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ILS Autopilot landing B747

PostPosted: Thu Jan 13, 2005 2:59 am
by BeeBoss
Hi all,

This is my first post on the forum, hope anyone can give me some advice.

After a a long flight from KJFK to KLAX I decided to let the AP do the landing for me on RW7R. Turned on AP, Approach hold, Auto throttle set to 188kias, gear down and flaps set. But as i got closer to the landingstrip the plane started to 'bounce' increasingly and in the end i had to switch off the AP and scared the s#@!t out of my passengers by attempting the wost B747 landing ever.

Can anyone tell me how to land a B747 with AP in a more 'professional' way?

Tnx in advance
BeeB

Re: ILS Autopilot landing B747

PostPosted: Thu Jan 13, 2005 3:30 am
by BiggBaddWolf
Welcome to the forum
Autopilot wont land the beast for you.... :o
Most generally I fly in as far as the middle marker, then fly in by hand the rest of the way, and make sure when you turn of the AP that you also turn off the A/T

Re: ILS Autopilot landing B747

PostPosted: Thu Jan 13, 2005 3:34 am
by commoner
Hi BB..welcome to the forum.....I don't usually fly the big one but think you are maybe flying far too fast with too much flaps ...this will lift the nose I think and start you on that bouncing sequence ....landing at 140 kts and full 30 flaps just before touchdown with flaps 1 at 190kts and working through the flaps and dropping speed in the recommended way would be better.....and cut the AP at about 150 feet or you will most definately crash the beast...there isn't much room for error with the 747...Take the flying lesson if you want to do the whole thing right ;)...commoner

Re: ILS Autopilot landing B747

PostPosted: Thu Jan 13, 2005 4:01 am
by BeeBoss
Yes the A-T was also a factor. I got a 'little' short on runway because I stroke the wrong keyboard shortcut (CTRL-R in stead of SHIFT-R) to turn off the A-T.  :-/

Anyways, tnx a lot aleady, I've saved my flight at turning into final so I'll try it tonight.

Re: ILS Autopilot landing B747

PostPosted: Thu Jan 13, 2005 8:54 am
by Nexus
Yeah, you're going a tad too fast.
A 747will (like most airliners) fly the approach with an upward pitch of say 3 degrees. Now with landing flaps extended, you cannot fly with a 3 degree pitch and maintaining that glideslope if you are flying too fast   :)

For instance I really don't have to know the correct landing speed, I just put the nose up and adjust power to get that required 700-800fpm descent I need. Then at around 40ft I gently rise the nose furthermore to 4 -5 degrees and slowly retards the throttles.  :)

Re: ILS Autopilot landing B747

PostPosted: Thu Jan 13, 2005 9:59 am
by beefhole
Everyones already covered everything already, just thought I'd mention 180 kts w/30 flaps is the landing speed when the landing weight is 180,000 lbs. Look down on the reference sheet and you should see speeds for when the aircraft is 140,000 lbs and below (should be around 145 kts). And never, EVER hit the ground going 188 KIAS. And Nexus-I second that motion. :) I have a preliminary VREF, and then adjust that to get the FA pitch I want.

Re: ILS Autopilot landing B747

PostPosted: Thu Jan 13, 2005 2:35 pm
by JerryH
Hi beefhole,

You've misunderstood a part of the question. BeeBoss is flying a B747. Your weight numbers are for something much smaller.

Do you have similar numbers for the 747?

Regards,
JerryH

Re: ILS Autopilot landing B747

PostPosted: Thu Jan 13, 2005 3:03 pm
by commoner
Hi beefhole,

You've misunderstood a part of the question. BeeBoss is flying a B747. Your weight numbers are for something much smaller.

Do you have similar numbers for the 747?

Regards,
JerryH



  VREF - Landing Approach Speed gear down  
880,000 lbs (flaps 25)    188 KIAS
880,000 lbs (flaps 30)   181 KIAS
450,000 lbs (flaps 25) 134 KIAS
450,000 (flaps 30) 129 KIAS
 This is what FS9 gives for the 747-400 JerryH all these lists should be on the kneeboards if not there is an HTML file called Ref in each individual aircrafts folder in the main FS9 Aircrafts Folder..commoner ;)

Re: ILS Autopilot landing B747

PostPosted: Thu Jan 13, 2005 9:09 pm
by Nek
Hi Beeb
I've never tried landing an ac on AP. I guess it can be done but sound like an awful lot of extra work. With a 747 at about 140 kts out I start reducing the AT speed to 220. At 220 kts I start my descent at 1800 fpm. At about 40 kts out I'm at my approach level of 7 or 8 thousand ft. This is were I cut the AP and AT completely just before contacting the tower for final permission. At 25 or 30 kts out I get my permission and then its flaps (spoilers if required) progressively to get me down to my landing speed of aprox 140 kts. Then it's just keep her nose up and slide her in on the markers. I'm gonna try the AP thing just to see what happens. Cheers.

Re: ILS Autopilot landing B747

PostPosted: Thu Jan 13, 2005 9:09 pm
by beefhole
There ye go... I didn't misunderstand the question, I was remembering things from memory and I was in school (which means my brain was in its non-thinking mode), had I looked at what I had just typed I would have corrected it. Thanks for clearing that up commoner.