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In-Depth Information
2 The Importance of Human Role in System Operations:
Lessons Learned from United Airlines Flight 232
The more technology advanced, the more complex and complicated mechanical
products became and it sometimes went beyond the human capabilities to operate
them. Therefore, engineers moved toward automating the entire system and elim-
inate the unpredictable and unreliable humans as much as possible. Thus, when
they considered humans in their designs, it is nothing other than the mechanical
elements because their roles are only to perform as they expect.
The famous accident of United Airlines Flight 232 in 1989 reminds us, however,
how important human role is in operating a system and how wise humans can be in
making a decision when some unexpected events happen.
This plane suffered engine failures when
fl
flying over Iowa and in spite of the loss
of
fl
flight control, the crew managed to control the remaining, but failing engines and
succeeded to land the plane, although 111 died out of 296 on board.
This accident is well known as a very successful example of crew resource
management [
1
]. The captain Alfred C. Haynes told later that he and his crew were
really upset when they found out almost all engines went out. But the crew regained
their composure because the air traf
!
c controller responded in a very unperturbed
and composed manner. Then, he realized that they were not
fl
flying over the
mountains, but they were
fl
flying over the
fl
flatland of Iowa. Runways were every-
where. He thought he could
!
find some ways to bring the plane back to the ground.
This shows how emotion is important in making decisions when some critical
events happen.
What this accident teaches us is the following. Designers cannot foresee or
cannot take every precaution against accidents. They have to leave the
!
final deci-
sion to humans when something unexpected happen. Thus, they have to design a
system that leaves ample allowance for such human interventions.
What Haynes and his crew did was not taught or not trained. But they managed
to control the engines independently and brought the plane back on the ground.
Such operational management was possible because the plane was DC-10 and was
not so complicated and complex as the ones today. The engines could be managed
independently. Thus, there were still ample allowances where humans could
intervene, although engineers did not design that way intentionally. We have to
learn that making things complex or advancing technology far ahead does not
necessarily solve the solution. Sometimes, simplicity provides the key to success. In
this sense, we have to look back into the future. It is interesting to note that Boeing
is designing their planes today with allowance to human interventions or to human
decision making.
