In real-world piloting of 'heavies', is it standard practice to switch to ALT HOLD & SPD from VNAV once you reach cruise altitiude, or does it vary from aircraft to aircraft or airline to airline?Martin

leave it on vnav.

Why do you say that? I have a book called 'Flying the Big Jets', with a detailed record of cockpit activity in a b777 between Heathrow and Boston. It seems there that they switch from VNAV to ALT HOLD. What is the usual procedure?M

Procedure is whatever the airline tells you to do.

Then put it in alt hold, it does the same thing, the only thing with vnav is if you leave it there the autopilot will start the descent automaticaly at T/D provided you reset the mcp and it also controls the speed on its own according to fmc, i beleive if you put it in alt. hold you have to dial in a speed( i know its not a big deal, but in vnav its all automatic) I dont think there is a benefit in putting it in alt. hold. But really doesnt matter, i leave it in vnav for the flight as everything is automatic in that setting.P.S disregard what I wrote as I just realized that you stated "real world" and I dont really know what they do, even being a real world commercial pilot, i really dont knowMy apoligies

Edited February 18, 201214 yr by flyinpilot212121

Why do you say that? I have a book called 'Flying the Big Jets', with a detailed record of cockpit activity in a b777 between Heathrow and Boston. It seems there that they switch from VNAV to ALT HOLD. What is the usual procedure?M

It's quite simple really. The airplane is on VNAV the whole flight, it's just that once it reaches cruise altitude the autopilot "basic mode" is ALT HLD. Try and look for the other modes during other phases of flight (climb, descent). I'm not familiar with the 777 per se, but the same basic principle applies to Boeing airplanes. You should look on the FMA (Flight Mode Annunciator) for "THR HLD" (Throttle Hold) on descent and something with "SPD" on it on climb in one of the FMA columns, the autothrottle or speed column to be precise, which is the one on the top left corner.It's just the way the airplane manages its own basic automation modes to achieve the more complex function of VNAV itself.