747 FMC readings

[Guest trev0238]

Hi All, I would be grateful if someone could answer this liitle query.EGKK-HESH the departure was fine, cruise and fuel usage OK.Step climbed from FL310 to FL350 when told to by the FMC, 60nm before TOD as indicated by the Progress page and the next waypoint being SISIK ( this in itself being 40nm from TOD ).The legs page in the FMC was showing FL320 for the SISIK waypoint yet I was still in cruise at FL350. How did this happen with the SISIK waypoint being approx 40nm from the TOD as indicated on the ND.Hope I've explained this properly.RegardsTrev

[downscc 1,327]

Trev, I don't know.Normally, the 747 will not program a step climb that is within about 300 nm (my memory problem again) of the TOD. Also, was your step set for 1000 for 4000? Anyway, you got a strange one.

[Airbrakes 0]

Did you update VNAV with the new cruise altitude?+1 for the TOD. The FMC shouldn't suggest a S/C when you're within 200nm of the TOD. Progress page 1 should give a ETA to the TOD from 200nm out.

[Guest trev0238]

Hi All, thanks for all your help. I will do the same flight again this week and see what happens.It's my guess I have done something wrong.RegardsTrev