- - - - - -Last updated on Saturday, July 12, 2012
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Source: Flight Instructor’s
Safety Report AOPA AIR SAFETY FOUNDATION 421
AVIATION WAY, FREDERICK, MD 21701 Volume 12, No. 1 Another
Free Service of the AOPA Air Safety Foundation January
1986 Editor: Dick Gless, Vice President Operations
Contributing Editor: Bob Carter, Director, Flight Instructor Department Ralph F. Nelson, Executive Vice President
By Russell Lawton, ASF Staff and Richard Clarke and
Ludwig Benner,Jr., Events Analysis Inc. The crew of a commuter flight departed IFR for their final
destination of the day only 40 flying minutes away. Shortly after takeoff, the
left engine generator failed. The first officer incorrectly identified the
failed generator and actually disconnected the right engine generator. Despite
repeated attempts, he was unable to restore power to the aircraft's electrical
system. Although darkness had fallen, the
crew elected to continue the flight in instrument conditions believing it could
be completed with the battery power remaining. Cloud bases in the area were
2,000 feet MSL with tops at 10,000 feet. Visibility below the cloud bases was
one mile in rain and there were scattered thunderstorms in the area. Thirty minutes later (with almost
all electrical equipment shut down) the captain asked the first officer to
"Watch my altitude, I'm going down to twenty four hundred (feet)."
Minutes later, with battery power all but depleted, the captain asked, "Do
you have any instruments, do you have a horizon?" Shortly thereafter, the
aircraft struck the ground in a descending right turn. There were no survivors. Every flight forces the pilot to
adapt to changes to ensure successful flight completion. An important idea that
goes with adapting to change is the concept of "success." Some pilots
believe that a flight is successful only if it is completed from the point of
departure to the intended destination. On the other hand, seasoned aviators
know that a flight is successful as long as it ends safely either at the intended
destination or, due to circumstances beyond the pilot's control, somewhere
else. No flight can be considered successful if it results in damage to the
aircraft or injury to its occupants. As flight instructors, we must
teach our students to assess and cope with the risks associated with flying.
Pilots must understand the decision‑making
process in order to adequately assess these risks. The National Transportation
Safety Board (NTSB) tells us that 80-85% of all general aviation accidents
involve "pilot error." This is another way of stating that errors in
the decision‑making process are
involved in a large portion of unsuccessful flights. By exerting a positive influence
on the decision-making process of their
students, flight instructors can reduce the number of unsuccessful flights.
Much data has been collected and analyzed to give pilots information about
unsuccessful flight or accidents. Figure 1 lists the ten most common causes of
general aviation accidents according to NTSB.
Notice that the majority of these
factors involve decision making, reflecting the unsuccessful outcome of the
pilot's decision-making process. With this in mind, how can we help pilots use
this knowledge to reduce the odds of being involved in accidents stemming from
these causes? The decision-making process which enables pilots to
complete flights successfully is a five-step
process which can be learned and practiced. The five steps are: 1.
Recognize changes
that affect flight outcomes. 2.
Assess the
risk(s) involved due to changes. 3.
Decide what
action(s) would control the changed risks. 4.
Take action
according to the decision(s) reached. 5.
Monitor the
effectiveness of the actions. Traditional flight training
provides pilots with the necessary skills to take action once the decision‑making process reaches step 4, but
pilots usually don't receive much training in recognizing problems that may
develop, especially the self-induced problems of attitude or those caused by
outside circumstances. The commuter flight at the
beginning of this article is a good example. The crew recognized that a
generator had failed, but incorrectly diagnosed the problem by misidentifying
the failed generator. The risks involved with continuing the flight on battery
power under instrument conditions were probably ignored by at least one of the
pilots due to an overwhelming desire to return to home base for repairs. Based
on this decision, the crew elected to continue
instead of returning to the departure airport under VFR conditions or landing
at one of six other airports along their route. In the remainder of this article,
we will discuss Step 2 of the decisionmaking
process, i.e., risk assessment. In assessing risk, pilots need to have a systematic way of knowing where to look for
risk. One of the simplest and most effective
ways to think about risk is to consider it as occurring in four distinct
aspects of flying. These four areas can be considered the four basic elements
of risk in flying: — The
Pilot — The
Aircraft — The
Environment — Time Each of these basic risk elements
applies not only to the flight
itself, but also to the "mission" or reason for the flight. For
example, some risks such as unexpected
icing may be encountered during a flight, but other risks such as the desire to
reach home on a Sunday night prior to a big day at work are part of the flight
before it ever leaves the ground. The purpose of showing our
students how to develop or improve their decision‑making
skills is to give them a way to manage major and minor risks that occur
naturally as part of flying. No flight can be conducted without risk, so
decision making is a continuous process of neutralizing that risk. To apply the
decision‑making process, a
developing or potential hazard must first be detected, then the four risk elements must be reviewed. The pilot
must take action to reduce or eliminate the effect of increased risk and the action must be monitored to be sure it
works. At this point, it would be useful to consider what makes up each risk
element. THE PILOT
A pilot's performance may be affected
in many ways during a flight. The risk raisers that affect pilots are called
"stressors." The four types of pilot stressors are: Physical stress ‑ Conditions associated with the environment that affect a pilot's well
being, e.g., temperature, humidity, noise, vibration and lack of oxygen. Physiological stress ‑ Pilot physical conditions such as illness, lack of sleep, inadequate meals,
etc. Psychological stress ‑ Internal emotional conditions such as perfectionism or
stresses such as the need to make decisions, fly, communicate and navigate. Sociological stress ‑ Outside emotional stresses such as marital problems, family illnesses or deaths
and job pressures. Each of these stressors can raise
the total risk during any flight. The following
is a partial list of items we can recommend to our students to help balance or neutralize pilot risk raisers. —
Learn about stress. —
Assess yourself realistically. —
Approach problem solving in a systematic manner. —
Avoid distractions in flight. —
Keep your flight workload as low as possible. —
In emergency situations, don't rush. —
Keep current in your aircraft. —
Know the limits of your skill and condition. —
Don't accumulate concern over mistakes. Worry about
things after you land. Pilots must not only assess their
stress level, but also their ability to conduct a flight feeling adequately
prepared and qualified. First in preflight, then in flight, pilots should ask
themselves, "Have I had recent practice or instruction that allows me to fly the airplane in a proficient manner
to the places I intend to visit; and, does my proficiency meet the requirements
of the changing weather, condition of the aircraft, and other factors?"
The answer to such a question may be "no", in that case, some other
plan of action which is less demanding or uses stronger skills needs to be
developed. THE AIRCRAFT
This risk element focuses on the
aircraft equipment, its condition
and its suitability for the "mission" or intended purpose of the
flight. If IFR weather is expected, would a single radio, single VOR aircraft
without pitot heat be appropriate?
The best time to make this assessment
is on the ground during preflight
planning. During the flight, if VFR weather unexpectedly changes to IFR
weather, the same assessment must be made. If, during a preflight assessment of the aircraft and the other three
elements, the pilot decides that the flight can proceed then a continuing
process of risk assessment should begin. Another part of the aircraft
assessment would be the condition
of the aircraft. Do all of the
radios work satisfactorily? Does
the engine still develop its original horsepower? Will the fuel endurance
enable the flight to reach the intended destination with adequate reserve?
These and other questions which relate to the aircraft form part of a pilot's
assessment of the aircraft. Although
many pilots already make such an assessment during preflight planning, few
realize that it is part of a risk assessment
process. In flight, the assessment needs
to be done continuously since the conditions change with time even if nothing
dramatic appears to be happening. For example, no matter what the flight circumstances, fuel is being burned every
instant the engine runs. A successful pilot frequently compares the onboard
fuel load with the fuel required to bring the plane to a safe landing at the
destination or at a diversion
airport. THE ENVIRONMENT
This risk element is wide
reaching and includes situations outside the aircraft
which might limit, modify or affect the aircraft, the pilot and the time elements. One environmental "risk
raiser" which pilots usually consider is the weather. Considering the high
involvement of weather in fatal
general aviation accidents this definitely deserves attention. The regulations governing
aircraft operations are another
less obvious "risk raiser" that should be considered. Pilots must fly
safely and legally in compliance with FAR Part 91 and other applicable FARs.
Another environmental aspect would be the airports which may be used during the
flight. Items such as density altitude, runway length, obstacles, landing aids, etc., must be considered before and during the flight. TIME
Time risks are brought on by
other factors, e.g., fuel being consumed, pressure
to arrive by a certain time or an advancing
front. Time does not stop. This makes it slightly different than the other
three risk elements mentioned above. The passage of time can be easily
overlooked as a pilot sits in the
cockpit totally involved in a
problem and wondering how to cope with a worsening situation. In the case of
the commuter accident discussed
earlier, battery power was depleted
before the crew could accurately assess the amount of time available to power
the aircraft's flight instruments. This problem could have been alleviated by
returning to the departure airport or landing en route to diagnose the
situation. If time is short or perceived to
be short, impulsive and inappropriate actions
may result. Time can complicate an already complex situation. It doesn't just
add to the overall level of risk, it multiplies it. The less time available or
perceived to be available, the greater the negative effect on the pilot. HOW PILOTS ASSESS RISKS
Within each of the four risk
elements, the individual risks which accumulate are called "risk
raisers" since they work to raise the level of risk for the flight. In
assessing risk, pilots must be aware of the possibilities for risk accumulation
so they can determine the need for neutralizing
or balancing the risk raisers. Risk can be assessed in a number of ways. One easy way to evaluate how severe risks are and how they compare to each other is to rate them on a scale; this is similar to the familiar process of rating something "on a scale of I to 10." Since we train pilots in a variety of aviation subjects, they usually have a good sense of why one risk is greater than another. Figure 2 shows a "risk balancing beam" with risk at the right end.  Like any
other balance, the farther out the beam the risk
is located, the more severe its effect. If the center of the beam were numbered
zero and the far end were numbered four, you would have a "scale of 1 to
4." The pilot's task is to detect the risks, rate them in each of the four
risk elements, and apply balancing action on the opposite side. This achieves or regains a safe balance of risk during
flight. To
illustrate the use of this "balancing" process in risk assessment,
let's discuss the situation of a non-instrument
rated pilot who encounters deteriorating weather conditions in flight. A
non-instrument rated private pilot and his family are
returning from a weekend in New Orleans to their home in Houston, Texas, a
route he flies frequently. He prepares for the flight by estimating fuel
requirements and calculates that he can fly nonstop at 8,500 feet and still
have 45 minutes reserve since the winds aloft are forecast to be light. The
flight service station briefer indicates that a weak front will be near
Houston, but ceilings are forecast to remain above 2,000 feet with possible
isolated afternoon thunderstorms. He expects to be able to see these storms
from his relatively high cruising altitude and decides that he will be able to
go around any storms encountered en route. The
family departs at 5:00 pm, two hours late due to delay in getting the air. craft
serviced. By 7:30 pm, they are halfway home and
notice lightning flashing in the distance illuminating a large area of
thunderstorms. It is dark, and the airplane
unexpectedly flies through the edges of a few clouds. The pilot resorts to instrument
flying momentarily to get back to VFR conditions. The situation is not what he
expected. He determines that a trend has established and starts to assess the
situation. The aircraft ‑ His
aircraft is instrument equipped and everything is fully operational;
however, he is a little behind his fuel plan due to
dodging clouds. If he descends below the clouds, his fuel plan will change for
the worse due to a lower true airspeed and
groundspeed. The environment ‑ The
weather is worse than forecast. The "weak" front seems to be quite
solid and the scattered cumulus have become broken. He cannot legally fly IFR.
He doesn't know the current weather ahead and his family is getting anxious. The pilot ‑ He is not
instrument rated; his wife is not a pilot and does not enjoy flying. His last
flight training was a BFR over one year ago. They need to get home tonight
since the children have school tomorrow and he has several appointments to
keep. Time ‑ Fuel is
becoming a problem. The weather is deteriorating while they move forward
at two miles a minute. The risk factor assigned to fuel can increase geometrically
as fuel (time) remaining decreases. For example, with two hours remaining,
the risk factor might be 1, but with 20 minutes remaining, the risk factor
might increase to 3. The pilot finally starts to rate the risks listed above. On
a scale of 0 to 4, he rates the aircraft as a 2 since it's in good condition
but limited for the situation he will encounter if he continues. The environment
gets a 4 rating due to the lightning, flight through clouds that aren't
supposed to be there, darkness and the tense family situation. He rates the
pilot a 3 since he is current but not instrument rated. Time gets a 3, on a
scale of 1 to 3, since they want to get home this evening and are continuing to
fly into deteriorating conditions. With the evaluation complete, he checks the
total: Aircraft 2, + Environment 4, + pilot 3 = a total potential
risk of 9 (maximum value 12). When multiplied by the time element 3, total potential
risk is raised to 27 (maximum value 36), Note that the maximum potential risk is 12 and 9 is a fairly
high potential value. The pilot feels that the time risk is high, resulting in
an effective risk of 27 which is two‑thirds of the maximum value of 36. Based on the effective risk level, the pilot starts to
determine how he can balance his risk. The weather behind him is VFR and
there are airports with good facilities where they can spend the night. A
retreat to these airports would result in an immediate improvement in his
feeling about the environment outside, and the anxiety of his family. A
turn to better VFR conditions and a diversion to a VFR airport within
30 minutes flying achieves a
large drop in criticality since he has one‑and‑a‑half hours
of fuel remaining. Having detected the problem, assessed the risk and
identified balancers, the pilot decides to turn around. A check of the weather
confirms that Houston is under an area of severe thunderstorms. The pilot
checks the weather at the new destination and compares the time required
to his fuel remaining. This is the fifth and final step of the decisionmaking
process, i.e., monitoring the revised plan to be certain that it works. SUMMARY
Good pilot decision making depends on an understanding of,
and an ability to use, an orderly decision‑making process. We need
to convince students that being a good decision maker in aviation does not mean
acting hastily based upon "gut" feelings. With an accurate assessment
of the risks associated with each of the four risk elements, pilots are best
able to arrive at decisions that ensure a successful conclusion to a flight,
even if it means not taking off. Success in decision making is measured very
simply; the measure is maintaining the pilot, passengers and aircraft in good
health and condition no matter the airport at which the takeoff and landing
occurs. END | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||