TNAG-2856-FCO40-4109-Hong-Kong-compensation-claim-regarding-Korean-Air-Lines-Flig-1993 — Page 107

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as to the words spoken, due to the very low recording level." The report also concluded that simultaneous crosstalk from channel 3 to channel 4 occurred ten seconds later.

1.15.1.4 The segment of the tape in question was not recorded during or as a radio transmission. The comment could have been recorded as a result of crosstalk from a landline that was recorded at the same time on a different audio channel in Anchorage ARTCC. However, because the original Anchorage ARTCC tape was no longer available, it was not possible to listen to the other nineteen channels in this specific time period to determine if an intelligible recording of this comment existed on another channel.

1.15.1.5 It was concluded that it was not possible to determine what was said. At that particular time, 14:34 hours, KE 007 tried to establish radio communication with Anchorage ARTCC to report passing NABIE at 14:32 hours. The report was relayed by KE 015 at 14:35 hours. At 14:34 hours KE 007 was about to penetrate the Alaskan Air Command buffer zone in the vicinity of Saint Matthews Island.

1.15.2

1.15.2.1

Tokyo ATC tape

The representatives of Japan made available the Tokyo ATC tape from 31 August 1983. The Tokyo ATC tape confirmed the radio communications between KE 007 and Tokyo Radio, and to a large extent also the radio communications between KE 007 and Anchorage Radio, because Tokyo and Anchorage Radio operated on the same HF frequencies.

1.15.2.2 The Tokyo ATC tape contained a time signal which was used as a time reference. The radio communications with Anchorage IFSS, Anchorage ARTCC, Anchorage CD/TWR/APP, and the communications at the Soviet Air Defence command centres as well as the CVR and the DFDR, were adjusted to UTC using Tokyo time.

1.15.2.3 During the transcription of the Tokyo working HF channel for the North Pacific (channel 3) twenty-two silent periods were noted between 15:59 and 18:47 hours. The silent periods varied in length: eight were less than a minute and five were over four minutes. In addition, between 18:35:25 and 18:40:10 hours, and between 18:59:09 and about 19:11:30 hours, all channels including the time signal channel were silent.

1.15.2.4

1.15.2.5

The representatives of Japan provided the following explanations on 29 April 1993:

"1. Since the channel 3 was the 'NP [North Pacific] WORKING' channel, the channel 3 will automatically be 'silent' when an operator changes the operating mode from 'WORKING' to 'GUARD'.

2. It is impossible to trace the facts on the 'silence' of all channels from 18:35:25 to 18:40:10 and from 18:59:09 to 19:11:30 because almost 10 years has passed since the tragedy."

It appeared that the radio transmissions during the silent periods on channel 3 were recorded on either channel 4 (the guard HF frequencies for the North Pacific) or channel 11 (the Tokyo- Haneda local HF frequency). A copy tape of radio communications on the Tokyo ATC tape, which had