VFR transit clearance and radio failure in Class C airspace
You are pilot-in-command of a Cessna 172 on a VFR flight from a satellite aerodrome toward a Class C control zone. The aircraft is at 2,500 ft AMSL, 25 NM from the zone boundary, with Mode C selected and two persons on board. You request a transit through the zone. ATC replies: “November 123AB, cleared to enter the control zone via the November arrival, maintain 2,000 ft or below, report 5 NM.” You read back: “Cleared to enter the control zone via the November arrival, report 5 NM, November 123AB.” ATC does not correct the readback. Two minutes later, cloud forces you to climb to 3,200 ft. You continue and enter the zone at 3,200 ft. After passing the zone boundary, the radio fails completely. The aircraft has a serviceable transponder and you are still VFR.
1. Was the pilot’s readback acceptable, and what should the pilot have done about the omitted altitude restriction?
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The readback was not acceptable. A clearance readback must include all safety-related elements, and an altitude restriction is one of them. By omitting “maintain 2,000 ft or below,” the pilot left the controller unsure whether the restriction had been copied. ATC should have corrected the incomplete readback, but the pilot remains responsible for complying with the clearance as issued and for seeking clarification if any part is not understood or cannot be accepted. The correct action was to read back the full clearance or ask: “Confirm maintain 2,000 ft or below.” Climbing to 3,200 ft without an amended clearance was a deviation.
2. What are the pilot’s obligations and options after the radio failure while inside the Class C zone?
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After the radio failure, the pilot should squawk 7600, remain in VMC, and continue to a suitable aerodrome to land. In Class C airspace, a VFR aircraft with radio failure is expected to remain clear of cloud and to land at the nearest suitable aerodrome, then notify ATC. The pilot should not climb into IMC or enter further controlled airspace without a clearance. Because the transponder is serviceable, 7600 alerts ATC; if the aircraft has a handheld radio, try the emergency frequency. The pilot should also watch for light signals and avoid known traffic.
3. If the clearance conflicts with a cloud-avoidance requirement, what should the pilot have done before entering the zone?
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The pilot should have advised ATC before entering: “Unable to maintain 2,000 ft or below due to cloud, request 3,500 ft or amended routing.” If ATC cannot issue an amended clearance, the pilot should remain outside the zone and divert. Entering at 3,200 ft without a clearance was not acceptable, even if the deviation was for weather. A clearance is not a suggestion; if it cannot be complied with, the pilot must negotiate a new one.