Title: Re: Possible 250kts below 10k bug (Any chime-ins?)
Post by Alex T on Apr 29th, 2020 at 12:34am
logan3db wrote on Apr 29th, 2020 at 12:08am:
Alex T wrote on Apr 28th, 2020 at 10:17pm:
Aussiesix8 wrote on Apr 28th, 2020 at 9:44pm:| The B744 has a similar thing where by if you don't put in the speed restriction under speed trans then it will speed away. |
Not quite the issue here, let me explain more.
On all Boeing FMCs: 737,747,757,767,777 nothing needs to be entered into SPD TRANS, unless it needs to be different than 250/10000 on climb or 240/10000 on descent for a specific company/atc/performance reason.
The question I'm asking is this: There's obviously no way to enter a speed restriction on the VNAV CRZ page, there is no box for SPD TRANS or SPD REST or anything. So, if the airplane changes to the CRZ phase, will it honor either the restriction from the climb, or the Descent, or none at all? If the real plane won't honor one (sounds crazy but I could see this being the case), then Captain sim got it right. That's what we're trying to figure out here. |
It's been quite a while since I have cruised below 10k so I can't really recall what the FMC did in CRZ... I'm pretty sure I didn't even operate in VNAV that low.
However, the "fix" or way to cope would be to enter 250 in the ECON SPD. That will honor the speed of 250 below 10. In VNAV CRZ there is not speed/altitude constraint since you would be in level cruise flight.
I'll have a chance to play with the plane this weekend, so I'll check to see what it does with a cruise below 10. |
Exactly what I was thinking! There's always a workaround haha. Thanks so much, please report back with some info, that would be cool!
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