I flew the NGX from EGGD to LEAL.

 

The flight plan fuel :

Fuel used : 10569 lbs

Reserve fuel : 5709

Total: 16277

 

Based on the reserve fuel, i entered 5.0 as reserve.

 

Heres where the confusion lies :

 

 

 

Why has the ''useing res fuel'' warning came up if i have 7.2 in the tank?

Why has the ''useing res fuel'' warning came up if i have 7.2 in the tank?

 

Because that 5.0 you placed in there is telling the system that's the 5.0 you're not going to use for the flight.  So, when the system estimates your flight is going to use more than the mere 2.2 that you left for the flight, it will pop up and tell you that you're using the fuel you told it that you weren't going to use.

 

It's called reserve fuel for a reason: it's reserved for unplanned instances, not your normal flight  :wink:

Thanks Kyle, makes perfect sence.

 

But..

 

It still seems illogical to tell me im useing reserve fuel, when actually im not.(based on the 7.2 remaining)

 

I understand its telling me that the rest of the flight will use more than 2.2 and start eating into the reserve eventually, but why doesnt it tell im useing reserves untill i actually am ( fuel guage reading 5.0) ?

Thanks Kyle, makes perfect sence.

 

But..

 

It still seems illogical to tell me im useing reserve fuel, when actually im not.(based on the 7.2 remaining)

 

I understand its telling me that the rest of the flight will use more than 2.2 and start eating into the reserve eventually, but why doesnt it tell im useing reserves untill i actually am ( fuel guage reading 5.0) ?

What it's telling you is the current flight plan will use reserve fuel, so it is "using reserve fuel" in other words.  You aren't using it yet, but you will do.  In reality this would be a signal to the pilot to divert.

 

[...] but why doesnt it tell im useing reserves untill i actually am

 

Because at that point, it could be too late.

 

You don't want to be descending from your STAR onto your approach to an airport, in the soup, and then *BING* SURPRISE GUY! YOU'RE ABOUT TO RUN OUT OF OPTIONS - YOU'VE JUST STARTED USING RESERVE FUEL!

 

No.  You need to know that information well in advance.

 

Say you get this on the ground at your origin, before even leaving:

It means the fuel numbers from dispatch are off, so you coordinate with them, get the proper numbers and perhaps a fuel truck.

 

Say you get it in the air:

It means that the headwind could have been stronger than normal.  Coordinate with dispatch well as soon as you get the message, and work out a plan (divert, continue, etc).

 

 

 

Say you only got it when you started using reserves, as you mentioned:

You're now likely in a high workload environment closer to your destination, and the last thing you need is to start troubleshooting your fuel issue at the last moment.

 

Your reserve fuel is meant to be used only in the case that it has to be.  In other words, as Kevin mentioned, you shouldn't be using any of it on your normal route of flight.  If the automagic detects that you will be using your reserve then there are problems in your fuel numbers that need to be addressed as soon as they are known.  This is why it'll ding you as soon as it knows, instead of when you actually start using them.

 

This is the same reason you check the weather before you fly, instead of showing up at an airport with:

SURPRISE!  Huge red cell!  Good luck!

The others above are correct, but please read the second tutorial flight that comes with the airplane - I spent a large section in it discussing how to come up with realistic fuel planning and reserve numbers to use.

Thanks Kyle / Kevin

 

All makes sence..seems obviose really ^_^

 

Thanks Ryan, i shall  use it to calculate my fuel myself as fuelplanner.com seems off for the 700.

 

Again thanks all for clearing that up for me.

You're welcome!

 

...and Ryan's right.  There's a huge reason why he's suggesting the tutorial, and once you read his answer in the tutorial it'll all start to make sense!

You should change your sig to read ''the manual in full !!'' :lol:

also another reason why it is not illogical is that, even though you may have more than the final reserve at the moment, it is a requirement to declare emergency if you think you're going to land with less then final fuel reserve.

You should change your sig to read ''the manual in full !!'' :lol:

 

Haha - I haven't.  I just use it as a resource when I have questions.  That's what it's there for, unless you're getting paid to read it in full.

 

also another reason why it is not illogical is that, even though you may have more than the final reserve at the moment, it is a requirement to declare emergency if you think you're going to land with less then final fuel reserve.

 

Careful - this is not the case in the FAA environment.  This is definitely the case for ICAO (just about everywhere else).

 

Regarding FAA-land:

 

"There is no regulatory definition as to when, specifically, a pilot must declare “minimum fuel” or a fuel emergency. Air carriers typically develop such guidance for their pilots and include it in their General Operations Manuals[.]"

Source

Careful - this is not the case in the FAA environment.  This is definitely the case for ICAO (just about everywhere else).

well i didn't know what the fuel policy is outside of europe, thanks for clearing that up

 

well i didn't know what the fuel policy is outside of europe, thanks for clearing that up

 

I don't blame you.  I don't really pay much attention to ICAO where I don't need to, so I can't fault you for not knowing FAA stuff.  I'm just trying to make sure the guys who fly over here don't start spreading info that isn't true for FAA-land, that's all.

just type 1 in the scratchpad an press lsk4 to enter it in, voila !

 

Eric Wallace

If you have a look at your Performance page on your FMC and then look at the fuel for your destination it would have shown you less than 5,  easy way, load your flightplan load your enroute wind data and have a look at the estimated fuel, if it less than 5 then add some more