Cruise

(See also Instrument Approach Procedure) Used in an Air Traffic Control (ATC) clearance to authorize a pilot to conduct flight at any altitude from the minimum Instrument Flight Rules (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 may not return to that altitude without additional ATC clearance. Further, it is approval for the pilot to proceed to and make an approach at destination airport and can be used in conjunction with: 1) An airport clearance limit at locations with a standard special instrument approach procedure. The Federal Aviation Regulations (FAR) require that if an instrument letdown to an airport is necessary, the pilot shall make the letdown in accordance with a standard/special instrument approach procedure for that airport, or 2) An airport clearance limit at locations that are within/below/outside controlled airspace and without a standard/special instrument approach procedure. Such a clearance is NOT AUTHORIZATION for the pilot to descend under Instrument Flight Rules (IFR) conditions below the applicable minimum IFR altitude nor does it imply that ATC is exercising control over aircraft in Class G airspace; however, it provides a means for the aircraft to proceed to destination airport, descend, and land in accordance with applicable FAR's governing Visual Flight Rules (VFR) flight operations. Also, this provides search and rescue protection until such time as the IFR Right plan is closed. (FAA4)