Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
Martin Spott wrote: This does not have to be as difficult as it is with the V-22. The Osprey is designed for being stuffed into _very_ small space below a ship's deck. If they had more space then it would have been possible to improve security simply by increasing the wing span, The problem, I think, is not in the wing span. In transition the aircraft is working around the stall speed for the wings. I would think that a larger wing would decrease rather than increase stability, no? Oh, you get heavily increased torque from the ailerons for manouverability and you get much more lift from large wings at low speed - especially because on the current design at least 90 % of the wing area suffers from the down-wind generated by the two the rotors, Martin. -- Unix _IS_ user friendly - it's just selective about who its friends are ! -- ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
Martin Spott wrote: Martin Spott wrote: ... Oh, you get heavily increased torque from the ailerons for manouverability and you get much more lift from large wings at low speed - especially because on the current design at least 90 % of the wing area suffers from the down-wind generated by the two the rotors, Ah yes, prop wash helps improve control effectivity at low speeds. It isn't going to be great, but should help. So how smooth is it when lift become significant on the wings? The wash off the rotors should be strong, but very turbulent. Air flow around the wings ought to be one very nasty numerical analysis problem, especially near wing stall. I can only imagine what surprises it held for the designers. Regards, Charlie H. -- You're not drunk if you can lie on the floor without holding on. ---Dean Martin ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
Martin Spott wrote: The big problematic area ... regime is unstable and recovery difficult. This does not have to be as difficult as it is with the V-22. The Osprey is designed for being stuffed into _very_ small space below a ship's deck. If they had more space then it would have been possible to improve security simply by increasing the wing span, The problem, I think, is not in the wing span. In transition the aircraft is working around the stall speed for the wings. I would think that a larger wing would decrease rather than increase stability, no? Regards, Charlie H. -- C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do, it blows away your whole leg. - Bjarne Stroustrup ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
Carsten.Hoefer wrote: Forgetting about all 'unsafe' situations in helicopters, do we have one in flightgear? Is it possible to model one with the existing flight models we use? Not without a lot of code work. Helicopters have a bunch of effects that don't exist in the current FDMs. Things like asymmetric lift effects would need to be revisited. Both YASim and JSBSim model P factor, which is what the same effect is called on a fixed wing propeller aircraft, via a hack that isn't general enough to handle ~90 degree AoAs. Other stuff, like blade flapping and precession of the main rotor just don't exist and would need to be done from scratch. For myself, I don't find PC simulation of helicopters very interesting. Existing throttles don't have anywhere near enough precision to simulate a collective, IMHO. Helicopter pilots maintain altitude by feeling for very slight changes in vertical acceleration and adjusting with tiny movements of the collective. There's no way we can simulate that well. We could do it with an autopilot like device, of course, but where's the fun in that? You might as well just install Commanche MCMXIV or whatnot to get same level of simulation realism. :) If you want to try hovering in FlightGear, try the Harrier. That thing is really difficult to hover, for all the same reasons that the real aircraft is difficult to hover. Andy -- Andrew J. RossNextBus Information Systems Senior Software Engineer Emeryville, CA [EMAIL PROTECTED] http://www.nextbus.com Men go crazy in conflagrations. They only get better one by one. - Sting (misquoted) ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
Curtis L. Olson wrote: Tony Peden writes: --- Jim Wilson [EMAIL PROTECTED] wrote: Hmmmthat should thin the ranks down on Wall St even more. ... IMHO that thing even looks dangerous :-) More dangerous than a helicopter? ... It sounds like avoiding the vortex ring state... I think the big danger is at landing or takeoff. ... The big problematic area for this class of aircraft historically has been the transition between hover, or rotor based operation and flying, where the wings are important. That regime is unstable and recovery difficult. Regards, Charlie H. -- C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do, it blows away your whole leg. - Bjarne Stroustrup ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
I think the big danger is at landing or takeoff. If you lose an engine or have any sort of mechanical failure on a single side, you are going to hit hard at some really odd angle. The engines are capable to deliver _enormous_ power for a short time in case of an engine failure - I believe this only works for a couple of minutes, afterwards the are fried ;-) But their most error prone part are not the engines but the way too short time frame for such a difficult development. Several prototypes and at least one pre-series plane crashed because of software failures killing several crews and passengers :-((( Martin. -- Unix _IS_ user friendly - it's just selective about who its friends are ! -- ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
The big problematic area for this class of aircraft historically has been the transition between hover, or rotor based operation and flying, where the wings are important. That regime is unstable and recovery difficult. This does not have to be as difficult as it is with the V-22. The Osprey is designed for being stuffed into _very_ small space below a ship's deck. If they had more space then it would have been possible to improve security simply by increasing the wing span, Martin. -- Unix _IS_ user friendly - it's just selective about who its friends are ! -- ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
[Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
Bell/Agusta V-22 derivative commercial BA609: http://www.bellagusta.com/html/aeroNet/downLoads/20393_609_AB_Brochure.pdf Fascinating. Pretty pictures, too. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
Hmmmthat should thin the ranks down on Wall St even more. It's hard to imagine they are selling civilian versions while there's talk about nixing the Osprey because of safety concerns. Well maybe not that hard. IMHO that thing even looks dangerous :-) Best, Jim Jon S Berndt [EMAIL PROTECTED] said: Bell/Agusta V-22 derivative commercial BA609: http://www.bellagusta.com/html/aeroNet/downLoads/20393_609_AB_Brochure.pdf Fascinating. Pretty pictures, too. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
Jim Wilson wrote: Hmmmthat should thin the ranks down on Wall St even more. It's hard to imagine they are selling civilian versions while there's talk about nixing the Osprey because of safety concerns. Well maybe not that hard. IMHO that thing even looks dangerous :-) It looks like a power ranger ... Erik Jon S Berndt [EMAIL PROTECTED] said: Bell/Agusta V-22 derivative commercial BA609: http://www.bellagusta.com/html/aeroNet/downLoads/20393_609_AB_Brochure.pdf Fascinating. Pretty pictures, too. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
--- Jim Wilson [EMAIL PROTECTED] wrote: Hmmmthat should thin the ranks down on Wall St even more. It's hard to imagine they are selling civilian versions while there's talk about nixing the Osprey because of safety concerns. Well maybe not that hard. IMHO that thing even looks dangerous :-) More dangerous than a helicopter? That fixed wing makes me feel better about it. I wonder if gliding in that thing is any better than autorotation in a helicopter ... It sounds like avoiding the vortex ring state is doable but will likely require a fair amount of training (and possibly some control law mods) Best, Jim Jon S Berndt [EMAIL PROTECTED] said: Bell/Agusta V-22 derivative commercial BA609: http://www.bellagusta.com/html/aeroNet/downLoads/20393_609_AB_Brochure.pdf Fascinating. Pretty pictures, too. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel __ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
Tony Peden writes: --- Jim Wilson [EMAIL PROTECTED] wrote: Hmmmthat should thin the ranks down on Wall St even more. It's hard to imagine they are selling civilian versions while there's talk about nixing the Osprey because of safety concerns. Well maybe not that hard. IMHO that thing even looks dangerous :-) More dangerous than a helicopter? That fixed wing makes me feel better about it. I wonder if gliding in that thing is any better than autorotation in a helicopter ... It sounds like avoiding the vortex ring state is doable but will likely require a fair amount of training (and possibly some control law mods) I think the big danger is at landing or takeoff. If you lose an engine or have any sort of mechanical failure on a single side, you are going to hit hard at some really odd angle. At least with a helicopter you are probably going to land butt first and might have a chance to try an autorotation. 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
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
On Tue, 10 Dec 2002 13:09:03 -0600 Curtis L. Olson [EMAIL PROTECTED] wrote: I think the big danger is at landing or takeoff. If you lose an engine or have any sort of mechanical failure on a single side, you are going to hit hard at some really odd angle. At least with a helicopter you are probably going to land butt first and might have a chance to try an autorotation. I would be very surprised if the engines are not cross-coupled such that each engine drives both props, as in the V-22. A single engine failure would not cause one rotor to be unpowered. The gearbox for the V-22 was one of the main design challenges for the Osprey, IIRC. The other components of the drive train/propulsion system are made for extremely high reliability for that very reason. They are mostly Criticality 1 items. I agree that the big danger is at takeoff and landing, for sure, but it's because of the aero phenomena. I wonder if clever placement of sensors about the aircraft and some Expert Systems logic could potentially sense dangerous conditions and adapt appropriately? Jon Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
It sounds like avoiding the vortex ring state is doable but will likely require a fair amount of training (and possibly some control law mods) Speaking of which - a recent issue of Aviation Leak that I have mentions that they've been unable to properly account for/simulate the VRS in the flight simulators for the V-22. g. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
Gene Buckle writes: I think the big danger is at landing or takeoff. If you lose an engine or have any sort of mechanical failure on a single side, you are going to hit hard at some really odd angle. At least with a helicopter you are probably going to land butt first and might have a chance to try an autorotation. Curt, there is a central transmission in the wing that will transfer the drive to the operating engine automatically so that won't happen. If they both fail at once though You could also imagine that something downstream of this central transmission could fail, again leaving you in an unhealthy state. I agree with the people who are saying this can be made to fly safely within reasonable tolerances, but I also think there are certain phases where it's probably always going to be a little less safe than a helicopter, or perhaps you could say that certain types of failures at certain times would be less survivable in the BA-609 ... Regards, 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
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
On Tue, 10 Dec 2002 15:22:05 -0600 Curtis L. Olson [EMAIL PROTECTED] wrote: a helicopter, or perhaps you could say that certain types of failures at certain times would be less survivable in the BA-609 This (above) might be more true than your first statement. One thing that comes to my mind though, for V-22, is that survivability might be increased in one way due to less time spent in the combat area. You dash in fast, you drop down and pick up the downed airman, then you dash out fast. It's got the advantage over helicopters in that respect, at least. If the BA_609 proves to be as safe as helicopters I can see it really taking off. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
Curt, there is a central transmission in the wing that will transfer the drive to the operating engine automatically so that won't happen. If they both fail at once though You could also imagine that something downstream of this central transmission could fail, again leaving you in an unhealthy state. I agree with the people who are saying this can be made to fly safely within reasonable tolerances, but I also think there are certain phases where it's probably always going to be a little less safe than a helicopter, or perhaps you could say that certain types of failures at certain times would be less survivable in the BA-609 ... Well one of my favorite quotes goes something like this: If your wings are moving faster than you are, you're in a Helicopter and are therefore unsafe. :) g. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
Gene Buckle writes: Well one of my favorite quotes goes something like this: If your wings are moving faster than you are, you're in a Helicopter and are therefore unsafe. :) I suppose the related quote would be something along the lines of If your wings are moving slower than you, they are probably not still attached (and are therefore unsafe.) 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
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
On Tue, 2002-12-10 at 13:22, Curtis L. Olson wrote: Gene Buckle writes: I think the big danger is at landing or takeoff. If you lose an engine or have any sort of mechanical failure on a single side, you are going to hit hard at some really odd angle. At least with a helicopter you are probably going to land butt first and might have a chance to try an autorotation. Curt, there is a central transmission in the wing that will transfer the drive to the operating engine automatically so that won't happen. If they both fail at once though You could also imagine that something downstream of this central transmission could fail, again leaving you in an unhealthy state. I agree with the people who are saying this can be made to fly safely within reasonable tolerances, but I also think there are certain phases where it's probably always going to be a little less safe than a helicopter, or perhaps you could say that certain types of failures at certain times would be less survivable in the BA-609 ... I don't know ... it sound like you are really starting to stack up the failures. Regards, Curt. -- Tony Peden [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
On 10 Dec 2002 15:18:48 -0800 Tony Peden [EMAIL PROTECTED] wrote: I don't know ... it sound like you are really starting to stack up the failures. I don't know ... I was thinking the other day: what if the pilot was pouring a can of Coke into a cup on the flight deck and dropped the can and it rolled under the pedals and he set his cup down and reached down to pick up the can but knocked the yoke which rolled the plane and made him push his foot forward and the can got stuck under the pedals with the rudder all the way over and the partial cup of Coke was knocked over into some electrical stuff and shorted it out and killed all the engines on one side and the stewardess fell onto the pilot so he couldn't see and then ... Geez, I'm not flying anymore. ;-) ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
On Tue, 2002-12-10 at 15:27, Jon S Berndt wrote: On 10 Dec 2002 15:18:48 -0800 Tony Peden [EMAIL PROTECTED] wrote: I don't know ... it sound like you are really starting to stack up the failures. I don't know ... I was thinking the other day: what if the pilot was pouring a can of Coke into a cup on the flight deck and dropped the can and it rolled under the pedals and he set his cup down and reached down to pick up the can but knocked the yoke which rolled the plane and made him push his foot forward and the can got stuck under the pedals with the rudder all the way over and the partial cup of Coke was knocked over into some electrical stuff and shorted it out and killed all the engines on one side and the stewardess fell onto the pilot so he couldn't see and then ... Geez, I'm not flying anymore. ;-) Curt, I apologize for even beginning to suggest that you were stacking things up ... ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel -- Tony Peden [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
On 10 Dec 2002 15:37:08 -0800 Tony Peden [EMAIL PROTECTED] wrote: On Tue, 2002-12-10 at 15:27, Jon S Berndt wrote: I don't know ... I was thinking the other day: what if the ... Curt, I apologize for even beginning to suggest that you were stacking things up ... Hey! It could happen! :-) Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
On Tuesday 10 December 2002 4:22 pm, Curtis L. Olson wrote: You could also imagine that something downstream of this central transmission could fail, again leaving you in an unhealthy state. I unhealthy state you guys crack me up. Sounds more like brown trousers time to me ;-) agree with the people who are saying this can be made to fly safely within reasonable tolerances, but I also think there are certain phases where it's probably always going to be a little less safe than a helicopter, or perhaps you could say that certain types of failures at certain times would be less survivable in the BA-609 ... Regards, Curt. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
Re: [Flightgear-devel] [OT] BA-609, V-22 derivative aircraft
On Tue, 2002-12-10 at 19:24, John Check wrote: On Tuesday 10 December 2002 4:22 pm, Curtis L. Olson wrote: You could also imagine that something downstream of this central transmission could fail, again leaving you in an unhealthy state. I unhealthy state you guys crack me up. Sounds more like brown trousers time to me ;-) Fighter pilots do it best, they talk about how a missile could ruin their whole day. agree with the people who are saying this can be made to fly safely within reasonable tolerances, but I also think there are certain phases where it's probably always going to be a little less safe than a helicopter, or perhaps you could say that certain types of failures at certain times would be less survivable in the BA-609 ... Regards, Curt. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel -- Tony Peden [EMAIL PROTECTED] ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
