Communication

Request repetition or clarification of the uncertain part. Do not fill the gap with what you expected to hear.

No. It acknowledges receipt of the last transmission. WILCO conveys understanding and intended compliance, but neither replaces a required readback.

The applicable lost-communications procedure depends on the airspace in which the aircraft is operating. EASA/SERA and the current worldwide ICAO baseline are not identical.

Common initial actions

Attempt to establish communication using all available means: the previous frequency, another frequency appropriate to the route, the appropriate ATS unit, another ATS unit, another aircraft, datalink, satellite voice or any other available means. If necessary, transmit the message twice, preceded by “TRANSMITTING BLIND”.

If communication cannot be restored, select Mode A Code 7600 and, where applicable, the corresponding ADS-B indication.

1. EASA / SERA airspace — SERA.14083

Since 1 May 2025, SERA uses a single 20-minute period, whether or not an ATS surveillance service is being provided:

1. Maintain the last assigned speed and level, or the minimum flight altitude if higher, for 20 minutes:
   - following the failure to make a required report; or
   - when receiving a surveillance service, following the selection of Code 7600 or the corresponding ADS-B indication.
2. After those 20 minutes, adjust level and speed in accordance with the filed flight plan, as amended by accepted delay or modification messages.
3. If being vectored or flying an RNAV offset, apply the specific rejoining provisions in SERA.14083. Then continue on the last received and acknowledged route to the designated navigation aid or fix serving the destination.
4. Commence descent at the last acknowledged Expected Approach Time (EAT) or, if none was received, as close as possible to the Estimated Time of Arrival (ETA).
5. Complete the normal instrument approach and, if possible, land within 30 minutes after the later applicable time.

If a specific radio-communication-failure procedure is published for the SID or STAR being flown, that published procedure must be followed.

If an IFR flight subsequently encounters VMC and the pilot-in-command decides to continue in VMC, SERA requires Code 7601, landing at the nearest suitable aerodrome and notification of arrival.

2. ICAO baseline outside SERA — Annex 2, 3.6.5.2.2

Under the ICAO baseline applicable on 26 July 2026:

• Where radar is used in the provision of ATC, maintain the last assigned speed and level, or the minimum flight altitude if higher, for 7 minutes, beginning at the latest of:
• reaching the last assigned level or minimum flight altitude;
• setting Code 7600; or
• failing to report over a compulsory reporting point.
• Where radar is not used in the provision of ATC, maintain the last assigned speed and level, or the minimum flight altitude if higher, for 20 minutes after failing to report over a compulsory reporting point, unless a regional air navigation agreement prescribes otherwise.
• After the applicable period, adjust speed and level in accordance with the filed flight plan, then apply the ICAO route, descent, approach and landing provisions.

ICAO Annex 2 does not currently establish 7601 as a worldwide lost-communications code. ICAO Amendment 49 is expected to change the global procedure later in 2026, so this distinction must be reviewed before 26 November 2026.

Operational note: State AIPs, regional procedures, published SID/STAR procedures and the operator’s Operations Manual must always be checked and may differ from the general baseline.

References: EASA SERA.14083 — Regulation (EU) 2024/404; ICAO Annex 2 — Rules of the Air.

United States and Canada

United States: under 14 CFR 91.185, if VFR conditions are encountered after a two-way-radio failure, continue under VFR and land as soon as practicable. In IMC, use the AVEF route priority (Assigned, Vectored, Expected, Filed), the highest applicable altitude, and the clearance-limit timing rule.

Canada: CAR 602.137 requires listening on an appropriate frequency, selecting 7600 and attempting direct or relay communication before following the applicable CAP/CFS procedure or specific ATC instruction. CAR 602.138 contains the VFR failure rules for controlled airspace; it is not a universal instruction simply to land at the nearest suitable aerodrome.

Official references: 14 CFR 91.185; CAR 602.137/602.138.

ADS-C stands for Automatic Dependent Surveillance – Contract.

It is a type of position reporting system used in remote and oceanic airspace where radar and real-time surveillance are not available. Unlike ADS-B, ADS-C sends reports according to contracts between the aircraft and an ATS unit: automatically at agreed intervals, when specified events occur, or in response to a demand.

How it works

• A contract is established between the aircraft avionics and an ATS unit through the data-link system. CPDLC is a separate messaging application that may share the communication infrastructure and logon context.
• The aircraft automatically sends position reports based on:
• Time intervals (periodic contract)
• Waypoints crossed or other event (event contract)
• Request from ATC (demand contract)

What data is transmitted

• Current position (latitude, longitude, altitude)
• Time of position report
• Estimated time and position at next waypoint
• Navigation intent information (e.g. route and flight plan data)

Benefits of ADS-C

• Enables ATC surveillance in non-radar areas such as the NAT HLA, Pacific, and Indian Ocean FIRs
• Supports reduced separation minima when combined with RNP-capable systems
• Provides reliable position monitoring in remote environments

Note: ADS-C is a key component of FANS (Future Air Navigation Systems) and works in conjunction with CPDLC to improve communication and surveillance beyond radar coverage.

References: FAA AC 90 117 data link applications and procedures.

The essential phrase transmitted by the pilot is:

“[ATS UNIT], [CALLSIGN], CANCEL DISTRESS”

The pilot should then provide useful information about the aircraft’s current condition and intended action. For example:

“WALDEN TOWER, G-CD, CANCEL DISTRESS. ENGINE SERVICEABLE, RUNWAY IN SIGHT, REQUEST LANDING.”

This message is transmitted by the aircraft. It means that the serious and/or imminent danger requiring immediate assistance has ended.

Cancelling the distress condition does not automatically cancel a separate landing request or every remaining need for assistance. If an urgency condition remains, it should be stated clearly.

After receiving the cancellation, the ATS unit controlling the distress communications — when authorised to do so — terminates the distress traffic and any associated radio-silence conditions by transmitting:

“ALL STATIONS, [ATS UNIT], DISTRESS TRAFFIC ENDED.”

The distinction is therefore:

• CANCEL DISTRESS — transmitted by the aircraft to cancel its distress condition.
• DISTRESS TRAFFIC ENDED — transmitted by the controlling ATS unit to terminate the distress communications and radio-silence conditions on the frequency.

References: EASA SERA.14095(b)(5) — termination of distress communications and silence; ICAO Annex 10, Volume II — communication procedures; ICAO Doc 9432, §9.2.3 — Manual of Radiotelephony.