PPRuNe Forums - 744 speed logic

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- - 744 speed logic (https://www.pprune.org/tech-log/568146-744-speed-logic.html)

How about somebody tries it in the sim. See my earlier post.

Jammed, the answer is simple.

" if you are positioning on base leg in VNAV PTH and select Flap 1 "

The speed bug will go to the F1 reference speed.
Exactly like the bus - F, S and G.

As I said before the answer is D for a 744 and A for a -8.

Just confirmed in the SIM, the BUG is forced down with VFE-5, select the flap up again and the BUG goes back up again.

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.

You definitely don't want to auto land in LNAV/VNAV :=

OK, I know you wouldn't want to......
So, as you engage the approach mode at the last minute. it would.

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.

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

Quote:

"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."

It woud be nice to actually see a copy of the letter, if it's still available (even if partly redacted). JammedStab?

Quote:

Originally Posted by cf6-80c2b5f (Post 9131297)

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?

Strictly a quote from a company memo that was sent out to pilots in which they quoted a response from Boeing when asked about the subject. I suspect that there is no official publication of this info. That's the best I can do.

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?