Re: [Flightgear-devel] C172P Model Year?
On 12/18/04 at 7:15 PM Dave Martin wrote: While you're there, is there any chance of a magneto-related performance loss? ie: when you run left mags only you get a power loss. Cheers :) Hmm, I thought I already had, but it seems I'm mistaken. It's in the LaRCsim code (IO360.cxx), but never made it over to JSBSim's FGPiston.cpp. I believe I was gunning for about 25 rpm drop on one vs. two magnetos in the original code. I'll port it over... Of course, oversights like this would get picked up more easily if an adept 3D modeller added a magneto switch to the 3d C172 and pa28-161 :-) A master-on switch would be great as well :-)) Cheers - Dave This message has been scanned but we cannot guarantee that it and any attachments are free from viruses or other damaging content: you are advised to perform your own checks. Email communications with the University of Nottingham may be monitored as permitted by UK legislation. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] C172P Model Year?
On 12/20/04 at 11:41 PM David Luff wrote: Of course, oversights like this would get picked up more easily if an adept 3D modeller added a magneto switch to the 3d C172 Oops, found it, bottom left! and pa28-161 :-) It is missing from that though. Cheers - Dave This message has been scanned but we cannot guarantee that it and any attachments are free from viruses or other damaging content: you are advised to perform your own checks. Email communications with the University of Nottingham may be monitored as permitted by UK legislation. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
RE: [Flightgear-devel] C172P Model Year?
Hmm, I thought I already had, but it seems I'm mistaken. It's in the LaRCsim code (IO360.cxx), but never made it over to JSBSim's FGPiston.cpp. I believe I was gunning for about 25 rpm drop on one vs. two magnetos in the original code. I'll port it over... Dave: There are two active branches, now: the main branch and JSBSim_NEW_XML (IIRC). If the changes are small, let me know what they are and I can copy it to the new XML branch unless you want to do that, too. The engine execution code has not changed much, if at all. Only the loading code. Jon ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] C172P Model Year?
Dave Martin writes: On Friday 17 Dec 2004 22:27, David Megginson wrote: Totally up to you, but my 172P POH is for the 1981 model However, I also discovered that the early 172s had more dihedral and a slightly different shape to the aerofoil. Comparing this the FG 172P, which has little dihedral. It looks like 'our' one is a fairly-late 172P. I've always assumed that it's a fairly late model injected 172, in order to justify the current lack of carb heating in the engine model ;-) Cheers - Dave ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] C172P Model Year?
On Sat, 18 Dec 2004 15:27:09 +, David Luff [EMAIL PROTECTED] wrote: I've always assumed that it's a fairly late model injected 172, in order to justify the current lack of carb heating in the engine model ;-) The 172P is carbureted, unfortunately. All the best, David -- http://www.megginson.com/ ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] C172P Model Year?
While you're there, is there any chance of a magneto-related performance loss? ie: when you run left mags only you get a power loss. Cheers :) On Saturday 18 Dec 2004 17:37, David Luff wrote: David Megginson writes: On Sat, 18 Dec 2004 15:27:09 +, David Luff [EMAIL PROTECTED] wrote: I've always assumed that it's a fairly late model injected 172, in order to justify the current lack of carb heating in the engine model ;-) The 172P is carbureted, unfortunately. Ah! Carb heating has just moved several places up my TODO list! Cheers - Dave ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] C172P Model Year?
On Sat, 18 Dec 2004 17:37:35 +, David Luff [EMAIL PROTECTED] wrote: Ah! Carb heating has just moved several places up my TODO list! I'm not sure that the engine model should even be dealing with carb heating -- it would be just as easy for something else to tell the engine the temperature of the air it's getting, since carb heating is separate from the engine proper (it's actually heated before it gets to the carburetor, usually by passing through an exhaust shroud or something similar). More relevant is the different starting procedures for carbureted and fuel injected. All the best, David -- http://www.megginson.com/ ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] C172P Model Year?
On Sat, 18 Dec 2004 19:15:46 +, Dave Martin [EMAIL PROTECTED] wrote: While you're there, is there any chance of a magneto-related performance loss? ie: when you run left mags only you get a power loss. It would be nice to see that generalized a bit, so that we can eventually model fouled plugs and pre-detonation as well. Some day, the piston engine model will handle each cylinder in its own routine, but we're not quite ready for that yet. All the best, David -- http://www.megginson.com/ ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] C172P Model Year?
Simulated carb icing might be exciting too (coupled to weather, of course :-) ) It would certainly make you remember to pull the lever ;) On Saturday 18 Dec 2004 19:39, David Megginson wrote: On Sat, 18 Dec 2004 19:15:46 +, Dave Martin [EMAIL PROTECTED] wrote: While you're there, is there any chance of a magneto-related performance loss? ie: when you run left mags only you get a power loss. It would be nice to see that generalized a bit, so that we can eventually model fouled plugs and pre-detonation as well. Some day, the piston engine model will handle each cylinder in its own routine, but we're not quite ready for that yet. All the best, David ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] C172P Model Year?
On Sat, 18 Dec 2004 20:20:37 +, Dave Martin [EMAIL PROTECTED] wrote: Simulated carb icing might be exciting too (coupled to weather, of course :-) ) It would certainly make you remember to pull the lever ;) Some day, we might model then entire air induction system, the way that we model the electrical or vacuum system. For example, the early Cessna 172s, like the Cessna 150/152, used Continental engines with the air intake right under the propeller, a couple of inches from the carburetor -- you can imagine that it didn't take much to get carb icing, or even just to block the intake air filter with impact ice. In my Warrior, on the other hand, the air scoop inlet is a bit to the right of the prop (looking from the cockpit), then it goes through a duct about 15 inches long, heated by nearby exhaust pipes before turning 90 degrees to pass through the air filter (i.e. no direct impact ice) and then travel a bit further into the box that controls air input into the carb above it. Needless to say, carb icing in a Cherokee is extremely rare, and pulling carb heat is not a regular part of the landing procedure. I think that the later Lycoming 172s like the 172p have a similar induction system, but I haven't looked under the cowling of one. I've heard from several sources that pulling carb heat with every power reduction in the later 172s is just a holdover from the earlier 172 procedures. All the best, David -- http://www.megginson.com/ ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] C172P Model Year?
Dave Martin wrote: Just wondering if the C172P is supposed to represent a specific model year? I've come to the point of placing a landing light on the aircraft but the location is different between early 172s; in the wing with a taxi light and late 172Ps (early 80's) where it is located in the nose with no taxi light. I did notice that there is a 'taxi light' switch but which way do you think I should go? Hi Dave, In the absence of anyone with a strong opinion, I think consistency is the most important thing to focus on. In an open source project it's generally it's the people doing the work that get to make the big decisions, so if no one writes back with a compelling argument either way, go with what you think is best. Once you pick a year or a model, try your best to keep everything consistent for that year. Best regards, Curt. -- Curtis Olsonhttp://www.flightgear.org/~curt HumanFIRST Program http://www.humanfirst.umn.edu/ FlightGear Project http://www.flightgear.org Unique text:2f585eeea02e2c79d7b1d8c4963bae2d ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] C172P Model Year?
On Fri, 17 Dec 2004 20:38:33 +, Dave Martin [EMAIL PROTECTED] wrote: Just wondering if the C172P is supposed to represent a specific model year? Totally up to you, but my 172P POH is for the 1981 model, for what that's worth. I cannot even remember the light positions on the planes I trained on; in any case, it's worth noting that many owners have moved the lights around over the years (some people like to install wingtip landing lights so that they look like a jet coming in). All the best, David -- http://www.megginson.com/ ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: [Flightgear-devel] C172P Model Year?
On Friday 17 Dec 2004 22:27, David Megginson wrote: Totally up to you, but my 172P POH is for the 1981 model As it happens I did a bit more research and discovered that the in-wing (landing+taxi) lights were a factory option to the end of the P's production run. So no clues there ;) However, I also discovered that the early 172s had more dihedral and a slightly different shape to the aerofoil. Comparing this the FG 172P, which has little dihedral. It looks like 'our' one is a fairly-late 172P. So, because of the panel switch for 'taxi' lights, I'm going to *try* to do the in-wing lamps without spending too many polys. (Failing that, the switch can always come out). In a productive day (today) I have: Slightly changed the nose area shape to match sillouette Slightly increased the spinner diameter and slightly shortened it. Move the outer ends of the struts inboard to the point where the taper starts. Moved the pitot tube about .5m inboard. Slightly changed the shape of the rear-screen (more rounded). Made the tail light (white) move with the rudder. Moved the lower intake (texture) Joined the maingear to the fusealage (there was a significant gap before) Reduced the size of the nosewheel tyre. Remodelled the nose strut a little. Fitted a static Oleo guide to the nose-leg (IIRC they don't rotate with the nosewheel). Made the nosewheel rotate about its own shaft (And I've been patting meself on the back all day over that ;) ) Modified the dash-shroud so it no longer protrudes outside thru the windscreen Move the VHF aerials aft to their usual position. Its not neccesarily looking that much nicer but it is more accurate now :). ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
