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We have a "flight plan" which states how much fuel we require for each flight based on the distance we fly, amount of passengers and baggage, fuel weight, head/tail wind, flight level flown, expected departure and approach procedure, indivudual aircraft engine burn performance, as well as holding fuel, diversion fuel etc.

Using this info and our own experience of the route and possible weather issues, we calculate the required fuel we need.

Growler!!!

nd001 wrote: »

thats great appreciate that. Do the flight crew know the fuel required based on knowledge of previous sectors flown or is their more to it

The pilots will get a Pilot LOG (PLOG) from their flight planning department which will advise them of the fuel burn at various altitudes. The optimum level will generally have the lowest fuel burn. But the captain can select a different level if for example the winds are more favourable or the time is shorter.

The fuel carried will be the total used for:

Taxi
Trip - how much used from A to B
Contingency - 5% of trip fuel to allow for changes in weather
Alternate - how much used from B to C if needed
Final Reserve - minimum in tanks to hold over the airfield for 30 minutes
Extra fuel - additional fuel carried at captains discretion

Everything except for Extra fuel, is considered the absolute legal minimum to dispatch with.
A prudent captain will always carry a little more.

ProfessorPlum

Growler!!! wrote: »

The pilots will get a Pilot LOG (PLOG) from their flight planning department which will advise them of the fuel burn at various altitudes. The optimum level will generally have the lowest fuel burn. But the captain can select a different level if for example the winds are more favourable or the time is shorter.

The fuel carried will be the total used for:

Taxi
Trip - how much used from A to B
Contingency - 5% of trip fuel to allow for changes in weather
Alternate - how much used from B to C if needed
Final Reserve - minimum in tanks to hold over the airfield for 30 minutes
Extra fuel - additional fuel carried at captains discretion

Everything except for Extra fuel, is considered the absolute legal minimum to dispatch with.
A prudent captain will always carry a little more.

Well now, that's going to cause a row!

nd001

thats great clears things up for me thanks for the replies sounds like theres a bit more to it than just opening the fuel tank and filling up .

eatmyshorts

Growler!!! wrote: »

Everything except for Extra fuel, is considered the absolute legal minimum to dispatch with.

Contingency fuel can be used after the fuel bowser is disconnected, so it is legally possible to dispatch without having it on board.

Growler!!!

ProfessorPlum wrote: »

Well now, that's going to cause a row!

I was referring to myself:D

eatmyshorts wrote: »

Contingency fuel can be used after the fuel bowser is disconnected, so it is legally possible to dispatch without having it on board.

I'll have to check that out.
My understanding is that Contingency fuel is included in the total at the bottom of the plog ie. it is needed for dispatch. Could be due to different ops procedures as my company use 5% of trip fuel, there are other methods mentioned in OMA. Looks like my poor F/O will be learning about fuel today on the longer sectors;)

youknowwho

Does "taxi" fuel include running the APU while sitting on the ground. In bad weather a plane could be just sitting for quite a while or do they wait until a fix time before departure to fill the tanks with the calculated fuel load?

billie1b

youknowwho wrote: »

Does "taxi" fuel include running the APU while sitting on the ground. In bad weather a plane could be just sitting for quite a while or do they wait until a fix time before departure to fill the tanks with the calculated fuel load?

While the a/c is sitting on the ground at the gate, its connected to a GPU (Ground Power Unit), it enables the plane to be powered up without the use of the a/c's APU (using no fuel). Some GPU's are mobile and powered by diesel, some are in ground GPU's and powered by electricity. Some a/c could be fuelled up 6 hours before the departure time and not use a drop of fuel until pushback.

bkehoe

youknowwho wrote: »

Does "taxi" fuel include running the APU while sitting on the ground. In bad weather a plane could be just sitting for quite a while or do they wait until a fix time before departure to fill the tanks with the calculated fuel load?

Yes, but APU fuel usage is minimal (in the region of 100KG/hr on a 737/320, but depends on whether its used for electrical power only, or air conditioning as well) on normal sectors as billie already mentioned. In some airports we'd leave the APU running for the turnaround if there is no ground power available, or if the cabin is too hot or too cold (even though some airports supply conditioned air, sometimes it seems as if they may as well just give you a fan to blow the hot air around!).

Also, in some airports (e.g. BCN, MAD) there are strict noise regulations on when you can run the APU - e.g. only 5 minutes before departure.

My understanding of contingency is that it's required at the point of commencing the takeoff run.

Jack1985

Is the 5% EU-OPS contingency included regardless of discretionary contingency fuel?

ProfessorPlum

Jack, what exactly do you mean by 'discretionary contingency fuel'?

Here's the relevant bit from EU ops (1.255). As an aside, the required contingency doesn't have to be 5%, operators may be allowed to use 3% if they have an en route alternate, and there are other methods of calculating reduced contingency fuel.


http://www.skybrary.aero/bookshelf/books/818.pdf

An operator shall ensure that the pre-flight calculation of usable fuel required for a flight includes:
1. Taxi fuel; and
2. Trip fuel; and
3. Reserve fuel consisting of:
(i) contingency fuel (see OPS 1.192); and
(ii) alternate fuel, if a destination alternate aerodrome is required. (This does not preclude selection of the depar- ture aerodrome as the destination alternate aerodrome); and
(iii) final reserve fuel; and
(iv) additional fuel, if required by the type of operation (e.g. ETOPS); and
4. extra fuel if required by the commander.

smurfjed

Do you have any rules pertaining with the selection of an alternate? I have seen people use Orly as an alternate for LeBourget so the resulting figures are about 4 minutes flight time and 24 miles. To me this isn't adequate, so I'm interested in knowing if there are any European rules dealing with this?

ProfessorPlum

smurfjed wrote: »

Do you have any rules pertaining with the selection of an alternate? I have seen people use Orly as an alternate for LeBourget so the resulting figures are about 4 minutes flight time and 24 miles. To me this isn't adequate, so I'm interested in knowing if there are any European rules dealing with this?

There are lots of rules for selection of alternates as you can image, but there is nothing to stop you selecting one right next door. In fact, if you look at the regulations, you may not have to select one at all (our company policy is always to select at least one alternate, and usually 4 are selected). As Growler said above, a prudent captain may take more fuel than required, so in my experience, for example, if weather at destination is an issue, and the nominated alternated is close to destination, we will take fuel for a further alternate.

Jack1985

ProfessorPlum wrote: »

Jack, what exactly do you mean by 'discretionary contingency fuel'?

Here's the relevant bit from EU ops (1.255). As an aside, the required contingency doesn't have to be 5%, operators may be allowed to use 3% if they have an en route alternate, and there are other methods of calculating reduced contingency fuel.


http://www.skybrary.aero/bookshelf/books/818.pdf

An operator shall ensure that the pre-flight calculation of usable fuel required for a flight includes:
1. Taxi fuel; and
2. Trip fuel; and
3. Reserve fuel consisting of:
(i) contingency fuel (see OPS 1.192); and
(ii) alternate fuel, if a destination alternate aerodrome is required. (This does not preclude selection of the depar- ture aerodrome as the destination alternate aerodrome); and
(iii) final reserve fuel; and
(iv) additional fuel, if required by the type of operation (e.g. ETOPS); and
4. extra fuel if required by the commander.

Cheers for that, should have been clearer, I was referring to discretionary as the captains final reserve outside of regulation requirements.

StevieNicksFan

crazygeryy wrote: »

bit of a weird one but someone might know.

what is the name for the "kite" like thing at mainly small airports that gauges how soft or strong the wind is?
its shaped like a tube that has a big opening at one end(where the wind goes in) and small opening at the other end and is attached to a stick thats stuck into the ground.

god i hope im explaining this well enough.:rolleyes:

A windsock? http://en.wikipedia.org/wiki/Windsock

bkehoe

smurfjed wrote: »

Do you have any rules pertaining with the selection of an alternate? I have seen people use Orly as an alternate for LeBourget so the resulting figures are about 4 minutes flight time and 24 miles. To me this isn't adequate, so I'm interested in knowing if there are any European rules dealing with this?

Many, probably most, airlines will have a policy for the minimum amount of reserve fuel to carry. My airline has such a policy, so even if something tiny like 600kg is needed for the alternate, there will be extra already added on automatically to ensure there's never less than the minimum amount decided by the company.

the_monkey

Hi , the plane at the start of this video here is an A340 yeah ?

http://www.youtube.com/watch?v=gTuTIkO2R1w

Seems strange they flew on an A340 from Munich - London ..

Jack1985

the_monkey wrote: »

Hi , the plane at the start of this video here is an A340 yeah ?

http://www.youtube.com/watch?v=gTuTIkO2R1w

Seems strange they flew on an A340 from Munich - London ..

Chartered flight.

ProfessorPlum

bkehoe wrote: »

Many, probably most, airlines will have a policy for the minimum amount of reserve fuel to carry. My airline has such a policy, so even if something tiny like 600kg is needed for the alternate, there will be extra already added on automatically to ensure there's never less than the minimum amount decided by the company.

All airlines must have a fuel policy which is approved by the authority which they operate under. The final reserve fuel is a legally defined amount (time) and is separate and independant of the alternate fuel. I think your use of terminology might be confusing for those not completely familiar with the process.

bkehoe

ProfessorPlum wrote: »

All airlines must have a fuel policy which is approved by the authority which they operate under. The final reserve fuel is a legally defined amount (time) and is separate and independant of the alternate fuel. I think your use of terminology might be confusing for those not completely familiar with the process.

For clarification, I was referring to the total amount of reserve fuel, not just final reserve.

the_monkey

Jack1985 wrote: »

Chartered flight.

But still an A340 right ? ...

amen

Jack1985 wrote: »

Chartered flight.

While it may be charted you could also see a wide body on a short flight if
1: New type entering service i.e. BA flew the A380 London/Paris for training and then expanded to other routes
2: Maybe a smaller plane went technical at a remote location and multiple flights at that location impacted. Makes more sense to send a single wide body to pick up all the passengers in a single trip.

Jack1985

the_monkey wrote: »

But still an A340 right ? ...

Yep

amen

The speed of sound decreases with altitude and decreasing temperature.

As as the planes altitude increases do you see an increasing mach number or do you always fly to an specific mach number irrespective of altitude or are you just flying to IAS (in knots) ?

eatmyshorts

amen wrote: »

The speed of sound decreases with altitude and decreasing temperature.

As as the planes altitude increases do you see an increasing mach number or do you always fly to an specific mach number irrespective of altitude or are you just flying to IAS (in knots) ?

Flying at a constant IAS, Mach No will increase as the aircraft climbs.
In a climb we will hold 320kts until that equals M0.83 (approx FL290). Then climb at a constant M0.83 so the IAS will then begin to decrease.

Growler!!!

amen wrote: »

The speed of sound decreases with altitude and decreasing temperature.

Just to be pedantic. LSS is dependent on temperature ONLY. In an inversion temperature does not decrease with altitude.

basill

It will largely depend on how the respective company wishes you to fly their aircraft. Ours prefers an economy climb based on a specific cost index from the flight plan. By leaving the speed "managed" the airbus will climb initially at a set of fixed speeds till the changeover point and then fly at a Mach No. Of course airmanship on the day may mean that we select a climb speed and/or Mach for wx avoidance or to facilitate an ATC request etc.

amen

LSS is dependent on temperature ONLY

So if for instance you are flying along at 10,000m and Mach .083 (with your decreased IAS) and there was very very cold weather would it be possible for your plane to be flying at the required Mach Number but with an IAS that is now close to the stall speed of the aircraft ?

Growler!!!

amen wrote: »

So if for instance you are flying along at 10,000m and Mach .083 (with your decreased IAS) and there was very very cold weather would it be possible for your plane to be flying at the required Mach Number but with an IAS that is now close to the stall speed of the aircraft ?

What you're talking about there is Coffin Corner.

http://en.wikipedia.org/wiki/Coffin_corner_(aerodynamics)

TheBoss11

Okay so, I got the opportunity to get a spin the the a320 sim in simtech recently. Without a doubt the best experience of my life, way better than I expected!! My question is though. After years of flying does it get boring as an airline pilot?