Open Climb Above Fl 300
 

Is it recommended to use OPEN CLMB above FL 300 and why?that's what I've been told by some falks.

NO, no longer required. It was, (almost history) but loooooong time ago. Your "falks" urgently need an update. :cool:

thanks is there any reference.

It was an OEB back around 1998/89 and was effective for about 1-2 years. Can't remember any more than that.

mcdhu

Possibly it was meant as OPEN CLIMB (or CLB) as opposed to V/S, as the V/S mode has no speed protection and it could decrease all the way to Vls if you select too high a rate of climb.

in the old days (history:cool:), with the ancient software, there was obviously a risk that once above FL300 and in a very, very shallow climb, the thrust channel "thought" you are doing a Level Flight now and so reduced the power, while the pitch channel still was engaged in CLIMB.

So easy to see what could have been the consequence on this, if you did not always check your instruments. Soon from below a very long coloured band appeared on the speed scale.:sad:
Hope this helps.
But again: History.
BTW: it never ever happened to me or to anybody I know, so I guess very rare events. Even with MSN 0025, the oldest I flew, MANAGED climb up to 390, incl shallow climb phases, not any problems.

A321 is right, I don't have a reference either, but it did happen to me once, the two computers were not in sync, as soon as I reached my final altitude, the thrust went to idle.

I still prefer to use VS when I'm heavy, keeps the airplane from wandering around.

Dear friends,

Thank you for you valuable information