TSB Recommendation A24-02

A robust approach to preventing accidents resulting from a loss of visual references must include multiple defences that will assist in the avoidance of, and recovery from, inadvertent flight into instrument meteorological conditions (IIMC). This is particularly true for commercial VFR helicopters, which routinely operate at lower altitudes than commercial VFR airplanes. Recommendation A24-01 identifies the need for pilots to possess the skills necessary to recover from IIMC. However, equally important is the need for pilots to be provided with information that will help maximize situational awareness and support pilot decision making (PDM) before or after entering IIMC. There are several ways that technology can be used to prevent IIMC accidents.

In this occurrence, the pilot encountered flat light and whiteout conditions as the helicopter crossed Griffith Island. The helicopter was equipped with flight instruments; however, the pilot relied on the “avoid-at-all-costs” approach to these conditions, which is permitted under the CARs and was part of his training. Thus, the pilot was trained to fly solely on outside visual references in situations of reduced visibility. Additionally, the occurrence helicopter was not equipped with technology capable of alerting the pilot to the helicopter’s height above ground or rate of descent. Therefore, the pilot had no way of being warned of the impending collision with terrain that occurred shortly after he likely attempted a visual 180° turn in instrument meteorological conditions.

One of the most basic examples of technology that can help prevent IIMC accidents is flight instrumentation. The CARs outline specific flight instrumentation requirements for aircraft operated under IFR;^{Footnote 1} however, the requirements are significantly lower for aircraft operated under VFR.^{Footnote 2}

Specifically, VFR aircraft are not required to be equipped with flight instruments that are critical to aircraft control in conditions such as flat light and whiteout conditions, which have been repeatedly associated with IIMC accidents,^{Footnote 3} just like in this occurrence.

In 1990, the TSB issued Recommendation A90-84 calling on Transport Canada (TC) to require all commercially-operated helicopters to be equipped with appropriate instrumentation for the conduct of basic instrument flying. TC does not support this active recommendation. Therefore, given the lack of progress, the Board considers TC’s response to Recommendation A90-84 as Unsatisfactory.

During the investigation into this occurrence, the TSB discovered that some Canadian commercial helicopter operators with management staff who possess IFR flight experience consider it essential that VFR helicopters operating above the tree line during the winter months be equipped with flight instruments necessary for IFR, and pilots be trained for IIMC recovery. Some of those operators also consider it vital to equip those aircraft with radar altimeters, and one operator has begun using synthetic vision systems. In contrast, some VFR helicopter operators do not see a need to implement these defences. In the case of GSH, the company’s management pilots, who were VFR-only rated pilots, did not feel it was necessary to implement similar defences, even though some pilots had requested it. GSH’s management pilots were also aware that, in 2015, the company’s predecessor had an accident in flat light and whiteout conditions that resulted in several internal recommendations. However, the absence of formal requirements to equip VFR helicopters with basic flight instruments has likely contributed to a perception among some VFR helicopter operators that the use of basic flight instruments, and the training needed to use them, will not necessarily prevent IIMC accidents. As a result, VFR helicopter pilots continue to be dispatched to areas prone to environmental conditions such as flat light and whiteout without basic flight instrumentation and without training on how to use that instrumentation if all visual references are lost. This places VFR helicopter pilots and the passengers who fly on those aircraft at increased risk of collision with terrain following an IIMC encounter.

In addition to basic flight instrumentation, several technological advances have emerged to enhance pilot situational awareness and, therefore, assist in the reduction of IIMC accidents. Many of these systems can alert pilots to unintended flight profile changes that increase the risk of an IIMC accident. For example, some systems can be used to establish “en-route decision triggers,” such as a minimum height above ground, and alert the pilot if the helicopter’s height above ground drops below the preset threshold. This can be particularly beneficial in conditions of flat light and whiteout because of their insidious nature, which can make it difficult for a pilot to accurately assess height above ground.

More advanced forms of technology, such as helicopter terrain awareness and warning systems, can also warn of an impending collision with terrain or of excessive rates of descent close to the ground. These types of alerts can help a pilot recognize, in a timely manner, that emergency action must be taken to prevent a collision with terrain. Another form of technology that has become more widespread in recent years is synthetic vision systems, which are capable of providing pilots with a virtual 3-dimensional map on a display in the cockpit, or in a tablet-based application such as ForeFlight. This same application can, with some minor aircraft modifications, provide the pilot with a set of backup flight instruments like a modern glass cockpit.

The above-mentioned forms of technology help maximize pilot situational awareness by providing the pilot with information that may not otherwise be available if solely relying on outside visual references. With proper training and procedures, these technologies can greatly reduce the risk of IIMC accidents by warning the pilot when safety margins are being eroded or by assisting the pilot to escape IIMC.

In 2002, following a series of accidents involving VFR helicopters in flat light, the U.S. National Transportation Safety Board issued a safety recommendation calling for the installation of radar altimeters in commercial helicopters operating in areas where flat light or whiteout conditions routinely occur.^{Footnote 4} After several additional accidents involving these conditions, the U.S. Federal Aviation Administration chose to expand the scope of this recommendation and amended the Federal Aviation Regulations to require all commercial helicopters be equipped with a radar altimeter or a device that incorporates a radio altimeter. According to the Federal Aviation Administration, “radio altimeters help increase situational awareness during inadvertent flight into instrument meteorological conditions (IIMC), night operations, and flat-light, whiteout, and brownout conditions.”^{Footnote 5}

In 1990, the TSB issued Recommendation A90-83 calling on TC to require all helicopters engaged in commercial passenger carrying operations be equipped with radar altimeters. TC did not support this recommendation. In September 2012, given the lack of progress addressing the safety deficiency associated with Recommendation A90-83, the Board considered TC’s response to be Unsatisfactory and changed the recommendation status to dormant.

The TSB has previously attempted to address safety issues related to helicopter collision with terrain accidents, calling for increased requirements for flight instrumentation and other systems such as radar altimeters. To date, TC has not taken the measures needed to address these recommendations, which were issued more than 30 years ago. The Board believes that more must be done to reduce the incidence of loss of visual reference accidents, which are more than twice as likely to involve a helicopter than they are to involve an airplane. Many forms of technology now exist that, if required by regulation, could greatly reduce the risk of IIMC accidents, particularly in areas prone to flat light and whiteout conditions. Because there is no requirement for VFR helicopters to be equipped with technology that can assist pilots with the avoidance of, and recovery from, IIMC, the pilots and passengers who fly on those helicopters remain at increased risk of collision with terrain.

Therefore, the Board recommended that