This incident involves China Eastern unknowingly transmitting blind, (possibly by accidentally keying the mic) and being unable to receive transmissions from TWR.
Notice how China Eastern was able to transmit but not receive. In the circumstances above how could TWR identify that the aircraft had a problem and was unable to respond?
Vocabulary - blind transmission
A blind transmission, in telecommunications, is a transmission made without obtaining a receipt, or acknowledgment of reception, from the intended receiving station. Blind transmissions may occur or be necessary when security constraints, such as radio silence, are imposed, when technical difficulties with a sender's receiver or receiver's transmitter occur, or when lack of time precludes the delay caused by waiting for receipts.
The usual reason for "transmitting blind" would be that the captain of an aircraft knows or suspects that the aircraft's receiver has failed. The captain would still proceed according to the flight plan
, and under obligation to let other people know of his whereabouts and decisions.
For more radiotelephony listening comprehension activities