When I am programming the FMC and have selected Vref then select the takeoff runway I get the message "Take Off Speed Deleted" Am I doing something wrong or is this a "bug"Andrew.

Hi Andrew,I don't know if this is a bug or how the real thing works, but if you select your departure runeway before setting the V-speeds, you'll be fine.Cheers,Gosta.http://hifi.avsim.net/activesky/images/wxrebeta.jpg

Thanks, I knew there would be someone with the answer. Having flown a couple of flights there have been only a few minor variation to the Dreamfleet FMC. This has helped flying the 737NG quicker than expected,Andrew

Andrew,This happens because the runway length is considered in the v speeds if it's provided. I'm not sure if NOT being forced to provide it is a bug (I don't think so, but this is just my guess) but if you provide a runway after doing the speeds the FMC will recalculate them taking the runway length into account. Like Gosta said, just entering a runway first if you're going to enter one will prevent the speeds from being deleted. I just thought I'd fill in the "why". :)-Shaun

Shaun --To the best of my knowledge that is not a bug. And you are right, if you don't provide the RW, and you calc VSpds for takeoff, and then you chose a dep rw, you will need to recalculate V1, and VR, but not V2.

Guys, that's why there's a pre flight flow when programming the FMC. It's also true as have been stated that it's correct for the FMC to remove the v speeds if you change the TO runway.[h5]Best Wishes,Randy J. Smith[/h5][h6]The Next Great one? PMDG's 737NG is here![/h6][h3]" A little learning is a dangerous thing"[/h3] [h5]AMD XP 2200 |MUNCHKIN 512 DDR RAM |ECS[/b ][i] K7S5A MB[/i] |GF3 64 MEG @ 215/545|WIN XP PRO |MITSUBISHI DIAMOND PLUS 91 19"[/h5]

Fred,Yeah thanks for pointing that out, I didn't think to mention that. :) Obviously V2 isn't going to change as it has nothing to do with runway length.-Shaun