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Safety communications related to TSB investigation A18Q0030 – February 2018 runway overrun in Havre-Saint-Pierre, Quebec

The occurrence

On the morning of 26 February 2018, a Beechcraft King Air A100 operated by Strait Air (2000) Ltd. was conducting an instrument rules flight from Sept-Îles, to Havre-Saint-Pierre, Quebec, with two crew members and six passengers on board. In preparation for landing, the aircraft conducted an approach onto a snow-covered runway, in reduced visibility due to heavy snow showers. It continued to land and touched down approximately 3800 feet beyond the threshold, before continuing its landing roll until it came to rest in a large snowbank, approximately 220 feet beyond the end of the runway. The aircraft sustained substantial damage, and four of the occupants received minor injuries.

Recommendations made on 21 May 2020

In designing instrument approaches, the published minimum visibility represents the minimum visibility at which a pilot on approach at the decision height (DH) or the minimum descent altitude (MDA) should be able to establish and maintain the visual reference required up until landing.

International Civil Aviation Organization (ICAO) standards and recommended practices stipulate that an instrument approach shall not be continued unless the reported visibility is at or above the specified minima. These minima are published on approach charts based on the approach type and lighting.

Various civil aviation authorities throughout the world (such as the U.S. Federal Aviation Administration [FAA] and the European Union Aviation Safety Agency [EASA]) have established that the authorized visibility minima are those specified and published for the approach. Therefore, to determine whether an approach is authorized, it is simply a matter of comparing the reported visibility with the visibility published on the approach chart. Consequently, air traffic control (ATC) will not clear an aircraft for approach if the reported visibility is less than what is published on the approach chart.

In Canada, visibilities published on approach charts are provided for information purposes only.

To determine whether an aircraft can legally land at an aerodrome in Canada, consideration must first be given to the operational restrictions that apply to the aerodrome in question to ensure that the aerodrome is suitable for the manoeuvre being executed. One of the determining factors is the aerodrome’s operating visibility, which is defined in the Canada Air Pilot (CAP 5) in the general pages pertaining to operating minima.  This operating visibility limit is published in the Canada Flight Supplement (CFS), specifically in the box reserved for runway information. If an aerodrome’s operating visibility limit is not published in the CFS, it means that operations are not authorized when visibility is less than ½ statute mile (SM).

Next, the minimum visibility for an approach ban must be calculated to determine whether the approach can continue to the DH or the MDA. This minimum visibility is calculated based on the visibility published on the approach chart, and varies depending on the type of operations:

According to this calculation, the minimum visibility for an approach ban in Canada is less than the visibility published on the approach chart in every case. Consequently, it is likely that, once at the DH or MDA, pilots are not able to establish the required visual reference that will help them make a safe landing.

In Canada, due to the complexity and variations in minima based on the type of operations, it is difficult for ATC to determine whether the planned approach is banned. It will clear an aircraft for approach regardless of the published minima, contrary to what is done elsewhere in the world. Therefore, it is up to the pilot to interpret the approach ban, and to decide whether or not to continue with the approach.

In this occurrence, based on his interpretation of numerous conditions and exceptions relating to the approach ban, the captain incorrectly believed that he was allowed to conduct the approach. The first officer was aware that weather conditions were below the approach minima published in the CAP, but he did not understand all of the details involved in the approach ban. He was therefore unable to challenge the captain’s decision to conduct the approach.

Given that it was difficult for the flight advisory service and the aerodrome operator to determine whether the approach was banned, they could not inform the pilots that the approach was banned under the existing conditions, despite the fact that visibility was one quarter of what was published on the approach chart. Therefore, if Transport Canada (TC) does not simplify approach and landing operating minima, flight crews may proceed with an approach that is actually banned, thereby increasing the risk of approach-and-landing accidents (ALAs), including runway overruns.

Therefore the Board recommends that:

the Department of Transport review and simplify operating minima for approaches and landings at Canadian aerodromes.
TSB Recommendation A20-01

In this occurrence, the approach ban in effect in Canada did not prevent the captain from continuing with the approach in weather conditions that were one third of the authorized visibility minima and one quarter of the visibility published on the approach chart. During the approach, when the aircraft arrived at the MDA, it was up to the pilot alone to determine whether or not he had established the visual reference required to continue the descent and landing. Therefore, it is reasonable to conclude that the approach ban was ineffective in stopping this approach while visibility on the ground was below the minimum required for an approach ban, which contributed to the runway overrun.

As this occurrence demonstrates, if there is no mechanism to stop an approach that is in fact banned, then pilots may choose to continue their approach, which increases the risk of an ALA.

Consequently, the Board recommends that:

the Department of Transport introduce a mechanism to stop approaches and landings that are actually banned.
TSB Recommendation A20-02

Safety concern

Transport Canada regulatory oversight of standard operating procedures

Since 2019, TC has required all commercial air operators to provide contemporary crew resource management (CRM) training. However, although TC performs regular inspections of operators, these inspections are generally limited to documentation of the systems put in place by the company. For example, in this occurrence, the standard operating procedures (SOPs) complied with Canadian Aviation Regulations (CARs) requirements from a formal standpoint, but their effectiveness was not evaluated by TC. In this context, it is impossible to assess the effectiveness of training, CRM, threat and error management (TEM), decision making, and the degree to which SOPs are applied or complied with and their effectiveness on board aircraft during operations.

SOPs are not only guidelines for the general use of aircraft; they are universally recognized as fundamental to safe aviation operations, creating a framework for the application of concepts such as CRM and TEM. The Flight Safety Foundation (FSF) and the FAA have released several recommendations pertaining to SOPs to reduce the risk of an ALA.

Between 1999 and 2019, SOPs were mentioned in 113 findings as to causes, contributing factors, and risks in TSB aviation investigation reports. The deficiencies identified were primarily associated with a lack of precise directives, differences in procedures, and deviations from procedures. In this occurrence, a deviation from SOPs at a critical moment of the flight was a key factor that contributed to the runway overrun.

The Board is concerned that if TC does not provide oversight of flight operations by assessing the effectiveness of CRM, TEM, decision making and SOPs, including the degree of application and compliance, these SOPs may not be effective, increasing the risk of an accident, particularly an ALA.