Aircraft Accident Brief Ntsb/aab-02/01 (Pb2002-910401): Egypt Air Flight 990, Boeing 767-366er, Su-Gap - National Transportation Safety Board Page 27

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The CVR recording started at 0119:13, as the flight was cleared for takeoff from
runway 22R at JFK. As previously discussed, the cessation of the CVR recording at
0150:38.47 (shortly after the FDR recorded the airplane’s loss of engine power) was
consistent with the loss of electrical power to the recorder that occurred after the engines
were shut off.
Two transcripts were prepared of the entire 31-minute 30-second recording, one in
Arabic/English words and phrases exactly as spoken on the accident flight and the other
with Arabic words translated to English. As stated previously, throughout the CVR
transcript, the Cockpit Voice Recorder Group provided as direct a translation as possible,
without attempting to interpret the words or the intent of the speaker. According to
participants in the Cockpit Voice Recorder Group (which included several Arabic/English
speakers), occasionally the direct translation of Arabic words into English resulted in
awkward or seemingly inappropriate phrases.
Cockpit Voice Recorder Sound Spectrum and Speech Studies
The Safety Board conducted CVR speech and sound spectrum studies to document
any unknown sounds and to verify and expand on the information contained in the CVR
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transcript.
The results of these studies are discussed in the following sections.
Audio Information Recorded by First Officer’s Hot Microphone
The Safety Board’s study of the CVR information recorded by the hot microphone
at the first officer’s position during the accident flight revealed that, at 0141:03, the CVR
recorded a decrease in the audio level of the first officer’s hot microphone system, and, at
0141:11, the CVR recorded a rustling sound through the first officer’s hot microphone
system. According to a member of the Speech Examination Study Group, this rustling
sound resembled the sound of the headset being stowed as the command first officer
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The Safety Board uses the following categories to classify the levels of CVR recording quality:
excellent, good, fair, poor, and unusable.
An excellent recording is one that is very clear and easily transcribed.
A good recording is one in which most of the crew conversations can be accurately and easily
understood. The transcript that is developed may indicate unintelligible several words or
phrases. Any loss in the transcript can be attributed to minor technical deficiencies or
momentary dropouts in the recording system or to a large number of simultaneous
cockpit/radio transmissions that obscure each other.
A poor recording is one in which a transcription is nearly impossible because a large portion of
the recording is unintelligible.
The quality of audio information recorded by the hot microphone at the first officer’s position is
discussed further later in this report.
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The captain apparently did not use the hot microphone system; however, depending on the nature and
volume of the captain’s communications, the sounds were recorded by the CAM.
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For additional sound spectrum and speech study information, see the Cockpit Voice Recorder Group
Chairman’s Factual Report/Sound Spectrum Study and the Speech Examination Study Factual Report.
NTSB/AAB-02/01

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