曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
The evidence available does not rule out that there were no
airplane-related mechanical malfunctions or failures as only
73% of the wreckage was recovered, most of which was highly
fragmented. It is for this reason that NTSC has not made any
conclusions on this. NTSC has taken the consistent position
throughout the final report that conclusions must be backed
by evidence.
N-7
2. The accident can be explained by intentional pilot action.
a) The accident airplane’s flight profile is consistent with sustained
nose-down manual flight control inputs.
The engineering simulations just discussed indicated that manual manipulation of
the primary flight controls in multiple axes would result in a descent time history that was
similar to the last recorded radar points. Without the use of horizontal stabilizer trim, this
would require control column forces greater than 50 pounds and large control column
inputs; if those forces were relaxed, the airplane would have initiated a return to a noseup
attitude due to its inherent stability. However, the simulations indicated that a
combination of either control column inputs and/or changing the stabilizer trim from
about 4.5 to 2.5 units nose-down trim (which would have “unloaded” the high control
forces) in conjunction with aileron inputs, would result in a descent time history similar to
that of the last recorded radar points. It is important to note that the physical evidence
indicated that the horizontal stabilizer trim was set at the maximum airplane nose-down
main electric trim limit (2.5 units) at the time of impact.
Therefore, on the basis of the engineering simulations, it is very likely from the
time it departed from cruise flight until the end of the recorded data, that the airplane was
responding to sustained flight control inputs from the cockpit.
NTSC’S COMMENTS:
There is no evidence to conclude that there was manual
intervention. After the stoppage of the FDR, which occurred
before the airplane started its descent, there was no data
available on the inputs made to flight control surfaces or
engine thrust levers up to the point of impact.
b) The evidence suggests that the CVR was intentionally disconnected.
The NTSC draft Final Report states that no reason could be found for the stoppage
of the flight recorders and recommends that “a comprehensive review and analysis of
[FDR and CVR] systems design philosophy by undertaken . . . to identify and rectify
latent factors associated with the stoppage of the recorders in flight.” This
recommendation implies that the NTSC believes the flight recorders stopped because of
mechanical malfunction. However, this implied conclusion is not supported by the
evidence. Rather, the evidence suggests that the CVR was intentionally disconnected.
There is also no evidence to indicate that the digital flight data recorder (DFDR) stopped
as a result of mechanical malfunction.
N-8
NTSC’S COMMENTS:
Although it may be possible that the CVR was intentionally
disconnected, there is no evidence to suggest as such. The
evidence only showed that the stoppage was not caused by an
over load or short circuit.
The first indication of an anomaly in the flight occurred at 09:05:15.6, when the
CVR ceased recording. As further discussed later in this document in detailed comments
on section 2.6.1 of the draft Final Report, evidence (including the sound signature at the
end of the recording) indicated that the stoppage of the CVR was consistent with the
removal of power going to the unit through activation (“pulling”) of the circuit breaker,
rather than the CVR stopping as a result of a mechanical malfunction or a short circuit or
other electrical condition.3 Further, the evidence from the last recorded minutes on the
CVR indicates that during the 4 minutes that elapsed after the last meal service and before
the recording stopped, only the captain and first officer were present in the cockpit. The
HPG determined that the captain’s statement at 0904:55, “go back for a while, finish your
plate,” indicated that he was leaving the cockpit and told the first officer to finish eating.
In addition, the CVR also recorded sounds that were consistent with seat movement and
removal of a seat belt just before the captain offered the first officer water at 0905:00.
This sequence of events is consistent with the captain preparing to leave the cockpit.
The circuit breaker panel located directly behind the captain’s seat contains the
circuit breakers for both the CVR and FDR. It was determined that the cockpit door did
not open before the CVR ceased recording at 0905:15.6, thus it is evident that the captain
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NTSC Aircraft Accident Report SILKAIR FLIGHT MI 185 BOEING B(50)
