Please Help: C.G problem (aircraft won't takeoff)

[victorlima01 2]

Hi guys, here I am again, getting my butt whipped by the NG. Just kidding, but a new problem arose yesterday and I couldn't fix it. I decided to change the 737-700's weight in the load manager for a heavy takeoff. I then started FS2002 and when I got the aircraft up and running, realized with the spot-view that the nose wheel was sunk on the ground (about half of the tires were below ground-level). At first I thought it was no biggy but then as I initialized my FMC and entered the weight data, it calculated a c.g of -58%! During the takeoff run I got a PMDG message saying that my cg was off and the aircraft would not takeoff. Needless to say, the aircraft did not rotate and here I am. By the way I'm using kg instead of lbs, is that ok? (I have gone to options menu and under international chosen "metric system". I've also gone to the PMDG "styles "menu and also chosen kg). Cheers, Victor

[Guest Hawkeyeted]

Are you using the FS9 load manager, or the PMDG load manager? Reason I ask is that what you are experiencing is what happens when you use the FS9 load manager.......The PMDG load manger equally distributes weight throughout the cabin.

[victorlima01 2]

I

[Guest Hawkeyeted]

Not a merged panel/aircraft is it? I'm scratching my head on this one......

[victorlima01 2]

Nope... the installation worked flawlessly, I just downloaded a couple liveries and went flying. For the first couple of days the plane was flying well - whenever I changed the loadout there was no trouble whatsoever, the C.g was always within limits. I think that the only other add-on that was installed in this mean-time was the Active Camera 2002. I thought that that's where the problem might've come from; so I uninstalled this little program. However that didn't help. Just one more thing: if I change the loadout to zero (0 pax 0 payload), the aircraft goes back to an acceptable c.g. Maybe it's a problem with the load-managaer program???

[Mats_J 2]

Miss Nameless,Please take a minute to read the forum guidelines that states that you have to sign each and every post with your name.You might want to copy the WEIGHT & BALANCE section of the affected aircraft here for us to take a look at it. I've seen the coordinates for the loads to reset for some users causing it to be nose heavy.The main reason (where we found a reason) for this was using some load manager not familiar with the PMDG coordinates.Hope it helps,

[victorlima01 2]

Thanks for the help Mat, sorry about the posts without a signature, which btw wouldn't be a Miss, but Dr. Anyway, here's what I got for my aircraft file:[WEIGHT_AND_BALANCE]reference_datum_position= 52.730, 0.000, 2.120empty_weight_CG_position=-48.170, 0.000, 0.000max_number_of_stations=50empty_weight=83000.000empty_weight_roll_MOI=1411540.000empty_weight_pitch_MOI=1821510.000empty_weight_yaw_MOI=1518876.000empty_weight_coupled_MOI=230.000//station_load.0=1440.0, 0.000, 0.000, 0.000//max_gross_weight=153500.000CG_forward_limit=0.133CG_aft_limit=0.330station_load.1=17460.0, 0.000, 0.000, 0.000station_load.2=4880.0, 0.000, 0.000, 0.000thanks for the help, Dr. Lima (or Victor if you prefer ;)

[Mats_J 2]

Dr. Lima, Victor,You sure seem to have the wacko coordinate error. If you look at all the station_load values you have four sets of numbers delimited by commas. The first number is your actual weight for that station load. The three consecutive figures are the coordinates for x-, y- and z-axis respectively.Now, these values are not supposed to be zero on the PMDG aircrafts. The origo of the PMDG a/c is at the tip of the nose as opposed to most other FS aircraft where the origo is set to the aircrafts center of gravity. The above figures means you have a total weight of approx 24,000 lbs on the tip of the nose. No wonder your nose gear sunk down through the tarmac! ;-)OK, so you you have to revert the coordinates to the default values. From the empty_weight and the empty_weight_CG_position I see you are using the -700. Copy and replace the below coordinates to all your station_load value coordinates (the three last numbers )station_load.0=23000.000, -48.350, 0.000, 1.050Hope it helps,

[victorlima01 2]

Capt. Mats,Thanks once again for the prompt help. I'll get to fixing this minor problem as soon as I get home. Could you also please post the values for the B736 too? I think that aircraft.cgf file is corrupted as well. Now I'd just like to know how the heck all this started since everything was going fine till the day before yesterday... One more question and then I'm done. If I upgrade to the 800/900 will I get the new FMC features and the EFIS/map display working for the 600 and 700 on FS2K2? Cheers, Victor

[Mats_J 2]

Victor,First the bad news. The 800/900 upgrade does not work with FS2002. I don't think you will be disappointed with FS2004 though if you would choose to change platforms.And here are the numbers for the -600 default load station:station_load.0=16800.000, -45.450, 0.000, 1.050Hope it helps,