Suspect climb performance

[Guest Muppet22]

HiHere's the situation.Flight - EGLL to LTBA (Istanbul)ZFW 122.2FUEL 21.0 hence GR WT is 143.2 with an expected TOW of 143.-Take off 27L DVR4G departure, after accelaration height of 1000ft I select VNAV and CLB1 power and continue to fly manually until about FL080.For this flight I did not select a speed on the MCP - i let VNAV do all the work.Aircraft climbs reasonably well until about FL240/250 where I get a continous VS of +500ft until my cruising height of FL370. Anyone have any ideas to why? It took 31 minutes to reach FL370 from the beginning of the take off roll. This is far too long - a 767 with this sort of weight should be reaching 370 in about 20-25 minutes with CLB2 power.I set 4 units of trim before take off which can't be the cause.I set a de-rate take off of 50 degrees C so that can't be the cause.I must add that all of my flights are generally like this but today for some reason it really bugged me.I am using the PIC/POSKY merge.Any help/suggestions greatfully recieved.Thanks

[Guest]

Hi Tom,In my experience with 767PIC, the CLB2 setting is under-rated. I only use it for simulated noise abatement procedures. This means, I select CLB2 at around 1.000ft for thrust (and noise) reduction, then select CLB1 at around 5.000ft until top of climb. In my opinion, this provides for the most realistic performance.However, in my merged PIC/POSKY I have found the aircraft underpowered. I have solved this by editing the .cfg file (the POSKY one) by reducing drag scaler to 1.25 and upgrading the engine to 64.000 lbs of thrust. Incidentially, I mainly fly the SAS 767 (looks soooo goood and reminds me of home) which is powered by PW4064 engines, providing 64.000 lbs of thrust. So really, I haven't cheated :)Oh, and autopilot on as low as FL080? Hmm, normally Nigel's fly their iron manually to FL100 as per their SOP. Just kidding mate, the SOP actually allows for A/P on anywhere above 1.000ft MSL. However, and this is true, being the slowest guys in town, Speedbirds have this terrible habit of reducing to 250IAS at top of descent unlike the rest who descent at 300/330. Moving obstructions the Nigels are :) Trust you descent at a more agreeable speed mate.Have fun

[Guest Muppet22]

TopheavyLOLOLOL :-)Thanks for that reply, will give it a go!