Class D Transit with a Radio Failure Mid-Clearance
You are tracking toward a Class D control zone in a recreational aircraft at 2,500 ft AMSL, 8 NM from the zone boundary. The tower clears you to enter and track via a reporting point, and you read back correctly. Two minutes later your radio transmits but receives nothing - the headset is fine, the volume is up, and you can hear other aircraft faintly but not the tower. You are now 4 NM from the boundary, still outside controlled airspace, with 40 minutes of fuel and a passenger aboard. The zone's hours of operation are published; you are inside them. Weather is VMC with 15 km visibility.
1. State the actions you should take and the order in which you should take them.
Read the worked answer
First, do not enter the zone - you are still outside, and an inability to receive means you cannot comply with further instructions. Squawk the radio-failure code if your transponder supports it, and try the alternate radio or a second frequency, because a failed receiver on one box is different from a failed radio. Turn away from the boundary, climb or descend only as needed to stay clear, and hold outside. Then attempt contact via a relay: another aircraft, or a phone call to the tower if one is available, stating your position, altitude, and intentions. If contact is established, request instructions. If not, remain clear and route around the zone. The passenger does not change the rule; VMC does not authorise entry without a clearance you can receive.
2. Explain why 'the clearance was already issued' does not authorise you to continue, and what you should do about the passenger and fuel.
Read the worked answer
A clearance is an instruction you must be able to receive and comply with; once you cannot hear the controller, you cannot know whether the clearance has been amended, cancelled, or superseded by traffic. Continuing on a remembered clearance is a guess, and controlled airspace entry depends on a current, two-way clearance. With 40 minutes of fuel and a passenger, the prudent course is to divert to a non-controlled aerodrome, land, and re-plan or wait for the radio to be repaired. Fuel is not the binding constraint at 40 minutes if a suitable aerodrome is within 20; if it is not, declare the situation by whatever means available before fuel becomes the emergency. Brief the passenger calmly and explain the diversion.