Jim ....
Those recommended power settings should be "fairly accurate" because the indicated engine performances are closely based on data we obtained for 2 types of RR RB211 turbofan engines.
That data presented in each of my Flying Guides is just a "GUIDE" only though. It was written on the basis of
FS observations recorded during several test flights using each L1011 type .... operating at MGTOW .... using the AT system from T/O to final approach .... limiting the simulation to a roughly 1500 FPM to 1800 FPM initial ROC after T/O then increasing this to 2000 FPM after clean up .... and with the AT system set for a 270 KT target airspeed throughout the climb (for the L1011-100) and allowing the AT to automatically adjusting power in order to maintain airspeed according to pitch attitude throughout the climb to altitude.
For the L1011-100 I'm observing the following engine performances ....
- N1 77% to N1 78% (it will reduce to N1 75% shortly after cleanup and at around 6000 FT with the AT still slowly reducing/adjusting power after cleanup) and N2 90% to N2 89% .... between 4000 FT and 10000 FT with a 2000 FPM ROC.
- N1 77% to N1 79% .... and a fairly stable N2 of 89% (although there's a fair bit of range within that "N" number too) .... between 10000 FT and 14000 FT with an 1800 FPM ROC.
- N1 77% to N1 80% .... and N2 88% to N2 89% .... between 14000 FT and 18000 FT with a 1500 FPM ROC.
- N1 78% to N1 82% .... and N2 88% to N2 89% .... between 18000 FT and 22000 FT with a 1200 FPM ROC.
- N1 82% to N1 87% .... and a fairly stable N2 of 89% (again .... a fair bit of range exists within that "N" number) .... between 22000 FT and 26000 FT a 1000 FPM ROC
- N1 82% to N1 83% ....and with a fairly stable N2 of 88% .... between 26000 FT and 30000 FT with a 750 FPM ROC
- N1 83% to N1 77% .... and N2 87% to N2 86% .... between 30000 FT and 31000 FT with a roughly 250 FPM ROC.
Again .... these observations are based on a MGTOW T/O only .... using our L1011 simulation .... with a standard FS ambient ground temperature of around 15* C .... operating from the default KSEA airport .... and dependence on the AT system.
Where the quoted "N" numbers (above) appear to fluctuate represents the point at which my recommended ROC adjustments are applied .... and which then results in the AT reducing thrust, slightly, in accordance with the decreasing pitch attitude.
If trying to fly these aircraft as recommended by me (and I really don't know if what I recommend is how an L1011 should actually be flown in reality, but, it does work fine, for me at least, in FS) then you should be seeing nothing too vastly different from my quoted "N" numbers (above) and in relation to ROC versus altitude.
I'm "reasonably comfortable" with the performance figures .... given that they are based closely upon the engine performance data we obtained, and that this is our very first FDE edit for these aircraft/panels, and according to the current extent of our skills .... "whilst also bearing in mind certain FS limitations too", and that there are very definite improvements over the original L1011 FDE.
Following these Guides simply ensures that the indicated engine thrust settings don't become too ridiculous (with N1's perhaps starting to exceed N2's .... which can happen in FS) .... and .... it also ensures a reasonably good airspeed throughout the climb to altitude.
PLEASE NOTE THOUGH .... if reducing aircraft weight below that imposed by recommended fuel adjustment data within each of the Guides .... then the lighter aircraft weight is definitely going to result in lower engine parameter indications. Higher weights imposed by no fuel adjustment (meaning the aircraft is probably being flown overweight) will result in different engine parameter observations again .... primarily hight "N" number than quoted.
Remember .... the figures quoted in my Guides are all based around MGTOW only.
Hope that helps you .... somewhat !
Although I never recorded EPR values throughout the climb (because as Chris states these are variable and subject to air temperature/altitude etc .... and the fact that "N" numbers are more appropriate anyway) .... Chris's quoted EPR values are "pretty close" to what I've been seeing well into the climb anyway .... and that's without having seen the ZAGORAN data prior to writing my guides.
Following my recommended guides .... the indicated EPR values will never, at any stage, exceed their maximum EPR 1.56/EPR 1.57 rating.
My Guides are generally intended to aid enjoyment using these aircraft .... and does work within the imperfect FS aviation environment !
Mark C
AKL/NZ
