Presentation to IASS 2017
View document in PDF [1016 KB]
Chair, Transportation Safety Board of Canada
23 October 2017
Check against delivery.
Good morning, and thank you for the invitation to speak to you today.
At the Transportation Safety Board of Canada (TSB), we very much appreciate the great work done by the Flight Safety Foundation. Indeed, we often quote your studies and reports in our investigation reports.
Today I'd like to cover two topics: The TSB's 2016 Watchlist, and the collision with terrain of an A320 in Halifax, Nova Scotia, in March 2015.
I'll start with the Watchlist.
Our first Watchlist was released back in 2010, and the purpose was to highlight those issues that posed the greatest risk to Canada's transportation system. Many of the problems were widely known, but they were nonetheless proving stubbornly resistant. Creating the Watchlist helped us focus industry and government attention, giving them a blueprint for change. It worked, too. Over time, the issues on the Watchlist have evolved. As old ones are addressed and removed from the list, new ones have emerged and taken their place.
Today the Watchlist features a total of 10 issues: 4 in rail, 1 in marine, 3 in aviation and 2 that are "multi-modal."
I'll describe the aviation and multi-modal issues here, along with the action being sought by the Board.
Slide: Unstable approaches
The first Watchlist issue I'd like to highlight is that of unstable approaches. Onscreen, you'll see a screen grab from an animation created by the TSB following our investigation into the 2011 crash of a Boeing 737 in Resolute Bay, Nunavut.
Among commercial operators—and in spite of airlines' stable-approach policies—your research indicates that while just 3.5% to 4% of approaches are unstable, 97% of those are continued to a landing. In other words, only 3% of the time do flight crews who find themselves on an unstable approach conduct a go-around. Unless more is done, unstable approaches will carry on being continued to landing—increasing the risk of approach-and-landing accidents.
I know this is a complex issue, and I commend the Flight Safety Foundation for continued research in this area, including gaining a better understanding of pilot decision-making.
Slide: Unstable approaches: action required
This issue will remain on the TSB Watchlist until:
- major airlines track stable-approach policy compliance through their flight data monitoring programs, and take action to reduce unstable approaches that continue to landing; and
- there is a reduction in the number of incidents of unstable approach and in the number of accidents in which approach stability was a causal or contributory factor.
Slide: Runway overruns
The second Watchlist issue I want to highlight is that of runway overruns.
Every year, there are millions of successful landings on Canadian runways. However, accidents do occur during the landing phase of flight, or if a takeoff is rejected. These accidents can result in aircraft damage, injuries, and even loss of life—and the consequences can be particularly serious when there is no adequate safety area at the end of the runway.
Of course, more than 10 years on, few of us can forget the powerful images of Air France 358, which went off the end of runway 24L at Toronto's Pearson International airport and burst into flames.
Slide: Runway overruns: action required
This issue will remain on the TSB Watchlist until:
- pilots receive timely information about runway surface conditions to calculate the landing distance required, no matter the season;
- Transport Canada requires appropriate runway-end safety areas (RESAs) at Canadian airports to reduce risks when a runway overrun occurs; and
- major airports provide adequate RESAs or other engineered systems and structures to safely stop aircraft that overrun.
Slide: Risk of collisions on runways
Runway incursions are rare given the millions of takeoffs and landings each year, but their consequences can be catastrophic. From 2011 to 2015, incursions averaged a little more than one a day across Canada, and only a small fraction of that—under 1 percent—were considered serious. But the risk is still too high.
Onscreen is a diagram of Runway 14 at Ottawa's Ottawa/Macdonald-Cartier International Airport, where a de Havilland Dash-8 and a Piaggio P-180 were involved in an incursion in December 2013.
Slide: Risk of collisions on runways: action required
At the TSB, we remain concerned that similar serious runway incursions will continue to occur until better defences are put in place. Specifically, we would like to see direct-to-pilot alerts that warn of an aircraft or vehicle on the runway being used for take-off or landing—to reduce the risk of a catastrophic collision.
Slide: Multi-modal issue: Safety management and oversight
All transportation companies are responsible for managing safety risks in their operations.
Some companies consider safety to be adequate as long as they are in compliance with regulatory requirements, but regulations alone cannot foresee all risks unique to a particular operation. That is why the TSB has repeatedly emphasized the advantages of safety management systems (SMS), an internationally recognized framework to allow companies to effectively manage risk and make operations safer.
Slide: Safety management and oversight: action required
This issue will remain on the TSB Watchlist until:
- operators with an SMS demonstrate that it works
- when TC intervenes, it is able to compel change to unsafe operating practices
Slide: Multi-modal issue: Slow Transport Canada progress addressing TSB recommendations
Since its creation in 1990, the TSB has made over 580 recommendations aimed at fixing high-risk, systemic safety deficiencies in the marine, pipeline, rail and air modes of transportation. Most of these recommendations were addressed to Transport Canada.
Although the wheel of progress is sometimes slow, too often, it has taken Transport Canada years to implement its planned actions in response to TSB recommendations. In some cases, decades.
For example, at the time we released the previous Watchlist, 52 recommendations directed to Transport Canada had not been fully addressed for more than 10 years, of which 39 had been outstanding for over 20 years. Those numbers have since grown larger.
Slide: Slow Transport Canada progress addressing TSB recommendations: action required
This issue will remain on the TSB Watchlist until:
- Transport Canada makes a clear commitment to take action on the outstanding TSB recommendations with which it agrees;
- the Government of Canada improves and accelerates the process for taking action on safety-related recommendations; and
- there is a marked reduction in the backlog of outstanding TSB recommendations, particularly those that will bring Canada back in line with international standards.
Slide: Ongoing Watchlist activities
- Since the release of the 2016 edition of the Watchlist, the TSB has taken a proactive stance. No longer is it enough to just point out a problem and then wait for government and industry to take notice. Instead, we've engaged in a targeted campaign, meeting with key stakeholders and industry leaders—including company owners, CEOs, and senior federal and provincial officials.
- Moreover, given the multiple runway incursions that have taken place at Toronto's Pearson International airport, the TSB announced earlier this year that we are conducting a special safety issues investigation. Our goal is to try to identify contributing factors, but we are also looking at the adequacy of existing defences and the potential for additional defences to mitigate residual risks.
That concludes what I wanted to say about the TSB's Watchlist. I'd now like to switch topics, and discuss a recent high-profile TSB investigation, one that I feel offers lessons for both operators and airports alike.
Slide: A15H0002 (animation)
Just past midnight on March 29, 2015, an Airbus A320 operating as Air Canada Flight 624 struck terrain 740 feet, or 225 metres, short of Runway 05 while landing at the Halifax Stanfield International Airport during a snowstorm. There were 133 passengers and 5 crew on board.
I'll now play you a short animation describing the basics of what happened, before discussing certain elements of the accident in detail, afterward.
Slide: Limitations of using Airbus FPA mode
This accident was the result of numerous factors. One of them was the pilots' use of the Airbus Flight Path Angle (FPA) guidance mode, which guides the aircraft to fly an FPA target that can be used to conduct a non-precision approach. This mode provides a fixed "angle in space" and does not provide fixed vertical guidance.
As a result, when flying in this mode, external perturbations—such as wind variations or turbulence—can cause the aircraft to move away from the selected FPA initial approach path. If the perturbations cause the aircraft to move below the initial approach path, then once the autopilot captures the selected FPA, the aircraft will continue to descend, but on a flight path that is below and parallel to the initial approach path.
If these perturbations continue throughout the descent and if the flight crew makes no adjustments to recover the initial approach path, then the altitude discrepancy between the initial and actual flight paths will continue to increase, resulting in the aircraft flying below the published approach vertical profile. While pilots may know this intuitively, they may not always consider the limitations of FPA compared to other forms of precision vertical guidance during an actual approach.
That's exactly what happened in this occurrence.
It was only in the last few seconds of the flight that the pilots disengaged the autopilot to land manually. Almost immediately, they realized they had flown too low too soon, leaving them short of the runway.
Slide: Air Canada SOPs
According to Air Canada's SOPs, the flight crew was not required to monitor the aircraft's altitude and distance from the threshold, or to make any adjustments to the flight path angle.
This practice, however, was not in accordance with Air Canada's flight crew operating manuals, nor those of Airbus.
No one caught this—not the operator, nor the regulator that initially approved the SOPs.
From Other Finding #5:
Although Transport Canada had reviewed and approved Air Canada's aircraft operating manual and the standard operating procedures (SOPs), it had not identified the discrepancy between the Air Canada SOPs and the Airbus flight crew operating manual regarding the requirement to monitor the aircraft's vertical flight path beyond the final approach fix when the flight path angle guidance mode is engaged.
Slide: Airfield lighting
During the approach, the flight crew requested that the controller change the approach and runway lights to their maximum setting. However, the controller was preoccupied with snowplows on the runway and a nearby aircraft on the taxiway and never did adjust the lights.
This was reflected in causal/contributory finding #7: "The limited number of visual cues and the short time that they were available to the flight crew, combined with potential visual illusions and the reduced brightness of the approach and runway lights, diminished the flight crew's ability to detect that the aircraft's approach path was taking it short of the runway."
Moreover, although the minimum published distance on that approach was 1 nautical mile, Air Canada had a Transport Canada-approved operating specification that allowed pilots to conduct approaches at half the published distance. Yet there was no link between this reduced distance and the approach lighting requirements.
This was reflected in Risk Finding #5: [onscreen] "If the type of approach lighting system on a runway is not factored into the minimum visibility required to carry out an approach, in conditions of reduced visibility, the lighting available risks being less than adequate for flight crews to assess the aircraft's position and decide whether or not to continue the approach to a safe landing."
Slide: Approach to CYHZ
So, an approaching aircraft was permitted to conduct a non-precision approach with just a half-mile of visibility. Yet the pilots were not required to cross check altitude against distance from the runway threshold.
Add a winter snowstorm to the mix and the risk increases.
Other finding #10: [onscreen] "The Air Canada Flight Operations Manual did not identify that the required visual reference should enable the pilot to assess aircraft position and rate of change of position in order to continue the approach to a landing."
Other finding #11: [onscreen] "In Canada, the minimum visibility that is authorized by the operations specification for non-precision approaches does not take into account the type of approach lighting system installed on the runway."
We also looked at what happened after the impact with terrain.
Slide: Airport emergency response: what went wrong
After the successful evacuation, it was almost an hour before all passengers were transported to an indoor facility. Part of this delay was due to the severe weather conditions, and the failure of backup power systems after the aircraft severed commercial power lines near the runway, disrupting the airport's radio operations network. But we also identified issues with the airline's and the airport's emergency response plans, and specifically with respect to making arrangements for the timely transportation of all occupants.
Slide: Passenger safety
All told, twenty-five people were taken to hospital, with injuries ranging from minor to serious.
The investigation revealed several issues concerning passenger safety.
- During the post-crash evacuation, some passengers exited with their carry-on luggage, creating a risk that could have impeded progress, especially to those who were injured. Yet instructions to leave personnel belongings behind in event of a crash were clearly depicted in the safety-features cards that were located in seatbacks.
- And although it was winter, some of the passengers were dressed in shorts and sandals, as opposed to clothing more appropriate to the season.
- There was one infant, held in a parent's lap, and both parent and the infant were injured in the crash. That's because it's simply not possible, in the event of a crash or sudden turbulence, for an adult to adequately restrain an infant just by holding on. Research has also proven that, just as in an automobile, the standard adult seatbelt isn't suitable for a young child. The TSB has previously issued a recommendation on this subject, calling on Transport Canada to work with industry to develop age- and size-appropriate child-restraint systems for infants and young children, so as to provide an equivalent level of safety to adults (A15-02)
- Safety briefings: We stressed afterward that it is important that all airline passengers pay attention to pre-flight safety briefings and review the safety-features card.
Slide: Medical issues (obstructive sleep apnea)
The captain had previously been diagnosed with Obstructive Sleep Apnea (OSA), a medical disorder characterized by partial or complete obstruction of airflow during sleep. It is a well-documented health risk and can lead to impaired performance during wakefulness. It is also associated with increased risk of occupational- and motor-vehicle accidents.
Clinically significant OSA that is not adequately treated is not compatible with certification.
Although there was no indication that fatigue played a causal or contributory role in this occurrence, given that the captain rarely used the associated medical therapy to treat his OSA, he would still have been at risk of experiencing fatigue related to chronic sleep disruption.
Moreover, given that the Transport Canada (TC) Civil Aviation Medical Examiner (CAME) is usually the only person who physically examines the applicant and makes a recommendation for medical certification, it would be reasonable to expect the guidance provided to CAMEs to include information related to OSA. However, TC's Handbook for Civil Aviation Medical Examiners (2004) does not provide specific information regarding OSA.
One of the most important parts of a TSB report is the section on Safety Action Taken.
Slide: Safety action taken
Following the accident, Air Canada pilots have been given more specific guidance to describe the visual references required to continue an approach, along with an explicit warning about the limitations of the autopilot and vertical navigation using the Flight Path Angle mode.
The company's Flight Operations Manual has also been changed, placing greater emphasis on instrument monitoring during all approaches below the minimum descent altitude.
Halifax International airport has upgraded the approach lighting system on Runway 05 and Runway 32, and Air Canada has recommended similar lighting upgrades at other airports nationwide.
The Halifax International Airport Authority has also taken steps to review, revise and update its emergency response plan and upgrade its emergency assets, including backup power.
NAV CANADA, meanwhile, has issued new lighting instructions to Air Traffic Control personnel regarding an anomaly found in the lighting panel preset buttons, and it has also accelerated the publication of revised global navigation satellite system procedures for Runway 05.
In Canada, airline accidents involving large jet aircraft are rare. And while this accident was very serious, the outcome could have been far worse. It should also be a lesson that all parties involved—Transport Canada, airports, airlines, flight crews, and yes, even passengers—must do their part to make sure every flight is as safe as it can be.
Slide: Contact us
Slide: Canada wordmark