Was it a simple matter of pilot error? The evidence was clear that he knew about the ice and snow on his aircraft and that he was aware of the hazards associated with attempting the takeoff under those conditions.

Perhaps the investigative team could simply go through the motions of evaluating the wreckage, interviewing witnesses, documenting weather data, and a myriad of other mundane tasks, to come to the evident conclusion that the captain made a poor decision. Fortunately, circumstances resulting from an ironically similar accident just four years prior caused the investigation to take a significantly different course. Instead of reaching an artless conclusion of pilot error, the search for why the veteran captain made the decision to depart with wet snow and ice adhering to his wings became the focus of one of the most comprehensive human factors investigations in the history of aviation. The lessons learned made a significant impact on air transportation systems worldwide.

On March 10, 1989, at 1209 CST, a Fokker F28-1000, operating as Air Ontario flight 1363, crashed shortly after takeoff from Dryden, Ontario, Canada.  After a longer than normal take-off roll, the aircraft rotated, lifted off briefly and then settled back down onto the runway. It rotated and lifted off a second time just 300 feet from the end of the runway, clearing the end at an altitude of 15 feet. Failing to gain additional altitude, it mushed into the trees in a nose-high attitude. The aircraft came to rest 3,155 feet from the end of the runway and was destroyed by a post-crash fire. Twenty-one passengers, 1 flight attendant, and both pilots were killed. Forty-four passengers and one flight attendant survived.

The crew was scheduled to fly a Winnipeg to Thunder Bay round trip (1362/1363) with an intermediate stop in Dryden, followed by another Winnipeg to Thunder Bay round trip without the intermediate stop. Low ceilings and snow were forecast for the region requiring extra fuel to reach distant alternate airports in the event that a diversion was necessary.

The captain reviewed the maintenance log confirming that the aircraft’s Auxiliary Power Unit (APU) remained inoperative, as it had for the previous 5 days. Without an operative APU, the engines could not be started without the aid of ground-based external power, which was not available in Dryden, or unless one engine was left running, and its power used to “cross-start” the other engine.

Flight 1362 departed Winnipeg 24 minutes late because the captain insisted that the aircraft was deiced to remove a layer of frost on the wings. The flight landed in Dryden 13 minutes late. The captain called the Air Ontario Systems Operations Control (SOC) in London, Ontario to discuss the weather for the next leg. Thunder Bay was reporting weather below landing minimums but was forecast to improve. The captain and dispatcher agreed that the flight should depart with the hopes that Thunder Bay would be above minimums by the arrival time. While en route, the weather improved and flight 1362 landed in Thunder Bay 20 minutes behind schedule.  

The release for flight 1363 (Thunder Bay to Dryden to Winnipeg) was not updated to reflect the addition of 10 extra passengers making the aircraft overweight for takeoff from Thunder Bay. Already 20 minutes behind schedule, the captain elected to offload the 10 passengers. However, the dispatcher overrode the captain’s decision and ordered the aircraft defueled. In addition to adding to the departure delay, the dispatcher’s decision would increase the refueling time necessary at Dryden, further inconveniencing the passengers. The flight departed Thunder Bay 1 hour late and landed in Dryden as snow began to fall. 

With one engine left running, the process of “hot refueling” began. The captain went to operations to discuss payload, fuel, and weather issues with SOC, described later as a “heated conversation.” The snow began to get heavier and the wings had accumulated ¼ to ½ inch of snow. Slush began to accumulate on portions of the runway by the time the captain returned.

While taxiing out for departure, the Kenora Flight Service Station advised that a Cessna 150 had declared an emergency inbound to Dryden because of difficulty with the weather. While waiting on the taxiway for the Cessna to land, the precipitation continued to accumulate on the aircraft and the runway. The combination of the slush on the runway, and the wet snow that had frozen into opaque ice on the forward half of the wings, would significantly degrade the aircraft’s performance capabilities.

Many of the passengers had connections to make in Winnipeg and were concerned about the delays. The flight attendants communicated the concern to the captain. Witnesses reported that the events of the day visibly changed the “good spirits” demeanor of the flightcrew. The captain commented to the passengers over the PA system, “…Well folks, it just isn’t our day…” Flight 1363 began its takeoff roll from Dryden 1 hour and 10 minutes behind schedule. 

Under normal procedures, the Canadian Aviation Safety Board would have had full responsibility for the accident investigation. Controversy however, surrounding an Arrow Air DC-8 charter, which crashed at Gander, Newfoundland on 12 December 1985 (when it departed with ice adhering to the wings), had created the need to appoint a Commission of Inquiry. Forming a multi-disciplinary team, which included human factors experts, the commission began their exhaustive investigation, interviewing over 160 witnesses. In March 1992, they published a 1,700 page report that described the details of the event, and made numerous recommendations with far-reaching consequences. The report, based on the commission’s desire to search deeper into the environment affecting the captain’s decision, is widely considered to be groundbreaking in the area of aviation human factors.

Although some of the methods and terminology used in the field of human factors have changed since the Dryden investigation, the principles have remained the same. A recently developed tool under increasing use is the Human Factors Analysis and Classification System (HFACS) which describes 4 levels of failure: 1) Unsafe Acts, 2) Preconditions for Unsafe Acts, 3) Unsafe Supervision, and 4) Organizational Influences. Accident investigations that emphasize an evaluation of human performance begin at the time of the accident and work backwards. Using the HFACS model, we can begin an analysis by itemizing the unsafe acts that may have occurred, including errors and violations of standards.

Unsafe Acts Performed by the Flightcrew

The most obvious error was the captain’s failure to have the aircraft deiced prior to departure from Dryden. The record reflects that the captain was conscientious about deicing.  For example, he had ordered the aircraft deiced earlier that same day to remove a layer of frost from the wings. The captain must have known about the weather conditions having walked to the terminal in a short sleeve shirt. Further, he asked the ground handlers about the availability of deicing and was advised that it was available if needed.    

Neither pilot performed a preflight walk-around inspection while at Dryden. That decision may have been influenced by the fact that an engine was running. It is possible that a closer inspection of the flying surfaces would have prompted a decision not to depart until the aircraft was free of ice and snow.

The captain allowed the aircraft to be “hot refueled” with an engine running. The Flight Operations Manual made no mention of this procedure but the manual used by the flight attendants allowed it under the provision that Crash, Fire, and Rescue (CFR) personnel were standing by. Though they eventually showed up, the captain allowed the process to begin prior to their arrival.  

The captain, a former check airman, had a reputation for strictly adhering to standards. It seemed to the investigators that his decisions were abnormal given his experience and reputation. The events of the day had somehow broken down his defenses allowing him to accept the less than optimum circumstances.

Unsafe Acts Performed by Others

Several passengers, including two deadheading captains, expressed their concern to the flight attendants about the accumulation of ice and snow on the wings. However, no one conveyed that concern to the pilots. The flight attendants assumed that the captain was already aware of the situation and one of the deadheading pilots would later report that it would have been unprofessional for him to question the decisions of another captain.

The dispatcher allowed flight 1363 to operate into (and out of) Dryden with an inoperable APU. There was no ground start equipment available at Dryden requiring the crew to leave an engine running during the short stopover. Shutting down both engines would have grounded the aircraft for many hours until ground start equipment could be flown in. This put the captain in a very awkward position as it was prohibited to perform ground deicing with an engine running. Ironically, the investigation ultimately revealed that it was the APU’s fire detection function that had actually failed, not the APU itself, as indicated in the maintenance log. Proper application of the provisions of the Minimum Equipment List (MEL) would have allowed the crew to shut down the engines and deice.

On the day of the accident, the SOC did little to help the captain resolve numerous issues of weather, alternates, passenger bookings, etc. An untrained dispatcher who had little knowledge of the operating characteristics of the F-28 prepared the flight releases. The releases contained several errors including an incorrect maximum take-off weight, inaccurate alternate fuel data, and an incorrect payload figure. There was evidence that these types of errors were common and that captains would contact their dispatcher to correct the errors prior to departure. Since the captain of flight 1363 did not call to correct these errors, the report concluded that he relied on erroneous data throughout the day. 

An amended terminal weather forecast for Dryden predicted freezing rain during the scheduled arrival and departure of flight 1363. Had the captain been armed with this information, he may have elected to overfly Dryden. Although the information was available while the aircraft was still on the ground at Thunder Bay, the dispatcher never disseminated the revised forecast to the flightcrew.

Preconditions for Unsafe Acts

One could argue that if the captain had simply fulfilled his responsibility, the accident would have never occurred. Such is the case with 80% of all aviation accidents. However, if we stop there, we will only understand the symptoms, not the underlying causes. Therefore, human factors investigators look next at the preconditions for unsafe acts.

By all accounts, the captain was a fly-by-the-book professional, committed to on-time performance and customer service. However, the events of the day leading up to the crash may have created an atmosphere of frustration. For example, the captain had a heated telephone discussion with the dispatcher just prior to departure and was exhibiting signs of stress upon his return to the aircraft. Stress and frustration can interfere with decision-making and sound judgment. Haste may have played a role as well. In addition to his concern for the passengers, the captain had a personal trip scheduled for the next day. That may have caused him to rush through some decisions, a symptom of get-home-itis.

The report also cited poor Crew Resource Management (CRM). For example, the first officer failed to properly monitor and challenge the captain and insist on a different course of action. Although evidence shows that he attempted to communicate his concerns to the captain, he exercised inadequate assertiveness. The report made it clear that the first officer was not happy flying with a captain who, as an experienced check airman, often behaved more like an instructor than a leader. This may have limited the first officer’s expectation for successfully convincing the captain to change course. Further, the captain failed to use all of his available resources by not being more receptive to the input of others. This may have directly influenced the flight attendants’ decision not to advise the captain about the concerned passengers. Overall, the crew acted more like a group of individuals, rather than as a well-coordinated team. 

Unsafe Supervision

Supervisors must provide an opportunity for their employees to succeed. A human factors analysis can point out deficiencies at the supervisory level contributing to errors made by subordinates.

The investigation revealed that inadequate training covering ice contamination had been provided to the various workgroups involved in the event. Such training may have made ground personnel more aware of the hazard, prompting them to say something to the captain. Further, no formal crew resource management (CRM) training was provided to any of the crewmembers. Perhaps a better understanding of CRM principles would have allowed the first officer to be more assertive in insisting that they not depart under those conditions and for the captain, who was identified as being difficult to work with, to be more inclusive of input from others.

Air Ontario supervisors provided ambiguous operating procedures to its F-28 pilotsresulting in non-standard operations. In addition to the previously discussed disparity covering hot refueling, 4 separate manuals on how to operate the F-28 were in play. Depending on where a pilot received his training, he was issued either a USAir or Piedmont Airlines operating manual, each with its own set of operating practices. While both manuals included restrictive guidance on taking off from contaminated runways (as compared to the onboard Fokker F-28 Flight Manual) there was confusion about which guidance to follow. Using USAir or Piedmont manuals, the maximum allowable takeoff weight from Dryden would have been so significantly reduced by the field conditions as to prohibit the operation. Further, the draft F-28 manual submitted to Transport Canada by Air Ontario contained no contaminated runway data at all. The investigation also revealed that there was no consensus among Air Ontario’s pilots on which guidance to follow. The existence of such a disparity between the 4 manuals meant that Air Ontario had no established policy about operating on a contaminated runway. 

Two inexperienced pilots were paired together. Though they were both veteran pilots, the captain and first officer’s total flight time in the Fokker F28 was 62 and 66 hours respectively. Accident investigations and other research data indicate an increased risk to flight safety when pairing crewmembers that are each inexperienced in a specific type of aircraft.

Organizational Influences

Decisions made by upper-level management directly impact the quality of the supervision provided. Errors made at this level have often gone unnoticed for lack of a clear framework for safety professionals to use in investigating them. Using the HFACS model, the next step for investigators is to evaluate the organizational influences that affected the operation.

Air Ontario was created through a merger of two very different airlines. Air Ontario Limited, which operated mostly in the Great Lakes area, was purchased by Austin Airways Limited described as a northern “bush” operation. The two companies had significantly differing cultures created by different fleets, operating environment, employee groups, and management styles. 

The non-unionized pilot group of Austin Airways had experience with the harsher northern flying environment and operated with less structure as compared to the unionized and more rigidly structured workgroup to the south. The difference resulted in what was described as an unhappy marriage. The negotiations to merge the two pilot groups resulted in a prolonged strike in the spring of 1988. Most relevant is the fact that flight 1363’s captain came from Air Ontario, the first officer came from Austin Airways. The report contends that the working relationship between the two pilots was probably not cordial, and likely impacted crew coordination.

The report concluded that the period following the merger was turbulent resulting in high management turnover, low morale, and poor performance, all of which may have affected flight safety. The commission asked, “…whether Air Ontario management was able to support the flight safety imperative during this period of distraction.” For example, individuals that were expected to play a major role in the F-28 program (the company’s first experience with transport category jet equipment) had left the company, resulting in a lack of quality coordination and effective management. The individual who ultimately became the program manager lacked experience in the F-28. His chance of success was also limited by the fact that he was overburdened by a variety of tasks including F-28 Chief Pilot, F-28 training pilot, F-28 company check pilot, Convair 580 Chief Pilot, and F-28 line pilot. The commission concluded that, “…deficiencies in the (F-28) project coordination were significant to the crash of flight 1363.”

In the two years leading up to the accident, the airline also experienced turnover in senior management positions, most significantly the Vice President of Flight Operations and the Director of Flight Operations. The instability undermined efforts to make the changes necessary by the introduction of the F-28. The report revealed evidence that the President/Chief Executive Officer would select senior management personnel on criteria other than merit including the appointment of close relatives to key managerial positions. The result was the formation of a management team whose experience level was inadequate for the task at hand.

The report concluded that although maintenance management remained stable during the 2 years leading up to the accident, numerous maintenance deficiencies existed including unfamiliarity with the F-28 and a purchase decision that resulted in an inadequate spare parts inventory. As a result, technicians and pilots were required to accept deferred maintenance items for extended periods of time.

The SOC had operational control defined as the authority to initiate, continue, divert or terminate a flight. Operational control provides a means of supporting the flightcrew with information that will help them make more informed, safe, and efficient decisions. This relationship is intended to prevent the circumstances like those presented to flight 1363’s flightcrew. SOC personnel testified before the commission that, “…the training and qualification of the Air Ontario dispatchers was inadequate.” The inquiry revealed that when the weather worsened, mechanical malfunctions affected operations, or whenever any irregular operations were encountered, the performance of the dispatchers deteriorated. The report concluded that this was a consequence of poor planning and organization within the SOC, a lack of training and qualification of the SOC personnel, and the failure of SOC personnel to fully appreciate the importance of their function.

The commission evaluated the Air Ontario’s Flight Safety program and, using 3 additional incidents as case studies, concluded that it was ineffective. All three of the events involved the F-28 program manager acting as pilot in command, two of which had similarities to the Dryden accident. The report suggested that safety culture was left up to each individual, rather than an organized approach under the leadership of a safety professional. The Flight Safety Officer had resigned in 1987 because of inadequate management support including a lack of access to the Chief Executive Officer. Despite suffering a DC-3 accident in November 1988, the company did not fill the position until February 1989. The commission concluded:

“The lack of continuity in the position of flight safety officer, the lack of adequate support of the FSO position by senior management, and the lack of a flight safety organization over the material time span was a managerial omission… The management assigned a low priority to the importance of filling the vacant position of FSO…This period of instability carried over into the introduction of the F-28 program had an impact on flight safety.”

The commission summarized the organizational influences leading up to the accident by concluding that the Dryden scenario was reasonably foreseeable. 

Outside Influences

In some cases, there are significant outside influences that affect the organization’s culture and environment that can be considered factors in an accident or mishap. Two examples from Dryden were Transport Canada, the Canadian aviation regulatory body, and Air Canada, which owned a controlling interest in Air Ontario and marketed it as a feeder network to its mainline operation.

During the decade leading up to the accident, Transport Canada, like other government organizations, suffered from an increase in workload and a decrease in resources with which to accomplish its mission. Despite warnings to the contrary, Transport Canada rapidly found itself in the difficult position of not being able to effectively meet its responsibilities.

A regulatory audit of Air Ontario was scheduled for February 1988. While some portions were completed, the portion covering flight operations was postponed because Air Ontario did not yet have an approved flight manual. After a few delays, the audit was completed in November 1988. Because the audit team had no experience with jets, the F-28 program was not evaluated. The commission described this as a serious omission, believing that an audit would have uncovered numerous deficiencies that, once corrected, might have prevented the accident at Dryden. Despite regulations to the contrary, Air Ontario did not receive the audit findings until 5 months after the crash at Dryden. The audit was described as poorly organized, incomplete, and ineffective.

Many of Transport Canada’s regulations governing air carriers were found to be deficient. Rules applicable to flight dispatch requirements, minimum equipment lists, approval of operating manuals, and qualifications for airline managers were outdated, in need of overhaul, or non-existent. Transport Canada’s operational staff agreed during testimony that regulations were inadequate and that the agency’s senior management took little action despite the seriousness of the concern. The report also stated that Transport Canada was, “…spending too much energy on minor violations that were of little safety consequence, while not enough effort was being put into overall education and safety promotion.”

Despite controlling ownership in the company, an effective public marketing plan, and the financial success of the arrangement, Air Canada did not use its expertise in scheduled jet operations to verify, monitor, or influence the operational procedures and flight safety standards of its subsidiary. On the contrary, they intentionally remained well clear of Air Ontario flight operations. Despite a mainline division operating well in excess of the minimum regulatory standards, and while holding its subsidiary to the highest marketing standards, Air Canada allowed Air Ontario’s operation to simply meet the minimum standards required under the law. A detailed comparison of operational policies demonstrated a double safety standard between the two carriers. 


The commission’s report did not include a probable cause but contained 191 recommendations to repair the latent errors that were part of the Canadian transportation system. The report states:

“The captain, as the pilot-in-command, must bear responsibility for the decision to land and take off in Dryden on the day in question. However, it is equally clear that the air transportation system failed him by allowing him to be placed in a situation where he did not have all the necessary tools that should have supported him in making the proper decision.”

That statement provides us with our mandate. We must hold flight crewmembers accountable for being the last line of defense. But we cannot stop there. If we are interested in preventing accidents, we must recognize that the decisions of pilots are not made in a vacuum. Only a systems approach to investigating and understanding accidents and incidents will reveal the most significant opportunities for intervention. Further, using this same approach, we can evaluate the issues proactively, identify deficiencies early, and prevent the most serious accidents from occurring. 


Though the final report pointed out flaws in the Canadian aviation system (including Transport Canada) it is useful to recognize that it is one of the safest systems in the world. Today, as a result of lessons learned from the accident, Canada (along with the U.S., Australia, and others) has embraced an organizational approach to both accident investigation and proactive safety programs designed to reduce mishaps. Human factors investigators work side-by-side with traditional “tin kickers,” each searching for different types of evidence, each as important as the other. Safety managers are trained in human factors to better understand the systems approach to safety management. Other company managers are more educated about their role in developing and maintaining a positive safety culture. 

Still, some individuals and organizations remain apprehensive about openly discussing flightcrew error or organizational flaws. Fear of embarrassment, punishment, or litigation drives some to the age-old habit of finger pointing.  In the U.S., programs such as ASAP and FOQA are designed to gather safety data while reducing fears of discipline or punitive consequences. Though progress is slow, the lessons of Dryden are having a positive impact. Your awareness of the events, and of the commission’s findings, will help you to make more informed and better quality decisions.

Put yourself in the role of each crewmember. How would you have prevented this accident?

As always, we invite your comments and questions. Please feel comment below or email us at safetychip@gmail.com.


Commission of Inquiry into the Air Ontario Crash at Dryden, Ontario, Final Report, Moshansky, Mr. Justice, 1992

Beyond Aviation Human FactorsPathogens in the Snow, Maurino, Reason, Johnston, and Lee, 1995 

The Human Factors Analysis and Classification System – HFACS, Shappell and Wiegmann, February 2000