Re: [Flightgear-devel] gear door sequencing
> 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
Re: [Flightgear-devel] gear door sequencing
James Turner wrote: On Thursday, September 25, 2003, at 01:20 pm, Erik Hofman wrote: Speed brakes are on the top of the wing ( the extrados ? ) and can be used flying, On civilian aircraft and gliders this is usually the case. Military types can have them in different places - such as the F16 (on top of the fuselage?), the Buccaneer (opening tail cone) etc. F-15 : top of the fuselage. F-16 : horizontally along the fuselage, between the horizontal tail and turbine compartment, at the end of the strakes. One thing I've never been clear on - is there a distinction between 'things you deploy in the air' and 'thing you deploy on touchdown'? I know the things I call spoilers on the wings of big jets can be extended in flight to slow the aircraft, as well as auto-deploying (more?) on touchdown to kill lift + decelerate. 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? I'm not really sure about the Fokker 100 (I *think* it is okay to deploy them in-air), but the F-16 definatelly allows for in-air deployement. For the F-16 it is even used to prevent the aircraft to go in an uncontrollable state by taking advantage of the pitching moment created by deplying the speed brake. 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? Not that I'm aware of. The F-104 buffet characteristics at high speed seem to be quite realistic though. 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. I think the fokker has this type of reverser. Playing with google image search turned up the following: (2nd is especially nice) Yep. Look at the Fokker 100 in external vier and press Ctrl-B ... http://www.thrustair.com/dc9_thrust_reverser.jpg www.robl.w1.com/Pix-4/ C970493.jpg 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 :-) I would suggest not trying to fly the F-16 then, it is almost impossible to stop! Erik ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] gear door sequencing
On Thursday, September 25, 2003, at 01:20 pm, Erik Hofman wrote: Speed brakes are on the top of the wing ( the extrados ? ) and can be used flying, On civilian aircraft and gliders this is usually the case. Military types can have them in different places - such as the F16 (on top of the fuselage?), the Buccaneer (opening tail cone) etc. F-15 : top of the fuselage. F-16 : horizontally along the fuselage, between the horizontal tail and turbine compartment, at the end of the strakes. One thing I've never been clear on - is there a distinction between 'things you deploy in the air' and 'thing you deploy on touchdown'? I know the things I call spoilers on the wings of big jets can be extended in flight to slow the aircraft, as well as auto-deploying (more?) on touchdown to kill lift + decelerate. 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? 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? 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. I think the fokker has this type of reverser. Playing with google image search turned up the following: (2nd is especially nice) http://www.thrustair.com/dc9_thrust_reverser.jpg www.robl.w1.com/Pix-4/ C970493.jpg 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 :-) H&H James ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] gear door sequencing
Matthew Law wrote: Speed brakes are on the top of the wing ( the extrados ? ) and can be used flying, On civilian aircraft and gliders this is usually the case. Military types can have them in different places - such as the F16 (on top of the fuselage?), the Buccaneer (opening tail cone) etc. F-15 : top of the fuselage. F-16 : horizontally along the fuselage, between the horizontal tail and turbine compartment, at the end of the strakes. F-104 : vertically alongside the fuselage, just aft of the main wing. Erik ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] gear door sequencing
> Am I correct when I say : > Slat are in front of the wing, Yes, but they can be on the trailing edge where the terms 'slat' and 'slot' can be used interchangeably. Generally in the UK they refer to them as 'leading edge slats'. Most modern aircraft include the 'slots' within the flap design (slotted flaps) but some older, weird and wonderful aircraft had them all over the place so it's worth noting the difference! > Speedbrakes are on the top of the wing ( the extrados ? ) and can be used flying, On civilian aircraft and gliders this is usually the case. Military types can have them in different places - such as the F16 (on top of the fuselage?), the Buccaneer (opening tail cone) etc. > Reverse are small doors on the engine nacelle that open once the plane is landed and > try to stop before the end of the runway. On all the planes I have seen, yes. I believe some of the older ones would allow you to engage reverse thrust while in flight. With potentially disastrous circumstances... Hope this helps, Matt. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] gear door sequencing
--- Frederic BOUVIER <[EMAIL PROTECTED]> wrote: > David Culp wrote: > > Wow Fred! It's been a while since I tried the A320. That's a > fantastic > > model, and the gear door sequencing looks great. > > Thanks, > > It is still missing the speedbrakes, slat and reverse. > BTW, as a non native english speaker, I need some clarifications on > terminology. > > Am I correct when I say : > Slat are in front of the wing, Yes. > Speedbrakes are on the top of the wing ( the extrados ? ) and can be > used flying, The panels on top of the wing are usually called spoilers but they can function as speedbrakes. Speedbrakes can, in general, be located anywhere on the aircraft. Though those mounted on the fuselage are usually on top (F-15) or somewhere aft of the wing (F-16). > Reverse are small doors on the engine nacelle that open once the > plane is landed and > try to stop before the end of the runway. Yes. Thrust reversers force some or all of the airflow out of the engine in the forward direction and slow down the aircraft. Note that depending on the design, the actual mechanisms involved can be quite large. > > Cheers, > -Fred > > > ___ > Flightgear-devel mailing list > [EMAIL PROTECTED] > http://mail.flightgear.org/mailman/listinfo/flightgear-devel > > __ Do you Yahoo!? Yahoo! SiteBuilder - Free, easy-to-use web site design software http://sitebuilder.yahoo.com ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] gear door sequencing
> Am I correct when I say : > Slat are in front of the wing, Yes. Actually, if it slides forward then it is called a slat. If it rotates down from a hinge it is called a "leading edge flap". Together they are sometimes called "leading edge devices" or LED. > Speedbrakes are on the top of the wing ( the extrados ? ) and can be used > flying. Yes. Sometimes they are called "spoilers", and it isn't always clear. Sometimes, if they are on top of the wing, they are called both at the same time. > Reverse are small doors on the engine nacelle that open once the > plane is landed and try to stop before the end of the runway. Yes. The part of the engine cowling that moves backwards is often called a reverser "sleeve". Dave -- David Culp [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] gear door sequencing
David Culp wrote: > Wow Fred! It's been a while since I tried the A320. That's a fantastic > model, and the gear door sequencing looks great. Thanks, It is still missing the speedbrakes, slat and reverse. BTW, as a non native english speaker, I need some clarifications on terminology. Am I correct when I say : Slat are in front of the wing, Speedbrakes are on the top of the wing ( the extrados ? ) and can be used flying, Reverse are small doors on the engine nacelle that open once the plane is landed and try to stop before the end of the runway. Cheers, -Fred ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] gear door sequencing
Wow Fred! It's been a while since I tried the A320. That's a fantastic model, and the gear door sequencing looks great. Dave -- David Culp [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] gear door sequencing
David Culp wrote: > Has anyone made an exterior model with proper gear door sequencing yet (i.e. > 1. gear handle up 2. gear door opens 3. gear comes up 4. gear door > closes)? Is there a way to do this in the animation config? > > If not, we'll need a gear door sequencing subsystem. I did that with the A320. I used interpolation tables like this : rotate GearDoorRight.1 GearDoorRight.3 /gear/gear[2]/position-norm 0.0 0.0 0.2 90.0 0.8 90.0 1.0 0.0 -0.719 0.099 -4.552 -1 0 0 My sequence has only 3 states : 1. gear door opens, 2. gear comes up, 3. gear door closes. Cheers, -Fred ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] gear door sequencing
David Culp <[EMAIL PROTECTED]> said: > Has anyone made an exterior model with proper gear door sequencing yet (i.e. > 1. gear handle up 2. gear door opens 3. gear comes up 4. gear door > closes)? Is there a way to do this in the animation config? > The answer is yes. Take a look at the c310u3a model to see an example of gear door operation. Also you could look at the 747 to get a similar idea. The 747 model doesn't have gear doors (i'm working on that), but it does rotate the gear up before stowing it. Both examples should give some hints on how to use the min, max, and factor to have animations occur while the gear property value gradually moves from 0.0 to 1.0 and vice versa. We probably don't need a gear animation subsystem, but it might be helpful to have a generic timer subsystem that could be used for things like this. A similar case would be the 747-400 glass cockpit display that shows the text "GEAR UP" for just 10 seconds after the gear up sequence is complete. Best, Jim ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] gear door sequencing
Has anyone made an exterior model with proper gear door sequencing yet (i.e. 1. gear handle up 2. gear door opens 3. gear comes up 4. gear door closes)? Is there a way to do this in the animation config? If not, we'll need a gear door sequencing subsystem. Dave -- David Culp [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
