Block Allocation?

Us little guys request blocking altitudes for turbulence, but often the big
guys are asking for it because they can slowly drift upward to higher altitudes
as they burn fuel and get lighter. I think they're doing this because it's more efficient to
fly at higher altitudes, but they cannot get there until their weight decrease.
Max T, MCFI


When a pilot requests a narrow block, it's usually because the ride is
unavoidably rough and he wants to be able to just hold a pitch
attitude rather than continually changing pitch and airspeed to
maintain altitude. It's easier on the airframe, easier on the
passengers, allows you to maintain a relatively constant airspeed so
it might be slightly more fuel efficient, and generally easier on the
pilot as well if he is hand-flying. I routinely ask for this when I
fly in convective weather, and so far I've always gotten it. Like
this pilot, I also generally ask for a 2000 ft block.

Michael