A recent investigation into the safety of Canada's air taxi sector contains lessons for future operation of eVTOLs as air taxis.
Earlier this month, the Transportation Safety Board of Canada released a report on safety in the air taxi sector, which operates under very different frameworks, infrastructure and schedules (or lack thereof) than most other segments of aviation. Some of the report’s conclusions may be applicable to the missions many expect electric VTOL aircraft to fly in the near future, but perhaps most critical are its findings regarding insufficient data collection for air taxi missions in Canada.
Studying the period from 2000-2017, where air taxi operations accounted for 55 percent of all accidents in Canadian commercial air services and 62 percent of all fatalities, the TSB investigation identified common factors contributing to accidents in this sector, including poor infrastructure in remote areas of Canada, out-of-date technology on many of the aircraft used for air taxi services, and acceptance by operators of unsafe practices.
These are not new findings. “The hazards and risks have been identified and mitigation measures have been recommended in numerous studies and reviews, some of which go back nearly 3 decades,” the report’s introduction states. “And yet the air-taxi sector continues to experience a high number of accidents and fatalities. Why do these accidents keep happening, and how can safety in the sector be improved?”
Many of safety risks identified by the report may have little relevance to future air taxi services as envisioned by Uber, Airbus, Bell and other leading players; these operations won’t involve 70-year old aircraft with outdated technology, nor are they likely to involve remote areas of northern Canada with little aviation infrastructure to speak of.
“When we look at air taxi accidents – first of all it’s a very different operating context,” Kathy Fox, chair of the TSB, told Avionics International. “The types of aircraft being used are smaller and in this case, older. They’re not able to take advantage of many of the technological advances that have been made whether in navigation, recording of flight parameters, or flight tracking that would likely be available for future vehicles.”
“The availability of current weather information forecasts will be very different … within urban areas, operators likely already have a lot more weather information available than is present for air taxi operators in rural areas,” Fox said.
In discussing the TSB report, Fox emphasized that this investigation was not intended to examine the yet-to-be-defined concept of operations for eVTOL-based air taxi operations. But other conclusions of the report —risks stemming from operational safety standards, or the availability of qualified personnel — may be relevant.
“The more different types of aircraft a fleet has … you’ve got to keep your maintainer current on the different types, or have people specialized,” Fox said of the challenges air taxi operators often face with diverse fleets. “You’re going to have more crews, more differences in operating procedures and training. If your pilots are only trained on certain types of aircraft, does that affect your ability to operate?”
Fox, a former air traffic controller, also pointed out the necessity of defined air routes and identifying appropriate separation minima for vehicles with potentially vastly different performance. She also shared questions on her mind about the regulatory framework operators will function under.
“What’s it going to take for operators to get approved?” Fox asked. “What kinds of certification are going to be necessary for these types of operations? How are we going to track the level of activity and occurrences? All of that needs to be laid out and defined.”
Critically, the TSB report found deficiencies in data collection around Canadian air taxi services, as Transport Canada no longer requires operators to report activity rates in the way that scheduled commercial air services must. As a result, Fox explained, it’s impossible to determine accident rates specific to the air taxi industry.
“If you asked me about the safety performance of aircraft in Canada, I can tell you that Transport Canada collects total hours flown by all registered aircraft in Canada, regardless of size or activity,” Fox said. “So based on an overall estimate of hours flown and the number of accidents, we can calculate an accident rate — but that’s for all registered Canadian aircraft. We don’t know a similar rate for air taxis versus scheduled carriers, so it’s very difficult if you start taking actions to improve safety to actually identify if those actions are having an impact.”
“We can say, overall, that the accident rate per total hours flown has improved two-fold from 2000 to 2018, but I can’t tell you why because I don’t know where most of that improvement is coming from,” Fox continued. “I know based on the number of accidents that it’s not coming from recreational and it’s not coming from air taxi.”
To better calculate accident rates and understand safety risks specific to air taxi services, Fox says operators must be required to report activity levels — how many hours flown, how many takeoffs and landings — by sector of aviation and by aircraft type flown, which was part of the TSB report’s recommendation to Transport Canada. This data used to be required and tracked, but the organization shed those requirements in a push to reduce the regulatory burden on small air taxi operators, which in some cases use the same aircraft as an air taxi in one direction and a commuter airline in the other.
The report also found the International Civil Aviation Organization’s accident categorization system, developed for airline operations, “did not usefully describe accident types in air taxi operations in Canada.”
ICAO, the European Aviation Safety Agency and Federal Aviation Administration did not respond to requests for comment on safety risks or data collection associated with air taxi services. The National Transportation Safety Board said it “has not published a similar/equivalent report that would answer [these] questions about air taxis.”
As efforts to roll out urban air mobility operations with eVTOL aircraft move forward, data collection requirements that enable mission-specific safety assessments will be critical to improving regulations and meeting the incredibly high bar set for safety in aerospace.
Proper data collection will also prove necessary for decisions on increased aircraft autonomy, for air taxi operations as well as commercial airliners and other sectors of aviation, as Luuk van Dijk, CEO of Swiss autonomy startup Daedalean.ai, explained at a recent EASA panel on digitalization in aviation.
“Before you can make the conclusion to take the pilot out of the loop, you need data on how often the pilots save the day because the traffic advisory and the resolution advisory were wrong,” van Dijk said, discussing fully autonomous aircraft avoidance systems. “And there’s very little data on that, or actually none. So, that pleads for routinely logging absolutely everything. I would welcome the regulators stepping in. Actually, for the special condition for eVTOLs, comprehensive logging has been made a part of the rules and regulations and I welcome that.”
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Currently, air taxi services represent a very small percentage of total aviation activity, and perhaps as a result the sector has been under-examined compared to commercial and business aviation. But in the future envisioned by those eager to manufacture thousands of eVTOLs for mass-market on-demand ridesharing services, that’s no longer the case — and there are lessons to be learned from the existing air taxi sector.
“Flying still comes down to technology, operational control and human decision-making around risk,” Fox said. “Certainly, those factors will still have to be considered in that future environment.”