Why do I just barely make it off the tarmac in time?

[JWill12220 0]

I am flying PMDG 737 800/900 series. I have read through the manual a few times now but I'm not fully understanding what I'm doing wrong on this one. My home field I like to fly out of is Atlanta Hartsfield. I have been taking off from rwy 8L numerous times now in short hops over to Charlotte. Well anyway..I notice that when I get to V rotate, I barely have enough runway left to get off the ground. I am able to do it, but I notice a lot of other heavys getting off the ground sooner than I do on the same respective runway, even much larger aircraft. When I pull onto the runway, I rev N1 to 40%, let off brake, hit the TO/GA switch on the MCP and off I go. I have set the speed (from takeoff page plus 5 )in the IAS/MACH selector. Flaps are set to 5. I have tried only using the max for N1 (24K) and CLB from the N1 limit page on FMC thinking this would give me max performance. Any thoughts as to what I am missing here?Thanks,Chris Williams

[Tabs 2,790]

Chris,What is your payload and fuel weight? Are you using any weather addons that could be screwing up the temp or pressure?

[Jeff Nielsen 1,385]

Chris,In addition to what Ryan said about your fuel and payload (make sure you set-add your fuel and payload in the 737 fuel planner util--I think found on PMDG's downloads page)...You need to also make sure you have hit all your PERF pages in the CDU/FMC so that it updates your correct gross weight.It sounds like to me you have probably missed those pages even though you set your Vr speeds.Good luck!

[downscc 1,327]

If the problem is the nose is stuck to the ground, it doesn't rotate at Vr, then check your trim. Too much nose down trim turns this baby into a big expensive bus.

[kfreire 0]

Also try taking off with more flaps. Try 20 and see what happens. Make sure you set the FMC for flaps 20 first.Good luck.Kaue.

[JWill12220 0]

I used the "aircraft load manager" that is under PMDG and set the 800 single to: forward 4574, aft 5656; Pax weight: 31500, cargo 10230, zfw 133030, max takeoff weight 173k, max zfw 136000, max fuel load 39970.I must say that I have not revisited this load manager since my maiden voyage when I got the software, so it was only set for the 800 single, not the 800 mixed or 900 single/mixed. I'm wondering now if that may have had something to do with it since I mainly fly the 900 series. I have attempted a different flap setting once (10) which really did not seem to make any difference. I'm now starting to question if it has been a situation with the fuel weight.Chris

[rocketfs 2]

Hi,Max Zero Fuel Weight for 737-800 is roughly 61,6 Tons. Normally 60 Tons is realistic (fully loaded)Don't try to use more flaps, it will increase drag.You said that your engines are limited to 24k. I don't use reduced thrust for t/o at that weight. 26k is needed.What are your V-Speeds? It's a good indication of your weight.To what value do you trim?Another thing you could do (short RWY). Brake manually, set thrust to 70% and once the engines almost spooled up to 70%, release brakes and apply full thrust.

[Ralgh 43]

Just for the record the only "normal" flap setting for takeoff (at least in the 800) are 1, 5 and 15. The only places I have ever used 15 is when we were heavy and flying out of LGA, DCA, or SNA.