"Cruise"

[CFII Kush]

A student recently asked me how some pilots are allowed to climb and descend at their will while IFR. I asked him to explain further and he mentioned that he went onto youtube.com and watched videos of pilots having fun in/around the clouds. I told him that if this was VFR, one could do so as he/she wished as long as they kept the appropriate vis. and distance from clouds req.

He said what about if they were IFR, on an IFR flight plan?
I said I would get back to him but that I believed it had something to do with a Cruise clearance.

From the FARs ... CRUISE: Used in an ATC clearance to authorize a pilot to conduct flight at any altitude from the minimum IFR altitude up to and including the altitude specified in the clearance. The pilot may level off at any intermediate altitude within this block of airspace. Climb/descent within the block is to be made at the discretion of the pilot. However, once the pilot starts descent and verbally reports leaving an altitude in the block, he/she may not return to that altitude without additional ATC clearance.

I also know that a cruise clearance may be issued if a pilot encounters turbulent conditions in which case it would be very difficult to maintain a given alt. on the dot, so ATC will issue a block of airspace.

With a cruise clearance, can you climb and descend as much as you want, as long as you are within this altitude or are you only allowed to descend, level off and required to report...?

[MidlifeFlyer]

I think "Having fun in and around the clouds" (as well as turblence) will more likely involve a "block altitude," wich is desigend for repeated "deviations" than a cruise clearance, which is really designed as a long-term discretionary descent.

[exleardriver]

further, from my freight days when you flew through anything basically, a 'block' gives you the flexibility required when it's more important to keep the wings level than maintain precise altitude in say, moderate to severe turbulence. i concur that this differs in general purpose from a cruise clearance, which as noted, is basically an ifr discretionary descent into an uncontrolled field.