Jim Wilson writes: > Not sure if this relates to the air pressure issue, seems to be a bit more > than that would account for. A few days ago someone reported unusual flap > effects, prior to the corrections to the YASim flight model. > > It appears that not only do the flaps not increase drag in the 747, but they > decrease it. Holding an altitude at 3000ft, with idle throttle, flaps > position one clearly decreases the rate at which airspeed is falling. Going > to flaps position 3 actually _increases_ airspeed (with throttle idle) and at > the same time starts pushing the aircraft up in elevation. > > This is without the David's latest air density patch (using CVS from about > 3:30pm Today 2002-06-05). Under the right conditions, not observed in a > reproducable/reportable way (but generally lower airspeeds and altitudes) the > aircraft can speed up drastically and skyrocket into the air at a rate over > 10kfps.
I think that even from the beginning, yasim flaps have increased drag, but have always reduced drag so the end result of lowering flaps is that your speed increases and/or you climb faster (or descend less rapidly). Andy is aware of this issue, but says that it is "hard" to fix. Curt. -- Curtis Olson IVLab / HumanFIRST Program FlightGear Project Twin Cities [EMAIL PROTECTED] [EMAIL PROTECTED] Minnesota http://www.menet.umn.edu/~curt http://www.flightgear.org _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
