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Auto Pilot

PostPosted: Thu Jun 07, 2007 2:45 pm
by BuzzDatAzz
When you are trying to land and you turn off the auto pilot right before touch down, is there away to keep the plane from pitching or banking when you turn AP off. It has caused me to kill myself and quite a few others many times!!! :'(

Re: Auto Pilot

PostPosted: Thu Jun 07, 2007 2:57 pm
by garymbuska
When you are trying to land and you turn off the auto pilot right before touch down, is there away to keep the plane from pitching or banking when you turn AP off. It has caused me to kill myself and quite a few others many times!!! :'(


Try turning off the auto pilot right after you intercept the glide slope this way you have a little room to allow for the pitching of the aircraft which is normal. It is not a good idea to turn off the auto pilot just befor the mains touch down as you have found out. 8-)

Re: Auto Pilot

PostPosted: Thu Jun 07, 2007 4:04 pm
by BuzzDatAzz
Thanks for your help!  ;D

Re: Auto Pilot

PostPosted: Thu Jun 07, 2007 5:01 pm
by JBaymore
If you are "flyin' it by the numbers" on short final, the AP will have the aircraft pretty well trimmed and running pretty straight on course for the runway, because the airspeed, the pitch of the aircraft, and the engine thrust will all be set "correctly" for a certain level of FPM descent.  So when the AP kicks off,..... you are not WAY out of trim, and you haven't been swinging left and right trying to "hold on to" the localizer.

What you describe seems to indicate that you likely are coming in either too fast.... or way too slow.  Likely the former.  For any given landing weight, there will be a specific airspeed that you need to be at and a certain descent rate in a given aircraft.  Check to make sure that you are close to this on approach.

It might help.

best,

.......................john

Re: Auto Pilot

PostPosted: Fri Jun 08, 2007 9:50 am
by Nav
BuzzDatAzz, this might help. Covers the point that you mention, the need to re-trim, and maybe adjust power, as you turn off the autopilot, anyway:-

http://www.simviation.com/cgi-bin/yabb2/YaBB.pl?board=COF;action=display;num=1111322151

Re: Auto Pilot

PostPosted: Fri Jun 08, 2007 10:31 pm
by beaky
When you are trying to land and you turn off the auto pilot right before touch down, is there away to keep the plane from pitching or banking when you turn AP off. It has caused me to kill myself and quite a few others many times!!! :'(



The only way I know of to stop an airplane from pitching and banking with AP turned off is to... uh... what do they call that again...?
Oh yeah- you have to fly the airplane, whatever that means... ;D

Seriously, though, even push-button pilots have to consider trim and whatever changes dialed in while the autopilot is engaged.  ;)

More seriously, consider this: although it assumed that an autopilot will fly an approach "better" than a human pilot, in most cases an AP will fly it somewhat differently than a pilot might by hand, particularly in the case of slaving the AP to the nav radio to track an ILS. Start using autothrottle as well, and things get a little more different.
So... when you disconnect "Otto", you can easily find yourself with an airplane that is "set up" for him, not for you.
The best way to avoid this is to try to "fly" the AP as much as possible. I don't mean making a lot of changes so much as perhaps flying a few ILS approaches by hand as best you can and then "teaching" the AP to do it your way. It's hard to explain exactly how that works, but that's pretty much how I learned to use the AP in general, having learned to fly by hand properly already.

 Naturally, it's also vital to be aware of what the AP is doing at that moment before you disconnect: just because you're on the glideslope, have the correct airspeed and sink rate, and are on center doesn't mean the AP has established all this and is now doing nothing to the airplane. Definitely not, especially if there is any sort of wind.  

Re: Auto Pilot

PostPosted: Sat Jun 09, 2007 3:48 am
by stuart1044
It has caused me to kill myself and quite a few others many times!!! :'(



Wow it really is as real as it gets, i better be careful on my next landing ;D

Re: Auto Pilot

PostPosted: Sat Jun 09, 2007 4:23 am
by Fozzer
It has caused me to kill myself and quite a few others many times!!! :'(


Wow it really is as real as it gets, I better be careful on my next landing ;D


... ;D...!

Now you know why I spent the past 8 years constantly practicing in my Cessna 152 Trainer, and perfecting it, before I ever went anywhere near one of those fancy, shiny aluminium, jet propelled, passenger Buses*...:)...!

I am always amazed at the number of Toddlers who fire up the Flight Sim for he first time and rush for the "Heavy Stuff" before getting any advanced training in the little piston prop trainers first...;)...!!

Would you trust a 14-year-old Captain, with no previous experience, piloting your '747 to the Algarve...?

NAH!...didn't think so... :o...!


Paul...G-BPLF... 8-)...!

* I still avoid them, even now...;)...!!

Re: Auto Pilot

PostPosted: Sat Jun 09, 2007 7:27 am
by Brett_Henderson
*nodding in firm agreement*

Re: Auto Pilot

PostPosted: Sun Jun 10, 2007 10:47 am
by microlight
Yeh, Paul, but where's the fun in that?! Half the joy of getting an A380 softly onto the ground is so that you don't kill the 500 people directly behind you, not to mention yourself! One of my panels has a sound effect built-in, so that if you collapse the undercarriage, you can hear all the passengers screaming!  ;D

Seriously though...

Nose rising or dropping when you switch off the autopilot on approach can also be a symptom of the flight dynamics not being effectively balanced. The trim should be set by the autopilot on the way down, so that when you turn it off, the plane's attitude should stay the same until the pilot alters it, using the trim controls. If you have to make rapid trim adjustments to stay in control, then balance is a likely culprit. If you want to check it, get to level cruise, and turn the autopilot off. If you begin to wish you were wearing bicycle clips, then this'll confirm it!

;)

Re: Auto Pilot

PostPosted: Sun Jun 10, 2007 11:18 am
by Sean Grenyer
This exact same thing happened to me no matter how well I was doing on the approach. But, I was flying with the keyboard. As soon as I plugged in a decent joystick (mine is the excellent Saitek AV8R), it behaves perfectly.

Sean