Human Factors in Aviation: Incident Analysis and Recommendations

This report delves into the critical role of human factors in aviation safety, analyzing two significant aircraft accidents: American Airlines Flight 965 and United Airlines Flight 173. It examines the causes of these incidents, focusing on pilot errors, crew resource management failures, and situational awareness deficiencies. The report provides a detailed account of each accident, including the sequence of events, contributing factors, and the investigations' findings. By comparing the two cases, the report highlights common themes and lessons learned, such as the importance of effective communication, adherence to procedures, and maintaining situational awareness. Ultimately, the report offers recommendations for preventing similar accidents in the future, emphasizing the need for improved training, standardized operating procedures, and a strong safety culture within the aviation industry. This work aims to contribute to a deeper understanding of human factors and their impact on aviation safety.

Human Factors in Aviation 1
HUMAN FACTORS IN AVIATION
By Name
Course
Instructor
Institution
Location
Date

Human Factors in Aviation 2
Human Factors in Aviation
Introduction
When boarding a plane for any short or long distance travelling, no one ever imagines of
any probable cause of a crash. It is a constructive thing never to worry and always have in mind
that travelling through a plane is always one of the safest means of transportation. Despite being
one of the safest means of transportation, it is also prone to most accidents. Accidents always
occur due to many reasons. Analysis of aviation accidents is often carried out in order to find out
the major reasons for the occurrence of an error that subsequently led to an accident. In the most
current situations, the analysis results are used to perform a database analysis of the previous
accidents in a bid to avoid future similar occurrences (Wiener & Nagel, 2015). The resulting
models have also been used for the purpose of future studies. In the aviation industry, several
accidents have been mainly as a result of human errors. In comparison to other causes, human
error makes up for majority of the commercial and aircraft crashes.
Literature Review
Human factors have become increasingly common in the aviation related accidents. It has
become evident to the commercial aviation industry that human error and not mechanical failure
have resulted to most aviation incidents and accidents. Flying an aircraft is often associated with
several inherent risks (Endsley & Strauch, 2017). Statistics from the department of National
Transportation and Safety Board (NTSB) have reported that general aircraft accidents have
greatly reduced over the years and the resulting fatalities have equally reduced. The decline in
commercial aircraft accidents has been very encouraging and is a major achievement in the
efforts that the relevant authorities have invested on. Despite the positive trends in aviation

Human Factors in Aviation 3
accidents, there still exist fatal accidents in various flights. Whereas unsafe weather conditions
and faulty machines play a major role in the some aviation accidents, several aviation experts
have reported that human factors are in the lead as the major causes of several aircraft accidents.
The most affected flights crashes have been the Boeing planes which represents up to 80% of the
accidents. Human error may involve mistakes made by several individuals that are directly
involved in the daily activities of managing or running a plane. This can include pilots, plane
mechanics, air traffic controllers as well as other crew members in charge of maintenance
(Wiegmann & Shappell, 2017. All these individuals are human and can make mistakes or wrong
decisions can could directly results to aircraft accidents. Reports have indicated that pilots are
more likely to make mistakes that could lead to plane crashes. Up to 90% of accidents caused by
human error have been due to mistakes or errors made by the pilots.
This report presents case studies of common fatal aircraft accidents that were mainly caused by
various human factors. It provides an analysis of the main mistakes that could have been
performed by the various individual in charge of managing the ill-fated planes. The accidents
presented several lessons to the aviation industry and the report discusses how they can be used
to prevent further occurrences of similar accidents. The occurrence of any incidence in the
aviation industry should always present a learning opportunity to the stakeholders. Proper
recommendations on the possible steps that can be taken by the relevant authorities towards
ensuring that the rates of accidents resulting from human causes are reduced have also been
discussed (Helmreich & Foushee, 2013).

Human Factors in Aviation 4
Findings and Discussions
Case studies
Cali Air Disaster: American Airlines Flight 965
The American airlines flight 965 was a scheduled flight that was regularly operating from Miami
International Airport, Miami to Alfonso Bonilla Aragon International Airport located in the city
of Cali, Colombia. On 20th December 1995, while on its regular flight, developed a failure and
crashed into the Buga Mountain in Colombia. The crash was so fatal that it resulted to the deaths
of 151 passengers and crew members. Only 4 individuals were able to survive the crash. The
crash represented the US owned 757 planes to be involved in an accident and is one of the most
fatal accidents to ever occur (Wiegmann & Shappell, 2011). The relevant Colombian authorities
performed detailed investigations to determine what could have led to such a fatal crash and the
outcome of the investigation is that the cause could be traced back to navigation mistakes by the
flight crew.
Tracing the American Airlines last flight
The aircraft was a Boeing 757-223 with registrations N651AA. It made its inaugural flight in
august 1991 being the 390th Boeing to be developed. The plane was run on 2 Rolls-Royce RB211
planes. Poor weather conditions brought by a winter storm made the flight to depart 1 hour 21
minutes past its initial departure time of 5.14 pm. The cockpit team were made of highly
experienced pilots, Captain Nicholas Tafuri and first officer Don Williams (Pronovost et al,
2014). The cabin crew were also made of individuals who had vast experience in the industry.
The air traffic controllers had no operating radar that could monitor the plane given that it had

Human Factors in Aviation 5
been destroyed by some terrorist groups way back in 1992. Cali’s strategy made use of various
radio beacons in order to direct the pilots amidst mountains and canyons that surrounded the
town. The fight management system of the plane did have the beacons programmed and they
ought to have directed the pilots on where to climb, turn and descend (Maurino, Reason,
Johnston & Lee, 2017).
Given that the weather was calm, the pilots agreed on a straight-in approach rather than going
around the runway 1 hoping that they compensate for the lost time. The pilots proceeded by
mistakenly clearing the approach waypoints from the navigation computer (Gaur, 2015). When
asked by the controller to check back in over Tulua, the pilots were not any more programmed
into the computer. The pilots therefore had to trace the location using a map (Shappell &
Wiegmann, 2011). While trying to find them, they extended the speed brakes of the plane so as
to slow it down and equally accelerate its descent. When the pilots finally located Tuluas
coordinates, they had already gone over it. They therefore tried to program the navigation
computer for the following approach waypoint, Rozo. They faced a setback given that the Rozo
NDB was identified on their charts as R but the Colombia list of waypoints did not identify Rozo
NDB as R but by its name ROZO. In situations where a state allowed duplicate identifiers, they
were mostly listed with the largest city of the country first. Choosing on the first R from the list,
the autopilot begun flying the plane to Bogota hence turning east in a wide semicircle. The plane
was already in a valley flying roughly north south and parallel to the course they should have
taken by the time the pilots noticed their mistakes. They had put the plane on a collision course
with a 3000m mountain. Close to 12 seconds before the plane reached the mountain, the system
of ground proximity warning was activated therefore announcing an upcoming collision of
terrain by sounding an alarm (Gramopadhye & Drury, 2015). The fire officer disengaged the

Human Factors in Aviation 6
autopilot within one second of the alarm, the aircraft captain made attempts to climb clear of the
mountain but unfortunately, none of them had recalled to disengage the speed brakes that had
been deployed previously thereby lowering the rate of climb. The aircraft finally crashed at 9.41
pm.
From the crash investigation report, the following factors were realised to be the major cause of
the accident;
 The failure of the flight crew to effectively plan and carry out the approach to runway 19
as well as the inappropriate use of automation
 The flight crew inexistence of situational awareness relating to vertical navigation,
closeness to terrain and the virtual location of vital radio aids (Shappell et al, 2017).
 The flight crews failure to discontinue approach into Cali despite of several alerting cues
on the inadvisability of proceeding with the approach.
 The flight crews failure to return to basic radio navigation when the flight management
system became challenging and required an extra workload in vital flight phases.
United airlines flight 173
This was a scheduled flight that traded its course on John F. Kennedy International Airport
located in New York City to the Portland International Airport located in Portland, Oregon. It
often made scheduled stops in Denver, Colorado. On 28th December while on its major
schedules, it ran out of fuel and subsequently crashed into the Suburban Portland neighbourhood.
In charge of the flight were very experienced cockpit crew made up of Captain Malbum
McBroom and first officer Roderick Beebe. The flight left Denver at around 14.47 having 189
individuals on board. It had an estimated flight time of 2 hours and 26 minutes to the next

Human Factors in Aviation 7
destination and was therefore to arrive in Portland at 17.13. From the flight plan and monitoring
system, the total amount of fuel needed to reach Portland was 31900 lbs and the plane had on
board 46700 lbs of fuel as it left Denver (Wiegmann & Shappell, 2017).
While lowering the landing gear as the aircraft approached Portland International Airport, the
crew noticed an abnormal aircraft yaw and vibration. There were also no indicator lights to
indicate successful lowering of the gear (Funk et al, 2016). The crew therefore asked for a
holding pattern in order to find out what was the problem. For close to one hour, the crew tried to
identify the landing gear status as well get ready for a probable emergency landing. While all
these procedures occurred, no crew member remembered to monitor the fuel levels. While
getting ready for the final approach for emergency landing, they lost number 1 and number 2
engines due to flameout. At this point, there was a declaration of a mayday, this being the final
radio transmission to the air traffic control. The aircraft crashed into a wooden segment of the
populated Portland suburb. The crash result to the deaths of ten individuals including two crew
members, while other experienced severe injuries (Wiegmann et al, 2015).
Crash investigation and report
The NTSB performed an investigation to determine the major cause of the crash.it became
evident that the crash symbolise a continuous problem. The problem is that of a breakdown
between the management of the cockpit and teamwork during incidences that involve aircraft
malfunctions in a plane. The main conclusion was that crew members failed to effectively relate
the amount of fuel that was left and the rate of flow for the fuel to the distance and time that they
had to the airport, this was mainly because they all shifted their attentions towards finding a
solution to the landing gear issue (Li, Harris & Yu, 2018). The captain failed to effectively

Human Factors in Aviation 8
handle fuel state of the aircraft as well as responding to the low state of fuel. This led to the
exhaustion of all the engines hence the crash.
Conclusion
The above two instances represents situations where human error led to the occurrence of fatal
plane crash. The National Transportation and safety Board have been involved in several
accident investigations of similar cause. Form their investigations; they are entitled to come up
with several recommendations and possible solutions that will ensure similar incidences never
occur in future. From the above case studies, they present a growing need to have a continuous
understanding amongst the cockpit team that will enhance quality teamwork in the occurrence of
any form of aircraft malfunction (Shappell & Wiegmann, 2015). Any breakdown within the
cockpit management increases the possibility of a lapse in concentration that could result to
error. The NTSB is equally required to issue bulletin operations to all inspectors of carrier
operations to have their assigned operators ascertain that their flight crews are well indoctrinated
with the flight resource management principles.

Human Factors in Aviation 9
References
Endsley, M.R. and Strauch, B., 2017. Automation and situation awareness: The accident at Cali,
Columbia. In Proceedings of the ninth international symposium on aviation psychology
(pp. 877-881).
Funk, K., Lyall, B., Wilson, J., Vint, R., Niemczyk, M., Suroteguh, C. and Owen, G., 2016.
Flight deck automation issues. The International Journal of Aviation Psychology, 9(2),
pp.109-123.
Gaur, D., 2015. Human factors analysis and classification system applied to civil aircraft
accidents in India. Aviation, Space, and Environmental Medicine, 76(5), pp.501-505.
Gramopadhye, A.K. and Drury, C.G., 2015. Human factors in aviation maintenance: how we got
to where we are.
Helmreich, R.L. and Foushee, H.C., 2013. Why crew resource management? Empirical and
theoretical bases of human factors training in aviation. Academic Press.
Li, W.C., Harris, D. and Yu, C.S., 2018. Routes to failure: analysis of 41 civil aviation accidents
from the Republic of China using the human factors analysis and classification system.
Accident Analysis & Prevention, 40(2), pp.426-434.
Maurino, D.E., Reason, J., Johnston, N. and Lee, R.B., 2017. Beyond aviation human factors:
Safety in high technology systems. Routledge.
Pronovost, P.J., Goeschel, C.A., Olsen, K.L., Pham, J.C., Miller, M.R., Berenholtz, S.M.,
Sexton, J.B., Marsteller, J.A., Morlock, L.L., Wu, A.W. and Loeb, J.M., 2014. Reducing
health care hazards: lessons from the commercial aviation safety team. Health Affairs,

Human Factors in Aviation 10
28(3), pp.w479-w489.
Shappell, S., Detwiler, C., Holcomb, K., Hackworth, C., Boquet, A. and Wiegmann, D.A., 2017.
Human error and commercial aviation accidents: an analysis using the human factors
analysis and classification system. In Human Error in Aviation (pp. 73-88). Routledge.
Shappell, S.A. and Wiegmann, D.A., 2011. Applying reason: The human factors analysis and
classification system (HFACS). Human Factors and Aerospace Safety.
Shappell, S.A. and Wiegmann, D.A., 2015. A human error analysis of general aviation
controlled flight into terrain accidents occurring between 1990-1998. FEDERAL
AVIATION ADMINISTRATION OKLAHOMA CITY OK CIVIL AEROMEDICAL
INST.
Wiegmann, D., Faaborg, T., Boquet, A., Detwiler, C., Holcomb, K. and Shappell, S., 2015.
Human error and general aviation accidents: A comprehensive, fine-grained analysis
using HFACS (No. DOT/FAA/AM-05/24). FEDERAL AVIATION
ADMINISTRATION OKLAHOMA CITY OK CIVIL AEROMEDICAL INST.
Wiegmann, D.A. and Shappell, S.A., 2011. Human error analysis of commercial aviation
accidents using the human factors analysis and classification system (HFACS).
Wiegmann, D.A. and Shappell, S.A., 2017. A human error approach to aviation accident
analysis: The human factors analysis and classification system. Routledge.
Wiegmann, D.A. and Shappell, S.A., 2017. A human error approach to aviation accident
analysis: The human factors analysis and classification system. Routledge.
Wiener, E.L. and Nagel, D.C. eds., 2015. Human factors in aviation. Gulf Professional
Publishing.

Human Factors in Aviation 11