VFR Radio Failure Before Class D Entry
You are flying a Cessna 172 VFR at 3,500 feet, 15 nautical miles west of a Class D airport where you intend to land. The weather is 10 statute miles visibility with a 5,000-foot ceiling. While checking in with approach, your radio transmits only a carrier and then goes silent; the circuit breaker is not popped, and you have no handheld. The transponder and altitude encoder are working. You are squawking 1200 and have 1.5 hours of fuel. The Class D tower is open, and you need to land, but you have not received an entry clearance. You can see the airport and several aircraft in the pattern. There is a non-towered airport 20 nautical miles east with fuel. You must decide whether to enter Class D, what to squawk, and how to use light signals and relay options without creating a conflict.
1. What transponder code and immediate radio actions should you take after the radio failure, and why?
Read the worked answer
Set transponder to 7600 and keep Mode C on. Attempt a radio check on the current frequency, then on 121.5; check headset, volume, squelch, and intercom before concluding the transmitter is dead, but do not delay the approach decision. Make blind broadcasts: “Cessna 12345, 15 miles west of [airport], 3,500 feet, radio failure, squawking 7600, remaining outside Class D.” Listen on 121.5 for relay. 7600 tells ATC you have a communication failure; do not use 7700 unless the situation becomes an emergency. Because you are VFR and the weather is VMC, you can continue to navigate visually, but you need a plan for landing.
2. May you enter the Class D airspace? What alternatives and light-signal procedures apply?
Read the worked answer
VFR radio failure does not authorize entry into Class D. Unless you receive a light signal or other ATC instruction, remain clear of the airspace. Orbit outside the boundary, clear of the final approach course, and watch the tower for light-gun signals. A steady green means cleared to land; flashing green means return for landing; steady red means give way and continue circling; flashing red means the airport is unsafe-do not land; alternating red and green means exercise extreme caution. If no signal comes, divert to the non-towered airport 20 miles east, land, and telephone the tower. Do not enter the pattern and hope the controller sees you; that creates an unresolved conflict.
3. How would you use light signals after landing, and what would you do if you receive no signal?
Read the worked answer
After landing, if the tower is still using light signals, watch for ground signals: steady green means cleared to taxi; flashing green means cleared to cross a runway; steady red means stop; flashing red means taxi clear of the runway in use; alternating red and green means exercise extreme caution. If no signal is received, stop clear of the runway, park in a safe area, and contact the tower by telephone. Do not taxi across runways without a signal or instruction. Before shutdown, record the time and nature of the failure and advise the tower. For the flight home, do not depart until the radio is repaired or a handheld is available; a second failure in the same airspace would repeat the risk.