- ISSUE 3/2007
- Copyright and Credits
- Guest Editorial
- To the Letter
- Flight Operations
- Regulations and You
- Feature: Evaluation — Single-Engine Turbine Airplanes Transporting Passengers
- Bryan Webster Wins the Transport Canada Aviation Safety Award
- Maintenance and Certification
- Recently Released TSB Reports
- Accident Synopses
- Debrief: “Show and Stall” Usually Fatal
- Call for Papers—CASS 2008
- Authorized? Be Sure! Runway Incursions Are Real! (poster)
- Full HTML Version
- PDF Version
- What Can You Learn from Accident Reports?
- NAV CANADA Safety Forums Focus on Sharing Safety-Related Information
- COPA Corner-The Benefits of Flying More Often
- A Different Way to Fly
- Human Factors in Gliding
A lot of people who work in aviation like to read accident reports. The reports serve as good reminders that aviation can be dangerous and that we always need to be vigilant. But if we were all being completely honest, sometimes we read them because it makes us feel smugly superior to the people who messed up. So, how much do we really learn from reading accident reports? Surprisingly, there has been very little research to see if accident reports actually have any positive effect on the people reading them. It seems very obvious that accident reports would be helpful, but there are a number of things that interfere with our ability to learn lessons from them.
Our brains process information and organize it before it is presented to our conscious attention. This processing follows certain relatively predictable patterns, which serve to help us understand the world around us. However, this processing can also distort our view of things, as information gets processed in such a way as to protect our self-esteem and our confidence. The patterns of processing that are very relevant to our understanding of accident reports are hindsight bias, attribution error, andinvulnerability.
Readers will recall Heather Parker’s series of articles on the "new view" in the past three issues of the Aviation Safety Letter (ASL). In these articles, she described hindsight bias and attribution error. These concepts also apply when we are reading accident reports. By way of a brief review, hindsight bias refers to our tendency to look back at events and believe the events should have been predictable beforehand. A classic example of hindsight bias is the Monday-morning critique of the weekend’s sporting events by armchair athletes. The coach should have anticipated the other team’s strategy. They should have known that the goalie would get re-injured if they put him in so soon. In reality, as we try to anticipate what will happen next, there are many different potential outcomes and we make the best decision we can with the information that we have available. As we read an accident report, we already know how the flight ends, and so we tend to judge all the decisions that led up to the accident with hindsight bias, believing that the pilot should have known better.
Attribution error refers to our tendency to overestimate the contribution of personal factors when we observe other people’s errors. This means that when we see other people making a mistake, we tend to believe that their errors are a result of their own inadequacies (ignorance, incompetence, laziness), rather than a result of situational factors. Even when a situation arises over which the pilot had no control, we still tend to believe that they were at fault for allowing themselves to get into that situation.
Invulnerability refers to our tendency to believe that bad things will not happen to us. Of course, there are hazards all around us, so in order to enjoy life we suppress our fear and deny the possibility that anything will happen. But an unrealistic sense of invulnerability actually places us in danger. Young people, especially males, have higher levels of invulnerability, and this can be observed in the number of accidental injuries and deaths among young males. A strong sense of invulnerability will prevent us from taking the lessons of an accident report to heart.
In combination, these three factors make it easy to read an accident report and learn very little. It would be almost natural to believe that the pilot should have known better, that their errors were caused by their own ignorance or incompetence, and that this kind of thing could never happen to you.
I recently had an opportunity to conduct some research to see if accident reports were having an impact on readers. Eighty-nine college aviation students participated in the study by completing a questionnaire, and then six weeks later reading an accident report and completing another questionnaire. The questionnaire was intended to measure invulnerability and attribution error.
The participants’ responses to the questions on invulnerability showed very clearly that they did not believe they could be in an accident. The participants also clearly demonstrated a willingness to place the entire responsibility for an accident on the pilot, even when a number of situational factors contributed to the accident. However, the most interesting finding was that there was a remarkably consistent, but small, decrease in the measures of invulnerability immediately after reading an accident report. This means that reading an accident report does have an impact on the reader and does help to make a pilot think about their vulnerability to an accident.
The participants read one of two accident reports. One was a typical accident report format, while the other was written in a narrative format, describing the unfolding events from the pilot’s perspective. Both report formats achieved the same level of change in invulnerability. However, the latter format was able to build sympathy for the pilot so that participants who read this style of report were more likely to believe that they could commit the same errors and be in a similar type of accident.
This is good news for those of us who read a lot of accident reports. It really does give us a more realistic sense of the fact that we could be in an accident if the wrong set of circumstances hit us. In addition, earlier research (see http://psy.otago.ac.nz/cogerg/Remembrance of Cases Past.pdf) conducted in New Zealand, and repeated here in Canada, demonstrates that we do recall lessons from accident reports while in flight. However, in order to make the most of these lessons, we need to keep some things in mind. Here are some practical suggestions for reading accident reports:
- Be aware of the fact that hindsight bias and attribution error do alter your perspective on an accident. As you read a report, think about how the unfolding events might have appeared to the pilot. Think about the decisions the pilot made, and try to ignore the fact that they resulted in an accident. Could you have made the same decisions? What circumstances might have led you to those decisions?
- Be aware of the fact that the majority of people have an unrealistically optimistic belief about the probability that they will be in an accident. Ask yourself if you are really being as cautious as you should be.
- Finally, as you read an accident report, remember that the pilot’s actions made sense to them at the time. If you cannot make sense of the actions, you do not understand the situation as the pilot understood it. Try to step into the pilot’s shoes and see if you can build sympathy for their predicament. Could you fall into the same trap? Could some external pressures or stresses cause you to behave in this way?
If we all use this kind of strategy as we read accident reports, we are more likely to learn valuable lessons from them, and this may prove to be the critical piece of information in some future decision you need to make. In the next issue, I will look at how to apply these same ideas to the way organizations think.BR>
The sharing of safety data between organizations is recognized worldwide as a critical component in enhancing safety in the aviation industry. Sharing safety data helps mitigate the problem of "transfer of risk," where one part of the aviation system inadvertently transfers risk to another part. For example, existing air traffic control (ATC) procedures may be less compatible with highly automated aircraft compared to conventional aircraft. Including all the involved parties to discuss common problems, such as missed readbacks/hearbacks, altitude busts, and runway incursions, also helps lead the way to creative solutions that benefit all stakeholders.
In 2006, the Safety and System Performance Group in NAV CANADA’s Operations Department initiated a series of safety forums specifically aimed at sharing safety-related data and concerns. The Regional Safety Managers in Vancouver (Lana Graham), Edmonton/Winnipeg (Larry Ellis), Toronto (Jeffrey Wearn), and Montréal/Moncton/Gander (Serge Thibeault) led the forums in their respective regions, inviting local representatives from private, commercial and business aviation; aircraft manufacturers; airports; the Canadian Coast Guard; the Canadian Forces; the Transportation Safety Board of Canada (TSB); and Transport Canada.
Participants were provided an overview of operational safety data collected and analyzed by the Safety and System Performance Group, which focused primarily on events reported by controllers and flight service specialists through the Aviation Occurrence Reporting System(AORS), as well as through the contributing factors identified in operations safety investigations. Afterthe presentation, participants were invited to discuss the various issues from their perspective.
Feedback from participants was very positive, prompting NAV CANADA to plan a similar series of meetings for 2007. In an effort to create a more in-depth exchange of data, the format of the meetings in 2007 will be changed: a few months prior to each meeting, participants will be requested to identify areas for discussion. Based on these suggestions, an agenda will be developed to focus on specific concerns, thereby allowing participants preparation time for gathering data or background information on the issues from their organization’s perspective. NAV CANADA is also planning to invite more controllers and flight service specialists to participate in the forum to ensure a front-line operational focus.
If you would like more information on these forums, please contact Larry Lachance, Director, Safety and System Performance, NAV CANADA at
firstname.lastname@example.org or 613-563-5426.
Does flying more often make you a better pilot?
Most people would agree that it does, but where is theevidence?
Our sister organization in the USA, the Aircraft Owners and Pilots Association (AOPA), recently published a report on pilots and aging that looked at accidents in relation to recent flying time, to see if there was any connection to aging. In looking at the accident records, AOPA found that, "time in type or hours in last 90 days by each pilot age group did not reveal any significant difference between groups. The less the time flown, the greater the incidence of accidents in all age groups."
This information is interesting for several reasons. It shows that all pilots can reduce their accident risk by flying more often. It also shows that this effect is the same for pilots of any age-older and more experienced pilots benefit from flying more often as much as younger pilots do.
Why would flying more often be of benefit in reducing accidents? It is pretty clear from literature on the psychology of learning, that physical skills such as aircraft handling, along with cognitive skills such as making weather decisions, are both subject to deterioration over time. Use of these skills on a regular basis keeps them sharp, and that reduces accident risks. Having more practiced skills allows pilots to devote more attention to changes in flying conditions, such as dealing with deteriorating weather conditions. If pilots are not loaded up with the task of flying, then they can also more quickly detect other outside events that can affect the flight itself, such as the appearance of another aircraft in the circuit. The sooner a pilot can detect changes, the sooner they can act rather than react to those changes, whether it’s turning around because of poor weather or lengthening the downwind leg of the circuit to accommodate another aircraft.
The key question is, "how much more do you have to fly to be safe?" Unfortunately, that depends greatly on the type of flying you do, the type of aircraft you are flying, whether you are part of a crew, and the weather conditions that you fly in. There is no evidence that says that flying fewer than "X" hours every 30 days isn’t safe. There is little doubt that flying a single-engine aircraft
Flying often means getting into the books, meeting other pilots and discussing issues of common interest-all of which contribute to a safer experience.
solo in a night IFR environment in low weather takes more recent flying experience to feel comfortable than day VFR flying when the winds are light and the sun is shining. There is also little doubt that pilots flying single-engine aircraft at night in IFR conditions would need to do it more often in order to keep their skill level high and their accident risk low. Fewer accidents mean fewer insurance claims and fewer reasons to raise premiums. Anything that can help make flying less expensive would be great news for all pilots.
So is this an area that calls for more rules, e.g. if you don’t fly "X" hours per year, you are grounded until you do a check ride? Definitely not. The amount of flying you need to do to keep your risks lower varies greatly and there is no good science to indicate how much is enough for all types of flying and for all individuals. This is very definitely an area of aviation where pilots need to look out for themselves. If you haven’t flown much recently, if you don’t feel up to speed on crosswind landings, then get some instruction and get back to a comfortable level of skill. How much flying do you need to do? Perhaps just abit more than you did last year.BR>
Dieter was a shy but friendly student pilot. Early lessons with him were exciting. The stocky, middle-aged bachelor flew our Cessna like it was the skid-steer loader he drove at the municipal dump. In time, he managed to master the Cessna’s controls and passed his flight test. The written exam took longer, but he made it.
"I’m going to buy an airplane!" he declared.
It was the unrealized intention of many new pilots, but I didn’t discourage him. "We can help you find the right one when the time comes," I replied.
Dieter was back in the office four days later. "I bought a homebuilt," he announced. "Got it from the builder. He’s being flying her from a grass strip on his farm."
"Ah, Dieter, did you have a mechanic check it over first?"
"No, she just had an annual inspection. The owner did it himself. He said everything is good to go."
Dieter described the airplane as a low-wing, open cockpit, single-seater built from plans. "She’s mostly wood and fabric," he said. "I can work on her myself."
I cringed. "When do you close the deal?" I asked.
"It’s mine now," he answered enthusiastically. "I just need help transferring the ownership."
"Dieter, you’re buying a homemade airplane maintained and inspected by the builder. It would be a really good idea to have a mechanic look at it."
The new pilot frowned. "The guy said she was government inspected when she was new, eh," he replied hopefully.
"When was that?"
He smiled nervously, "1978, but he said she’s always been kept in a hangar."
"I’ll help you with the paperwork, but I’d feel better if our mechanic checked her over. It’s the only way to be sure of the condition inside the structure and the engine."
"I’ll think about it."
"Then you need flight instruction in a tail-wheel airplane. They can be difficult on takeoff and landing. We can cover that in the flight school’s Super Cub."
We flew a lesson in the Cub and used part of it to visit the homebuilt at its airstrip. We landed and parked beside a ramshackle wooden shed. Dieter watched my face as Iwalked up to the airplane. The faded blue paint looked rolled on. The fabric covering was creased in places. The tires were bald. The engine was small. The four cylinders stuck out of the cowling.
"Well, it’s a homebuilt," I declared, searching for something positive to say.
Dieter helped me take the canvas off the cockpit. There wasn’t much to see. The control stick was a length of pipe growing out of the floor, topped with a bicycle grip. The number of instruments in the panel could be counted on one hand. There was no electric equipment.
Dieter danced around like a kid with a new bike.
"She’s kind of neat, eh?" he said.
I moved the stick. Control cables slapped the insides. I checked that the ignition was off and then flipped the wooden propeller. The engine wheezed through two complete rotations.
"Dieter, she’s neat, but I don’t know about airworthy. I wouldn’t fly it without a third party inspection."
I talked him into it. The next week, the flight school mechanic drove to the farm and checked the airplane over. I figured that he’d condemn the old homebuilt. The man’s approach to backyard airworthiness caught me off guard.
"It’s fine," he declared.
"What!? What about the creases in the fabric?"
"The creases are fine. The fabric is just covering plywood. Creases would be a problem at high Mach, but we don’t worry about the sound barrier in airplanes like that."
"What about the engine compression?"
"What compression? It’s 65 horsepower, enough to turn the propeller. There is no afterburner."
"And the bald tires?"
"If your man stays on grass, he should change them in five years."
"Did you check the slack in the control cables?"
"I tightened them." He was getting impatient with me. "Look, it’s not a Cessna, it’s a kite, an airplane for floating around on nice days. The finish is not best-of-show but the structure is sound and the engine runs. There is nothing else to check. Your man should have fun with it."
I gave Dieter the good news. "Let’s do another lesson in the Super Cub before you try it."
"We have a big problem," he replied. "There is no handbook for the airplane."
"It’s a homebuilt, Dieter. Each one is different depending on the engine, materials and construction."
"What about all the numbers and charts you taught me to use in the Cessna manual?"
Now it was my turn to make excuses. His recreational pilot training had emphasized knowledge of the pilot operating handbook and detailed flight planning.
"Did the former owner give you any information?"
"Bring it with you and we’ll talk before we fly the Cub."
We sat at a table in the office. Dieter read from a scrap of paper. "Climb 60 mph, cruise 80, approach 60 and stall 45. The owner said she burns about four gallons per hour. The tank holds 16. That’s it."
"How about take-off and landing distances?"
"The guy said he always clears the trees departing from his strip. It’s 2 500 feet long."
"That could be all the information you need," I said.
"What about all the stuff in the Cessna manual; performance versus density altitude, weight and balance, checklists and emergency procedures?"
"They all apply to the homebuilt," I replied, "but they’re simplified because the airplane is so basic."
He frowned and waved the piece of paper at me.
"Almost. The owner gave you the worst-case take-off distance. It’s 2 500 feet. That’s in grass, at gross weight, in the summer, over an obstacle, and sometimes in light wind. Any other conditions will shorten that distance. Don’t try to take off in a tail wind, up a slope or from anything less than 2 500 feet long, and you’ll never have a problem."
"What about landing distance?"
"Simple. It’s 2 500 feet. Don’t land anywhere you can’t depart."
Dieter scratched his head.
I continued. "All of the speeds are between 45 and 80 mph. Climb is 60 mph. Consider that the best rate of climb speed and best angle, with or without flaps. There are no flaps and the two speeds will be within a couple of miles-per-hour of each other, so stick to 60. Ditto for the approach and glide speeds.
"Cruise at 80 mph. That will come around 2 200 rpm. If the engine will turn the propeller faster, don’t bother. It’ll only make more noise, not speed. Fly slower if you want, but I don’t think you will. With the rpm at 2 200, the fuel consumption will be fixed at four gallons per hour. There is no mixture control."
"What about higher altitudes?"
"Forget them. There’s no heater. If that engine could take you over a few thousand feet, you’d freeze to death."
"So the range is fixed at four hours?" Dieter asked.
"Close. The endurance is fixed at three hours, with an hour for reserve. With a 20-mph headwind, ground speed will be 60, so use 180 miles as the range until you know the airplane better. If the wind is over 20 mph, don’t fly."
"Weight and balance?"
"There is no place for passengers or baggage. Keep the gas tank topped up, and your weight and balance stays fixed. It would be helpful to know if the empty weight is close to normal for that model."
Dieter’s face lit up. "That’s no problem. It’s a folding wing design. We have a truck scale at the dump. I’ll tow her to work. I can show her to the guys."
"Good. Now, everything you learned about pre-flight inspections, checklists and emergency procedures apply, but are simplified. There are no antennae to check or cowlings to open. There is only one fuel drain. There are no doors to latch, no master switch to turn on or radios to set. Use the Cessna handbook as a guide and write your own operating manual."
"OK, I guess."
"Let’s fly the Super Cub. We’ll use 1 900 rpm for full power, 1 750 for cruise, and we won’t extend the flaps."
I showed Dieter how to hand-start the Cub from behind the propeller and had him practise it.
On the runway I said, "take-off power is 1 900 rpm. Climb with the nose in its usual attitude and tell me the resulting airspeed."
The Cub broke ground at 1 000 ft. It climbed to 50 ft in another 1 000 ft at a speed of 65 mph. We departed on a local flight. The 1 750-rpm cruise gave us 70 mph. I had Dieter fly turns, climbs and descents. He flew the Cub better than ever. It handled more like the skid-steer loader at the reduced power and speed.
"OK, back to the airport. Use 65 mph but no flaps on the approach."
We flew a few circuits and then went back to the office.
"I have three more suggestions," I said. "First, hound the previous owner for operating and maintenance information. Second, join the local aircraft amateur-builders chapter, go to their next meeting, plead insanity and tell them what you bought. They’ll welcome you like a lost brother."
He smiled. "OK."
"Lastly, plan on taking your first flight when the former owner can be there. I’ll come too. We’ll make sure you have fun."
Garth Wallace is a former flying instructor who lives near Ottawa, Ont. He has written 10 aviation books published by Happy Landings(http://www.happylandings.com/). The latest is Wing Nuts. He can be contacted via e-mail at: email@example.com.BR>
The study of human factors (HF) is an important part of learning to fly. We know that in almost 80 percent of accidents, pilots contribute most to the problem. In the remaining 20 percent, there is usually an HF component. An example would be pressure to fly when the pilot knows it would be unwise to do so. We may be able to think of typical examples! We can all benefit from a review of HF.
Ultimately, the safety of our flights comes down to how we, as pilots and equipment operators, relate to our equipment, procedures, other people and the environment. Accident statistics from many years show that the greatest risks occur during takeoff and landing, when the cockpit workload is high. Add a long flight, and the landing phase is seen to demand the most attention, now from the fatigued pilot.
The top three major areas of concern in gliders worldwide are judgement or decision making, the stall/spin, and mid-air collisions. The first two can arise from problems with circuit planning, especially when flying cross-country, and when trying to make a safe landing after an emergency during the launch. Inattention and becoming distracted, perhaps by the newer in-cockpit electronics, have been implicated in mid-air collisions. How can we avoid these hazards and reduce the risks?
Humans receive many stimuli on which we base our decisions. We receive data, evaluate or process it, make a decision and then act on that decision. Sound familiar, does it? The mnemonic device, SOAR, learned early in your training, is just that: S for see the situation, O for what options do we have, A for act on the best and safest option, and R for repeat the sequence.
We assess the situation by gathering information that tells us how the flight is progressing; what the situation isright now:
- Are other gliders in sight nearby, and do we understand the eye’s limitations?
- Does this control movement feel and sound right?
- What do the aircraft’s movements and the Gforces tell us? Is our food and water intake okay?
- How do we feel-hot, cold?
Psychological influences are very important:
- Have we just had an argument leading to emotional stress?
- Are we in a good, positive mood, and able to make sound decisions?
How is the glider performing-height, climbing or descending, and location relative to our goal, and the changing weather? We constantly evaluate all inputs so that we can make the best decisions for a safe continuation of the flight.
Judgment is the ability to identify useable options and make good decisions from experience. What do you know about yourself with respect to HF? For example, how will you perform under low- or high-intensity situations? This can explain our fright-or-flight response and our ability to react to unusual high-risk events. Experience shows some people perform better in emergencies when they have had similar exposures during training. Others may have difficulty thinking, or a tendency to freeze.
HF is also about risk management. Develop your own comfort zone. This means finding your personal level of satisfaction within the risks in gliding by identifying elements that protect you and make you comfortable. Learn causes of typical accidents and how to recognize departures from your usual routine by knowing your limits. Develop your personal discipline to include items such as checklists, weather minima, personal routines, etc. You need to discipline yourself to take the actions needed to break an accident sequence (the domino effect) or to correct a missed pattern. This is why your instructors will expose you to checklists such as IM-SAFE, SOAR, CISTRSC-O, and will explain what to do when one may be interrupted. The bottom line is to learn proper flying practices, apply consistency, personal discipline, and set and keep high standards in your flying.
For further information about human factors, read Transport Canada’s publication: Human Factors for Aviation-Basic Handbook, TP 12863 (E) (09/2003).
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