From: Bertrand C. <bco...@gm...> - 2009-05-15 15:41:14
Attachments:
patch737-reverser.diff
reverse-thrust.nas
|
Hi all, Not sure it is the right mailing list to post this but I have made a patch to activate the reverse on the 737-300 of FlightGear. I have seen on FG Wiki that David Culp and Innis Cunningham are the authors of the 737 model so I have put Dave on copy of this e-mail. However I do not know Innis' e-mail address hence this post. Basically, this patch activates the reverse functionality for the 737. It is based on code from other airliners of FG with the same key binding (Delete) and the relevant animation (fortunately the 3D model allows this animation without any modification). However there are some small specificities in my patch: 1. The reverse can only be actuated while the engine is idle. I do not know if there is indeed a system which prevents that in the real 737. But I don't think this can be done anyway with engines running at full or intermediate power because the actuators won't have enough power to overstow the pressurised cowl in order to disengage the locks. 2. I have added some drag when the reverse is deployed. Indeed on some airlines, when the weather conditions allow it, the pilots use the reverse as a mere speedbrake: they deploy the reverse when landing and leave the engines idling. This is to save fuel and engine wear. The drag that I have included in the model allows to reproduce such a procedure. No need to say that the value 0.018 in the formula is just a guess so that the drag of the reverse is in the neighbourhood of the gears drag. I did not find any indicator of reverse deployment on the cockpit panel (even when scrolling the panel with SHIFT+F7/8). So I guess that it needs to be added. I will search the internet but if anybody has any information/picture regarding that I will be more than happy to use them. I am a poor 3D modeler so I cannot update the model myself. But for those who can and are interested in: there are several subtle errors on the model regarding the deployment of the reverse. 1. The Inner Fixed Structure (IFS) should be masked by the grids of the reverser (see http://www.airliners.net/photo/Scandinavian-Airlines--/Boeing-737-683/1214710/L/&sid=b5f6ee391864d2b58be0ef928940e316 ) 2. The 12 o'c and 6 o'c bifurcations are missing on the IFS. However I am not sure this is relevant if the grids are added to the model. If the authors are happy with this patch then I plan to add some details to it. The first one will be cockpit indication and the second one reverser inhibition. FAA allows the 737 to be used with one reverser inhibited. I think it can be a small challenge to land with only one reverser (and compensate the moment with the rudder). Any comment / suggestion please let me know. Cheers, Bertrand. |
From: Heiko S. <aei...@ya...> - 2009-05-15 16:05:00
|
Hi, Some time ago, I started to improve the 737-300. I let it stall: no times, experiences I had with the developement of the c172p and some personal things. I have still a copy on my local system but give up developement There are some people which have my model, but what they do with it- no real idea. Hoepfully the best. But I included also a reverse thrust so some thoughts and infos from me: >1. The reverse can only be actuated while the engine is idle. I do not >know if there is indeed a system which prevents that in the real 737. >But I don't think this can be done anyway with engines running at full >or intermediate power because the actuators won't have enough power to >overstow the pressurised cowl in order to disengage the locks. No idea if there is a lock in the real thing, but sounds very reasonable! >2. I have added some drag when the reverse is deployed. Indeed on some >airlines, when the weather conditions allow it, the pilots use the >reverse as a mere speedbrake: they deploy the reverse when landing and >leave the engines idling. This is to save fuel and engine wear. The >drag that I have included in the model allows to reproduce such a >procedure. No need to say that the value 0.018 in the formula is just >a guess so that the drag of the reverse is in the neighbourhood of the >gears drag. If you modelled a real reverse, there is no need for adding a drag imho. I used <property>fdm/jsbsim/propulsion/engine[1]/reverser-angle-rad</property> <value>180</value> as solution for reverse thrust. Works, and you have a slight drag with engine in idle. >I did not find any indicator of reverse deployment on the cockpit >panel (even when scrolling the panel with SHIFT+F7/8). So I guess that >it needs to be added. I will search the internet but if anybody has >any information/picture regarding that I will be more than happy to >use them. Werll, the 737-300 has in real life a analog panel. The current model but has the panel of a 737-NG. On the 737-classic there is deployment sign on the panel. (near the flap indicator if I remember right.) >I am a poor 3D modeler so I cannot update the model myself. But for >those who can and are interested in: there are several subtle errors >on the model regarding the deployment of the reverse. >1. The Inner Fixed Structure (IFS) should be masked by the grids of >the reverser (see >http://www.airliners.net/photo/Scandinavian-Airlines--/Boeing-737-683/1214710/L/&sid=b5f6ee391864d2b58be0ef928940e316 >) >2. The 12 o'c and 6 o'c bifurcations are missing on the IFS. However I >am not sure this is relevant if the grids are added to the model. There are some more subtle errors: the dimensions and proportions of the fuselage aren't right and some smaller things. Well, when the current 737 was bulit, there wasn't such a mount of informations available for free. But the wings are well done, and the flap animation is still outstanding! >If the authors are happy with this patch then I plan to add some >details to it. The first one will be cockpit indication and the second >one reverser inhibition. FAA allows the 737 to be used with one >reverser inhibited. I think it can be a small challenge to land with >only one reverser (and compensate the moment with the rudder). >Any comment / suggestion please let me know. >Cheers, >Bertrand. A improved 737 would be still great- fine to see that someone is working on that! Regards HHS |
From: Gene B. <ge...@de...> - 2009-05-15 16:17:48
|
The thrust reversers require that you go to idle power to engage them. However, after that you can run the power back up. In the real aircraft there is no "indication" that the reversers are on. This is because the reverser lever is attached to the throttle arm for each engine. To activate the reverser, you'll pull this lever up and aft. In its open position, it's very obvious. :) g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://gpl.openqm.com - Get it _today_! |
From: Heiko S. <aei...@ya...> - 2009-05-15 16:24:54
|
Indeed- no indicator. There is only a indicator if the reverser is unlocked- I mistook this. >The thrust reversers require that you go to idle power to engage them. >However, after that you can run the power back up. In the real aircraft >there is no "indication" that the reversers are on. This is because the >reverser lever is attached to the throttle arm for each engine. To >activate the reverser, you'll pull this lever up and aft. In its open >position, it's very obvious. :) >g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://gpl.openqm.com - Get it _today_! ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ Flightgear-devel mailing list Fli...@li... https://lists.sourceforge.net/lists/listinfo/flightgear-devel |
From: John W. <ca...@mm...> - 2009-05-15 17:37:03
|
Gene Buckle wrote: >The thrust reversers require that you go to idle power to engage them. >However, after that you can run the power back up. In the real aircraft >there is no "indication" that the reversers are on. This is because the >reverser lever is attached to the throttle arm for each engine. To >activate the reverser, you'll pull this lever up and aft. In its open >position, it's very obvious. :) > >g. > > > > Perhaps Dave might want to expand on this or correct any errors.... There are reverse "REV" indications in the cockpit located above the N1 gauges and digital readout window on the EICAS display. To deploy the reverse thrusters the forward throttles must be in the Idle position. The reverse thrust lever is blocked at the reverse idle position until the reverse thrust sleeve is more than 60% deployed. (the "REV" indication goes to amber when the sleeve has moved from the stowed position ; between 10 and 90% and then green when more than 90% of travel to deployed position ) then the interlock is released and the reverse thrust levers may be raised to accelerate the engines. when in reverse thrust the forward thrust levers CANNOT be advanced. When exiting reverse thrust, the reverse thrust levers are stowed and once the thrust sleeves have retracted, the forward throttles may be advanced as desired for taxi. Reverse thrust may not be selected in-flight; however when the radar altimeter is less than 10' (3 meters) the T/R control system allows for deployment. For more details on the electro-mechanical and hydraulic details, switches, interlocks, etc see the respective flight manuals. Hope this helps JW |
From: Gene B. <ge...@de...> - 2009-05-15 17:45:12
|
> > There are reverse "REV" indications in the cockpit located above the N1 > gauges and digital readout window on the EICAS display. To deploy the Is that indication present on the -200 series? If so, I'd never noticed it. :) That's the only model I have experience with (specifically the Conductron-Missouri 737-200 simulator, circa 1967) g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://gpl.openqm.com - Get it _today_! |
From: John W. <ca...@mm...> - 2009-05-15 18:07:14
|
Gene Buckle wrote: >>There are reverse "REV" indications in the cockpit located above the N1 >>gauges and digital readout window on the EICAS display. To deploy the >> >> > >Is that indication present on the -200 series? If so, I'd never noticed >it. :) That's the only model I have experience with (specifically the >Conductron-Missouri 737-200 simulator, circa 1967) > > >g. > > > The info was only for 737's with glass. Imagine the mechanical stuff and sequencing is the same, but the cockpit displays could be totally different for older models, even non-existent as Gene pointed out. We built a 747 quadrant with the interlocks, it was a bear of a project, especially trying to prevent pilot "wannabes' at trade shows who had no idea how to operate the system from trying to overide/overpower the interlocks and bend the metal. ;-) JW |
From: Gene B. <ge...@de...> - 2009-05-15 18:38:17
|
>> > The info was only for 737's with glass. Imagine the mechanical stuff > and sequencing is the same, but the cockpit displays could be totally > different for older models, even non-existent as Gene pointed out. > Ahh, ok. I'll have to see if I've got a 737 N1 indicator I can tear down and see if it's got a REV flag in it. > We built a 747 quadrant with the interlocks, it was a bear of a project, > especially trying to prevent pilot "wannabes' at trade shows who had no > idea how to operate the system from trying to overide/overpower the > interlocks and bend the metal. ;-) I've got one or two of the real arms w/reverser on it and they're pretty cool mechanically. I'd be standing behind the "Guest" with a bat, wearing a T-shirt that reads, "You bend IT, I bend YOU." :) g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://www.scarletdme.org - Get it _today_! |
From: Innis C. <in...@ho...> - 2009-05-16 01:05:49
|
Hi Bertrand You or anybody can modify the 737-300 as long as it does not become messed up. Thank you Heiko for the compliment on the flaps it is nice when little things get noticed. Maybe I should get off my rear end and model the thrust reversers for the engines. Cheers Innis > > Hi all, > > Not sure it is the right mailing list to post this but I have made a > patch to activate the reverse on the 737-300 of FlightGear. > I have seen on FG Wiki that David Culp and Innis Cunningham are the > authors of the 737 model so I have put Dave on copy of this e-mail. > However I do not know Innis' e-mail address hence this post. > Bertrand. _________________________________________________________________ View photos of singles in your area Click Here http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fdating%2Eninemsn%2Ecom%2Eau%2Fsearch%2Fsearch%2Easpx%3Fexec%3Dgo%26tp%3Dq%26gc%3D2%26tr%3D1%26lage%3D18%26uage%3D55%26cl%3D14%26sl%3D0%26dist%3D50%26po%3D1%26do%3D2%26trackingid%3D1046138%26r2s%3D1&_t=773166090&_r=Hotmail_Endtext&_m=EXT |
From: Bertrand C. <bco...@gm...> - 2009-05-17 14:07:41
|
Hi Gene, 2009/5/15 Gene Buckle <ge...@de...>: > > The thrust reversers require that you go to idle power to engage them. > However, after that you can run the power back up. This is a very interesting information. Thank you. > In the real aircraft > there is no "indication" that the reversers are on. I think it is quite not true. Deployment of the reverse must be controlled and monitored by the pilots since its inadvertent deployment can be catastrophic. See the crash of Lauda Air Flight 004 for an example. Or to be a bit less pessimistic if you command the deployment of the reverse during landing but only one reverser correctly deploys (the other one being jammed at mid-course of instance) then I think the pilots need to know that they will have asymmetric thrust if they pull the reverser thrust lever. So I can hardly believe there is no indication of the correct deployment of the T/Rs on the cockpit panel. Cheers, Bertrand. |
From: Bertrand C. <bco...@gm...> - 2009-05-17 14:12:08
|
Or may be the indication is only available on the more modern aircrafts ? 2009/5/17 Bertrand Coconnier <bco...@gm...>: > Hi Gene, > > 2009/5/15 Gene Buckle <ge...@de...>: >> >> The thrust reversers require that you go to idle power to engage them. >> However, after that you can run the power back up. > > This is a very interesting information. Thank you. > >> In the real aircraft >> there is no "indication" that the reversers are on. > > I think it is quite not true. Deployment of the reverse must be > controlled and monitored by the pilots since its inadvertent > deployment can be catastrophic. See the crash of Lauda Air Flight 004 > for an example. > > Or to be a bit less pessimistic if you command the deployment of the > reverse during landing but only one reverser correctly deploys (the > other one being jammed at mid-course of instance) then I think the > pilots need to know that they will have asymmetric thrust if they pull > the reverser thrust lever. > > So I can hardly believe there is no indication of the correct > deployment of the T/Rs on the cockpit panel. > > Cheers, > > Bertrand. > |
From: Alan T. <ajt...@v-...> - 2009-05-17 14:42:35
|
-----Original Message----- From: Bertrand Coconnier [mailto:bco...@gm...] So I can hardly believe there is no indication of the correct deployment of the T/Rs on the cockpit panel. Cheers, Bertrand. ---------------------------------------------------------------------- It is quite obvious to the pilot when he has selected reverse thrust. The whole of the top of the throttle levers is opened backwards. It isn't an insignificant toggle switch which could have been inadvertently operated. The only need for a panel indication is to show that the reverse-thrust buckets have deployed (or not). Similarly it is not usual to have a panel indication of the control column or the rudder pedals, although some modern aircraft may indicate the control surface positions. Flightsim on a PC without a complete cockpit is a different thing altogether, and here an indication would have practical benefit. Alan |
From: Gene B. <ge...@de...> - 2009-05-17 16:01:09
|
On Sun, 17 May 2009, Bertrand Coconnier wrote: >> In the real aircraft >> there is no "indication" that the reversers are on. > > I think it is quite not true. Deployment of the reverse must be > controlled and monitored by the pilots since its inadvertent > deployment can be catastrophic. See the crash of Lauda Air Flight 004 > for an example. > > Or to be a bit less pessimistic if you command the deployment of the > reverse during landing but only one reverser correctly deploys (the > other one being jammed at mid-course of instance) then I think the > pilots need to know that they will have asymmetric thrust if they pull > the reverser thrust lever. > > So I can hardly believe there is no indication of the correct > deployment of the T/Rs on the cockpit panel. > Bertrand, the thrust reverser lever in a 737 throttle arm extends about 4-6" *above* the throttle "knob" when active. You'd have to be a an idiot of an exceptional kind to NOT notice this huge metal handle sticking straight up. :) g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://www.scarletdme.org - Get it _today_! |
From: Bertrand C. <bco...@gm...> - 2009-05-17 14:08:28
|
Hi Heiko, 2009/5/15 Heiko Schulz <aei...@ya...>: > > Hi, > > Some time ago, I started to improve the 737-300. I let it stall: no times, experiences I had with the development of the c172p and some personal things. I have still a copy on my local system but give up development > There are some people which have my model, but what they do with it- no real idea. Hopefully the best. But I included also a reverse thrust so some thoughts and infos from me: Is it possible to have a copy of your model ? > >>1. The reverse can only be actuated while the engine is idle. I do not >>know if there is indeed a system which prevents that in the real 737. >>But I don't think this can be done anyway with engines running at full >>or intermediate power because the actuators won't have enough power to >>overstow the pressurised cowl in order to disengage the locks. > No idea if there is a lock in the real thing, but sounds very reasonable! I have no clear idea either but I cannot believe that the actuators are pulling the cowl during all the flight to prevent the reverser from opening. There must be a system to prevent the hydraulics to be stressed during all the flight and the most obvious is locks. > >>2. I have added some drag when the reverse is deployed. Indeed on some >>airlines, when the weather conditions allow it, the pilots use the >>reverse as a mere speedbrake: they deploy the reverse when landing and >>leave the engines idling. This is to save fuel and engine wear. The >>drag that I have included in the model allows to reproduce such a >>procedure. No need to say that the value 0.018 in the formula is just >>a guess so that the drag of the reverse is in the neighbourhood of the >>gears drag. > If you modelled a real reverse, there is no need for adding a drag imho. This is an interesting remark and I did not think about that. I have made some further investigations and my conclusions are : The "reversed thrust" when the T/R is operated is the addition of two forces: 1. The ram drag of the engine itself which is basically equal to the airflow multiplied by the aircraft speed 2. A portion of the airflow which is indeed ejected forward and produces in reaction a backward thrust. The first component is obviously proportional to the airspeed while the second one is proportional to the thrust. So my initial proposal was obviously wrong since it used qbar which is proportional to the square of the airspeed. On the other hand, if you look at the thrust table of Engines/CFM56.xml you will see that the idle thrust is more or less constant over the speed range of a landing airplane (i.e. 0<Mach<0.2). So your suggestion only includes the second component and does not reproduce the reality either. However the current turbine model of the engine does not compute the airflow or the ram drag of the engine so I will stick with your idea until I can do something better. > I used > <property>fdm/jsbsim/propulsion/engine[1]/reverser-angle-rad</property> > <value>180</value> > > as solution for reverse thrust. Works, and you have a slight drag with engine in idle. Oddly the value "180" suggests that you entered the angle in degrees while it should be entered in radians (which means that you have entered an angle of 180 mod 2*pi = 4,071 rad = 233.24 deg). With such a value the reversed thrust is almost 60% of the forward thrust. After some investigations, the performance of most thrust reversers is in the area of 40%. Hence an angle of acos(-0.4) = 1.98231 rad = 113.58 deg should be reasonably close to reality. Yes I know, my first guess was not this value... :-/ > > A improved 737 would be still great- fine to see that someone is working on that! > Regards > HHS The 737 (Classic) was one of my favourite airplanes on MS Flight Sim (booh shame on me). Hence my interest on it. Cheers, Bertrand. |
From: Heiko S. <aei...@ya...> - 2009-05-17 14:43:06
|
Hi, >Is it possible to have a copy of your model ? Of course: www.hoerbird.net/737-classic.zip It includes the 737-300 and the 737-400. But there will be maybe still some bugs and it needs work though....But should work with 1.9.1 and CVS >This is an interesting remark and I did not think about that. I have >made some further investigations and my conclusions are : >The "reversed thrust" when the T/R is operated is the addition of two forces: >1. The ram drag of the engine itself which is basically equal to the airflow multiplied by the aircraft speed >2. A portion of the airflow which is indeed ejected forward and >produces in reaction a backward thrust. >The first component is obviously proportional to the airspeed while >the second one is proportional to the thrust. So my initial proposal >was obviously wrong since it used qbar which is proportional to the >square of the airspeed. >On the other hand, if you look at the thrust table of >Engines/CFM56.xml you will see that the idle thrust is more or less >constant over the speed range of a landing airplane (i.e. 0<Mach<0.2). >So your suggestion only includes the second component and does not >reproduce the reality either. However the current turbine model of the >engine does not compute the airflow or the ram drag of the engine so I >will stick with your idea until I can do something better. I only thought at the ejected reversed thrust, but not at the airflow which is also ejected. >Oddly the value "180" suggests that you entered the angle in degrees >while it should be entered in radians (which means that you have >entered an angle of 180 mod 2*pi = 4,071 rad = 233.24 deg). >With such a value the reversed thrust is almost 60% of the forward >thrust. After some investigations, the performance of most thrust >reversers is in the area of 40%. Hence an angle of acos(-0.4) = >1.98231 rad = 113.58 deg should be reasonably close to reality. Yes I >know, my first guess was not this value... :-/ D’oh!, I didn't noticed that. You are right, I wondered if the real 737 brakes that hard. The autobrakes aren't modeled correct too- the real one has different retarding values for each autobrakes-setting, the FGFS-model different brake-power values. But at least they are working and rejected takeoffs are also possible!>The 737 (Classic) was one of my favourite airplanes on MS Flight Sim >(booh shame on me). Hence my interest on it. The 737 classic's are great to fly- I heard in realllife too, and in FGFS it is one of he favourite aircrafts of the users too! Btw: the reverser can be locked- the panel-pic I used for modelling shows two signs which indicates if the reverser are unlocked! Cheers HHS ------------------------------------------------------------------------------ Crystal Reports - New Free Runtime and 30 Day Trial Check out the new simplified licensing option that enables unlimited royalty-free distribution of the report engine for externally facing server and web deployment. http://p.sf.net/sfu/businessobjects _______________________________________________ Flightgear-devel mailing list Fli...@li... https://lists.sourceforge.net/lists/listinfo/flightgear-devel |
From: Bertrand C. <bco...@gm...> - 2009-05-17 16:22:46
Attachments:
patch737-reverser2.diff
reverse-thrust.nas
|
First of all, sorry for sending so many e-mails to the mailing list. I grouped the answers to several other e-mails in this one in order to stop flooding everybody's mailbox. 2009/5/15 John Wojnaroski <ca...@mm...>: > Perhaps Dave might want to expand on this or correct any errors.... > > There are reverse "REV" indications in the cockpit located above the N1 > gauges and digital readout window on the EICAS display. To deploy the > reverse thrusters the forward throttles must be in the Idle position. > The reverse thrust lever is blocked at the reverse idle position until > the reverse thrust sleeve is more than 60% deployed. (the "REV" > indication goes to amber when the sleeve has moved from the stowed > position ; between 10 and 90% and then green when more than 90% of > travel to deployed position ) then the interlock is released and the > reverse thrust levers may be raised to accelerate the engines. when in > reverse thrust the forward thrust levers CANNOT be advanced. When > exiting reverse thrust, the reverse thrust levers are stowed and once > the thrust sleeves have retracted, the forward throttles may be > advanced as desired for taxi. Thanks for these very valuable information. > > Reverse thrust may not be selected in-flight; however when the radar > altimeter is less than 10' (3 meters) the T/R control system allows for > deployment. > OK this explains why the reverse can be deployed very early (like in this case http://www.airliners.net/photo/Southwest-Airlines/Boeing-737-7H4/1455214/L/ ). I have added this check in my patch. Thanks for the information. 2009/5/15 Gene Buckle <ge...@de...>: >> >> There are reverse "REV" indications in the cockpit located above the N1 >> gauges and digital readout window on the EICAS display. To deploy the > > Is that indication present on the -200 series? If so, I'd never noticed > it. :) That's the only model I have experience with (specifically the > Conductron-Missouri 737-200 simulator, circa 1967) > There are some photos of the flight decks of several versions of the 737 here : http://www.b737.org.uk/panelcentreinst.htm and as far as I can tell, one can see "Reverser unlocked" indication on all panels but the one of the 737-200 Adv and 737 NG. I doubt the indication has been removed on the NG. It may just be that the indication is only displayed on the screen when relevant. For the 737-200 Adv picture, it is very difficult to distinguish what are the indicators at the top center of the picture. They may be reverser indicators ? Or may be not ? 2009/5/16 Innis Cunningham <in...@ho...>: > Hi Bertrand > You or anybody can modify the 737-300 as long as it does not become messed > up. > Thank you Heiko for the compliment on the flaps it is nice when little > things get noticed. > Maybe I should get off my rear end and model the thrust reversers for the > engines. > > Cheers > Innis OK thanks Innis. 2009/5/17 Alan Teeder <ajt...@v-...>: > > It is quite obvious to the pilot when he has selected reverse thrust. The > whole of the top of the throttle levers is opened backwards. It isn't an > insignificant toggle switch which could have been inadvertently operated. OK. I guess this is the normal operation when your aircraft is a sound configuration. However I also guess that when you have a failure in your thrust reverser, things are not that obvious and the position of your lever may not be reliable enough to determine if your thrust reversers are correctly engaged/deployed or not. Hence the indicator which should be based on sensors located in your T/R. > > The only need for a panel indication is to show that the reverse-thrust > buckets have deployed (or not). Not sure. You should also need to check that your reverser is correctly locked (or not). > > Similarly it is not usual to have a panel indication of the control column > or the rudder pedals, although some modern aircraft may indicate the control > surface positions. > > Flightsim on a PC without a complete cockpit is a different thing > altogether, and here an indication would have practical benefit. I agree. 2009/5/17 Gene Buckle <ge...@de...>: > On Sun, 17 May 2009, Bertrand Coconnier wrote: > > > Bertrand, the thrust reverser lever in a 737 throttle arm extends about 4-6" > *above* the throttle "knob" when active. You'd have to be a an idiot of an > exceptional kind to NOT notice this huge metal handle sticking straight up. > :) > > g. OK :) OK :) I think you have all guessed that I am not a pilot. I am working at the "other end" of the aerospace industry (design/stress office) and I tried to bring my point. It may just be that in the design/stress we are a bit too much focused on the failure cases. Well, following this most interesting discussion, I have diverged a bit from my initial questions which were: * Is the T/R can be only operated at idle ? The answer is unanimously yes. * Is there an indicator for the T/R operation ? The answer is it depends. It is the case for the most recent versions of the 737 (from Classic to NG). It is unclear for previous versions. Many thanks to all of you for this very interesting feedback which, honestly, was unexpected. I have attached an updated patch (added a check that the AGL altitude is lower than 10', removed the drag calculation and corrected the reverser-angle-rad value). Of course, feedback is very welcome :) Cheers, Bertrand. |
From: Gene B. <ge...@de...> - 2009-05-17 16:33:44
|
> > Many thanks to all of you for this very interesting feedback which, > honestly, was unexpected. I have attached an updated patch (added a > check that the AGL altitude is lower than 10', removed the drag > calculation and corrected the reverser-angle-rad value). Of course, > feedback is very welcome :) > Here's another reverser related tidbit for you - the C-17 transport aircraft has a flight mode called a "combat drop" where the reversers are activated at altitude in order to cause a drastic drop in altitude over a short horizontal distance. I've been told that it essentially causes the aircraft to free-fall while remaining upright and level. g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://www.scarletdme.org - Get it _today_! |