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Natstrackalpha
2nd Jun 2014, 20:09
The Airlines.

The Principal of Minimum Fuel.

The Authorities.
The principal of carrying sufficient fuel for the taxi, flight, climb, step climb, cruise, descent, approach and landing. Plus reserve amounts of fuel for a go around, holding, diversion to a primary and secondary alternate airport at a lower altitude. Adequate fuel for engine failure and drift down to lower altitude, thereby burning more fuel at the lower altitude plus the extra fuel required to offset the drag caused by the single engine failure and the increase in fuel due to the second engine having to compensate for the failed engine.

Modern technology.
The principal of accurate information on weather conditions, by online weather reporting - delays, congestion and trends in traffic flow which could cause a delay or information on unserviceable facilities etc. and instant communication access by telephone, email, Skype, Satcom and others – thus readily accessible by pilots and operations.
The original safety requirements for pilots to include fuel for every eventuality were created in the early days of aviation due to unreliable meteorology forecasting – sporadic long range communication by landline telephone which at times were equally unreliable and lack of information regarding traffic flows on a global basis – unlike today where knowledge, information and communication are increasingly homogenous.
Communication between dispatcher operations and pilots is three-dimensional compared to the old airliner days of the19 40s and 1950s. This is when many of today’s regulations and laws on the carriage of reserve fuel amounts were created.
Today operations offices can communicate directly from their offices on the ground to the flight crew in the cockpit whether the aircraft is on the ground or in the air – by ACARS, by CPDLC and by sat-phone – flights can be kept ahead of events like no other time in the history of aviation.
So accurate is the weather forecasting and alongside the real-time updates of the Aircraft Crew Alerting and Reporting Systems – pilots are able to make pre-emptive decisions on whether or not to divert to another airport more readily than ever before thus saving the necessity of having to descend to a lower altitude, reject an approach and climb back up to a, perhaps lower cruise altitude to arrive at the alternate airport with adequate amounts of fuel for the approach and landing plus any contingencies.
It is for this reason that airlines can now employ strategies that will save fuel, time and money with no risk to the flight - as the reserve fuel for contingencies can be much reduced due to this greater access of information technology. Applying different strategies for long haul (long range) and short haul (short range), island destinations in remote areas of ocean and oceanic routes compared to mainland routes and destinations.
Flight Crews are still required by law to carry reserve fuel – but today, this reserve can be much constrained within the parameters of the greater and more accurate information available.
However, some pilots still prefer to take larger amounts of fuel than the `minimum` fuel required and there is dispute between some pilots and airlines as to how much fuel must be carried. The disputes become heated if any airlines apply to take an amount of fuel less than the legal required minimum.
There is also the `green` aspect of using less fuel in order to save fuel in an ever increasing fuel starved planet.

BOAC
2nd Jun 2014, 20:45
The AF 319 incident at CDG (http://www.pprune.org/spectators-balcony-spotters-corner/539846-air-france-a319-lfpg-engine-1-fuel-starvation.html)highlights one of the risks of carrying 'minimum fuel'....

framer
2nd Jun 2014, 21:55
Communication between dispatcher operations and pilots is three-dimensional compared to the old airliner days of the19 40s and 1950s
And yet we still got ourselves in trouble when the forecasters got the weather wrong in a Adelaide and Mildura.
Today operations offices can communicate directly from their offices on the ground to the flight crew in the cockpit whether the aircraft is on the ground or in the air – by ACARS, by CPDLC and by sat-phone – flights can be kept ahead of events like no other time in the history of aviation.
They can't at my airline because although we have new 737's we rely on HF radio when out of VHF range and it works about 50% of the time.
So accurate is the weather forecasting and alongside the real-time updates of the Aircraft Crew Alerting and Reporting Systems – pilots are able to make pre-emptive decisions
We still get unforecast fog every year so it's not that accurate.
However, some pilots still prefer to take larger amounts of fuel than the `minimum` fuel required
That's me 70% of the time. The other 30% of the time I agree that the FOD on the plan will cover any unforeseen issues.
Technology is often helpful but not always. Having an Ops controller in possession of critical weather information is of no use if they don't recognise the importance of it. We have ops controllers with no formal training on pretty low wages with a moderate turnover. I doubt any of them could tell you the difference between a TTF and a TAF. So with all the technology available, the human is still the bit where it most easily falls over .
and there is dispute between some pilots and airlines as to how much fuel must be carried.
It's pretty obvious why. The two groups have different motivators. The Pilots are motivated by their legal responsibility to carry enough fuel to safely negotiate any circumstances that arise during the flight combined with the desire to have a long career. The Airline managers are motivated by their legal responsibility to the shareholders. Two different jobs, two different skill sets, two different points of view, one has final say. Simple.

Piltdown Man
2nd Jun 2014, 21:57
BOAC - I don't agree. No matter what fuel was loaded, this event was waiting to catch an unsuspecting crew. This event clearly demonstrates the need to reconcile the fuel indicated with the actual amount in the tank.

But with regard to minimum fuel, as a European short haul pilot I have no problems whatsoever departing on statistically calculated minimum fuel - just so long as no one objects to me diverting or carrying more if I want to. I have now been flying on minimum fuel for nearly ten years which means I have flown in the order of 5,000 flights under this regime. Only occasionally do I or my company decide to put on more than minimum. In the last few years my only diversions were for en-route repairs and I'll also admit I've been close to diverting quite a few times.

But let us be clear. More fuel does not give you increased safety. It's how and where you burn the fuel that matters. More fuel certainly makes it easier to fly without thinking and it also means you can holder for longer. And when you can no longer hold, you will almost certainly come and and join me at the diversion airport. But my pax will have knicked the busses, I will be fuelled up and ready to depart. And you will be with the whingers wanting to know when you'll be getting the steps, fuel, busses etc. Additional fuel is an insurance policy for the company to minimise diversions. And remember, I fly in Europe and because of our warmongering past I'm spoilt for choice with regard to diversionary airfields. But if I flew long haul or out in the sticks I might have a different opinion.

framer
2nd Jun 2014, 22:40
But if I flew long haul or out in the sticks I might have a different opinion.
Actually that's worth thinking about. I normally lose the ability to go to a different airport when descending through about 20,000ft. I imagine Piltdown that you would have alternative options all the way down to the circuit even when carrying flight plan minimum fuel?

underfire
3rd Jun 2014, 00:52
The principal of accurate information on weather conditions, by online weather reporting - delays, congestion and trends in traffic flow which could cause a delay or information on unserviceable facilities etc. and instant communication access by telephone, email, Skype, Satcom and others – thus readily accessible by pilots and operations.emphasis added..

:mad: have you ever seen Steve Martin in "the Jerk" when he is operating to stand at the circus? He points to the whole background of available prizes, but when it comes down to it, only 2 are actually available...

BOAC
3rd Jun 2014, 06:53
This event clearly demonstrates the need to reconcile the fuel indicated with the actual amount in the tank. - you'll have to explain how, with an UNKNOWN significantly under-reading fuel gauge, you regularly refuel to avoid this possibility? How do you calculate required uplift? Do you drip on every turn-round?

Piltdown Man
3rd Jun 2014, 08:44
I may not have made myself clear. The AF A319 was missing some 1,280 fuel. That is a lot of fuel. If that happened on one flight, it should have been noticed either by the operating crew or at least error checking software when fuel burns were checked and analysed. The next barrier might be Engineering regularly performing a cross check of dips with ECAM. If none of these things were ever done, every crew flying this particular aircraft may have been flying with less fuel than they thought they had. But the point I'm making is that flying with minimum fuel would not have altered the outcome, unless of course we take some for Mum and the kids, a bit for Gran and a tonne and a half extra for possible gauge error - or should it be five tonnes?

And Framer, I normally (but not always) have diversion fuel when I park - as I said, I'm spoilt for choice.

BOAC
3rd Jun 2014, 09:19
But the point I'm making is that flying with minimum fuel would not have altered the outcome - I am generally with you as you should know on the topic, but the point I was making is that if you are 'short' by F Reserve when the company may wish you to land with FR (+ cont) does focus the eyes a little and DID alter the outcome ie the engine flamed out! The fact that the topic has been 'demoted' to 'Spotters' amazes me - presumably by a '5 tonnes for mum' pilot?

........and 'normally' having div fuel when you park means you are NOT flying with EU-OPS min fuel a lot of the time - ie no div required if etc etc.

Piltdown Man
4th Jun 2014, 16:11
I don't think EU-OPS prescribes how much fuel above final reserve you must land with. It is certainly clear about how the fuel calculations should be made and how much you should have before starting engines. But once they are started, the regulations are less rigid.

BOAC
4th Jun 2014, 17:13
I don't think EU-OPS prescribes how much fuel above final reserve you must land with- no, but it does requre you PLAN to land with at least RF. It is certainly clear about how the fuel calculations should be made and how much you should have before starting engines - it was 'clear' to the crew of that AF but just did not work! Replace 'have' with 'think you have'?