Hello dear pilots,I was wondering if anyone could shed some light on the 737 FMC speed and altitude restrictions.Example(with no aid from atc); a chart tells me I must be at the xyz vor at FL60 and a minimum speed of 210kts so now during flight planning I check my fmc LEGS and see if this is correct,if not I amend it.. or do I? Should I leave the legs page as it is and enter the restrictions in the DES/ SPD REST page prior to T/D,modify the LEGS and leave the SPD REST or modify both? I have read the manual and it states that the SPD REST feature when coupled with VNAV will be used in planning the deacceleratin prior to descent but does not talk about ammending the LEGS although in a sense VNAV is related to the planned LEGS.Sorry for the long winded questionKind RegardsJustin Harvey

That's how the real thing behaves. Just wait till u get the predictionfor the alt, then enter that atl as the alt restriction, along with the seed.

Ok so are you saying I do not need to modify my LEGS page for the restrictions,just use the SPD REST in the DES mode?RegardsJustin Harvey

Yes, you should enter any speed and altitude constraints from any charts into the FMC during preflight to predict an accurate TOD point.Floyd

Ok thankyou I'll continue to do so, now I just wonder when the SPD REST mode is actually used since you can enter the restrictions yourself in the LEGS page, maybe I'll do some more reading.Thanks for your repliesJustin Harvey

The LEGS page is where I do most of my constraint edits; once in awhile I'll find the SPD REST fields handy because it's not segment specific... some STARS slow you down higher or lower than 10,000 and I might set SPD REST in these cases.