> But, I can't imagine deploying the split tail brake of the Fokker 100 > while in the air .... is this actually ok, or is there some definite > separation of usage?
Some jet airplanes extend the speedbrake on final approach in order to keep the engines running at higher rpm. This gives a faster thrust response in case of go-around. This is especially important for slow-accelerating engines like high-bypass turbofans or engines with centrifugal compressors. You just have to remember to retract the speedbrake on go-around, ( or an automatic retraction may be installed ). The T-37 uses "thrust attenuators" instead of a speedbrake for this. The thrust attenuator is a door that swings out into the jet exhaust to reduce the thrust by redirecting some of it sideways. When you retract the attenuator you get instant thrust. The T-37 needs this because its engines have centrifugal compressors, which accelerate very slowly. > On a related point, do any of the FDMs / FlightGear model an increase > in buffet / vibration / noise when deploying spoilers (or indeed, lots > of flap) at high speed? The T-38 model has an aural indication of buffet due to flow separation. The sound used is the "rumble" sound also used for the wheels. This sound could also be used for the speedbrake. There is no visual buffet model yet, but maybe the turbulence code could be adapted? > For thrust reversers, as well as a sleeve, you also get two (or more?) > segments of the exhaust pipe that pivot at their rear end, to redirect > the thrust. The two main types that I'm aware of are the sleeved type, and the clamshell type. With the sleeved type, usually found on wing-mounted pod engines, the aft part of the cowling slides back and "blocker doors" or "cascade vanes" intrude into the exhaust stream to redirect the gases out through the opening between the sleeve and the forward part of the cowling. In the clamshell type, the exhaust nozzle splits in two and pivots to redirect the gases. > Anyway, the sooner FG / the FDMs / the planes support more of these > devices, the happier I'll be - because I habitually fly my approaches > too fast, and auto-spoilers really help stick the plane to the ground Amen. We can use the landing gear weight-on-wheels property to signal touchdown, but we also need an arming switch to prevent the spoilers from coming up on takeoff, when there is also weight on the wheels. Dave -- **************************** David Culp [EMAIL PROTECTED] **************************** _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
