pmdg fuel problems

[Guest sixstring2k]

hello. I love pmdg 737ng but for some reason i keep getting the the insuffient fuel msg on the cdu. I made all the fuel calculation using the pmdg fuel planner, and i have taken into consideration the wind and still always happens. can you guys help?

[downscc 1,327]

I will occasionally get the message early in a flight, which turns out to be a "false positive" alarm. It usually extinguishes itself by the time I reach cruise (737-700).

[johndrago 4]

>hello. I love pmdg 737ng but for some reason i keep getting>the the insuffient fuel msg on the cdu. I made all the fuel>calculation using the pmdg fuel planner, and i have taken into>consideration the wind and still always happens. can you guys>help?Is the amount you specify in the "reserves" field greater than the amount that is calculated by the FMC to be available when landing?- John

[Guest sixstring2k]

I will try that and get back to you guys

[neilbradley1 2]

It appears to be a bug for the B737NG series. My experience is that for flights over 800 miles you get it. However provided you are happy with you initial fuel calculation, then when it happens just do a fuel check and confirm you have enough plus reserves as you originally planned. You will find that as you approach your destination the figures on the 'PROGRESS' page of the FMC will begin to correct themselves and by the time you reach 50 miles out everything will be as it should be fuel wise.I would hope that this will be addressed in the FSX upgrade of the B737's.NeilYPAD

[dave_paige 11]

>It appears to be a bug for the B737NG series. My experience>is that for flights over 800 miles you get it. However>provided you are happy with you initial fuel calculation, then>when it happens just do a fuel check and confirm you have>enough plus reserves as you originally planned. You will find>that as you approach your destination the figures on the>'PROGRESS' page of the FMC will begin to correct themselves>and by the time you reach 50 miles out everything will be as>it should be fuel wise.>>I would hope that this will be addressed in the FSX upgrade of>the B737's.>>Neil>>YPADI can assure you that this is not a bug. The FMC is constantly recalculating estimated fuel usage and this message may result depending on conditions. Once you enter your reserve fuel into the FMC on the PERF INIT page, any time that the FMC 'believes' that, given current conditions, you will not arrive at your destination with that amount of reserve still on board, you will get that message. For example, if, during the takeoff roll and climbout, when fuel burn is quite high, the FMC may calculate that you will not arrive with your selected amount of reserve. The FMC will generate the 'insufficient fuel' message. It will almost always clear itself within a few seconds to a few minutes once, during cruise climb or cruise, the fuel burn has dropped to the point where you will arrive with sufficient reserves. I've found that an 'insufficient fuel' message that persists is always the result of poor planning.I will point out that because a few SIDs from www.planepath.com have hard altitude restrictions at their transition waypoints, the FMC will 'think' that your going to fly the entire route at that altitude and that my result in an 'insufficient fuel' warning because the fuel burn at that relatively low altitude will be much higher than you've probably planned for. Examples are the Richmond One (RID1) DP out of KDTW or the Hornet Two (HOR2) out of KCLT.The solution here is to either edit those procedures to remove the hard restrictions or delete the restriction from the FMC after selecting one of those SIDs as part of your route.

[neilbradley1 2]

Dave,From my experience your reasoning is unreasonable. Try NFFN to PHNL or PHNL to KSAN. You will find that the message will appear late during climb to cruising level, and continue literally for hours in spite of the fact that the fuel gauges show that based on the cruise fuel flows there will be statutary reserves plus holding and alternate fuel on arrival at the destination.I have sent the information including screen shots of the gauges to technical support and they are working on it.NeilYPAD

[dave_paige 11]

Well I wasn't really 'reasoning', that really is how the FMC works. And in all the flying I've done with the PMDG 737NG series I've never come across this 'bug'. This is also the first I've ever heard of this 'bug'. And none of the other PMDG drivers I know have ever mentioned it. Have you tried reporting this to PMDG support? I'll try one of your suggested routes and see what happens. Could you tell me your fuel and payload info for the PHNL to KSAN flight? Also what were your route winds? Thanks.

[chrispeel 0]

This had been raised before some time back.I haven't seen a definitive reply yet.It happens with mine,and always has done. I just ignore it and as mentioned above,it goes away.Irritating but not crucial.

[neilbradley1 2]

Dave,PHNL - KSANDistance 2300nmFL330 - 370Average W/V 246/35 OAT -44B738ZFW 60300kgFlight Fuel 13700kgReserves 1400Alternate 1500Holding 1500 Total 18100GTOW 78100PLW 64400As I said I have sent details of the flight to Paul Golnick and he is researching it, and yes there have been a number of people reporting this problem in the past.NeilYPAD