The flight plan fuel assumes that you’ll arrive, do an approach followed by a go around and divert to the alternate where you do another approach and land with fixed reserve plus possibly contingency fuel. It doesn’t allow for re sequencing following a runway change or the extra holding involved when everyone diverts at the same time. It assumes you’re the only aircraft in the sky.

Contingency fuel gets reduced while the delays get increased, contingency will cover one item not the multiple ones which are becoming increasingly common. On a recent 4 hour flight I had 12 minutes contingency fuel, half of which I would have used with a cruise level 2000’ below the planned optimum which isn’t uncommon. This leaves enough for one holding pattern, then change to the less favourable arrival runway and I arrive with below minimum diversion fuel. But the weather forecast is good so it’s okay, until the MET man gets it wrong and the thunderstorms arrive early.

Flight plan fuel is simply the legal minimum departure amount rather than a real world figure.

What is sufficient fuel for you? Minimum plus 2XX kgs and landing before the engines flame out?

"declaring a Mayday early kept them safe”. Are you serious? There are clear rules when you have to declare a fuel emergency.
At least in one point I can support you. You should try to be ahead, before situations like this develop. This begins with captain’s decision on the amount of fuel required. 2XX kgs extra fuel which equals about 7 minutes flying time for a potentially very busy airport like MAD with parallel approaches and crab weather is a joke.

One Captain telling another captain how much fuel they should take, is about as productive as telling them how to do their hair.

Nothing in principle, but on the A330 that amount of fuel (4.6T) would have generated a L + R Wing TK LO LVL ECAM warning for almost the entire flight. :bored:

To add a little context (and no meat of my own)

Minimum fuel quantity for takeoff..................................................... ......................5 200 kg (11 461 lb)
The ECAM alerts that are related to fuel low level in the wing tanks (FUEL WING TK LO LVL, etc.)
must not appear for takeoff.

Minimum weight...................................................... .........................................121 000 kg (266 760 lb)

FUEL L + R WING TK LO LVL:
>> Depending on the pitch attitude and fuel density, the alert may be triggered when fuel in one of the inner tank is between 1 100 kg (2 425 lb) and 2 520 kg (5 556 lb).

crunching some numbers:

ADDT fuel for planning with no alternate and independent runways (15 mins holding) ....... 1100 kg
FRSV IFR EASA rules (30 mins holding)............. 2200 kg
CONTG mnm 5 min ................. 400 kg

TAXI fuel ...................................400 kg

TOTAL = TAXI + TRIP + CNTG + ALTN + FRSV
4600 = 400 + TRIP + 400 + 1100 + 2200
TRIP = 500 kg

(exits stage through the trap door, you keep the coat)

At our outfit we carry 20-30 mins extra on average (even with clear weather), we're doing fine, thank you :)
There is something called gauge error.
If you're unlucky, they will all be on the negative side, and you'll end up taking off with a few percent less fuel than legal minimum :)

Also if anything happens during taxi out, you have to go back to the gate hahaha

My simple fuel calculation when the weather and the weatherman was suspect was MLW+FBO-ZFW.

If you think carrying extra fuel is expensive, have a look at the adjusted insurance premiums after flaming out on short final.

I think that the discussion over how much “extra” fuel people take is a bit of a red herring. You can get short of fuel through changing circumstances no matter how much you took to start with, so it’s really down to what you do with what you’ve got left, which the crew in question appear to have executed to the best of their ability. Statistically you expect this kind of thing to happen, albeit very rarely, and these guys were presented with something that most pilots go through their entire careers without experiencing. Nothing was broken and nobody got hurt, which is the desired end result - Reserve Fuel is there to cater for these exact kind of situations, it’s not unusable, just that you never plan to use it.

It’s all very well saying you would take more fuel and divert early, but you are still vulnerable to unforeseen externalities. You can’t load fuel for every eventuality as you would be too heavy to take off, so there must be a balance. Personally, I find FP fuel adequate for most of the flights I do but have no hesitation in loading more when appropriate; what I don’t do is add an amount to every flight whatever, as that feels unprofessional - I am paid to be safe but also commercially aware. If I can identify a reason to uplift more and think that it will noticeably increase the chances of making it to destination, then I’m happy to do it as it actually saves time and money in the long run.

What is sufficient fuel for me? Sufficient for the circumstances. There is no 'set number', it will vary as the circumstances vary.

I am very serious that declaring a Mayday kept them safe. As you said "You should try to be ahead" and that was exactly what they did: They saw the ATC 'system' getting overloaded and causing delays, they did not have the fuel for additional delays, so they said so and they landed safely. (That A340 didn't... and almost didn't.)

Correct.

Correct. You plan for the circumstances. And the circumstances can be very different on different days. As you say: "I am paid to be safe but also commercially aware." It's a balance of those two. And not paying proper attention to safety can become a commercial disaster.

Declaring MAYDAY fuel gets you priority for landing but it doesn't do much about the thunderstorm that's closed the airport.

The problem comes in when everyone is declaring MAYDAY fuel at the same time because margins have been cut to the bone, and ATC are supposed to sort it out. The system can and must be able to deal with a genuine emergency. An aircraft low on fuel because of a technical problem obviously needs priority. It's unreasonable to rely on getting priority whenever you dip into the red area because you're operating right on the edge.

I had a 'conversation' with HR one day about carrying a little extra fuel. I just told them two things:

1. If you think its expensive to carry a little extra fuel, try carrying not quite enough. That can get real expensive, real quick.

2. When I sign the Tech Log I am signing underneath the written statement that 'I certify that there is enough fuel and oil on board the aircraft for the purpose of the intended flight.' So if I am not happy with the fuel on board I can't legally accept/sign for the aircraft.

The 'conversation' ended pretty quickly after that.

Too close for comfort-easyjet lands with 18m fuel
 

Bana ; You might not, on occasion be happy but beancounters will say that the fuel on board was legal. . They might even have the Company Lawyer present as you open your third packet of bourbons. They will try to ease with things, like, carrying 125 kgs contingency on the N Atlantic is legal because it is an ERA operation. You are paid to sign for legal acceptance of the aircraft. Not as a statement of happiness.

On the other hand…
 

those same beancounters and lawyers will have a different view of this matter whenever they and/or their families are on board.

Don't force your luck
 

@NoelEvans

Once again you cannot declare a fuel emergency “prematurely” just to become number one. If you’re not familiar with the rules ask your chief pilot. Obviously you avoid to give an answer to the STN flight. For today, 13.12.2023, there were 57 scheduled flights into MAD between 9am and 10am local time. Let’s assume the airport stopped arrivals for about 40 Minutes for any reason and all flights would have approached MAD with minimum fuel plus peanuts, like the STN flight. About 40 flights would have had to divert, many of them to VLC as a close and suitable airport. Do you believe VLC can handle many diversions beside the normal traffic and one by one declaring emergency?

I don’t understand it, when a professional claims that minimum fuel plus 6-7 min. is sufficient in weather conditions like this.

If you are diverting and are, for example, given routing to a point to hold or you are being given very extensive routing possibly to fit in with other traffic and you do not have the fuel for that hold or that extended routing, you declare a fuel emergency, a Mayday. (In the situation that you are referring to, apparently one aeroplane did not declare an emergency and landed very, very low on fuel; the question should be why did they not declare an emergency?)

I don't need to 'believe' anything. If those diversions do not have the fuel for any further delays, then they need to declare emergencies. It is not up to the pilots in the air and running low on fuel to consider if ATC "can handle" that situation, it is up to the pilots in the air and running low on fuel to get their aeroplane, their passengers and (most importantly!) themselves safely on the ground. If the ATC concerned "cannot handle" a situation like that, that is an entirely different matter and a matter very, very much worthwhile investigating. I am almost wondering if you are giving a reason for adding extra fuel being "ATC might not be able to handle the situation"??

You say "If you’re not familiar with the rules ask your chief pilot." My last chief pilot in any situation like that would have asked me why I had departed with so little fuel to end up in a position like that...!

It looks we will not find each other. At least you admit, without writing it down, that the fuel on board the STN flight was inadequate. They probably didn’t check the latest weather forecast for their destination before departing Stansted! The LAN flight didn’t declare a fuel emergency although the should have done. Unfortunately a big part of our job is to x-check others. More and more pilots are unfamiliar with rules and not willing to improve. It starts already on the ground. E.g. wingtip clearance is not assured until all traffic is in the correct position for which they had been cleared. We have had too many accidents because of this.

In my opinion you have to consider what to expect for each flight. Weather, your colleague in the flight deck, flight attendants, ATC, traffic etc. Yes, I take into account the overall situation such as number of flights that could be approaching and possibly diverting at the same time in weather situations like this and also ATC controllers. I am responsible to bring the aircraft with all souls on board safely on the ground. Maybe you stuck with your car from time to time in a traffic jam. Do you call your airline “I don't make it as the streets couldn’t handle the traffic”? At least you can shut down your engine.
By the way I had once an unpleasant experience on a flight to VLC. One controller cleared us to the VOR, the next controller cleared us for the ILS XX. I insisted that our clearance limit is the VOR and asked what he wants we should fly. The controller repeated his clearance without any explanation.

What do you think about another fuel emergency two days ago? GF250 staying in a holding over the destination for 1h and than diverting to the alternate declaring a fuel emergency? For me it looks like they couldn’t cross the border to Myanmar as ATC couldn’t handle a flight without a “valid flightplan”. In your opinion pilots shouldn’t consider problems like this.

That’s the difference between you and me. When I was in a delicate situation, my thoughts were first on the passengers and not on me.

If I arrived somewhere safe and sound, so did my cargo.

After reading this thread I can only say how thankful I am that I fly for a common sense Company who is more than happy for me to take as much fuel as I deem neccessary to deliver my rich clients safely to their destination (or Alt, if required), no questions askes, Ever!
Ok, my jet is realtively small compared to the big aircraft you guys are flying, but I really dont think size matters it comes to spearing in!

Declaring a Fuel Mayday does not automatically make you number 1.

During mass diversion events there can be double digit numbers of fuel maydays.
It’s nothing to do with ATC not being able to handle you just common sense that you can’t all land straight away.
And expect increased spacing between fuel maydays to ensure landing clearance. 😮

Unfortunately these mass diversion events tend to be from sudden and unforeseeable events (runway surface break up, aircraft accident, drone activity, etc) so adding extra fuel on bad weather days doesn’t always obviate the risk.