Step climbs?

[OuterMarker]

Hello everyone,

is there a (correct) way to enter step climbs into the FMS? Or do I just initiate the climb when it's time to do so without telling the FMS beforehand?

Thanks

[softreset]

AFAIK the functionality to auto step (like in the 777) does not exist. If your flight plan calls for a step, you would need to perform the action manually. I tried a step climb from 380 to 400 last night and this is what I did:

• Dial up altitude knob from 38,000 to 40,000
• Changed the Cruise altitude from 38,000 to 40,000 in the FMC
• Changed thrust rating from CRZ to CLB
• Went into flight level change .80 (which was my current cruise speed)

You could probably also do it in V/S but I'd keep the initial ROC to <500 FPM until you establish your thrust/climb capabilities, because you'd lose speed protection.

[OuterMarker]

27 minutes ago, softreset said:

AFAIK the functionality to auto step (like in the 777) does not exist. If your flight plan calls for a step, you would need to perform the action manually. I tried a step climb from 380 to 400 last night and this is what I did:

• Dial up altitude knob from 38,000 to 40,000
• Changed the Cruise altitude from 38,000 to 40,000 in the FMC
• Changed thrust rating from CRZ to CLB
• Went into flight level change .80 (which was my current cruise speed)

You could probably also do it in V/S but I'd keep the initial ROC to <500 FPM until you establish your thrust/climb capabilities, because you'd lose speed protection.

Thanks! That's more or less how I've been doing it as well. For more accurate fuel calculations I tried entering the step levels to the respective waypoints during preflight but you have to do it seperately for each waypoint and that felt like they were recognized as constrains and not as a new cruise level.

[Graeme_77]

IIRC the FMS will update automatically, so it’s just a case of winding the altitude up, FLC mode and you’ll be fine. If you need to nudge the mach number back a tiny bit to help it climb that’s fine, but if a bigger change than 0.02 mach is needed then you’re probably asking it to fly a bit too high. There are limiting weights for cruise levels shown in the Ops Reference manual, and I’ve found the SimBrief step climbs to be pretty accurate too.

I don’t know the best way to get fuel predictions including a future step, so will do some investigation when I get a chance.