Cabin Alt/IAS hold/Flight Dynamics |
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Shaun.
Check-In Staff Joined: 25 Jan 2012 Location: UK Points: 8 |
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Posted: 01 Oct 2013 at 7:12pm |
**Edited** I had an issue with the cabin altitude, but it seems that I didn't engage the packs at the right time. The IAS hold has some serious issues on descent, pulling 6,000 fpm. Also I find the aircraft underpowered and very difficult to control. |
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hifly
Chief Pilot Joined: 04 Jan 2012 Location: Hastings UK Points: 1012 |
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Shaun, I have both these planes and have not encountered the problems you have described. For the 146 the IAS only works when changing altitude. The 146 AP is very different from others. Have you read the manual correctly?
As for the MD81/82 I have had no problem getting up to 29,000 ft and have found the handling very good. What yoke are you using?
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Must Fly!
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Shaun.
Check-In Staff Joined: 25 Jan 2012 Location: UK Points: 8 |
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Sorry, I did mean the 146-300 struggles to gain altitude.
I may not have changed the altitude bug prior to descent, I'll try that. Although it still should be a smooth initiation of descent with IAS, like with ascent.
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Lemmerp
Check-In Staff Joined: 10 Oct 2013 Location: South Africa Points: 5 |
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Hey Guys
I have the same problem and I can't figure it out. I change my altitude bug and then when I engage the IAS, it also goes into a serious dive. It is my understanding that as my throttles are set to the cruise speed, when I engage IAS, it should stay level and only go into a smooth descent as a slowly lower the power or am I missing the picture here?
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Deltahotel
P/UT Joined: 10 Jun 2011 Location: Wallingford, UK Points: 105 |
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Yes the IAS hold function is far from accurate, but I have no idea how true to reality that is. You know it is done, or tries to be done, via pitch change through the elevators. I guess you have sussed the practical workaround for initiating a descent (or climb)... select IAS hold, retard throttles a teeny bit, hit the VS button as you approach your desired rate of descent, then use throttles to regulate your IAS. Annoyingly, I find controlling the speed by throttles is surprisingly sensitive ... keeps you awake though.
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Dave H
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Lemmerp
Check-In Staff Joined: 10 Oct 2013 Location: South Africa Points: 5 |
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That's what I'm doing, or at least trying to do. Again, not sure if I understand this incorrectly, but my understanding is when you reach your altitude, the aircraft maintains altitude and you have to control the speed via the throttles, obviously. But now logic tells me that because I'm controlling speed, if I were to keep my throttles the same, when I engage IAS, it should in theory stay in straight and level flight. Then decreasing the throttle gently, it should ease into a descent until I reach the 1800fpm at which stage I should engage the VS. But it doesn't. It just goes into a death dive.
With that said, I haven't tried this, but I will the weekend. If I disengage altitude hold, then decrease throttles to ease into descent and engage VS once I reach my 1800fpm, therefor bypassing the IAS hold step, would that not work? I'm going to try it and give feedback on this.
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Deltahotel
P/UT Joined: 10 Jun 2011 Location: Wallingford, UK Points: 105 |
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Lemmerp I'm sure that would work fine - it may take a little longer to initiate the descent, or you could just give it a nudge with a touch of down trim after disengaging the ALT hold. Either way you will be playing the throttles for speed control in the descent. d
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Dave H
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Lemmerp
Check-In Staff Joined: 10 Oct 2013 Location: South Africa Points: 5 |
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Playing with the throttles to control the speed is fine, part of flying, it's just to stop my virtual passengers from messing up my cabin and sparing my virtual ground crew from cleaning up the cabin just because of the nose dive it likes doing.
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