Failures and Emergencies — Page 115, Lesson 95

I want to walk you through the start of the chapter on Failures and Emergencies. This is a critical part of your training because, as with any field of human endeavour, flight operations do not always go according to plan. In the worst case, we may have to apply procedures designed to gain assistance in difficult situations. So in this chapter we will consider communications failure and emergency procedures. Let's begin with communications failure. Occasionally — and I mean rarely — communication between aircraft and ground stations can break down. It could be that either party has a partial failure, meaning your receiver has failed but your transmitter is okay, or vice versa. It could even be a total failure of equipment. The breakdown may be caused by interference or by wrong selection of a frequency. Now, the most common reason for lack of communications is usually what we call "finger trouble" — pilot error. So before you assume a real equipment failure, you should check several things. First, that the correct frequency is selected. Second, that the volume control is not turned too low or the squelch level too high. Third, that your microphone and headset plugs are fully home — fully inserted into their jacks. Fourth, that the aeronautical station you're trying to reach is actually open for watch — for example, military training bases often close after 1700 hours. And fifth, that you are within radio range of that station. If those checks don't solve it, then it could be that your equipment — or the other station's equipment — is actually malfunctioning. It is possible that your receiver has failed but you are still transmitting satisfactorily. Here's an important point: in VMC — Visual Meteorological Conditions — and operating under VFR, or Visual Flight Rules, some aircraft still operate with no radio fitted at all. So unless you need an Air Traffic Control service, there is no cause for concern. However, if you do need a service — for example to join a traffic pattern to land — then you should follow the general procedure outlined here. First, attempt communication on another frequency. If those attempts fail, continue to transmit your message twice on the designated frequency. And if you know that your receiver has failed, transmit your reports — or position reports — at the scheduled times on the frequency in use. There is also a specific ICAO requirement here: an aircraft which is receiving Air Traffic Control or Advisory Service shall also transmit information regarding the intent of the pilot-in-command with respect to the continuation of the flight. So even if you can't hear them, you must tell them what you plan to do. Now, a question: how else could you inform ATC of your radio failure? The answer is by using your SSR transponder — Secondary Surveillance Radar. You squawk code 7600. That code appearing on a radar screen informs the controller that the aircraft concerned has radio problems. So remember that number: 7600 is the radio failure squawk.