Originally Posted by
Sig229
Likewise!
You only need to use ALT INTV in the climb to set a new cruise alt in the FMC. For example: your FMC cruise ALT is FL380. You've leveled off at FL360 due to ATC. When they give you a climb to 380 you just set that in the MCP and the AP will go to ALT HOLD mode, when you re select VNAV it will resume the programmed CLB profile up to 380. If you later want to climb to 400 you simply set the MCP to 400 and press ALT INTV, it will automatically re cruise the FMC to 400 and begin a cruise climb at the calculated speed (Mach).
If you level off in VNAV below the FMC cruise altitude it will be in VNAV ALT. Pressing ALT INTV while in ALT HOLD does nothing, as ALT HLD isn’t a VNAV mode.