When do you enter the "Approach Vref" on the "Approach Ref" page of the FMC in the 737NG? I tried doing this on my preflight, but i cant seem to get the LSK to accept any of the choices available. -Adam Harmon

Adam,Why would you try this at preflight? The approach Vref is entered when you know what your actual landing weight will be as the Vref is dependent on that weight. I would guess somewhere before or during descent.Hope it helps,

I dont know why..im a newb :) Just wondering because I got a "Approach Vref" error popping up on my FMC during decent. Yes, your answer helps..thx.

enter that information before your TOD. i usually enter approach vref on the 744 5 min before i descend.tomas

I set Vref when handed over from center to approach, which is when ATC advises which approach to expect. Center can always put you in a hold before reaching the approach gate, which is usually the fix for which the STAR is named. Setting Vref flows with the activity of pulling the expected approach plate and reviewing it before IAF.

I do as you suggest during initial descent but I also think that the selection of of the flaps profile on the approach page specifies the flaps you will use but I would hope the V-Speeds would dynamicly change as the weight changes due to fuel burn-off during the approach.Always appreciate your contributions, Mats.

Airlines vary, but we do it before top of descent, and referencing it's selection and value is part of our descent cecklist.It's part of the whole arrival and landing planning package, checking the ATIS for weather and runway, figuring (sometimes guesing) as to actual arrival and runway and determining how much flap and autobrake is best.To determine your landing weight, reference the prog page to see what landing fuel is going to be and compare that value to current fuel and deduce your landing weight! Enter that value on the init-ref page and line select the flap 25 or 30 value to the blanc line, and there ya have it!Tom