IFR Communications Failure in Cloud
You are pilot of Cessna 208B Grand Caravan 5Y-GHI on an IFR flight from Nairobi JKIA (HKJK) to Kisumu (HKKI) at FL140. In IMC, 60 nm west of Nakuru, Nairobi Control clears: '5Y-GHI, climb to FL160, direct KIS VOR, squawk 4521.' Shortly after you read back, both COM radios fail; the audio panel has no power and the transponder still operates. You are in cloud, in radar coverage, with 2 hours fuel and no other failure. The last assigned level was FL140 and you were climbing. Your destination weather is VMC. You have a handheld GPS but no satphone. The aircraft is equipped with a serviceable mode C transponder and an ELT. The route is direct to KIS VOR; minimum IFR altitude on the route is FL110.
1. What are your immediate communication-failure actions, and what altitude should you maintain?
Read the worked answer
Select squawk 7600 immediately. If the transponder has a mode C check, ensure altitude reporting remains on. Continue the clearance you have already read back: climb to FL160 and track direct to KIS VOR. Because you are in IMC, the standard lost-communication procedure is to maintain the last assigned speed and level, or the minimum flight altitude if higher, for 7 minutes, and then follow the published procedure for the route. In this case FL160 is the last assigned level and it is above the minimum IFR altitude of FL110, so maintain FL160 for the 7-minute period rather than descending into cloud. Attempt to re-establish contact on 121.5 if any radio can be powered, and try the handheld if available. Do not change to 7600 and then immediately descend. The 7-minute rule gives ATC time to observe your squawk and protect your path. If you were in VMC, the procedure would be different: you would normally continue VFR and land at a suitable aerodrome, but here you are in cloud.
2. ATC sees your 7600 and transmits on 121.5. You cannot receive. What should you do, and how would you handle the approach?
Read the worked answer
If you cannot receive, you cannot acknowledge ATC. Continue transmitting blind if you have any transmitter: give your callsign, position, level and intention on 121.5 and on the assigned frequency if possible. Squawk 7600 remains displayed. Because your destination is VMC, you can expect to proceed to Kisumu and land visually, but you must still fly the cleared route and level until the lost-communication procedure allows a change. On arrival, look for light signals from the tower: a steady green light means cleared to land; a flashing green means cleared to taxi; a red light means give way or stop. If you are in doubt, do not land against a red light. If the weather at Kisumu were IMC, you would follow the published instrument approach procedure for the route, descend according to the procedure, and look for light signals or follow the published lost-communication approach. Keep the transponder on 7600 until you are on the ground and in contact with ATC.
3. What reports and actions are required after landing?
Read the worked answer
After landing, do not simply park and walk away. Inform ATC as soon as possible that you have arrived and that you experienced a total communications failure. State the aircraft identification, the nature of the failure, the time it occurred and the actions you took. ATC will need to close your flight plan and confirm that no search-and-rescue action is required. Complete the aircraft technical log and the operator's occurrence-reporting process; in Kenya, a serious incident or communication failure may also require notification to the regulator. Preserve any relevant data, such as the transponder code, radio settings and GPS track. Have the radios inspected before the next flight. Finally, review the event: the correct squawk, the 7-minute rule, the attempt on 121.5 and the light-signal recognition are all points that should be debriefed.