When the captain asks the first officer whether Hibbing’s control tower gave him
the weather, the first officer affirms it after a pause even though this did not happen.
According to the NTSB, at the time of the approach, the captain should have
made clear to the first officer what were his duties. The consequence of his failure is
indicated by a variety of orders given during the approach, distracting both pilots. At the
point the plane is scraping the trees, the following dialogue occurs:
Captain: did you ah click the ah airport lights .. make sure the co-common
traffic advisory frequency is set. [sound of seven microphone clicks]. click it
seven times?
First Officer: yup yeah I got it now. [momentary sound of scrape lasting for .1
secs]
The plane crashes.
3. DOING THE NUMBERS: MONITORING AND CHALLENGING ERRORS
In 1994 the NTSB (1994b) reviewed all serious airplane accidents between 1978
and 1990 subject to the conditions that (1) a voice recorder had to be required on the
plane, that (2) the NTSB had conducted a major investigation (limiting the number of
accidents to 75), and that (3) the flight crew’s actions were a causal or contributing
factor (limiting the number of accidents further to 37). Twenty-three of the 37 accidents
resulted in fatalities.
The NTSB found that after procedural errors, errors of the type
“monitoring/challenging” were the most common, occurring in 80 % of the accident
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