Engine Performance

[United744]

Hi,

I've been playing with the various engine types, and I'm intrigued by something:

The RB211 doesn't produce as much raw thrust as the PW4000, but it seems more capable at pulling the aircraft, not only during takeoff, but at altitude, too.

If the overall thrust output is lower, how does it appear to result in greater performance? There is clearly something beyond thrust output going on.

I'm also aware the stated thrust is STATIC THRUST. The only thing I can think is the efficiency improves with increasing forward speed.

[Hardy Heinlin]

If you're referring to EPR for your comparison: RR shows Integrated EPR, PW shows Core EPR. Big difference.

For further details: PSX manual page 522, 523, grey boxes bottom right.

[United744]

Thanks, but no.

I'm referring to actual aircraft performance at max power.

For example: climbing to FL380 wiith the RR engines at high gross weight, then switching to the PW engines. It is unable to maintain altitude vs. the RR engines, which I found curious.

The RR has good margin for climb, whereas the PW engines required a descent just to maintain speed.