Failures and Emergencies — Page 115, Lesson 97

I want to walk you through the Failures and Emergencies section of your communications syllabus. We're starting with what happens when you lose your radios, then moving into the formal states of emergency and the correct distress message format. Let's begin with communications failure in Visual Meteorological Conditions, or VMC. The Rules of the Air — that's Annex 2 to the ICAO Convention — lays down three things you must do if you lose two-way communications while flying in VMC. First, you continue to fly in VMC, which means you keep clear of cloud. Second, you land at the nearest suitable aerodrome. Third, you report your arrival by the most expeditious means to the appropriate ATC unit — in practice, that means telephoning ATC as soon as you're on the ground. There are two important notes attached to this rule. Note 1 says that if you are part of the traffic pattern — that is, in the circuit to land at a controlled aerodrome — you must keep a watch for instructions that may be issued by visual signals. So you're looking for light guns or signal panels from the tower. Note 2 introduces the term "Controlled VFR". This is common in other countries, and it requires two-way communications to operate. So if you lose your radios while operating under Controlled VFR, you are no longer compliant with that clearance, and the VMC failure procedure kicks in. Now let's move to Emergencies. The book classifies two states of emergency. The first is DISTRESS. Distress is a condition of being threatened by serious and/or imminent danger and of requiring immediate assistance. The second is URGENCY. Urgency is a condition concerning the safety of an aircraft or other vehicle, or of some person on board or within sight, but it does not require immediate assistance. So the key difference is immediacy: distress means you need help right now; urgency means there is a safety concern but you can manage without instant assistance. For emergency communications themselves, the rule is that distress and urgency traffic shall normally be maintained on the frequency on which such traffic was initiated. You stay on that frequency until it is considered that better assistance can be provided by transferring that traffic to another frequency. The note adds that 121.5 MHz, or alternative available VHF or HF frequencies, may be used as appropriate. In general, for distress and urgency communications by radiotelephony, the transmissions shall be on the frequency in use at the time. Now let's look at the Distress Procedures, specifically the Distress Message. The distress message must be preceded by the radiotelephony distress signal MAYDAY, preferably spoken three times. So you say "MAYDAY, MAYDAY, MAYDAY" before the message itself. The message shall be sent on the air-ground frequency in use at the time. It shall consist of as many as possible of the following elements, spoken distinctly and, if possible, in the following order: first, the name of the station addressed, time and circumstances permitting; second, the identification of the aircraft; third, the nature of the distress condition; fourth, the intention of the person in command; and fifth, the present position, level — that means flight level, altitude, or whatever is appropriate — and heading. So to put that together in your mind, a full distress message would sound something like: "MAYDAY, MAYDAY, MAYDAY, London Control, G-ABCD, engine failure, intending to ditch, five miles south of Dungeness, altitude two thousand feet, heading two seven zero." You give the station addressed first if you can, then who you are, what's wrong, what you plan to do, where you are, at what level, and which way you're pointing. That's the professional standard.