Each aircraft had an abrupt power cut less than a second after
the loud sound on the cockpit voice recorder. The nose has come
off after it was crumpled into the cargo door hole by the 300
knot CAS wind force.
"However, the decompression event caused a data loss of approximately
2 1/2 seconds. When the data resumed being recorded, all values
appeared valid with the exception of the pitch and roll parameters.
Lateral acceleration showed a sharp increase immediately following
the decompression. Vertical acceleration showed a sharp, rapid
change just after the decompression and a slight increase as the
airplane began its descent."
NTSB AAR 92/02. page 25
"From the CVR and DFDR, AI 182 was proceeding normally
en route from Montreal to London at an altitude of 31,000 feet
and an indicated airspeed of 296 knots when the cockpit area microphone
detected a sudden loud sound. The sound continued for about 0.6
seconds, and then almost immediately, the line from the cockpit
area microphone to the cockpit voice recorder at the rear of the
pressure cabin was most probably broken. This was followed by
a loss of electrical power to the recorder."
Canadian Aviation Safety Board Air
India 23 June 1985, page 21
"When synchronized with other recordings it was determined,
within the accuracy that the procedure permitted, that the DFDR
stopped recording simultaneously with the CVR." "Irregular
signals were observed over the last 0.27 inches of the DFDR tape.
Laboratory tests indicated that the irregular signals most likely
occurred as a result of the recorder being subjected to sharp
angular accelerations about the lateral axis of the recorder,
causing rapid changes in tape speed over the record head."
Canadian Aviation Safety Board Air
India 23 June 1985, page 22
"The analysis of the recording from the DFDR fitted to
N739PA, which is detailed in Appendix C, showed that the recorded
data simply stopped. Following careful examination and correlation
of the various sources of recorded information, it was concluded
that this occurred because the electrical power supply to the
recorder had been interrupted at 19:02:50 +- second."
UK AAIB Report 2/90 Page 37
"The analysis of the cockpit voice recording, which is
detailed in Appendix C, concluded that there were valid signals
available to the DVR when it stopped at 19:02.50 +- second because
the power supply to the recorder was interrupted. It is not clear
if the sound at the end of the recording is the result of the
explosion or is from the break-up of the aircraft structure."
UK AAIB Report 2/90 Page
38
"The wire that carried electrical power from the cockpit
to the tape recorder mounted in the rear of TWA Flight 800 ran
down the right side of he airplane. The wire that carried power
to the flight data recorder ran down the left side. Yet the two
were severed within an instant, without any warning."
News Reports from Associated Press,
Reuters, major newspapers, press releases from NTSB, FBI