NGX Reserves value

[tjeuten 1]

Hey,

just getting started with this planning software, and apart from some minor hickups, so far I'm liking it very much.

One question: once I get my OFP with the fuel breakdown and all that, how do I determine the value I need to put in the NGX "Reserves" box ? I guess it's not the same as the Final Reserves on the OFP ? Is it the sum of Final Reserves and Alternate fuel ?

Thanks

Mathieu

[alpha117 51]

Mathieu

If you mean in the FMC, then I do it this way.

1. Load route into FMC

2. Go to progress page and look at fuel at destination

3. Then in the reserve box place in that number or slightly lower.

That way you will not get the 'using reserve fuel message on the FMC scratchpad. Also when the message does happen then it a good indication of either planning or excessive headwinds during the flight.

Not sure if this is correct procedure, but it works for me

Clive

[tjeuten 1]

Thanks for your input.

I might be wrong, but your procedure looks like somewhat arbitratry.

I think I read somewhere (might be even in one of the official NGX Tutorials) that once you see "USING RSV FUEL" that you MUST divert to your alternate.

Hence my question: the value in the FMC reserves box, is it a value entered at the pilots discretion (maybe like the procedure you described above), or is it a "legal" value that should be calculated from the OFP fuel breakdown.

Like in below example (units are kg):

FUEL CORR ENDUR

TRIP 2633 ........ 01:05

CONT 5% 163 ........ 00:05

ALTN LFLB 858 ........ 00:19

FINAL RESV 979 ........ 00:30

MIN T/O 4633 ........ 01:59

EXTRA 0 ........ 00:00

TAXI 120 ........ 00:10

RELEASE 4753 ........ 02:09

I'd probably enter 979 + 858 = 1837 kg in the FMC reserves box, but not sure if that is correct, that's what I'm trying to figure out here.

Maybe even adding the contingency fuel (so 979+858+163 = 2000) is probably even better than omitting it...

Just would like to know if their is an "official" way of putting a value in the box there.

[Emi 5121]

I myself do it this way:
I take the fuel required to fly to my alternate and then I add the final reserve fuel. In my opinion this makes sense as I might even have to hold over my alternate or might even do a go around there.

[alpha117 51]

Hmm, so what happens if you place 1.0 in the reserve box? unless the planning is 'really' bad or very excessive HW then the 'using reserve fuel' message will never be 'triggered'

Quote from 'FMC USer Guide' by Bill Buffer

' Refer to your specific airline SOP. Usually alternate plus reserves. RESERVES represent fuel reserves required at destination after normal flight completion.'

'TECHNIQUE: Enter flight plan arrival fuel. Now, message USING RESERVE FUEL' will remind you if/when the predicted arrival fuel is less than flight planned'

Taken from page 63

Hope this helps

Clive

[tjeuten 1]

Ok, so it looks like the value depends on the airline policy rather than a legal regulation, correct ?

So FINAL RESV + ALTN looks indeed like a good value, as is your procedure.

I guess we're both kinda right then

[alpha117 51]

No, its just Reserve at destination unless your company SOP states otherwise. Now I think that most of us have been putting very small numbers in the reserve box, I know I have. Now it looks like these numbers will be bigger and more realistic.

The FMC only knows the 'route', until you tell it otherwise.

[ESzczesniak 25]

I fly in the USA, so our fuel planning rules are a bit different, requiring 45 minutes of holding time. This 45 minutes of holding time is labeled as FAR Reserve fuel and my understanding is that most airlines use this for the reserve entry.

[B777ER 5]

I fly in the USA, so our fuel planning rules are a bit different, requiring 45 minutes of holding time.  This 45 minutes of holding time is labeled as FAR Reserve fuel and my understanding is that most airlines use this for the reserve entry.

Good info. Thanks

Sent from Samsung Galaxy Note 2

[Chaders 97]

What you put in the reserves fuel is the sum of your final reserve fuel (30 mins usually under EASA) and your fuel to Alternate. So in the case above I'd put 1.9 in the FMC.

[CCarter 0]

Legally, it depends what rules you are flying under. FAA Domestic rules require a 45 min reserve, and that is the number you would put in that field. The closest you have is the FINAL RESV. Alternate fuel is not reserve fuel, from a technical definitions standpoint.

[artanisdg 0]

Well, it depends on your authority regulations and airline policy I'd say...

Back here in Korea, I've heard that KAL pilots enter 30mins of holding fuel as their reserve fuel, which is their minimum reserve fuel under Ministry of Transportation rules.

If a flight is using reserve fuel, (gets the FMC USING RESV FUEL message), he can request priority handling and declare emergency to ATC, so I've heard.

So, at least back here, the value's got to be quite small.