (EGSS mostly), final reserve(30 min), and a statistical amount of contingency fuel, which has a minimum of 5 min.
Now, this contingency fuel will in some cases be more than 20 min (as it is statistical), but more often it is closer to 10 min.
Regards.
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seat OA
The reference is at www.ais.org.uk
You need to register (free for change!)
AIC 36(P170)/98 entitled 'Fuel reserves for aircraft approaching the UK'
It's a .pdf file that I can't cut and paste from.
In essence it re-iterates the JAR fuel policy minima but goes to say that the London TMA is a bit of a special case because the 'no delay expected' of 20 mins quite often applies.
It goes on to point out that a diversion accross the TMA will probably not be a straight line.
The clear recommendation is not to arrive in the London TMA with the JAR legal minimum fuel - ie: have that 20 mins 'in the bank (tank?)
Have a read and make your own judgement.
Rgds
The reference is at www.ais.org.uk
You need to register (free for change!)
AIC 36(P170)/98 entitled 'Fuel reserves for aircraft approaching the UK'
It's a .pdf file that I can't cut and paste from.
In essence it re-iterates the JAR fuel policy minima but goes to say that the London TMA is a bit of a special case because the 'no delay expected' of 20 mins quite often applies.
It goes on to point out that a diversion accross the TMA will probably not be a straight line.
The clear recommendation is not to arrive in the London TMA with the JAR legal minimum fuel - ie: have that 20 mins 'in the bank (tank?)
Have a read and make your own judgement.
Rgds
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All
I keep statistics (sad maybe, I know), that I review in order to quantify probabilities.
In the last 9 months or so that I have kept stats, I have operated into LHR about 200 times for a large operator using shorthaul aircraft - ie fairly representative of an LHR user.
Now I'm not saying that I carry flight plan fuel by any means - far from it - but in those 200 rotations I have on only 8 occasions used more than trip + contingency fuel (15 mins), and on those occasions the most I have used above contingency was still only about 80% of my diversion fuel, in fact on only 2 occasions have I had to commit (the last time yesterday evening on a flight from a near European destination) as I usually plan to cover statistical holding at the 15% level from extra fuel.
LHR never fails however in it's capacity to catch you out, about 3 weeks ago, mid afternoon, 30 mins holding out of the blue in CAVOK esaterlies (18th Dec2002) and again yesterday evening - ok snow in am but lovely evening, but ground delays with no stands causing reduced flow rates inbound = 40 mins holding - very glad the ZFW was down 5 tonnes and I loaded 200 kg extra fuel!
Safe flying out there!
I keep statistics (sad maybe, I know), that I review in order to quantify probabilities.
In the last 9 months or so that I have kept stats, I have operated into LHR about 200 times for a large operator using shorthaul aircraft - ie fairly representative of an LHR user.
Now I'm not saying that I carry flight plan fuel by any means - far from it - but in those 200 rotations I have on only 8 occasions used more than trip + contingency fuel (15 mins), and on those occasions the most I have used above contingency was still only about 80% of my diversion fuel, in fact on only 2 occasions have I had to commit (the last time yesterday evening on a flight from a near European destination) as I usually plan to cover statistical holding at the 15% level from extra fuel.
LHR never fails however in it's capacity to catch you out, about 3 weeks ago, mid afternoon, 30 mins holding out of the blue in CAVOK esaterlies (18th Dec2002) and again yesterday evening - ok snow in am but lovely evening, but ground delays with no stands causing reduced flow rates inbound = 40 mins holding - very glad the ZFW was down 5 tonnes and I loaded 200 kg extra fuel!
Safe flying out there!
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Interesting that TopBunk mentions "commit".
Does this mean that some British operators decide unto themselves that they can use their designated alternate fuel, on a more or less routine basis, to commit to landing at LHR?
What happens if LHR suddenly closes, for whatever reason?
Do they land in the Thames?
Where I have worked, diversion is REQUIRED if down to alternate fuel reserves.
Does this mean that some British operators decide unto themselves that they can use their designated alternate fuel, on a more or less routine basis, to commit to landing at LHR?
What happens if LHR suddenly closes, for whatever reason?
Do they land in the Thames?
Where I have worked, diversion is REQUIRED if down to alternate fuel reserves.
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How much fuel do you carry?
My Company Ops Manual while not actually defining 'contingency fuel' describes it as compensating for:
-deviations of an individual a/c from expected fuel consumption data
-deviations from forecast met conditions
-deviations from planned routeings/cruising FLs.
No mention of holding. As I understand it, if I consider it likely that I will have to go into the hold on arrival I need to consider taking extra fuel and leave the contingency element out of the calculation completely.
-deviations of an individual a/c from expected fuel consumption data
-deviations from forecast met conditions
-deviations from planned routeings/cruising FLs.
No mention of holding. As I understand it, if I consider it likely that I will have to go into the hold on arrival I need to consider taking extra fuel and leave the contingency element out of the calculation completely.
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I think JAR OPS defines contingency. It's exactly as you describe.
The key element here is that contingency fuel is there in case something UNFORSEEN happens en route (different route, level etc).
Now if something is forseen, the CAA interpretation of likely holding in the London TMA for example, you should not plan to use contingency fuel for that purpose.
The decision to go below min fuel required to approach, go round and divert with 30 mins hold (Company Min Reserve or similar) is a difficult one but, of course, can happen.
Don't forget, there's no guarantee that your alternate will not close suddenly as well - but there are only so many contingencies you can reasonably plan for.
In the end, that's what we're paid for.
The key element here is that contingency fuel is there in case something UNFORSEEN happens en route (different route, level etc).
Now if something is forseen, the CAA interpretation of likely holding in the London TMA for example, you should not plan to use contingency fuel for that purpose.
The decision to go below min fuel required to approach, go round and divert with 30 mins hold (Company Min Reserve or similar) is a difficult one but, of course, can happen.
Don't forget, there's no guarantee that your alternate will not close suddenly as well - but there are only so many contingencies you can reasonably plan for.
In the end, that's what we're paid for.