Crew Resource Management 2
Abstract
On December 28, 1978, United Airlines Flight 173, a Douglas DC-8-6,
on the route from Denver to Portland lost the function of its right main
landing gear causing the plane to stay in the air. Improper fuel recognition
by the captain of the aircraft caused both engines to fail, leading to the
aircraft crashing 6 miles from its destination destroying an unoccupied
home. Due to the impact, 10 of the 189 passengers on board died, and 23
were seriously injured. The NTSB investigated the accident delivering causes
related to maintenance, pilot error, and crew communication. The Safety
Board’s investigation revealed that the landing gear problem was caused by
severe corrosion in the mating threads.
The corrosion combined with miscommunication and pilot error led to
the aircraft crash landing. An analysis of the case led to further research and
implementation of Crew Resource Management. To mitigate future incidents
of the same nature, CRM has been implemented and included in the training
of all crew members. This report will outline Crew Research Management and
explore the incident, its causes and preventions while exploring the
aftermath that led to advancements in CRM.
The History of Crew Resource Management (CRM)
CRM has technical origins beginning October 1927, with the first
known commercial flight when Pan American Airways flew a Fokker F-7
Trimotor from Key West to Havana. CRM is a philosophy for mitigating error
Crew Resource Management 3
and maximizing efficiency when operating an aircraft that leverages the
presence of more than one individual. (Cusick, P. 126) CRM includes any
individual or material that can have an impact on the outcome of a flight.
These individuals and materials are known as resources as CRM focuses on
the coordination of these resources to promote a safe flight. CRM was
developed to address errors that arise due to crewmembers inter-acting with
each other, be it through verbal exchange, nonverbal communication, or
assumptions of what a fellow crewmember knows or actions being
undertaken. (Cusick, P. 127) CRM is not a universally acceptable topic
though pilot and crew error are universal factors that contribute to accidents.
CRM became a known topic in the 1960s when NASA studied the group
dynamics of astronauts, but it would not become a serious issue until 1972
when a string of accidents started to occur. The string of accidents began
with Eastern Airlines Flight 401 flying into the Everglades in Florida. The
accident was a result of dysfunction in crew coordination. The Flight Safety
Foundation (FSF) and the International Air Transport Association (IATA)
convened conferences in 1974 and 1975 in Virginia and Turkey to address
the concern of human causes to commercial aviation accidents. (Cusick, P.
128) Just 2 years after the IATA conference, two Boeing 747 aircraft collided
in foggy conditions on the island of Tenerife, Spain, causing the worst loss of
life in any single accident in the history of commercial aviation. (Cusick, P.
128) A total of 583 people were pronounced deceased. One year later in
1978 United Airlines Flight 173 crashed near Portland, Oregon and would be
Crew Resource Management 4
the final straw to push for a drastic change. To further understand how
effective this final event was we will further explore the accident and the
changes made to CRM thereafter.
The Accident
December 28, 1978, United Airlines Flight 173 was making its way
from Stapelton Internation Airport in Denver to Portland International Airport.
Upon arrival at the Portland Airport, the Douglas DC-8-61 tried lowering its
landing gear, and only two of the three landing gear lights were coming on.
This signaled to the pilot that something was wrong. Instead of landing the
plane the pilot circled the vicinity of the Portland Airport to allow the crew
time to diagnose and fix the problem. After about an hour the crew decided
to prepare and conduct an emergency landing. Unfortunately, the decision
was made too late as the plane had now run out of fuel and was descending
crashing into a sparsely populated area near 158th and East Burnside Street.
The aircraft was destroyed. Of the 189 passengers on board the flight
engineer, a flight attendant and 8 passengers were killed. Of the remaining
179, 21 passengers and 2 crew members were seriously injured.
What went wrong?
The NTSB investigation concluded the following,” When the landing
gear was lowered, a loud thump was heard. That unusual sound was
accompanied by abnormal vibration and an abnormal yaw of the aircraft. The
right main landing gear retract cylinder assembly had failed due to corrosion,
and that allowed the right gear to free fall. Although it was down and locked,
Crew Resource Management 5
the rapid and abnormal free fall of the gear damaged a microswitch so
severely that it failed to complete the circuit to the cockpit green light that
tells the pilots that gear is down and locked. It was those unusual indicators
(loud noise, vibration, yaw, and no green light) which led the captain to abort
the landing so that they would have time to diagnose the problem and
prepare the passengers for an emergency landing. While the decision to
abort the landing was correct, the accident occurred because the flight crew
became so absorbed with diagnosing the problem that they failed to
calculate a time when they needed to land to avoid fuel starvation.
"The Safety Board believes that this accident exemplifies a recurring
problem --a breakdown in cockpit management and teamwork during a
situation involving malfunctions of aircraft systems in flight. Therefore, the
Safety Board can only conclude that the flight crew failed to relate the fuel
remaining and the rate of fuel flow to the time and distance from the airport
because their attention was directed almost entirely toward diagnosing the
landing gear problem."
Could the accident have been prevented?
The transcript of a Sunstrand V557 cockpit voice recorder serial No.
1427 that was removed from the United Airlines Dc-8 was reported as the
recorder used in the accident. The recorder revealed that at no point in time
did the flight crew calculate the time they had before the fuel ran out.
Several times the captain called back for the current fuel level, but it was
never communicated as to how much time was left at that current fuel level.
Crew Resource Management 6
The fuel level was communicated 3 times by the flight engineer before
engine failure which gave 3 attempts for someone to calculate or relay how
much time they had to assess the situation and get the plane on the ground.
The decreasing fuel levels were communicated to the captain several times
and each time he ignored it giving orders that would cause more fuel to be
wasted.
It was found that the crew did not contact the maintenance team until
30 min of being in the air and trying to correct the issue themselves. It was
at that time that maintenance confirmed that they had done all they could
do and at this point, the captain should have begun his landing approach.
The captain's inability to recognize how severe the situation was caused
more fuel to be wasted. The recording revealed that once the fuel was out
the engines began to fail and the captain's response to that was,” Why?” The
flight engineer who effectively communicated the fuel levels and relayed the
engine failure lost his life. After giving the captain several attempts to land
he was ignored and given a task that further wasted fuel and time. The
accident can clearly be defined as a crew coordination failure. The captain's
statement made it clear that he was very distracted making it difficult for the
flight engineer to convince him that the situation was getting dangerous
even when giving him status’s that would denote an emergency. From
reading the investigation and the transcript of the recording it is safe to say
that the crash was very much avoidable.
How did the accident change CRM?
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United Airlines was the first to adopt CRM in 1981 as it is said that the
accident became a catalyst for Crew Research Management (CRM) after it
was identified that crew communication was a key contributor to various
aircraft accidents. The United program was modeled closely on a form of
training called the ‘Managerial Grid’ developed by psychologists Robert Blake
and Jane Mouton (Blake & Mouton, 1964). CRM training included team
building, leadership skills and effective decision making. The results of the
implementation led to the FAA making it mandatory for all scheduled airlines
to implement CRM to its flight attendants, dispatchers, pilots, and
maintenance personnel with the Airforce following in 1994.
New Age Changes and CRM Implementation
Present-day, CRM methodology aims not only to eliminate, stop or
mitigate errors but also to identify and deal with the systemic threats to
security that arise in the complex world of aviation. (Daniel Muñoz-Marrón,
2018). In 1998 CRM training became mandatory for all the airlines in the
world (International Civil Aviation Organization, ICAO, 1998), yet until
recently not all crews were subject to the CRM training. The training has
transformed into an e-learning format that includes an instructor which
contrast the early annual and biannual CRM training sessions held in earlier
years. Advances in CRM have led to decreased airline accidents but Human
Error remains the top cause of aircraft accidents.
Crew Resource Management 9
Cusick Commercial Aviation Safety 6e. [VitalSource Bookshelf]. Retrieved from
https://online.vitalsource.com/#/books/9781307236965/
AC 120-51E - Crew Resource Management Training. (2019, July 26). Retrieved from
https://www.faa.gov/regulations_policies/advisory_circulars/index.cfm/go/
document.information/documentID/22879
HUMAN FACTORS IN AVIATION: CRM (CREW RESOURCE MANAGEMENT). (n.d.).
Retrieved from http://www.papelesdelpsicologo.es/English/2870.pdf
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