Crew Resource Management
Analysis of the major causes of air crashes in the 1970’s
revealed that more than 70% of aircraft crashes involved
human error rather than failures in equipment or bad weather.
The National Aeronautical and Space Administration examined
the role of human error in air crashes and found that the
majority of aircrew errors consisted of failures in leadership,
team coordination and decision making.
In response the aviation industry developed specific training
to aid aircrew in managing their cockpit environment. This
training focused on group dynamics, leadership, interpersonal
communications and decision making. This training was to
become known as Crew Resource Management (CRM).
CRM is now the active process employed by flight crew members
to identify existing and potential threats, and the process
by which the crew develops, communicates and implements
plans and actions to avoid or mitigate perceived threats.
Whilst CRM supports the avoidance and management of human
errors, the secondary benefits of an effective CRM program
is that it improves morale and greatly enhances the efficiency
of operations.
Evidence of how CRM may have saved lives can be found in
psychologist David Myers’ Social Psychology textbook,
comparing two airline crashes in the 1980’s:
The first example which clearly depicts flawed group dynamics
occurred when an Air Florida flight took off from Washington's
National Airport on a cold winter day in 1982. Ice in a
sensor caused the speed indicators to read too high, leading
the captain to apply too little power as the plane climbed
after departure:
First Officer: Ah, that's not right.
Captain: Yes, it is, there's 80 [referring to speed].
First Officer: Nah, I don't think it's right. Ah, maybe
it is.
Captain: Hundred and twenty.
First Officer: I don't know.
In fact the First Officer was correct and muting his concerns
ultimately led to the aircraft stalling and crashing into
a Potomac River bridge, killing all but five people on board.
The second example occurred in 1989 on a United Airlines
DC-10 flight from Denver to Chicago. The three person crew
all of whom had been trained in CRM worked as a model team
in responding to a catastrophic disaster when the centre
engine fan rotor disintegrated causing the loss of all three
of the aircraft's redundant hydraulic flight control systems.
Without hydraulics the aircraft was almost uncontrollable.
A post flight investigation showed in the 34 minutes from
the incident to the controlled crash landing just short
of Sioux City Airport the crew had to devise a strategy
for bringing the aircraft under control, assess the damage,
choose a landing site and prepare the crew and passengers
for a crash landing.
Detailed analysis of the cockpit conversations revealed
intense interactions between the crew members, 31 communications
per minute peaking at one per second. During this time the
crew members recruited a fourth pilot who was flying as
a passenger, prioritized their work, and kept each other
updated of the unfolding events and decisions.
Junior crew members freely suggested alternatives and the
Captain responded with appropriate commands. The recording
contained bursts of social conversation with provided emotional
support, enabling the crew to cope with the extreme stress
of the situation.
Ultimately 185 people of the 296 passengers on board the
aircraft survived what would have otherwise been a total
disaster.
Threat and Error
Management
Threat and Error Management (TEM) is an approach to flying
that seeks to equip the pilot with the skills to recognize
and counter everyday problems which, if ignored, could result
in accidents or incidents.
There are two skill sets that are required to fly an aircraft
safely:
• technical (stick and rudder), and
• non-technical airmanship.
TEM in aviation has been likened to defensive
driving for a motorist. The purpose of defensive driving for
a motorist is not to teach people to drive but rather to drive
more safely by minimizing the risks on the road. In this situation
drivers are taught how to control skids, tyre blowouts and
other potential road hazards. TEM does not teach pilots how
to technically fly the aircraft; it promotes a proactive ethos
and techniques for maximizing safety margins in the aviation
environment.
TEM shows that threats (which could include
adverse weather), errors (such as wrong settings on instruments
or equipment) and undesired aircraft states (such as altitude
deviations) are everyday events that flight crews must manage
to maintain safety.
Pilots need to manage various complexities
in their operating environment on any flight. In TEM such
complexities are known as threats.
Threats are defined as events or errors that:
- occur outside the influence of the flight crew, that is
they are not caused by the flight crew,
- increase the operational complexity of a flight, and
- require crew attention and action if safety margins are
to be maintained.
Some examples of these threats could be adverse
weather; this could include thunderstorms, turbulence, poor
visibility etc. Aircraft issues such as problems with aircraft
systems, flight controls, engines etc. Ground issues such
as aircraft loading issues, fuelling errors, improper ground
support etc.
TEM is all about how the crew anticipate
and respond to the threats.
From a TEM perspective an error is a crew
action or inactions that leads to a deviation from crew or
organisational intentions or expectations.
The TEM framework focuses simultaneously
on the operating environment and the humans working in that
environment.
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