Lost Communications in Controlled Airspace
You are on an IFR flight in controlled airspace under radar control. Your radio fails completely while you are at FL180 on a published route. You have a transponder with Mode C and a handheld backup radio that is not approved for IFR communication. The last clearance was to maintain FL180 and proceed direct to a VOR, then expect further clearance at a specified time. The weather is VMC above 10,000 ft but IMC below. You have 1 hour 30 minutes of fuel remaining. The destination airport has an ILS and is 30 minutes away. There is a nearby airport with a non-precision approach 15 minutes away.
1. What should you do first, and how should you use the transponder and backup radio?
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First, squawk 7600 to indicate lost communications. Continue on the last assigned route and altitude, and comply with the last clearance. The handheld backup radio may be used to attempt contact, but it is not approved for IFR communication and should not be relied on for clearances. If contact is established, the crew should request clarification but not assume the clearance is valid unless confirmed. The crew should also monitor the navigation aids and maintain the assigned altitude. The priority is to follow the lost-communication procedure for the airspace and route, then plan for an approach at the destination or a suitable alternate.
2. How should the crew plan the approach and arrival without communications?
Read the worked answer
The crew should follow the published lost-communication procedure, which typically requires continuing on the last assigned route, maintaining the last assigned altitude, and beginning descent at the expected further clearance time or at the published holding fix. The destination ILS is the preferred approach if the weather is suitable and the crew can comply with the approach procedure. If the destination weather is below minima, the crew should divert to the nearby airport with the non-precision approach, but must ensure fuel allows a missed approach and diversion. With 1 hour 30 minutes of fuel, the crew has limited margin. The key judgement is to avoid improvising; use the published procedure, and if the weather at destination is unsuitable, divert early rather than attempt an approach that may not be possible.