Abstract:
In conformity with advanced cockpit automation technology,
modern pilots have become airborne system managers
and have to satisfactorily manage complex sets of tasks to
complete a flight mission safely. Funk's (1991) normative
cockpit task management (CTM) theory defines CTM functions
as the initiation, monitoring, prioritization, allocating
of resources to, and termination of multiple and concurrent
tasks.
Though pilots are equipped with highly sophisticated,
automated devices, human error is still cited as the major
cause in 60 to 90 percent of past air incidents and accidents.
Among the different types of human errors in this
setting, this study identified and classified the CTM errors
appearing in past air incidents and accidents using
the following methods: 1) study of the National Transportation
Safety Board (NTSB) air accident reports, 2) study
of the Aviation Safety Reporting System (ASRS) incident
reports, and (3) experiments using a generic two-engine,
low-to-moderate-fidelity 3-D flight simulator.
The study of NTSB air accident reports indicated that
CTM errors were present in 25 percent of 300 reviewed accidents,
and errors in the CTM task initiation category
constituted the largest relative portion (37%). In the 144
ASRS incident reports extracted from a special request
(ASRS, 1991), and from studies by Monan (1979) and Porter
(1981), 15 percent revealed prominent CTM errors, and the
largest portion of errors fell into the CTM task monitoring
category (45%) . Laboratory experimentation based on simulation
indicated that resource requirement of task context
was the most significant factor that influenced subjects'
CTM performance for the following two dependent variables:
time to initiate a task and task prioritization score. A
qualitative pattern analysis of the subjects' performances
revealed that subjects performed salient tasks first in a
serial manner.
Based upon these three error studies, design guidelines
for a Pilot-Vehicle Interface with consideration of
CTM functions were provided.
