Air Traffic Control Clearances and Procedures
Anatomy of a clearance
Use CRAFT: Clearance limit, Route, Altitude, Frequency, Transponder. Read back every altitude, heading, speed, runway, frequency, and hold-short instruction. "Maintain" locks you at an altitude; "climb and maintain" or "descend and maintain" states the direction. "At pilot's discretion" lets you level off but never reverse direction. "Cleared for the approach" authorizes the approach, but you keep the last assigned altitude until established on a published segment.
Holding
Standard holding is right turns, with 1-minute legs at or below 14,000 ft MSL and 1.5-minute legs above. Maximum holding airspeeds are 200 KIAS through 6,000 ft, 230 KIAS from 6,001 to 14,000, and 265 KIAS above 14,000. Entries are direct, parallel, or teardrop.
Times that matter
An "expect further clearance" (EFC) time is your lost-communications trigger. A clearance void time works the opposite way: if you are not airborne by that time the clearance is gone, and you must obtain a new one before departing.
Traps
A cruise clearance authorizes descent to the MEA and an approach at the destination without further contact. A VFR-on-top clearance requires VFR cloud clearance and permits altitude changes, but you must advise ATC. "Cleared direct" never cancels a minimum IFR altitude.
Worked example: "Cleared to KXYZ via radar vectors, maintain 4,000, expect 6,000 in ten minutes." You climb to and hold 4,000, read back 4,000, and note 6,000 and the EFC for lost-comms planning.