Speed of AI

[bismarck]

Hi all, every time I set up some FP for a new aircraft, comes to my mind the usual question.
Which is the right cruise speed to be used?
Usually, the cruise speed indicated in the Aircraft.cfg is not reflected when the aircraft is in flight, or it is not always the same, depending from the altitude.
Some example from my "Russian" experience:
SBAI Mig-31 - Cruise speed 1346; at FL 210 707, at FL 330 659
SBAI Su-27 - Cruise speed 610 at FL 150 460, at FL 270 566
GAI An-124 - Cruise speed 505 at FL 150 414, at FL 270 496
This is also true for other aircraft and the speed is also different under 5-6000 feet.
Sometimes I set up some FP for test with different altitudes, took note of the speed, and configured the aircraft.txt accordingly. So boring....
Someone use a different method or you don't take care of this aspect?

Thanks in advance, Giorgio

[RKE]

As far as I know, the primary function of the cruise speed is to calculate which sector the aircraft is in at any given time. The speed should be somewhere in the region of the actual cruise speed (so something like 700 for the Mig-31). Some compilers (such as AIFP) will also use it to check if there's going to be enough time for the aircraft to arrive at its destination (ie. fly the approach, land, and taxi to parking) before the next departure time.