Description

Sleeping receiver is the term used to describe incidents when the radio apparently goes dead so that no incoming calls are heard, either those directed to the flight or those between ATC and other flights. Usually, the situation continues until the aircraft transmitter is keyed - often because the pilots have noticed the silence and wish to check their receiver; thereafter, radio operation is normal.

When this circumstance first began to be reported, the number of reports was low but there was some increase in reports for a period thereafter. After initial reports from UK airspace, the geographical extent of such occurrences appeared to expand. Deficiencies in one particular model of airborne transceiver and the introduction of offset carrier wave transmissions in some ACC sectors served by multiple ground transmitters was eventually associated with some reported events.