Couple of questions for you guys about the 800 / 900. Note.. all weights in pounds, in both the sim, and pmdg load mangager.Flying the 737-800 from LAS - SFO, (ZFW 130,665) using around 1,000 in the center, and 7,000 in each wing, I was wondering what the usual takeoff length would be. Using proper trip, and rotation techniques (as discussed ad nausem in this forum =P), and it takes me roughly 7,000+ feet of runway just to get airborne. This seems a bit long to me seeing as how the bird is VERY light and should have no problem getting airborne (as I see them jetting out of SNA all the time, that runway is only 5,700 feet long.) Flying the 737-900 today from PHX - SAN (ZFW = 136,662) with the same 1k in the center, and maybe 5k in each wing. Same as above, it took me roughly 9,000 feet to get airborne. I'm insanely curious with these figures because they are very light fuel loads, and not full passenger loads, and very light cargo loads. If I were to fly a longer trip, I'm rather worried I'd need about 20,000 feet of runway to takeoff, and unfortunately Area 51 has denied my requests for commercial air operations =PI hope.. I really do that I'm really stupid and missing something. I've RTFM about 4 times.. but I just can't figure it out. I'm not using a derated takeoff, for obvious reasons =P. I've gotten used to the stopping distance required and having to use autobrakes 3 almost all the time on the 8 / 9, where my 6,7 seem to stop on a dime, but this takeoff requirement boggles my mind, and it seems to limit my operations. I took the 737-800 from LAS - DTW and with 8k in the center, an dfull wings, and I swear it took me at least 200+ miles to get to FL330 when the opt was 336 max was 360.Help me Obi-PMDG-wan, you're my only hope.

It's being looked at Andy, thanks..[h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/forum/betaimg.jpgAMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | WD SATA 80 GIG | 512 DDR 400 |

Hey Andy,I'm not sure why you're having this problem, I can get both the 8 and 900 out in under 9000ft using the weights you supplied.My test was done at EGPF (Glasgow, my home town) which is 28ft AMSL (so no high alt trouble), the main runway is 8720ft long. Using flaps 10 and 5 on the trim. I was airborne before the aim point markers. I filled the aircraft up to Mzfw (the numbers you provided were only a few hundread pounds shy of Mzfw). After that I tried at Max take off weight (173000lbs for the 800 and 174200 for the 900), again max ZFW and filled the tanks to the weight limit (800 wings full 37304 center tank, 900 wings full 34416 center tank). Had no problems getting out of Glasgow. Took a little longer for rotate speed to arrive but it did come before the end of the runway.I didn't try flaps 15 but I'm sure it would help even more.During this testing I found out that the weight tables in the manual are out slightly although the weight and payload manager is spot on with the weights.Also some of the aircraft don't have the correct thrust rating on their engines but that doesn't really pose a noticable problem with the take off length.Sorry I couldn't be more of a help, I just thought I'd let you know my findings :)CheersDavid

>During this testing I found out that the weight tables in the>manual are out slightly although the weight and payload>manager is spot on with the weights.>The weight tables in the manual are based on an engine failing just before V1. If you are taking off with all engines operating, you should get much better performance than what's in the manual.Don S.

Hey Don,>During this testing I found out that the weight tables in the>manual are out slightly although the weight and payload>manager is spot on with the weights.I am basing this on the official weight tables from Boeing. Also some of the tables in the manual are 100% spot on (i.e. the 900) whereas some are, quite frankly, miles out (-600, 16500 lbs too low on the max taxi and takeoff weights). These tables generally have nowt to do with engine failure contigences, they are purely structural weight limitations.Cheers,David

Hi David,The structural weight limits depend on what the particular operator has purchased. Boeing offers several options, priced accordingly, i.e., a higher structural weight limit may cost more even though thre are no physical differences involved.Regards,Don

Hey Don,What I meant is that the tables I'm referencing are structural weight limit tables in the manual (Chapter 4 page 8), that's why I'm talking in terms of structural weights. The weights I'm comparing them to are from the weight limit tables in [a href=http://www.boeing.com/assocproducts/aircompat/acaps/7376sec2.pdf]this[/a] Boeing tech spec document.Your spot on in saying there are no physical differences between the aircraft with different structural weight limits. Boeing simply sells a rating for each limit to the customer. If at some time the customer wants to fly higher gross weights they simply buy a new license from Boeing and away they go (nothing physical changed with the aircraft).This means we should be able to fly these aircraft upto the maximum limit, all that would be required, in theory, would be some edits to a few files here and there....Anyway, :)CheersDavid