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Guest FactionOne

FL250 Concorde Misbehaves...

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Guest FactionOne

Hi Folks,As some of you may have seen from my posting in the Airbus support forums; I'm trying to make use of my PSS purchases but moreso, grow my FS abilities some (a report on my Airbus flight will follow on that thread soon!)...Concorde came up in a conversation with my father yesterday, and remembering that when I started FS today; I thought I'd give the PSS Concorde another try...I set my laptop up beside me with the Tutorial open, and loaded up all the files to my FS machine and started to work through it.After a little while I started to think "I'm getting the hang of this" and before too long I was in the air. As far as I can see I hadn't missed any of the instructions; and things did seem to be going fine...As I continued the climb towards FL260; I noticed speed rolling off, so I brought the nose down a little to compensate (I guess that ALT ACQ mode means that I control V/S and the autopilot will ALT HOLD when I reach the set-level (FL260)?) - again, everything seemed to be OK....Then I got to passing FL250 and the aircraft pitched up wildly, and lost pretty much all her airspeed immediately. At what I would call the "worst" of it; I had around 50 degrees nose up, 80 KIAS, and about -4000FPM - intestingly there was no stall alarm yet (not that the absence of the alarm makes a difference at this stage). I was applying full forward force to the flight-controls and it really didn't want to nose down (I suppse 50 degrees / 80 KIAS is pretty unrecoverable in anything, let alone something with a delta wing); but eventually it began to... At about 35 degrees / 115 KIAS (and still about -4000 FPM) the stall alarm started to sound - handy! ;)...Anyway, I kept fighting it until I began to regain airspeed (to around 250/260 KIAS) and a more acceptable V/S; and started to gently ease her towards FL260 once more...A picture of what started to happen (again) at FL250 is below... (Taken just before the massive pitch-up removes the last of the airspeed and the wildly positive V/S becomes the inverse...)I'm not sure whether it's the simulation (be it host or aircraft) getting something wrong, or me (I guess you'll be able to see on the panel in the sreengrab if anything was painfully incorrect?)... I feel reasonably confident it wasn't me though - I was following the instructions to the letter! - MWS was recalled with no warnings too... Bah, I dunno!Any ideas folks?Thanks in advance and best regards,Rob.(Perhaps forever to be a non-FMC fisher-price A330 pilot!)http://factionone.pwp.blueyonder.co.uk/con...misbehaving.jpg

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Guest FactionOne

OK, It's definately something to do with the Autopilot and/or the way I'm setting it...If I mix the settings to climb/accelerate etc. from the LFPG to KJFK tutorial and the "Test Flight to FL500" from this forum; and use a mixture of methods (a lot of V/S hold etc.) I can actually get her to cruise at FL580...So, is it confused plane or confused pilot that means the method in the tutorial PDF makes my bird throw a wobbler?Regards,Rob.

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Guest NormanB

Rob,The Concorde is one of those planes you simply can't get behind with. My method of flying it is to "chase the barber pole" - I trade vertical speed for horizontal speed every time.

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Guest FactionOne

Thanks for your reply Norman!That's not a 100% new concept to me... I flew some fisher-price A300s before my fisher-price A330; and the A300 certainly seems to be a craft you sprint to speed and pretty much hope that momentum plus its hairdryers get you to FL320!I managed to get some more progress as I mentioned above, by improvising my own autopilot scheme; mainly by using V/S hold and later max-climb. I guess this probably reflects your advice, in so much as I gained decent airspeed before starting the final part of the climb to cruise; but I'm still not sure where I went wrong in following the instructions in the LFPG - KJFK tutorial though.Anyway, I managed to get her past the 'sticking-point' so I guess it doesn't really matter. I had to kill the flight just after passing FL520 at around M2.00 though - unforunately my FS PC is also my Media Centre (side-effect of being a PC R&D engineer - apologies!) and Top Gear was starting!When I came back I got a little cheeky... I decided I'd load the flight plan, depart, and then follow ATC vectors to the route; figuring that as the PSS Concorde is able to use the FS9 Flight Planner/NavAids as reference, it should be possible without things getting confused...Everything was going fine; I started my climb and was proceeding with vectors from ATC (I employed one of my FS9-fooling techniques for the climb - eg. setting FL267 anticipating further climb when advised FL260 - so as to stop her levelling off before the controller gave further instructions).All seemed fine as ATC vectors brought me to meet the route; I noticed there was a good distance before I broke the coastline; and even though I had a really nice looking rate of climb/acceleration I decided to be nice to the french below; and I hit MACH HOLD as I reached something like M0.90 - planning to accelerate further once over water....This is when I hit problems again... But the more I think about it, the more my hobbyist's knowledge of aerodynamics/physics leads me to think that it was probably something that I should expect... As I continued to climb; I found that my speed was dropping again... All of a sudden I found myself climbing very slowly; and the speed was rolling backwards from M0.70 even though my Olympus were still screaming away at full tilt...The only rational explaination the aforementioned hobbyist's knowledge can suggest is that the wing becomes ineffecient when the altitude is greater than X while the airspeed remains less than Y. My thinking is that the higher you go, the quicker you need to go in order to have the same pressure differential acting on the wing (resulting in the same lift), given the rarification of the atmosphere......I guess then (if I'm not barking totally up the wrong tree), that Concorde would have a subsonic service ceiling considerably lower than that of supersonic... So all I have to do is ensure that I'm lower than altitude X when I reach the point I want to begin transonic acceleration (the JSY VOR for example), and I'll be able to maintain M0.90 until that point? Correct?So I guess my next question is... What is altitude X? Assuming some 'safe' variables - we'll say it's particularly cold/low-pressure at altitude, there's nominal wind, and my aircraft is full of passengers, jet fuel and caviar... What would you guys say is a ball-park figure I shouldn't climb above before accelerating again?- My plan then (again guesswork) would be: Depart, Climb @ M0.90 or less to acceleration point. At that point accelerate to maximum airspeed, then begin a second climb to cruise in MAX CLIMB mode? Sound fair?...And then I imagine my next challenge is stopping FS9 ATC from telling me to climb above altitude X (as they will just continue issuing climb instructions until I hit cruise) before I'm ready to accelerate? I suppose in theory, I could tell the Flight Planner I wanted to cruise at whatever altitude X is; then once I reach the acceleration point, begin requesting climb outside the flightplan (ie in-flight over the radio) to my actual cruisde of FL560 / FL580?...I know that's a bit of a mammoth post, but again it's evidence I think of someone armed with enough facts to know he wants to do something but not quite enough to know whether he's doing it correctly or not; so any comments/advice/instructions are gratefully received...Thanks in advance and best regards,Rob.PS> I guess this is more evidence I should be on VATSIM to be doing things properly (just like I found in the Airbus forum) - but there I'm back to the chicken and the egg... Do I learn my PSS Airbuses/Concorde/Dash-8 etc. first, so I can fly proper procedures on VATSIM, or do I fly my more basic models on VATSIM first to get used to it? Bahhhhhhh! :s

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