The message was revealed on a tape recording after the crash on 2 June 1994, a Royal Air Force flight-traffic control officer told the inquiry at Paisley, Strathclyde.
But there was no response to the transmission, Flight Lieutenant Hamish Miller said. "My opinion is that the transmission was not heard by the control staff."
A Belfast air-traffic controller told the inquiry that a transcript of the message showed the call sign of the Chinook as it passed out of her airspace at Aldergrove shortly after taking off.
The inquiry had already heard that the aircraft crashed at around 6pm - killing 10 senior Royal Ulster Constabulary officers, nine army intelligence officers, six MI5 officials, and the four-man RAF crew.
Earlier a crash investigator said he could not rule out jammed controls as a possible cause. Department of Transport inspector Anthony Cable also told the inquiry that wind conditions could have played a part.
The inquiry also heard that one of the two pilots, Fl Lt Richard Cook, voiced concerns about the engine computers on the day of the accident. The duty RAF authorising officer in Northern Ireland that day said he had asked Fl Lt Cook that morning how he was getting on with the newly introduced Mark Two Chinook and had been told there were some problems with the engine control units.
The inquiry continues today.Reuse content