744 speed logic
Joined: Jun 2001
Posts: 452
Likes: 0
From: In da north country
In a perfect world, as long as the speeds were pre-entered on the legs page and you could fly the whole arrival uninterrupted in VNAV/LNAV, All you would have to do is select the flaps to to the appropriate position prior to each new speed limit, and the machine will slow down accordingly and auto land itself.
Boeing really did a magnificent job with this airplane.
Boeing really did a magnificent job with this airplane.

Joined: Apr 2004
Posts: 2,166
Likes: 86
From: Planet Earth
Not at the last minute, you wouldn't want to do that either, don't know about the 744 but our 757 /67 operation has us engaging approach mode by 1500'
at the latest.
You have to give the system time to stabilize.
at the latest.
You have to give the system time to stabilize.
Joined: Aug 2010
Posts: 129
Likes: 1
From: Los Angeles
Reviving an older post, which I apologize to the OP because it may be veering way off topic:
http://www.pprune.org/questions/5393...ml#post8467405
It woud be nice to actually see a copy of the letter, if it's still available (even if partly redacted). JammedStab?
http://www.pprune.org/questions/5393...ml#post8467405
"Provided that an ILS that meets the autoland criteria, has been tuned, the airplane is being manually flown on the published ILS path in trim and on speed, and APP has been selected prior to 1500 feet AGL, selecting the autopilot prior to 600 feet AGL (which is the lowest altitude for LAND 2 or LAND 3 to be annunciated) should satisfy the logic for autoland. The time required for the autoland system to perform a self-test and confirm correct operation will vary depending on conditions. We recommend that the crew engage the autopilot as soon as possible in order to satisfy approach logic.
Note: The autoland status must be confirmed by the crew at 500 feet AGL.
Note: Late autopilot engagement is not a recommended practice."
Note: The autoland status must be confirmed by the crew at 500 feet AGL.
Note: Late autopilot engagement is not a recommended practice."
Joined: Apr 2008
Posts: 1
Likes: 2
From: nowhere
Reviving an older post, which I apologize to the OP because it may be veering way off topic:
http://www.pprune.org/questions/5393...ml#post8467405
It woud be nice to actually see a copy of the letter, if it's still available (even if partly redacted). JammedStab?
http://www.pprune.org/questions/5393...ml#post8467405
It woud be nice to actually see a copy of the letter, if it's still available (even if partly redacted). JammedStab?
Joined: Aug 2010
Posts: 129
Likes: 1
From: Los Angeles
Understood. Thanks, JammedStab. The memo mentions APP being selected prior to 1500' AGL. Just curious -- if you didn't select APP until you were at 1000', but you were on the loc and g/s, would you still get LAND 3 once the a/p is engaged?





