A Safety Study of Evacuations of Large, Passenger-Carrying Aircraft

Escape Slide Performance

Problems in operating emergency exits and deploying emergency slides delayed many evacuations, potentially compromising the success of the evacuation. Since 7 of 15 evacuations requiring slides were hindered as a result of problems related to deployment and/or angle of inclination, it appears that the intent of the current Airworthiness Standard is not being achieved. Given that the use of effectively deployed escape slides may be critical to the success of an aircraft evacuation, the Board recommends that:

The Department of Transport, in concert with industry, re-evaluate the performance of escape slides on all passenger-carrying aircraft registered in Canada, to confirm that they can be functionally deployed in accordance with the criteria of the Airworthiness Standard. (A95-03)

Transport Canada's Response:

The airworthiness standards applicable to emergency exit assist means have been upgraded over the years to address the types of problems presented in the Transportation Safety Board report. More recently, Transport Canada Aviation (TCA) in concert with the Federal Aviation Administration (FAA) and industry, recognized the need to further improve performance standards for emergency exit assist means. Issues being addressed by TCA, the FAA and industry include: slide strength, rate testing and slide illumination. A substantial rewrite of Technical Standards Order TSOc69 is in process.

From an operational perspective, TCA standards require flight attendant training programs to include procedures that describe the different aircraft attitudes possible as a result of accidents/incidents (such as gear collapse, off-runway, shift in centre of gravity) and the effect of environmental conditions in evacuations (such as strong winds, terrain, snow/ice). Flight attendants are also trained to manage situations or problems associated with evacuation slides.

Public Address Systems

The Board is concerned that, as a result of inoperable or inaudible PA systems, some cabin crew and/or passengers were unable to hear the initial command to evacuate and/or subsequent directions in eight occurrences. The Board is currently investigating the evacuation of a DHC-8 where announcements made by the captain on the PA system were inaudible by the cabin attendant and the passengers. Since cabin crew and passengers continue to be placed in a position of increased risk of delay in evacuations due to inaudible commands or instructions, the Board recommends that:

The Department of Transport review the adequacy of power supplies and standard operating procedures for PA systems in an emergency for all Canadian operators of large passenger aircraft. (A95-04)

Transport Canada's Response:

The airworthiness standards applicable to large passenger aircraft did not contain requirements for Public Address (PA) systems power supplies until recently. Amendments to add applicable requirements were introduced in 1989 and 1993. These will apply to new large passenger aircraft designs.

From an operational perspective, flight attendants are trained to not rely on aircraft power during an emergency requiring an evacuation; these emergency procedures form part of their training program and are approved by Transport Canada Aviation.

Flight attendants are also trained to direct passengers in emergency situations by the use of shouted commands. This includes commands to be used for each type of evacuation and the rationale behind each of the commands. Shouted commands training includes voice tone, pace, volume, diction, body language, and phraseology commands in unison.

Joint Crew Emergency Training Program

Ineffective crew communication created an environment in which passengers and crew were exposed to unnecessary risks during the evacuation process in at least 3 of the 21 occurrences examined.

Notwithstanding Transport Canada's efforts to promote effective crew communication by encouraging air carriers to implement joint crew training, the Board believes that lack of, or ineffective, crew communication continues to place the lives of aircraft occupants at risk during evacuation of large passenger-carrying aircraft. In view of the Canadian accident experience and demonstrated problems in crew coordination on a global basis, the Board recommends that:

The Department of Transport require that air carriers implement an approved joint crew emergency training program with emergency simulations for all air crew operating large passenger-carrying aircraft. (A95-05)

Transport Canada's Response:

Transport Canada Aviation (TCA) supports the requirement for joint crew training and has already confirmed this support in its reply to Justice Virgil Moshansky who headed the Commission of Inquiry into the Air Ontario Crash.

The draft Canadian Aviation Regulations (CARs) will contain provisions to require air carriers to implement crew training with pilots and flight attendants together in each annual requalification training year. It is anticipated that the draft CARs will be published in the Canada Gazette Part I in late spring 1995 and in the Canada Gazette Part II by the end of 1995.

Several Canadian air carriers currently conduct joint CRM training which includes flight attendants and pilots reviewing emergency procedures together and coordinated evacuation drills and communication. TCA continues to promote this type of training.

Pre-Landing Briefings

While the Board agrees with Transport Canada's recent initiative to require a standard safety briefing prior to landing on certain flights, there is concern that safety information found only on the safety features card, such as exit operation, recommended brace positions, floor proximity emergency path lighting, use of the escape slides, and life jacket location and donning instructions, will not be reinforced prior to landing.

Since most emergency evacuations are unplanned and occur during the landing phase, the Board recommends that:

The Department of Transport encourage carriers to include sufficient detail in their pre-landing briefings to prepare passengers for an unplanned emergency evacuation. (A95-06)

Transport Canada's Response:

Transport Canada Aviation agrees with the concept of providing passengers with safety information that would assist them in the event of an emergency requiring an evacuation. In fact, Canada will be a world leader in requiring the safety briefing prior to landing to include the location of emergency exits on flights of four hours duration or more.

The issue of prior to landing briefings has been thoroughly reviewed and was discussed extensively during the Canadian Aviation Regulation Advisory Council (CARAC) process. During this review it was felt that some safety information needed to be reinforced on long flights, however there was insufficient data to support a requirement to provide passengers with information relative to an unplanned emergency evacuation prior to every landing.

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