ANTIER Pierre a écrit :+ 1 avec Xedon, également intéressé par une réponse technique à cette question : car on parle beaucoup du trim "T" (fonction maintenant relativement bien assimilée) mais assez peu du frein du collectif "F" qui permettrait de mémoriser l'altitude, donc fonctionnalité paraissant importante pour maîtriser encore plus le vol de la bête.
Originally Posted by Siinji Alpha:Ok, I understand. But what happens if I don't press the F key, and just increase the collective and stabilize at a higher altitude? Will the autopilot descend back to the first altitude?Or am I just "working harder against" the autopilot when NOT pressing F and increasing collective?
You are just working against the autopilot. I will explain:
You are zipping along at a nice stable airspeed and altitude, let's just say 200kph and 500 meters (no special meaning here, just some numbers). You have all autopilot channels on, including altitude. Suddenly, you decide that you are too hot, and your ventilator fan just isn't helping, so you think to yourself "Self, we must get up higher where it is nice and cool!" (I think your self has a great idea, by the way!). So you pull in some collective (let's say for argument's sake, you just pull in a teeny tiny bit of collective), and lo and behold, nothing happens! You VSI stays pegged at zero! So you pull in some more collective, still nothing...then a bit more...until FINALLY your VSI starts to move. "Great!" says self. So your climb is initiated and you have the rate of climb you want (never fast enough when you're sweating and you want some cool air, eh?). Eventually, you start feeling that nice cool air up at 2,000 meters flowing into the cockpit, and you decide that you're high enough, so you reduce the collective until your altitude stabilizes (VSI back at zero).
(but it never "quite" stabilizes...oh it gets close, but something seems amiss...but along you go, oblivious, etc.)
Hey! It's time to turn! (or slow down or speed up or whatever) So you start your bank (or whatever) and the aircraft starts to turn (or whatever)...but then starts to lose altitude (or even gain, depending on what the "whatever" is). "What?!?" says self, very upset that his altitude channel is not working.
Well, your altitude channel IS working. It is trying to hold you at 500 meters. Well, you're way up at 2,000 meters! What is going on?!
Remember back when you were at 500 meters, and you wanted to climb, so you pulled in some collective (a teeny tiny bit, if my memory is correct)? Well your collective input to the collective servo moved (oh yes indeed it did, since it is physically connected, it has no choice!) But your collective control rods are not the only thing that tell the collective servo what to do. The autopilot also has a say. And you autopilot says it wants to stay at 500 meters, so as you're adding collective, the autopilot is taking it right back out. Not out of your control input, but out of the servo. Eventually, your collective movement will exceed 20 percent of its travel. (Note: I have an X-52 throttle, it moved about 10-15%.) When your collective input exceeds 20% of its travel, the autopilot runs out of authority, and your input starts to work. So your started climbing...up and up...until you got to 2000 meters, then you lowered the collective to zero your VSI. The catch here is that your autopilot still wants to lower the collective, but it can't, as it's already "lowering" it by 20% (which you have happily overriden by moving the collective more and more).
Now if you do any maneuver that would cause a change in altitude (just about anything in a helicopter will do that, they sure are touchy), then your altitude would start changing, because your autopilot has done all that it can do.
About this time, you realize the error of your ways, and you hit your collective brake button (just a tap here will do). You have just told your autopilot that you want to hold THIS altitude (2,000 meters). Here it helps to know that your autopilot's input to the servo is not really a direct mechanical linkage like your collective is (it's all computery, using little things called feedback sensors that tell the autopilot exactly where your collective is set and how much pitch is in the blades, etc....very complicated and all that). So when you hit that button, not only does it tell your autopilot to hold this new altitude, it ALSO zeroes your autopilots collective input! Now your autopilot once again has the authority to make minor changes to the collective servo to hold your altitude, and you're back to making turns, etc, without losing or gaining any altitude!
Yay! Everyone wins!
AlfaOneSix
Except make it easier for the pilot to move the collective? From what I understand (correct me if I'm wrong AOS), but in real life, the pilot needs to press the collective break any time he wants to move the collective to remove the stick force holding it in place. Obviously, flight simmers have no such restriction and for them, the collective brake only functions as the "altitude trimmer".
EvilBivol-1
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Originally Posted by EvilBivol-1 Except make it easier for the pilot to move the collective? From what I understand (correct me if I'm wrong AOS), but in real life, the pilot needs to press the collective break any time he wants to move the collective to remove the stick force holding it in place. Obviously, flight simmers have no such restriction and for them, the collective brake only functions as the "altitude trimmer".
What's funny here is that I had written "(at least in the game)" to my post in reference to the brake not doing anything, but I deleted it before submitting, thinking nobody would bring up the real thing. Silly me!
AlfaOneSix
Comment utiliser le couvert des arbres... si ceux-ci ne donnent pas de couvert ?
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