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Had you taken Groundschool for a pilot licence 20 years ago, this section in this course would not have appeared.  At that time, decisions made by pilots were not considered to be a “technical” component of aviation safety.  Fifteen years ago, however, commercial aviation—and in particular large commercial “transport” aviation—was just coming to terms with an extremely unfortunate incident that occurred in the Canary Islands, a small group of resort islands located off Morocco; this incident would forever change the way pilots, and especially air transport pilots, would be trained.  Transport Canada, like all civil aviation regulators world-wide, quickly instigated a program to train pilots that sound decision-making skills were fundamental to aviation safety—so much so that pilot decision-making became a mandatory component for recreational, private, and commercial groundschool training.


What happened in the Canary Islands off Africa is now legendary in the aviation community. [1]  At about 5 p.m. on the afternoon of March 27, 1977, two Boeing 747s collided on a runway at Los Rodeos Airport on the island of Tenerife.  Within seconds, the lives of 583 people were extinguished.  The cause—a Senior Captain with KLM Royal Dutch Airlines—with an astounding 30-years experience with that Airline—was in a hurry.

Airlines served the heavy tourist traffic in and out of the Canary Islands by way of Las Palmas Airport on Grand Canary, but in the early afternoon of March 27th a terrorist bomb exploded in the terminal.  Shortly after the explosion a bomb threat was received by the airport authorities regarding a second bomb, and Las Palmas Airport was quickly closed, forcing in-bound traffic to divert to the much smaller and ill-equipped Los Rodeos Airport on Tenerife.  By the time the KLM 747 arrived at Los Rodeos, the ramp and apron facilities were crowded aircraft bound for Las Palmas Airport, and conditions became even more difficult when a Pan American 747 arrived a half-hour later after being diverted on its trip from New York.

As flights became diverted, the facilities at Los Rodeos became overtaxed, and the pressure began to mount on the shoulders of Captain Jacob Veldhuyzen van Zanten, KLM’s chief training captain on the Boeing 747s.  Captain van Zanten’s responsibilities included ensuring that he and his crew’s “duty time”—the time that a flight crew remains at work without rest—did not expire.  If the duty time reached the allowed limit established by KLM, the crew would not be able to leave Los Rodeos until after an overnight rest.  He would have to find short-notice accommodation for his 234 passengers at considerable expense and inconvenience for the airline; Las Palmas Airport might not be re-opened before his crew’s duty time expired at 6 p.m. that afternoon.

The two 747s were parked tightly together on ramp bay near the threshold of the one runway that served Los Rodeos; when Las Palmas airport did re-open and aircraft began to depart, the positioning of the two 747s was such that the PanAm 747 could not taxi for takeoff until after KLM 747 taxied.  Earlier that afternoon, Captain van Zanten made the decision to refuel his aircraft, anticipating that there would be delays later when back-logged aircraft converged on Las Palmas.  As a result, when Las Palmas did re-open and aircraft began departing from Los Rodeos, the PanAm crew had to wait an additional 35 minutes while KLM aircraft was refuelled.  To add to the strain situation, the weather at Los Rodeos began to deteriorate as fog began to move in from off-shore.

At 4:30 p.m. the KLM requested a taxi clearance, but by this time the runway was almost entirely obscured by the fog with visibility fluctuating around 900’.  Because of the taxiway configuration, the PanAm 747 would have to follow the KLM 747, requiring that both would have to back-track (taxi) on the active runway.  When the PanAm crew contacted the tower controller as instructed, the visibility was such that the tower controller could not see the runway, and the PanAm crew cold not see the KLM aircraft which they were instructed to follow.  Now language became a factor as no longer could the crews and the controllers co-ordinate with one another using visual information.  While the controllers spoke English with heavy Spanish accents, the KLM crew spoke English with a Dutch accent.

While the controller instructed KLM to taxi back to position on the far end of the runway, the PanAm crew was instructed to leave the runway on the third taxi-way exit on the left.  The PanAm crew, however, was having difficulty identifying the taxiway intersections in the fog, not being sure of the number of taxiways they had passed.

At five minutes after 5 p.m. the KLM crew had reached the far end of the runway and had turned to position the aircraft for the takeoff roll.  As evidenced in the Cockpit Voice Recorder and the Flight Data Recorder, Captain van Zanten inexplicably advanced the thrust levers as soon as the First Officer completed the pre-takeoff checklist and the KLM aircraft began to move in the direction of the departure.  The PanAm 747 was still taxiing up the runway, but was now obscured from the view of the KLM crew owing to the fog.  “Wait a minute . . we don’t have an ATC clearance,” responded the KLM First Officer.  “No . . I know that,” responded Van Zanten, holding the 747 back with the brakes, “Go ahead and ask.”

The First Officer contacted the tower, reporting the KLM 747 was ready for takeoff.  Recordings of the transmissions indicate the Tower Controller responded by providing the KLM with its IFR routing clearance, but did not clear the KLM for takeoff.  But as the First Officer was reading back the routing clearance, van Zanten released the brakes and again advanced the throttles—this time to the takeoff-power setting.  The KLM was six seconds into its takeoff roll when the First Officer added: “. . we are now at takeoff.”  The Tower Controller responded: “Okay . . standby for takeoff . . I will call you.”

After Tenerife, the astounding trend became evident.

  • Back in 1970 an Overseas National Airways DC-9 ran out of fuel over the Caribbean and was forced to ditch at night—22 died; the cause was the crew’s miscalculation of fuel consumption.

  • In 1972 an Eastern Airlines DC-10 descended inadvertently into the Florida Everglades while distracted by a cockpit light bulb that failed to indicate the landing gear was down, killing 99 people, but leaving 77 survivors (.

  • In 1978 a United Airlines DC-8 ran out of fuel while making an approach into Portland International Airport.  The crew elected to circle south of the airport for almost one hour attempting to deal with a faulty landing gear problem.  Only 10 of the 189 occupants were killed, primarily because the cabin crew was already prepared for the planned emergency landing on the runway.

These are all but a few of the more dramatic cases of faulty pilot decision-making.


[1]  My comments on the Tenerife are based on the descriptions and analysis made by Macarthur Job in his excellent and highly recommended Air Disaster, Volumes 1 & 2 (1996, Fyshwick: Aerospace Publications Pty Ltd); there were many factors attributed to this infamous event at Tenerife and they are well documented and discussed by Job (see pp. 164-180 of Vol. 1).

What about you?

If you have not previously noticed local aircraft accidents reported on TV news or in newspapers, your decision to pursue a pilot licence will certainly change all that.  Stories or reports of missing aircraft or aircraft “crashes” have little meaning for the public (although they certainly grab the public attention—at least initially).  For you, however, this will change.

What about you?

As you hang out at airports, and develop your friendships with other pilots, you will eventually observe that pilots spend a lot of time doing “armchair” analysis of aircraft accidents and incidents; at the root of this is their desire to know about an unfortunate event so as to educate themselves.  They seek to ensure by casual, informal analysis that they do not suffer the same fate.  They use these occasions “gossip” and “hearsay” to reaffirm among themselves their safety practices, and to learn about what Donn Richardson calls the “gotchas” (hazards) of flying.  (Donn Richardson is a  Retired Transport Canada Inspector, Flight Instructor, a professional aerobatic pilot, and a former DC-3 pilot)

It is said by old pilots that, if you hang around aeroplanes long enough, you will see one bent.  Anyone who has seen a bent aeroplane knows how oddly “unrecognizable” they look, how they appear as tattered sheet metal, with little semblance of order and structure.  So if the old pilots are true, what can we do to stay out of trouble?  The solution is simple—learn from the mistakes of others, and never let it happen to you.  Is it really possible to ensure it doesn’t happen to you?  You bet it is.  A safe pilot is a pilot who is in control of every aspect of a flight.  He or she is the Pilot-in-command, and the command authority is rooted in the basic rule that the pilot can take whatever action is necessary for reasons of safety.  In developing your command authority as student pilot, assert command and control authority.  Practise your ability to effectively analyze situations related to flight operations, and develop your sound decision-making skills.  Take control aggressively to avoid potentially hazardous situations.

With command authority, there is privilege; but with this privilege there is responsibility.  You will learn the safety rules and rituals of flying—always get a weather briefing, always dip your fuel tanks prior to flight, always use a pre-takeoff and pre-landing checklist, set and never violate personal weather minimum, etc.—and these rules are crucial.  But the question remains—what happened to van Zanten?  And what could have caused all those other professionals to make simple errors in predicting fuel consumption.  Were they aware of the dire consequence of their decisions?

Human Factors and Pilot Error

Human Factors denotes the manner in which people relate and interact with their environments.  In the case of aviation, the focus is on how pilot performance is influenced or affected by such issues as cockpit design, temperature, altitude, physiology of the body, emotions, interactions, and communications.

Human Factors and Pilot Error
Accident and Incident Reporting

The Transportation Safety Board of Canada is responsible for investigating all transportation occurrences in Canada, including aviation occurrences.  The goal of an aviation safety investigation is to prevent recurrence.

Pilot Error is defined as the action or decision of the pilot that, if not caught or corrected, could contribute to the occurrence of an accident or incident, including inaction or indecision.

Accident and Incident Reporting

An aviation occurrence is any accident or incident associated with the operation of an aircraft.

A reportable aviation accident is any accident resulting directly from the operation of an aircraft where a person sustains a serious injury or is killed, or an aircraft sustains damage or failure that adversely affects the structural strength, the performance or flight characteristics of an aircraft, resulting in the need for major repair or replacement of any component parts.  A missing aircraft is also a reportable accident.

An incident is reportable only if it concerns the operation of an aircraft with a maximum certified takeoff weight of 12500 lbs.—the Piper Cherokee, for example, has a maximum certified takeoff weight of 2150 lbs., and this is typically of general avaition private aircraft.

The actions that must be taken in reporting a “reportable” aviation accident are described in the AIM, GEN 3.3.

It is required that no person displace, move, or interfere with an aircraft involved in an accident, except to extricate persons, or to prevent destruction by fire, or to avoid danger to any person or property.

Accident Rates
Accident Rates

Statistics demonstrate improvement in safety—at least this is the general trend based on records kept since World War II.  In 2001, the Canadian accident rate was 7.6 accidents per 100,000 hours flown, and less than 2 fatal accidents per 100,000 hours flown.[2]  Transport Canada reported for 2001 that there were 167 private aeroplane accidents in Canada, with 17 of these accidents involving fatalities.[3]  Pilots are generally considered to be the “cause” or “factor” in 84% of all accidents; in fatal accidents, pilot-related cause increases to 90.6%.[4]

[2] Transportation Safety Board of Canada’s Statistical Summary—Aviation Occurrences, 2001, P. 1.


[3] Ibid., P. 2.


[4] Ibid.


Accordingly, if a private or recreational pilot has a one-hour flight, once a week, he or she will have to fly for 148 years continuously before an accident is experienced.  The same person will have to fly continuously for 1584 years before experiencing a fatal accident.

Exposure to Accident Risk

The depiction above relates accidents to the phase of an average flight.  There are two obvious but significant observations here—accidents are most likely to occur during approaches and landings, and it is the landing phase—at the end of the flight—where the workload and fatigue factor are at their maximum.

Consider the depiction below showing what may be described as the normal decrease in safety margin during the course of an average flight.

Exposure to Accident Risk


Below is a table showing the cause of accidents that occurred between 1992 and 2001, relative to the phase of flight, and the first event that gave rise to the accident.  The numbers further emphasize the increased exposure to risk associated with takeoffs and landings.  Note that the landing risks are associated with events not associated with control or power loss, while these causes are prominent with takeoff accidents.  With respect to en route causes, note the significant risk from power loss—be cautious with fuel planning, and be sure to stay current in forced-landing (power-off) skills.

Accident Pilot Profile and Risk​

  • The pilot involved in the average accident is likely to be between 35-39 years of age.

  • The pilot involved in the average accident is likely to have between 100 and 500 hours flying experience.

  • The pilot is likely to be on a VFR personal flight.

  • The risk of acccident is highest 50 hours after receiving Private Pilot Licence;

  • The risk of accident is highest 50 to 100 hours after receiving Instrument Rating.


What accounts for the increased risk of an aircraft accident?


  • At the completion of a training program, students have a high level of skill and confidence, but have very little experience.   

  • Exposure to risk increases rapidly following training, as pilots are no longer in the protective cocoon of the training program where risks are monitored and controlled.  

  • Despite confidence, new initial pilots or newly rated instrument pilots have not yet developed the experience, knowledge, and skill to recognize and manage the increased risks of IFR flight.

Accident Pilot Profile and Risk​
Use of Checklists

It is estimated that as much as 70% of all accidents in which pilot error was a primary error could have been prevented with the use of checklists.

Checklists eliminate forgetfulness.  Everything you need to know is on the checklist, and the stress of any situation—where normal or non-normal—cannot change what is on the checklist.  A cockpit procedure is more likely to be completed safely by using a checklist than by relying solely on memory.

Disorientation—178 Seconds

What is experienced by pilots who inadvertently fly into cloud?  The following is published by Transport Canada in one of its safety-promotions brochures—Take Five for Safety:178 seconds— which describes (quite dramatically, actually) what could happen:

If you’re ever tempted to take off in marginal weather and have no instrument training, read this article before you go.  If you decide to go anyway and lose visual contact, start counting down from 178 seconds.

How long can a pilot who has no instrument training expect to live after he or she flies into bad weather and loses visual contact?  Researchers at the University of Illinois found the answer to this question.  Twenty student “guinea pigs” flew into simulated instrument weather, and all went into graveyard spirals or rollercoasters.  The outcome differed in only one respect: the time required until control was lost.  The interval ranged from 480 seconds to 20 seconds.  The average time was 178 seconds—2 seconds short of 3 minutes.

Here’s the fatal scenario:

The sky is overcast and the visibility poor.  That reported five-mile visibility looks more like two, and you can’t judge the height of the overcast.  Your altimeter says you’re at 1500 but your map tells you there’s local terrain as high as 1200 ft.  There might even be a tower nearby because you’re not sure just how far off course you are.  But you’ve flown into worse weather than this, so you press on.

You find yourself unconsciously easing back just a bit on the controls to clear those non-too-imaginary towers.  With no warning, you’re in the soup.  You peer so hard into the milky white mist that your eyes hurt.  You fight the feeling in your stomach.  You swallow, only to find your mouth dry.  Now you realize you should have waited for better weather.  The appointment was important—but not that important.  Somewhere, a voice is saying “You’ve had it—it’s all over!”

You now have 178 seconds to live.  Your aircraft feels in an even keel but your compass turns slowly.  You push a little rudder and add a little pressure on the controls to stop the turn but this feels unnatural and you return the controls to their original position.  This feels better but your compass is now turning a little faster and your airspeed is increasing slightly.  You scan your instrument panel for help but what you see looks somewhat unfamiliar.  You’re sure this is just a bad spot.  You’ll break out in a few minutes, but you don’t have much time left.

You now have 100 seconds to live.  You glance at your altimeter and are shocked to see it unwinding.  You’re already down to 1200 ft.  Instinctively, you pull back on the controls but the altimeter still unwinds.  The engine is into the red and the airspeed, nearly so.

You have 45 seconds to live.  Now you’re sweating and shaking.  There must be something wrong with the controls; pulling back only moves that airspeed indicator further into the red.  You can hear the wind tearing at the aircraft.

You have 10 seconds to live.  Suddenly, you see the ground.  The trees rush up at you.  You can see the horizon if you turn your head far enough but it’s an unusual angle—you’re almost inverted.  You open your mouth to scream but . . . . . . you have no seconds left.

Disorientation—178 Seconds
Use of Checklists

Hypoxia is when the cells of the body do not receive enough oxygen; a person who suffers from this is said to be hypoxic.

The form of hypoxia most commonly experienced by pilots is when there is not enough oxygen in the lungs, or when the lungs are unable to transfer oxygen in sufficient amounts to the bloodstream.[1]  Here is a description of the condition:

In all (cases) . . the net effect is the same—reduced oxygen to the body, more importantly to the brain and eyes, causing a reduction in performance capability.  As hypoxia increases, you become less and less able to function properly both mentally and physically.  Mentally, as less oxygen reaches the brain, your thinking becomes confused and you are less able to make good judgement calls.  Physically, your body increases its respiration in an attempt to get more oxygen.  You may also start to feel dizzy and nauseous and perhaps get a headache.  You also start losing motor-skill co-ordination and, in extreme cases, may pass out completely . .     Hypoxia is an insidious problem in aviation; its effects creep up on pilots without their knowing it.  Compounding the problem is the fact that one of the symptoms is a feeling of well-being; not only does hypoxia impair your ability to fly well, but it also makes you feel good at the same time.  How you perceive your performance may be quite different from how everyone else sees it (Transport Canada’s Human Factors for Aviation—Basic Handbook, Pp. 46-47).


[5] This is referred to as hypoxic hypoxia, while a second form of hypoxia—anemic hypoxia—is when there is sufficient oxygen in the lungs, but the blood is unable to distribute it to the body in sufficient quantities.  Anemic hypoxia occurs in carbon monoxide poisoning.


Hypoxia is practically measured by the time at which a person can maintain useful consciousness—function with reasonable competence.  As you can see in the table below, performance ability decreases rapidly with altitude.


The more physically active you are at altitude, the shorter the time of useful consciousness.

Smokers have shorter useful consciousness time—an altitude of 5000’ the symptoms and effects for a smoker are equivalent to those experienced by a non-smoker at 10000’.

Empty-Field Myopia

Two aeroplanes, a Piper and a Cessna, were flying straight and level on a cross-country flight at an altitude of 1500’ AGL.  Neither aeroplane was under radar contact.  Visibility conditions were seven miles in haze.  The two aeroplanes collided almost directly head-on.  There were no survivors.

Empty-Field Myopia


  • The haze conditions produced empty-field myopia in both pilots’ eyes.  Therefore, each aeroplane appeared smaller and more distant than it actually was.  With limited visibility, the danger did not become apparent until it was too late for evasive action.

  • Since the frontal area of the aeroplane profile is small, an aeroplane viewed directly from the front shows little relative movement.  Hence, detection by either pilot was difficult (Transport Canada’s Human Factors For Aviation—Basic Handbook, Pp. 77-78)

A pilot who experiences empty-field myopia is a pilot who is unable to see an aircraft in the distance, despite the unrestricted visibility.

To see something, the lens of the eye must be capable of physically focusing light from the object on the retina.  To do this, the eye must be stimulated by an image.  If the eye lacks this stimulation, the lens shifts to a resting state some three to five feet away.

When the sky is featureless—as is the case with unrestricted visibility, with hazy conditions, or dark night conditions—you effectively become near-sighted when you look out the windows as your eyes tend to resort to their natural resting state.

To counter empty-field myopia, it is a good practice to focus quite frequently on your own aircraft wing tips.  Also, when scanning, focus on distant visible objects or outlines at or near the horizon, stimulating the eyes to establish long-distance focal points.

Collision-Course Detection

Consider that a target (another aircraft) on a collision course appears fixed and increasing in size to the observer.  Changes in size are difficult to perceive, so a pilot who observes any fixed target should first immediately alter course, then assess its direction.

Collision-Course Detection

The Pilot Decision-making Process

When faced with a non-normal or critical event, effective management by the pilot will require an effective decision-making process that maximizes the potential for successful resolution.  Here are the phases of effective decision-making process:

The Pilot Decision-making Process


A situation is the set of circumstances that the pilot is faced with.  More specifically, the situation—insofar as we are concerned with here—is critical, and therefore the decisions made are critical.  The most important aspect of this part of the decision-making process, however, is that the pilot must be first aware of the impending critical situation.  Once you are aware of the situation, you can begin to find a remedy—if you are not aware of an unfolding situation, you cannot even get to first base.


The classic example of this is controlled flight into terrain—CFIT.  In all of the CFIT accident cases, the pilots were clearly not aware of the critical circumstances with which they were faced.  Quite a few years back, a Canadian Armed Forces C-130 flew into terrain in a controlled fashion while on approach into Alert.  The incident occurred at night and the pilot, still many miles back from the airport, had visual reference of the distant airport.  Surrounding the airport was utter blackness.  As the aircraft gradually descended dangerously close to the ice ridges, one of which the aircraft eventually made contact with, there must have been a period of time—albeit short—when the ridges where zipping past just below the aircraft fuselage.  The pilot, however, was not aware of the situation.

Perhaps the most classic case of CFIT is the Eastern 401 accident, which is presented below as a case study.  Here the transcript from the minutes leading up to ground impact are truly indicative of the factors that can conspire to make pilots unaware of the deadly situation in which they eventually—perhaps just before impact—find themselves.  Nevertheless, we must remember that the pilot decision-making process requires that the pilot is first aware of the situation—he or she must have situational awareness.  If we are not aware, we cannot begin to resolve matters towards a favourable outcome.  If there is situational awareness, the rest of the problem is quite straightforward and natural.


Once a problem occurs, and you are aware of it, the most important thing is to give yourself as many options as possible.  Two things to note here, the first is that options are—when faced with a critical situation—like gold.  The more options you have, the better your chances of a successful outcome.  Remember, options are often merely ideas which, when first considered as an option, may or may not be viable.  Further brain-time must be spent on them so that the outcome can be predicted.  Some options are better than others, so the more options you can think of, the greater the likelihood of success.  Sometimes, though, there is only one option and choice is therefore not involved—a classic example of this is an emergency forced approach resulting from a catastrophic engine failure.  There is only one option and you must follow it through successfully.  But single-option situations are incredibly rare birds.  Since they are so rare, you should be skeptical if you feel your options are limited—perhaps more options exist that you have not considered.


Assess risk and choose a course of action.  If the “option” phase of the decision-making process is based on creative ideas, the “choose” phase is based on creative assessment.  Again, this is a higher brain process, involving reason, and prediction.  If panic forms the basis of any choice, the rational assessment process is undermined.


Time is important.  A pilot encountering airframe-icing conditions without counter-icing equipment has only seconds to react.  Even in less critical circumstances, however, time is in fact a scarce resource for all pilots—time is related to fuel consumption.  On every flight there is only so much time you can spend in the air.  Be sure to take action before time—and fuel—runs out.

A second interesting feature of options is that they are the product of the “higher” brain—the cerebral cortex.  The cerebral cortex is designed to shut down and give way to the lower brain in moments of panic.  The cerebral cortex, for example, allows you to predict and reason that the chances of successfully defending yourself against a grizzly bear are in fact quite small—the size, the teeth, the strength, the claws, etc.  This is a reasoning process.  In contrast, a panic response is a “lower” brain function, which shuts-down the reasoning process—panic is powered by adrenaline, not reason, and therefore undermines the rational assessment of options. 


Time limits can take other forms.  After an alternator or generator failure, there is only so much electrical energy in the battery.  While battery energy may not be consequential to a day VFR flight, it would become critical for a night VFR or IFR flight.  Daylight is certainly a scarce resource for the float-plane pilot.

Time can also be controlled by the pilot.  Consider the decision to proceed on a cross-country flight into mountainous terrain.  The pilot who presses on to have “look-see” is suddenly placed in a time-limited environment, while the pilot who takes the time to sort out weather data prior to launch has all the time in the world.


Has the selected action been successful?  Once an act is committed, a new situation presents itself requiring new decision-making.

Loss of Situational Awareness

One of the greatest risks a pilot has when faced with a problem is that the pilot is simply not aware a problem exists.  This undesired state is referred to as loss of situational awareness.  Loss of situational awareness is like the boogieman sneaking up behind you—danger is imminent, but you are pleasantly unaware of it.  What are some of the causes of loss of situational awareness that pilots have become victims to?

Loss of Situational Awareness

Loss of situational awareness can be caused by something as simple as inattention.  A pilot is not aware of the 12 o’clock, 1-mile target on a mid-air collision course because he or she hasn’t been attentive in maintaining a traffic watch.  A pilot not supervising the refuelling of the piston-engine aircraft is not aware that jet fuel has been loaded into the fuel tanks.  A pilot inattentive during the pre-flight inspection is not aware that heavy rains and poor gas cap seals have conspired to put dangerous quantities of water in the fuel tanks.

Previous Experiences

Loss of situational awareness is certainly a function of experience and training.  A pilot from the prairies crosses the Straight of Georgia at 100’ ASL, oblivious of the hazards of having to ditch an aircraft in the water—unaware of how difficult it is to egress a dark, inverted cockpit that is submerged underwater.  A pilot on a fresh instrument rating is possibly unaware of just how rapidly dangerous amounts of ice can form on a aircraft after entering large cumulus clouds above the freezing level.  We can, of course, go on and on.

False Assumptions

An even more profound cause of loss of situational awareness is false assumptions.  In every one of the case studies reviewed below in this section, it is clear that the perceptions of every member of flight crews was undermined by false assumptions—the crew of PSA 182 thought they were clear of the Cessna 172, the crew of Eastern 401 thought the autopilot was still controlling the aircraft’s altitude.

Previous Experiences
False Assumptions

Here are some of the factors that are commonly at the root of false assumptions:

Ignoring bad news—e.g., subconsciously changing bad-news information into messages that are preferred.  This too is an element in PSA 182.  This is also a classic form of this cause is “gethomeitis

Extreme mental workload—after period of intense concentration, poor decisions are possible—e.g., after fighting bad weather a pilot lands downwind.

Fixation—e.g., you focus on one item while something more significant goes unnoticed—e.g., a warning light causes loss of control.  This is the central theme of the Eastern 401 disaster.

Great expectations—e.g., you hear what you want to hear and see what you want to see.  Watch for this in PSA 182.  We tend to shape our reality to fit our expectation.

Great expectations
Ignoring bad news
Extreme mental workload


Physical stressors: hunger, temperature, noise, vibration, lack of oxygen, being tired, poor physical fitness.

Physical stressors

Diminished capacity to cope: during a normal flight, pilots are exposed to variable demands.

Mental stressors: death, sickness, demotion, economic, workload.

Mental stressors
Diminished capacity to cope

Compromised safety margins: as demands increase, the safety margin between the work required to meet those demands and pilot capacity to perform the work decreases.

Compromised safety margins

Accumulating incomplete tasks:  remember, demands can pile up—e.g., an emergency during an approach.  Trouble occurs when demands of a task exceed ability to deal with them.

Accumulating incomplete tasks

Flight or fight response: stress often invokes an arousal response—flight or fight. Insufficient arousal causes boredom, while too much causes panic.

Flight or fight response

Common responses to stress:

  • Omission—failing to respond to a signal—a radio call or warning light.

  • Error—responding incorrectly.

  • Queuing—delaying certain tasks because of workload.

  • Approximation—accepting lower standards of accuracy and performance.

  • Fixation—concentrating on one item while ignoring another.

  • Regression—reverting to an earlier procedure or action.

  • Tremor—trembling or shaking caused by increased muscle tension.

  • Escape—giving up, panicking, and freezing at the controls.

Common responses to Stress
Cockpit stress management Rules of Thumb

  1. If an emergency does occur, BE CALM—think for a moment, weigh the alternatives, choose one, and then act.

  2. Remember that fear and panic are your greatest enemies during an in-flight emergency.

  3. Don’t hesitate to declare an emergency.  Let other people, including passengers, know about your situation.

  4. Don’t delay until it is too late.

  5. If you feel tension mounting, loosen your collar, stretch your arms and legs, open air vents.

  6. Don’t hesitate to ask ATC for help.  Lots of ground resources are available.

  7. Experienced passengers can be asked to look for landmarks and traffic.

  8. If you make a mistake that you subsequently correct, forget about it and concentrate on the task at hand.

  9. Focus on the situation, not the emotion.

  10. Always have a “plan” and an “alternate plan,” and leave yourself an “out.”

Cockpit stress management Rules of Thumb
Risk Management and the Pilot’s Checklist

Pilots should expand their concept of “being ready” for a flight; here is a wholistic pre-flight checklist for this purpose:


Do a pre-flight inspection on yourself.  Are you healthy?  Are you current?


Weight and balance.  Takeoff and landing performance.  Cross-wind limitations.  Navigation equipment.  Survival gear.


Weather; runway length; navigation aids.


Different operations impose different risks.  A pilot on a medevac assesses risk differently from a pleasure flight pilot.


The above risk areas compose a “situation.”  Upon considering them, fly accordingly.

Deal yourself a good hand: begin the above evaluation with a closed fist and raise one finger for each risk element that you believe is safe for the flight.  If you end up with less than a full hand, act accordingly.

Risk Management and the Pilot’s Checklist
Hazardous Attitudes

Here are some attitudes to flying you want to avoid:


Don’t like being told what to do.  This leads to rule and regulation violation; rules, regulations and procedures become unnecessary.  Antidote: follow rules; they are usually right.


When faced with a decision-making situation, the need to do something, anything, immediately.  There is a lack of careful consideration.  Antidote: don’t act so fast; think first.


“It won’t happen to me.”  You are therefore more likely to take chances.  Antidote: think that it can happen to you.


Proving you are better than someone else.  Antidote: “Taking chances is foolish.”


Good luck versus bad luck.  You can’t make a great deal of difference as to what is happening to you—leave the actions to others—for better or for worse.  Just be nice and go along with unreasonable requests.  Antidote: don’t feel helpless; you can make a difference.

Hazardous Attitudes

Case Studies

Case Studies
PSA 182 (Pacific Southwest Airlines), Lindbergh Field, San Diego, September 25, 1978

The following are transcripts of dialogue that precedes the collision between Pacific Southwest Airlines Flight #182 and a Cessna 172 over San Diego.[6]  The dialogue is reconstructed using recorded radio communications and the Boeing’s Cockpit Voice Recorder.  To establish the context, the Cessna is a training flight practising instrument flying near Lindbergh Field (San Diego’s main airport).  The sky is clear and the weather pleasant.  On board are an Instructor and a Commercial Pilot Student, and they are practising instrument approaches[7] at the Lindberg Field facilities.  The Boeing 727 is inbound to Lindberg Field after a short flight from Los Angeles.  Initially, the Approach Controller is working both aircraft.  Note that the PSA crew leaves the Approach Controller’s frequency and contact the Tower Controller at Lindberg Field.  Thus, the pilots of the two aircraft end up talking to different controllers on different radio frequencies.

PSA 182 (Pacific Southwest Airlines), Lindbergh Field, San Diego, September 25, 1978

[6] My information here is based on the great works of Macarthur Job, Air Disaster (Ibid) (see pp. 23-35 of Vol. 2).


[7] The student pilot is practising flying the aircraft for an approach just above the runway using only radio navigation displays inside the cockpit.  The student will likely be under the hood, while the Instructor keeps an eye out for other air traffic.

Transcript Notes


Captain James McFeron—14,000 hours flying experience.

First Officer Robert Fox—10,000 hours.

Flight Engineer Martin Wahne.

Flight Instructor Martin Kazy—in the Cessna, 5,000 hours.

APP:  Approach Controller

T:  Tower Controller

C:  Captain

FO:  First Officer

P:  Cessna Pilot

ODC:  Off-duty Captain in jump seat

UID:  unidentified person

Transcript Notes

APP:  Cessna 7711G, radar contact, maintain VFR at or below 3500, fly heading 070, vector (for) final approach course.[8]


P:  (to ATC): 7711G on the heading and VFR below 3500.

APP:  PSA182, traffic at 12 o’clock,[9] three miles, out of 1700.

FO:  Got him!

C:  (to ATC): Traffic in sight.

APP:  OK sir, maintain visual separation,[10] contact Lindbergh Tower 133.3.  Have a nice day now!

FO:  Flaps two.[11] 

C:  (to ATC): Lindbergh, PSA182.  Downwind.

T:  PSA182, Lindbergh Tower, traffic 12 o’clock, one mile, a Cessna.

FO:  Flaps 5.

C:  (to FO): Is that the one we’re looking at? [12]

FO:  Yeah—but I don’t see him now.

C:  (to ATC): OK—we had it there a minute ago.

T:  PSA 182, Roger.

C:  (to ATC): I think he’s passed off to our right.

T:  Yeah.


C:  (to F): He was right over here a minute ago.

FO:  Yeah.

T:  How far are you going to take your downwind, PSA182?  Company traffic is waiting for departure.

C:  (to ATC): Ah, probably about three to four miles.

T:  OK.

T:  PSA182—cleared to land.

C:  (to ATC): PSA 182’s cleared to land.

C:  (to FO):    Are we clear of that Cessna?

FO:  Supposed to be!

C:  I guess.

FO:  Flaps 15.

ODC:  (laughing): I hope!

C:  (positively): Yeah—before we turned downwind, I saw him about one o’clock—probably behind us now.

FO:  Gear down.

FO: There’s one underneath . . I was looking at that inbound there.

C:  Whoops!  (as FO pulls up).

FO:  Arghhh!

Metallic crunching noise.


ODC:  Oh ####!

C:  Easy baby, easy baby . . what have we got here?

FO:  It’s bad.

C:  Eh?

FO:  We’re hit man—we are hit!

C:  (to ATC): Tower—we’re going down—this is PSA.

T:  OK—we’ll call the equipment for you!

UID:  Whoo!

Sound of stall warning.

C:  (to ATC): This is it, baby!

UID:  ####

C:  (on PA system): Brace yourself!

UID:  Hey baby . .

UID:  Ma, I love you . .

End of Recording.


[8] “Cessna 7711G” is the expression used by the controller to identify the aircraft he is communicating to; “radar contact” means the aircraft has been identified by the controller on radar.  The controller instructs the pilot to remain VFR (visual flight rules), which means the pilot must keep sight of ground at all times.  The pilot must keep below 3500 feet and turn the heading of the aircraft to 070°.  “Vectors” means the controller will sequentially give the pilot headings to fly that will lead to the final approach course.


[9] The controller’s reference to 12 o’clock means the aircraft, or “target”, is directly ahead of the Boeing.  “Out of 1700” means the controller’s radar shows that the aircraft is climbing through 1700’.


[10] “Maintain visual separation” is the final instruction of the Approach Controller before the pilot is instructed to contact the next controller—in this case the Tower Controller at Lindbergh airport.  Keeping a safe distance from the target—the Cessna—is now the responsibility of the Boeing pilot.  It is important to know that the Approach Controller and Tower Controller are at physically different locations; all they have is a telephone connection, and while they are likely looking at the same radar display, the controllers do  not monitor each other’s radio communications—they are on different radio frequencies and neither will hear what the other is saying.


[11] The First Officer, who is flying, instructs the Captain, who is essentially in a support position in the cockpit, to set the flaps of the Boeing to 2°.  In supporting the First Officers, the Captain is also doing all radio communications.


[12] Importantly, the First Officer saw the target; the Captain did not.

Lessons from PSA 182
Lessons from PSA 182
12 o'clock Traffic Alerts

When air traffic controller report traffic at 12 o’clock (without an indication the traffic is “crossing” your projected flight path), they are relaying the information because there is a risk for collision.  To reduce the risk of collision, alter course.  There is no cost to do this.  It is a good practice to advise the controller of your action—left or right—as this will keep them in the play.

12 o'clock Traffic Alerts
Quick Action

Know when the timing of decision-making is critical.  An Boeing such as PSA 182 descending to join final approach is possibly traveling as fast as 180 KTS—or what is 3 NM per minute—will collide with a target 1 mile away in approximately 20 seconds.  Response to a traffic alert at 1 mile requires quick action.  Again, alter heading until the target is visible—this will create relative movement and easier detection. 

Quick Action
Beware of Ambiguous Language

It is well known in critical operations—such as flight operations—that ambiguous language indicates ambiguous thinking, and is a crucial first-alert of a potentially dangerous circumstance.  When ambiguity is detected, don’t allow an operation to continue unchecked until the ambiguity is resolved.

Beware of Ambiguous Language
Traffic below the Horizon

Know that traffic below the horizon is very difficult to see, as the backdrop of houses, buildings and other structures provide perfect camouflage, and make detection very difficult.  Adjust your reaction accordingly.

Traffic below the Horizon

Eastern Air Lines 401 (Eastern Air Lines), Lockheed L-1011, Miami International Airport, December 29, 1972

By way of background, the Eastern Air Lines flight originated from New York. [13]  On board are 10 crewmembers and 162 passengers.  It is proverbial dark night when the Lockheed crew approach Miami.  The Everglades, which stretch east of Miami Airport, are essentially uninhabited and there are no ground references visible at night—i.e., ground lights.  Again, dialogue is reconstructed using the Lockheed’s Cockpit Voice Recorder and recorded radio transmissions.

Eastern Air Lines 401 (Eastern Air Lines), Lockheed L-1011, Miami International Airport, December 29, 1972

[13] My description and comments here are based on the writings of Macarthur Job, Air Disaster (Ibid) (see pp. 98-111 of Vol. 1).

Transcript Notes


Captain Robert (Bob) Loft—30,000 hours flying experience.

First Officer Albert (Bert) Stockstill—total time unknown, but 300 hours on the L-1011.

Second Officer Don Repo—time unknown.[13]

ATC:  Air Traffic Controller

C:  Captain

FO:  First Officer

SO:  Second Officer

TO:  Easter Air Lines Technical Officer (jumpseat)


Transcript Notes

[13] The Second Officer is the third pilot in the cockpit—a position that has been phased out of newer transport aircraft.  The Second Officer’s job was supportive to the Captain and First Officer and included responsibility for monitoring aircraft systems.

C:  (over PA system): Welcome to Miami.  The temperature is in the low seventies, and it’s a beautiful night out there tonight.

ATC:  (Clears Eastern 401 to join the ILS[14] for Runway 09L, and advises the crew to contact the tower.)


C:  (to ATC): Cleared to ILS 09 left, call Miami Tower on 118.3.  Eastern 401, so long.

C:  (to ATC): Miami Tower, Eastern 401—just turned on to final.

ATC:  (no response)

C:  (to First Officer): Go ahead and throw them (the gear) out.

FO:  (complies)

C:  Miami Tower—do you read Eastern 401?  Just turned on to final.

ATC:  Eastern 401, heavy—continue approach to 09 Left.

C:  Continue approach—roger.

C:  (noting that only two of three green gear lights are on, to FO): Bert, is that (undercarriage) handle in.


FO:  No nose gear.

(Crew recycles gear; indications remain unchanged)

C:  (to ATC): Well.  Tower, this is Eastern 401.  It looks like we’re going to have to circle—we don’t have a light on our nose gear.[15]

ATC:  Eastern 401 heavy, roger.  Climb straight ahead to 2000—go back to Approach Control on 128.6


C:  Okay, going up to 2000—128.6

FO:  (reaches for gear lever)

C:  Put power on first, Bert—leave that damn gear down until we’ve found out what we’ve got.


SO:  (to Captain): Do you want to test the lights.

C:  Yeah—check it.

FO:  Bob, it might just be the light (itself).  Could you juggle it?

FO:  We’re up to 2000—you want me to fly it, Bob?[16]

C:  What frequency did they want us on, Bert?

FO:  128.6

C:  I’ll talk to them.

SO:  It’s right above . . that red one, isn’t it?

C:  Yeah—I can’t get at it from here.

SO:  I can’t make it pull out either.

C:  (to ATC): Approach Control—Eastern 401.  We’re right over the airport now, climbing to 2000 feet—in fact we’ve reached 2000—and we’ve got to get a green light on our nose gear.

ATC:  Eastern 401, roger.  Turn left, heading 360, maintain 2000—vectors to 09 Left on final.


C:  Left—360.


C:  Put the damn thing on autopilot.  See if you can get it out.[17]

FO:  (complies)

C:  (to the First Officer): Now push the switches just a little bit forward—you’ve got to turn it sideways.


FO:  No, I don’t think it’ll fit.


C:  You’ve got to turn it a quarter-turn to the left.


ATC:  Eastern 401, turn left—heading 300.


(Captain acknowledges; First officer complies.)


C:  (frustrated, to Second Officer): Hey—get down there and see if that damn nose wheel is down—you better do that.[18]


FO:  (continuing at removing the light): Got a handkerchief or something so I can get a better grip?  Anything I can do it with?

TO:  (to the First Officer): . . pull down and turn to the right.  Now turn it to your left one time.


FO:  It hangs out and sticks.


TO:  Try it my way.


FO:  (to Captain): It won’t come out, Bob—if I had a pair of pliers, I could cushion it with that Kleenex.


SO:  (about to climb down into the electronics bay): I can give you a pair of pliers.  But if you force it, you’ll break it—believe me.

ATC:  Eastern 401, turn left—heading 270.


(Captain acknowledges; First officer complies.)


C:  To hell with it!  To hell with this—(to the Second Officer): go down and see if it’s lined up on that red line—that’s all we care!  (Laughs)  Screwing around with a 20-cent piece of light equipment—on this plane.


(Others laugh too.)


C:  (to ATC): Eastern 401 will go out west a little further if we can . . see if we can’t get this light to come on.


ATC:  All right.  We’ve got you heading westbound now, Eastern 401.


(Captain and First Officer continue to manipulate the light assembly for an additional two minutes or so.)


FO:  Always something.  We could have made it on schedule.

(The Cockpit Voice Recorder records a C-chord chime at the Second Officer’s panel.  The Second Officer is not at his station.)


C:  (to First Officer): Leave it there.

SO:  (returning): I can’t see it down there.

C:  For the nose wheel there’s a place in there where you can look and see if it’s lined up.

SO:  I know—a little like a telescope.

C:  It’s not lined up?

SO:  I can’t see it.  It’s pitch dark.


TO:  Wheel well light on?

SO:  Yeah.  Wheel well lights are always on if the gear’s down.

(Second Officer and Technical Officer descend into electronics bay.)

ATC:  (Controller reads encoded altitude of 900’.)  Eastern 401—how are things coming along out there?


C:  Okay—we’d like to turn around now and come back in.


FO:  (Observes airspeed increased from 174 to 188 KTS, and responds by retarding the thrust levers slightly)


ATC:  Eastern 401—turn left, heading 180.

Captain acknowledge and the First officer complies. 


FO:  (noting the altitude): We did something to the altitude!


C:  What?


FO:  Were still at 2000—right?


C:  Hey—what’s happening here!


(Controller notes Eastern 401 has disappeared from radar.)

ATC:  Eastern 401, I’ve lost you on radar—and your transponder.  What is your altitude?


Pilot:  Miami Approach, this is National 611.  We just saw a big flash—looked like it was out west.  Don’t know what it means, but we wanted to let you know.


Pilot:  (This is) Lan Chile 451—we saw a big flash—a general flash, like some kind of explosion.

[14] “ILS” stands for “instrument landing system”, and this is a radio navigation system, displayed in the cockpit, that guides the pilot on final approach for landing.


[15] On aircraft with retractable gear, there is display lighting in the cockpit which indicates a green light when the gear is locked in the landing position.  One of the lights is not indicating.


[16] Note the Captain does not respond to the First Officer’s question.


[17] Neither the Captain nor the Second Officer can reach the gear indication lights that are on the First Officer’s side of the cockpit.

[18] The Flight Data Recorder shows a momentary negative vertical acceleration, which produces a 200’ per minute descent for half a minute.  It is believed that the Captain inadvertently disengaged the autopilot, which is designed to cut off if a pressure is exerted on the control wheel.

Post-accident Findings
  • The first record of inadvertent vertical descent—when the Flight Data Recorder shows a momentary negative vertical acceleration, producing a 200’ per second descent for half a minute—is believed to be the result of the Captain inadvertently exerting force on the control wheel as he turn to speak to the Second Officer.  This likely disconnected the Altitude Hold function of the autopilot.  It is believed that improper wiring of the autopilot indicator lights resulted in the First Officer’s “ALT” (indicating altitude hold function) stayed on, despite the function being inadvertently turned off. 


  • It is believed that the C-chord chime that sounded at the Second Officer’s panel (while the Second Officer was in the electronics bay) was in fact the altitude alert system indicating that the aircraft had deviated 250’ from the pre-selected altitude.  The chime was not heard by the crews.


  • The Controller reported that he had noticed the encoder readout for Eastern 401 indicated 900’ only 36 seconds prior to impact.  The controller reported that he wanted to see one more radar sweep to verify the deviation in Eastern 401’s altitude, but before this could be done, the controller had to respond to other air traffic.


  • It is believed that the First Officer’s response to increased airspeed indications—from 174 to 188 KTS—was a misinterpretation of the aircraft’s acceleration from descent—the First Officer interpreted this as acceleration in level flight.

Post-accident Findings
Lessons from Eastern 401

Lessons from Eastern 401
Beware of Fixation

When pilots become fixated on something—something that interrupts their normal flow of activity and expectation—they enter a most vulnerable state.  Situational awareness can collapse, and dangerous circumstances can prevail.  Recognize when you are fixated, and balance your workload accordingly—engage in the subject of fixation for brief periods of time, making a systematic and repetitive inventory of what else is going on with the aircraft—altitude, speed, location, fuel, etc.

Beware of Fixation
Effective use of Resources

When abnormal or emergency circumstances interrupt normal operations, reach out to others for assistance from others.  Passengers can read checklists, monitor the aircraft’s position, monitor altitude, and scan for traffic, for example.  Air traffic controllers can monitor altitude, position, and traffic.  Everyone is willing to offer assistance, but you have activate this assistance, and you have to specify their tasks.

Effective use of Resources
Fly the Aircraft

This seems to be obvious, but when people get tied up in a abnormal event, commitment to aircraft control is easily lost.  Under all circumstances, the pilot’s overriding responsibility is to fly the aircraft—altitude and speed control.  If flight assistance is obtained from others in the cockpit—another pilot, or a trained passenger—be sure their responsibilities for aircraft operation is clearly specified.

Fly the Aircraft
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