Why are Routine Flight Operations Killing Pilots and their Passengers?
by
Robert Baron, The Aviation Consulting Group
ABSTRACT
Routine flight
operations present pilots with a myriad of latent threats. Three
accident scenarios are presented that exemplify how a routine flight
operation can end in disaster. The pilot's complex and dynamic
psycho-cognitive behaviors are analyzed and show that satisfactory
technical training alone does not make a safe pilot.
More emphasis
needs to be put on the "human system," the most likely system to fail
in flight. Recommendations address the areas where intervention and
education may mitigate some of these issues.
SCENARIO ONE
The crew had just finished recurrent training. The instructor praised
both pilots for exemplary performance in the simulator, and attested
to that fact with positive comments on both pilot's grade sheets. Both
pilots had thousands of hours of flight experience and thousands of
hours of combined time in the particular make and model they were
flying. They were back on the line the following day.
Their first leg
back on the line proved tragic, as both pilots, and 27 passengers were
killed when the aircraft descended prematurely on a non-precision
approach at night. As usual, the first question asked was "what
happened?" How could such an experienced and well-trained crew commit
this type of error, especially the day after they received recurrent
training and were commended on their skills?
This is but one
example of a routine flight operation gone terribly wrong. The pilots
had flown into this airport on numerous occasions, albeit during
daylight hours. The weather was reported to be good Visual Flight
Rules (VFR), the wind was calm, and the runway was 10,000 feet long.
Visual Approach Slope Indicators (VASI's) were available to establish
a proper glide angle to the runway threshold. But for some reason, the
crew descended below the VASI's prematurely, causing the aircraft to
impact the ground a few miles from the end of the runway. Another
classic Controlled Flight Into Terrain (CFIT) accident has occurred. A
perfectly airworthy airplane, under complete control, was flown
unintentionally into the ground without any prior awareness by the
flight crew.
This example
shows us, in its purest form, where technical training ends and human
factors begin. This type of accident occurs more frequently than one
would be led to believe. The pilots assumed this was a routine flight.
After all, the weather was good and there was nothing wrong with their
aircraft just minutes before landing.
As it turns out,
the captain, who was the pilot flying, was compelled to attempt a
night visual approach to the runway, even though the VOR Runway 17
instrument approach was briefed and set up earlier. When the first
officer queried the captain on this discrepancy, the captain replied
that he "wanted to shoot the visual approach since the weather was
good and it would save some time." That was the last discussion
recorded on the Cockpit Voice Recorder (CVR) before the sound of
impact, approximately two minutes later.
In a
macro-analysis of this accident, it was concluded that the aircraft
impacted rising terrain approximately 2.3 miles from the runway
threshold. Additionally, the aircraft was 800 feet lower than it
should have been at that point if the pilots had executed the VOR
Runway 17 instrument approach. For a technically proficient crew,
which this crew was, the instrument approach alternative would have
been routine, and the outcome would likely have had a more successful
result.
WHY?
This scenario might be considered a quintessential example of failure
in human performance. A fully trained, experienced, and competent
flight crew committed a series of errors that lead to a Controlled
Flight Into Terrain accident.
Why?
"Why?"
as it relates to aviation accidents, is a very complex and challenging
question. The attempt to analyze a pilot's cognitive thought processes
extends far beyond the scope of this paper. After all, only the pilot
can really answer the question, "what were you thinking?" We can
however, use deductive reasoning to look at where some of the problems
manifest themselves.
For the sake of
simplification, we will look at only two distinct areas: (1) training
facility weaknesses, and (2) psycho-cognitive threats during routine
flight. A breakdown in these areas can pave the way for the highest
and most undesirable event, an accident.
TRAINING FACILITY WEAKNESSES
Not enough
emphasis put on the most unreliable system in the aircraft, (the
pilot):
Pilot training on a specific aircraft can last anywhere from a few
days, up to a few months, depending on the type of aircraft. Training
facilities put a large amount of effort into teaching systems in the
shortest amount of time possible. And while the importance of good
systems knowledge is undeniably important, the most failure-prone
system, the pilot, is often overlooked or disregarded.
Crew
Resource Management training is weak or non-existent at many
facilities:
Although many training facilities have begun to incorporate a fair
amount of CRM training into their programs, some facilities do not
have the time or properly trained facilitators to make a significant
impact during a normal training period. After a 2 hour training
period, a single CRM debriefing comment by the simulator instructor to
the affect of "you should speak up more next time," does not
adequately address the problem.
Simulator
training time is too compressed. Many emergency/abnormal scenarios
that are combined to save time are unfounded and are extremely
unlikely to occur in real life:
Some facilities, in the interest of time, will combine multiple
emergency/abnormal scenarios. It is extremely improbable that a modern
airliner or business jet will experience an engine failure and a total
hydraulic failure at the same exact time, and that the pilots will
have to execute a circle-to-land approach with the weather right at
landing minimums. Yet, these are the types of scenarios that some
facilities are training and testing pilots on.
"Routine"
flight operations are under-emphasized. Yet, routine flight operations
claim many more lives than non-routine operations:
Inasmuch as the previous topic depicted an overdose of non-realistic
scenarios, this topic highlights a relatively untouched realm of
training: Routine flight operations. Realistically, engine failures,
hydraulic failures, and popped circuit breakers are not killing pilots
and their passengers. The largest number of crashes and fatalities
occur when nothing is mechanically wrong with the aircraft.
PSYCHO-COGNITIVE THREATS DURING ROUTINE FLIGHT
The next level picks up where the training ends. At this point, the
crew has satisfactorily completed recurrent training and is back on
the flight line. All incidences referenced from this point forward are
considered "in-flight."
Keep in mind that
all three-accident scenarios in this report were due to a failure in
human performance, and not a mechanical malfunction. In other words,
the problems were not easily identifiable in training, but they became
blatantly clear later on.
During flight,
the pilot's psycho-cognitive system performs like a computer,
inputting thousands of bits of information, with the associated action
commands performed as an output. Occasionally, there is a "short
circuit" in these processes and the stage is set for problems.
The following
list breaks down the events for Scenario One into CRM marker clusters,
as defined in FAA Advisory Circular 120-51D. The author has
incorporated additional clusters for clarity. Refer to the figure
below for a graphical flow of the Captain's behavioral patterns.
- Proficiency
Training-
The crew was proficient with no training weaknesses noted
- Illness/Medication-Neither pilot tested positive for alcohol
or drugs, including over-the-counter medication.
- Fatigue-The crew was well rested
- Distractions-Distractions were not considered a significant
factor in the accident.
- Stress-Stress was low. During the approach phase of flight,
stress levels will normally be somewhat elevated.
- Workload-Workload was considered routine. During the approach
phase of flight, workload will normally be highest.
- Task Management-Management of tasks became somewhat ambiguous.
A last minute change of the approach procedure by the Captain was a
factor.
- Communicative Ability-The Captain's decision to change the
approach procedure and not re-brief was the beginning of the "red
zone."
- Complacency-The Captain displayed signs of complacency. He
considered this a routine approach and the weather was good. He had
also been into that airport many times before.
- Decision Making-Complacency likely influenced the decision
making misjudgment.
- Personality Traits-Ingrained and hard to change. The Captain's
personality included a large amount of machismo, according to pilots
who had flown with him in the past.
- Risk Taking-This is the area where decision making and
machismo converge. The Captain had decided to "take the risk."
- Assertiveness-The First Officer may have had the last chance
to trap the Captain's bad judgment. However, the F/O did not speak up
and challenge the Captain.
- Situation Awareness-Due to all the previous unmitigated
behavior problems, the crew experienced a loss of situation awareness.
A perfectly airworthy aircraft was flown into the ground without any
prior awareness by the flight crew.
SCENARIO TWO
The crew
successfully completed all of the training requirements required for
an annual pilot proficiency exam. As in the first scenario, the crew,
as a whole, was highly experienced both in total flight hours and in
the specific aircraft type.
This particular
leg was a repositioning flight. Only the pilots were onboard, who were
flying the aircraft to another airport to pick up their passengers and
fly them to their destination. The repositioning flight was very short
in duration, approximately 15 min. There were no known aircraft
anomalies and the weather was considered good for the short flight.
The airport facilities were well suited for the type of operation
being conducted by this flight crew.
For some reason,
the crew decided to perform a circle-to-land maneuver (which requires
excess maneuvering to line up with the landing runway, as opposed to
straight-in). During the circle-to-land, something had gone terribly
wrong. A post crash investigation revealed that the aircraft
experienced a loss of control at a low altitude and airspeed,
indicative of an accelerated stall. Both pilots were killed. The
investigation also verified no defects to the aircraft that may have
contributed to the loss of control.
The following
list breaks down the events for Scenario Two. Refer to the figure
below for a graphical flow of the Captain's behavioral patterns.
- Proficiency
Training-
The crew was proficient with no training weaknesses noted.
- Illness/Medication-Neither pilot tested positive for alcohol
or drugs, including over-the-counter medication.
- Fatigue-The crew was well rested
- Communicative Ability-The crew had very good communicative
ability. Checklists were called for and accomplished at the right
time, briefings were thorough, and there was no ambiguity as to what
actions were going to be taken next.
- Risk Taking-The Captain was not a known risk taker. In fact,
interviews with other pilots had indicated that he was rather
"passive" and "conservative" in his flying skills.
- Complacency-It did not appear that complacency played an
active role in this accident. The fact that a circle-to-land maneuver
is not executed that often would likely have raised the pilot's
awareness of the extra vigilance required for that particular
maneuver.
- Stress-Stress levels were in a high caution area for two
reasons: 1) Pressure for a timely arrival to pick up paying
passengers, and 2) An approach that requires a higher amount of
monitoring due excessive maneuvering at low altitudes.
- Workload-The combination of maneuvering the airplane, scanning
for other traffic, and properly aligning the airplane with the landing
runway significantly increased the workload. This was the beginning of
the "red zone."
- Task Management-Task management became an extremely high
threat as the Captain, who was the non-flying pilot, became
task-saturated in both monitoring the F/O's performance, scanning for
other traffic, and ensuring proper alignment with the landing runway.
- Distractions-Pervasive distractions during the most critical
phase of the approach drew the Captain's attention away from the F/O's
dangerously slow airspeed and steep bank angle.
- Personality Traits-The Captain had a Type-B Personality.
Immediate and corrective actions, such as taking the controls of the
airplane, may have been hampered by this personality trait.
- Decision Making-This is the area where distractions and Type-B
Personality converge. The Captain decided to let the F/O continue the
approach with no apparent intervention.
- Assertiveness-Assertion on the part of the captain in the form
of "callouts" or other verbal warnings were lacking. Additionally, the
Captain never made an attempt to take over the controls.
- Situation Awareness-Due to all the previous unmitigated
behavior problems, the crew experienced a loss of situation awareness.
A perfectly airworthy aircraft was flown into a dangerous flight
regime'an accelerated stall'close to the ground'from which recovery
was not possible.
SCENARIO THREE
The third and
final scenario once again involved a highly experienced crew. In this
case a commuter operation. Their last proficiency check included
positive remarks on the captain's training record reflecting "good use
of CRM," and "excellent Situational Awareness." The first officer's
training record had included a notation "excellent flying skills,
should be considered for upgrade shortly."
Both pilots were
well rested after having the previous four days off. This was their
first flight of the day. A routine flight was forecast for the short
leg with a passenger manifest of 16 and one flight attendant. The
weather would not be a factor. As a matter of fact, it was a
remarkably clear spring day. Mechanically, there were no open
airworthiness items that could affect the safety of flight.
Approximately one
and a half minutes after takeoff, the commuter plane collided with a
small general aviation aircraft. Pilots, all 16 passengers, and the
flight attendant were killed on the commuter. Additionally, the pilot
and two passengers perished in the Piper Cherokee single-engine
general aviation aircraft.
The following
list breaks down the events for Scenario Three. Refer to the figure
below for a graphical flow of the Captain's behavioral patterns.
- Proficiency
Training-
The crew was proficient with no training weaknesses noted.
- Illness/Medication-Neither pilot tested positive for alcohol
or drugs, including over-the-counter medication.
- Fatigue-The crew was well rested
-
Communicative Ability-
The Captain's communicative ability was cause for a moderate amount of
caution. In general, he tended to be very impulsive and act without
regard to input from previous F/O's that had flown with him.
- Situation Awareness-Situation awareness was also in a moderate
caution area. Pushback and taxi to the active runway was routine and
the crew was cognizant of their taxi route, departure clearance, and
other potentially conflicting ground traffic.
- Stress-Stress levels became elevated due to the crew's
acceptance of an immediate takeoff clearance before completion of the
Before Takeoff Checklist.
- Complacency-The Captain's decision to be rushed into a takeoff
clearance may have been partially influenced by complacency. This can
be corroborated by the Captain's comment of "I've done this a thousand
times before," captured on the Cockpit Voice Recorder. This was the
beginning of the "red zone."
- Workload-During the rushed takeoff procedure, workload
increased to a point where there were so many tasks (checklist
procedures) that needed to be accomplished in such a short period of
time, that some tasks were omitted.
- Task Management-Task management was severely degraded due to
the reasons stated in the previous cluster.
- Personality Traits-The Captain's personality traits included a
Type-A Personality, which can be classified as a very high caution
area. Other pilots who had flown with the Captain described him as a
person "always in a rush to get things done."
- Decision Making-This is the area where task management and
Type-A Personality converge. The combination of the Captain's
impulsive behavior, coupled with poor task management, led to a
spontaneous and risky decision (acceptance of a premature takeoff
clearance).
- Risk Taking-Both the Captain and F/O were willing to assume
the risk of an immediate departure based on a repetitive and
successful schema ("we've done this so many times before").
- Assertiveness-The First Officer may have had the last chance
to trap the Captain's bad decision. However, the F/O did not speak up
and challenge the Captain.
- Distractions-One of the items omitted on the before takeoff
checklist was turning on the Traffic Collision Avoidance System (TCAS).
Shortly after becoming airborne, the crew continued to try to "catch
up" on the checklist items that should have been completed prior to
takeoff. Both pilots were working inside the cockpit and neither was
looking outside for conflicting traffic. Due to all the previous
unmitigated behavior problems, a perfectly airworthy aircraft was
involved in a mid-air collision.
RECOMMENDATIONS
These accident
scenarios are a classic representation of human error in its purest
form. Human performance is a complex and challenging science. More
attention needs to be focused on "why pilots do some of the things
they do (or don't do)," and what the associated consequences of those
actions might be.
Recommendations for improving the system should address the following
areas:
1. Training facilities must put more emphasis on human performance.
This might be accomplished with a stand-alone training module that
addresses this area in more detail.
2. CRM
training needs to become mandated for all flight operations
(currently, the FAA does not require Part 135 on-demand charter pilots
to have formal CRM training).
3. CRM
Facilitators should have some formal training on proper training and
debriefing methods.
4. Simulator
training should concentrate on more realistic flight and
emergency/abnormal scenarios and avoid simultaneous unrelated systems
failures, compounded by the worst possible weather.
5. During
ground school and simulator training, an emphasis should be made that
"routine flight operations" can become a significant threat and
complacency can exacerbate the problem.
6. Pilot
selection, particularly below the airline level (i.e., Part 135
charter and corporate aviation) should implement or expand on the use
of psychological testing.
7. All pilots
should be required to take a formal (credit or non-credit) course on
psychology.
CONCLUSION
In summary,
routine flight operations, as benign as it sounds, can and will
continue to be a latent threat to flight crews. Training facilities
and pilots need to increase their vigilance of this threat and expand
on safeguards and awareness training.
On a research
level, both NASA and FAA have stepped up investigation into this area.
NASA's research on Cognitive Performance in Aviation Training and
Operations, and FAA's AAR-100 Human Factors Division, continue to
provide valuable data for incorporation into aviation training
programs at all levels.
REFERENCES
Federal
Aviation Administration. AAR-100 Human Factors Division.
National
Aeronautics and Space Administration. Research on Cognitive
Performance in Aviation Training and Operations. Available at
http://human-factors.arc.nasa.gov/flightcognition/index.html.
Presented
at the Human Performance, Situation Awareness and Automation
Technology Conference (HPSAA), March 24, 2004, Daytona Beach, FL.
Mr. Baron and The Aviation Consulting Group can be reached at
www.tacgworldwide.com or 800-
294-0872.
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