SA9501 - A Safety Study of Evacuations of Large, Passenger-Carrying Aircraft
Background
When the airplane landed the visibility in the cabin was virtually non-existent at heights higher than one foot above the cabin floor. The survivors stated that they barely possessed the strength and mental capacity to negotiate the exits. (1) (A83F0006)
From 1978 through 1991 there were 18 evacuations of large, Canadian-registered, passenger-carrying aircraft. In addition, there were 3 evacuations in Canada of foreign aircraft. These 21 occurrences involved 2,305 passengers and 139 crew members and resulted in 91 fatalities and 78 serious injuries. Some 36 fatalities and 8 serious injuries occurred during the evacuation process.
Objective
This safety study examines the Canadian experience with respect to the evacuation of passengers from large aircraft and identifies safety deficiencies associated with communications during evacuations, exit operation, passenger preparedness for evacuations, and the presence of fire, smoke, and toxic fumes.
Protective Breathing Equipment - Cabin Crew
In the context of the actual evacuation process, there is no direct evidence that a lack of PBE for cabin crew resulted in fatalities or injuries during evacuations. Yet, there is a paradox in that cabin attendants are expected to fight cabin fires, but, in many cases, they are not provided with PBE in the aircraft cabin. Ready access to portable PBE could improve their ability to fight fires and have the effect of reducing the risks faced by occupants during an evacuation. Therefore, the Board recommends that:
The Department of Transport require that sufficient portable protective breathing equipment units with full-face masks be carried in the passenger cabins of transport aircraft for cabin crew. (A95-01)
Transport Canada's Response:
Transport Canada Aviation concurs with the recommendation and has proposed a regulation that will require portable protective breathing equipment for all crew members for use when fighting fires in cargo compartments that are accessible to crew members during flight, in isolated galleys and in aircraft cabin areas.
Protective breathing equipment is defined as equipment to cover the eyes, nose and mouth, or the nose and mouth if accessory equipment is provided to protect the eyes, that will protect the wearer from the effects of smoke, carbon dioxide or other harmful gases.
The proposed regulation is contained in the draft Canadian Aviation Regulations. It is anticipated that these proposed regulations 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.
In the light of the number of fatalities that occur when fire, smoke, and/or toxic fumes are present, the Board believes that further research is required to determine whether passengers should be given the opportunity to carry appropriate protective breathing equipment. Accordingly, the Board recommends that:
The Department of Transport re-evaluate research regarding protective breathing equipment (PBE) for passengers with a view to determining the feasibility of the carriage of appropriate protective breathing equipment, on a voluntary basis. (A95-02)
Transport Canada's Response:
Passenger protective breathing equipment (PPBE) types currently available on the market are filter, chemical reaction producing oxygen and oxygen/compressed air cylinder generated. Depending on the presence or absence of dangerous goods in the PPBEs, they could be subject to the Transportation of Dangerous Goods Act, 1992. Current regulations do not permit passengers to carry PPBEs containing dangerous goods into the cabin of an aircraft. The Dangerous Goods Panel of the International Civil Aviation Organization is currently in the process of reviewing smoke hood (PPBE) specifications to evaluate the types and quantities of dangerous goods present.
In 1987 the British Civil Aviation Authority, in collaboration with three other aviation authorities (including representatives from Transport Canada Aviation), carried out research to assess the life-saving potential of PPBEs. The analysis showed there would be a reduced benefit overall and, in some accidents, additional loss of life was likely due to the delay caused by the donning of smoke hoods which would result in a slower evaluation. Although there is not sufficient benefit to require protective breathing equipment for passengers, a passenger may carry his/her own PPBE onboard if it does not contain dangerous goods.
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.
FOOTNOTE
(1) All events quoted in this study are excerpts from Transportation Safety Board of Canada (TSB), Canadian Aviation Safety Board (CASB), or National Transportation Safety Board (NTSB) accident investigation reports or witness statements.
A93H0023 - Controlled Flight into Terrain - Air Manitoba Limited - Hawker Siddeley, HS 748 Series 2A C-GQTH - Sandy Lake, Ontario 1 nm NW 10 November 1993
Synopsis
The flight departed Winnipeg, Manitoba, at 1438 central standard time (CST) for Sandy Lake, Ontario. On arrival at Sandy Lake at approximately 1549 CST, the crew attempted to land but were unable to because of the low ceiling and visibility. They then diverted to St. Theresa Point, Manitoba, landing at 1630 CST. After a normal turnaround, the flight returned to Sandy Lake and landed at approximately 1745 CST. The aircraft took off from runway 29 at Sandy Lake at approximately 1805 CST and immediately entered a right turn. After turning through about 120 degrees, the aircraft descended into 100-foot trees and crashed. All seven occupants of the aircraft were fatally injured, and the aircraft was destroyed.
The Board determined that, after take-off, the crew most likely lost situational awareness and, as a result, did not detect the increasing deviation from their intended flight path. Contributing to the loss of situational awareness was the lack of AC power to some of the flight instruments; the reason for the lack of AC power could not be determined.
Safety Action Taken
(as presented in the TSB Report)
Transport Canada (TC) Special Inspection
In January 1994, TC conducted a special inspection of Air Manitoba's Flight Operations and Maintenance departments. The findings of this inspection, primarily with respect to maintenance shortcomings, resulted in removal of the company's maintenance certificate and suspension of its operating certificate. The company subsequently contracted its HS 748 maintenance to another carrier and regained its operating certificate.
Flight Recorders
Flight recorder information is often invaluable in the investigation of occurrences and it most certainly would have assisted in determining the events leading to this accident. In the past, the Board has made recommendations concerning deficiencies on the retrieval and quality of recorded data and on the lengthy process required to update flight recorder legislation. Notwithstanding the emphasis that the Board has put on the importance of flight recorders for investigation and accident prevention processes, there has not been any significant progress in addressing these flight recorder deficiencies. Therefore, the Board recommended that:
The Department of Transport immediately verify through field audit that all existing FDR and CVR installations meet current regulatory requirements, and make public its findings; (A94-01, issued January 1994)
The Department of Transport revise its approval and monitoring process to ensure that all future FDR and CVR installations continue to meet regulatory requirements; (A94-02, issued January 1994)
The Departments of Justice and Transport promulgate the new Orders on flight recorders without further delay; and (A94-03, issued January 1994)
The Department of Transport streamline its processes to facilitate the timely Canadian implementation of updated flight recorder requirements. (A94-04, issued January 1994)
In response to these recommendations, TC has undertaken a program to review operator compliance with existing recorder requirements in order to identify areas of the monitoring and approval processes that need revision. In addition, TC stated its intention in April 1994 to issue two interim circulars to facilitate industry adjustment to the new recorder regulation expected to come into law in early 1995.
With respect to streamlining the recorder legislation process, TC stated that a new regulatory structure will have regulations which incorporate standards by reference in order to facilitate amendment in a timely way. TC's new approach to use standards to keep pace with changing requirements in aviation, and in particular flight recorder technology, is an important improvement in the regulatory process. Also, TC has reached consensus with industry to harmonize with the U.S. Federal Aviation Regulations (FAR) in finalizing the draft Canadian regulations.
The new regulation will state which aircraft will require FDRs and CVRs; the standards section will list parameters, operational requirements, and other technical specifications.
The Department of Justice has advised that it is prepared to carry out its regulatory functions as quickly as possible to ensure the regulations proposed by TC can be promulgated with the least possible delay.
Static Inverter Installation
Anomalies were found in the static inverter installation which had replaced the original rotary inverter system of the occurrence aircraft. Given that other Canadian operators may also be operating HS 748s with similar electrical system discrepancies, a TSB Aviation Safety Advisory was forwarded to TC. The Advisory concerned the requirement to verify that the inverter systems of all Canadian HS 748 aircraft conform to the applicable installation drawings.
Undervoltage Protection
Significant importance has been afforded the issue of undervoltage protection for the HS 748 aircraft. It was determined that Service Bulletins (SB) 24/60 and 24/97 are considered to be mandatory. A TSB Aviation Safety Advisory forwarded to TC addressed the need to confirm that all Canadian HS 748 aircraft meet the current electrical system requirements for undervoltage protection.
Accidents Involving Controlled Flight into Terrain
The circumstances of this occurrence are typical of a Controlled Flight into Terrain (CFIT) accident. CFIT occurrences are those in which an aircraft, under the control of the crew, is flown into terrain (or water) with no prior awareness on the part of the crew of the impending disaster. The Board notes with concern that, over the 11-year period from 01 January 1984 to 31 December 1994, 68 commercially operated aircraft not including those conducting low-level special operations) were involved in CFIT accidents. In view of the frequency and severity of such accidents, the Board is currently conducting a study of CFIT accidents to identify related systemic deficiencies.
Regulatory Audits and Surveillance
Analysis and information from this investigation and 18 others led to the identification of shortcomings in the regulatory overview process of air carriers. In particular, it was found that TC's audits sometimes lacked depth, and that the verification of corrective action following the audits was sometimes inadequate. Therefore, the Board recommended that:
The Department of Transport amend the Manual of Regulatory Audits (MRA) to provide for more in-depth audits of those air carriers demonstrating an adverse trend in its risk management indicators; (A94-23, issued December 1994)
The Department of Transport ensure that its inspectors involved in the audit process are able to apply risk management methods in identifying carriers warranting increased audit attention; (A94-24, issued December 1994)
The Department of Transport develop, as a priority, a system to track audit follow-up actions; and (A94-25, issued December 1994)
The Department of Transport implement both short and long term actions to place greater emphasis on verification of required audit follow-up action and on enforcement action in cases of non-compliance. (A94-26, issued December 1994)
In response to these recommendations, TC has indicated that both Recommendations A94-23 and A94-24 will be taken into consideration during amendments to the MRA. Also, TC will ensure that the Audit Procedures training program for inspectors takes into account Recommendation A94-24 so that risk management methods are clearly understood and applied.
With respect to Recommendations A94-25 and A94-26, TC replied that the MRA will be reviewed to ensure clear policy direction is given to ensure effective audit follow-up systems are in place. Furthermore, an enhanced National Aviation Company Information System (NACIS) should be operational by September 1995 to track audit follow-up on a national basis. In the interim, a policy directive will be issued to regions to require a review of respective regional follow-up systems.
Safety Action Required
(as presented in the TSB Report)
Global Positioning System (GPS)
The GPS installation in C-GQTH was used in instrument meteorological conditions (IMC) as a primary navigation aid during the approaches to Sandy Lake. The GPS installation was not approved for such use. The TSB has identified other occurrences in which pilots have misused GPS while conducting IFR flights, or in which pilots on VFR flights have continued flight into adverse weather while using GPS and encountered conditions with which the pilot and/or aircraft could not cope. Evidence suggests that both recreational pilots (seeking an inexpensive navigational system) and commercial, passenger-carrying operators are employing GPS in order to get into airports without approved instrument approaches. It is doubtful that these locally improvised GPS approaches take into account the obstruction clearance criteria used in the design of approved approaches, including the acquisition of valid local altimeter settings.
While the Board is concerned over the misuse of GPS, it recognizes the potential of this equipment and what it could offer to the Canadian aviation community. The potential benefits of GPS have been widely publicized; the safety implications of improvising in the use of GPS in a non-regulated environment have received less publicity. The benefits may be tempting pilots and operators to accept risks that would normally be unacceptable without GPS. Therefore, to reduce the potential for GPS-related occurrences resulting from the use of unapproved equipment, inadequate understanding of the system, or lack of approved approaches, the Board recommends that:
The Department of Transport expedite the implementation of approved GPS standards and procedures for use in Canadian airspace (A95-07); and
The Department of Transport initiate a national safety awareness program addressing the operating limitations and safe use of GPS in remote operations. (A95-08)
Transport Canada's Response :
Transport Canada Aviation (TCA) agrees with both recommendations. In fact, TCA has been devoting considerable resources to GPS. In late 1992, a Global Navigation Satellite System (GNSS) Working Group was established to explore the potential of GPS and develop safety standards. This was succeeded in July 1994 by a Satellite Navigation Progam Office (SNPO), with dedicated staff and funding. The SNPO coordinates TCA's GPS efforts; its priorities are to develop safety standards and to communicate with users.
A considerable amount of information has been provided to users. In February 1993, a section on satellite navigation was included in the Aeronautical Information Publication (AIP) Canada. The text, updated regularly, explains the operation, features and shortcomings of GPS. It specifically warns against using uncertified receivers for IFR. All major aviation organizations have been briefed, as have staff in regional offices. A "GNSS Update" newsletter provides technical information and the latest news on GPS. The first issue, published in April 1993, contained a clear warning against using uncertified receivers for IFR. In each region, a SNPO point of contact coordinates communications with local users.
These IFR GPS approvals are classified as supplemental (as opposed to sole means). Supplemental use imposes certain limitations. Firstly, the crew must always have available, and in some cases continuously monitor, a conventional navigation aid (ie. VOR or NDB). GPS can be used to navigate the aircraft, but because the chance of loss of service or provision of wrong information is greater than aviation standards permit, a navigation aid which meets the standards must be used as backup. This safeguard permits early benefits to the industry and increases operational experience with GPS. Secondly, the receiver used must be certified to the standards of TSO C129 and must meet installation requirements. This ensures acceptable receiver performance, user interface, compatibility with other aircraft systems, etc.
TCA has also been active in standards development. In 1992, TCA began working with the U.S. Federal Aviation Adminsitration (FAA) to explore the potential of GPS and to develop standards and procedures to ensure safe operations. A Technical Standard Order (TSO C129) for receivers was developed in the U.S. in 1992 and applies in Canada.
Joint TCA/FAA trials proved that TSO C129 receivers would support IFR en route and non-precision approach operations. This led to the first approval to use GPS for IFR in the U.S. in June 1993 and in Canada in July 1993. The TCA approval (revised in February 1995) is detailed in a Special Aviation Notice provided to all Canadian pilots. The Notice specifies receivers meeting TSO C129. In August 1993 TCA issued an Air Carrier Advisory Circular, encouraging all Canadian operators to use GPS and providing guidance to help them to obtain approval. During the same period, TCA Airworthiness developed receiver installation standards. An Aeronautical Information Circular (AIC) issued July 21, 1994 amended ANO V, No. 22 - IFR Flight Instruments and Equipment Order to allow a certified GPS receiver to replace one VOR or ADF receiver. TCA has designated 149 GPS non-precision approaches overlaying existing VOR and ND approaches to ensure safety while gaining experience with GPS. There is no overlay approach at Sandy Lake. All TCA documents specify that TSO C129 receivers must be used for IFR operations.
TCA is currently working with the FAA to develop GPS augmentations to permit sole means use and precision approach. TCA will ensure that these new systems are safe through trials, studies and participation in standards development.
In summary, TCA agrees with the recommendations, will continue to expedite the development of standards and will continue to promote the safe use of GPS. Specifically, an Aviation Notice and an article in the Aviation Safety Letter newsletter will be published at the next opportunity, highlighting the hazards of improper use of GPS.
Flight Instruments - Large Turbo-Prop Aircraft
Large turbo-prop aircraft, some capable of seating more than 50 passengers, are in wide use in Canada because of their suitability for commuter operations, and for flights into remote or smaller airports. A significant proportion of all passengers transported annually by Canadian air carriers are in such turbo-prop aircraft.
Many of these turbo-prop aircraft have a passenger-carrying capacity equivalent to that of mid-sized turbo-jet aircraft. Yet, unlike their turbo-jet counterparts, turbo-prop aircraft are not required to have either a standby attitude indicator or a Ground Proximity Warning System (GPWS). TC is currently revising the Canadian Aviation Regulations respecting the use of aircraft in a commercial air service through an advisory committee process. The regulatory committee will focus, in part, on maximizing the compatibility of the Canadian regulatory system with that of other regulatory authorities such as the Federal Aviation Administration (FAA) in the U.S.
Standby Attitude Indicators
The attitude indicator or artificial horizon is the pilot's primary reference for instrument flying at night, in low visibility, or in cloud. A standby attitude indicator provides a means to cross-check and validate information supplied by the primary attitude indicators and also serves as an independently powered backup system should the primary instruments fail.
In the United States, an independently powered standby attitude indicator has been a requirement on all turbine-powered large aircraft since October 199414 with no distinction made between turbo-jet and turbo-prop aircraft. The Board believes that the need for a standby attitude indicator on an aircraft should not be related to the method of aircraft propulsion; rather, the role of the aircraft and its passenger-carrying capacity are better indicators of the need for added safety precautions. Given the increased safety margin provided by a standby attitude indicator in the event of failure of the primary attitude indicator, the Board recommends that:
The Department of Transport require the installation of an independently powered standby attitude indicator on all turbine-powered, IFR- approved commuter and airline aircraft capable of carrying 10 or more passengers.
(A95-09)
Transport Canada's Response:
The Additional Bank and Pitch Indicator Order (A.N.O., Series II, No. 17), presently requires large turbo-jet aeroplanes to be equipped with a standby attitude indicator.
The draft Canadian Aviation Regulations (CARs) have recently been amended to require installation of a standby attitude indicator in all turbine-powered commercial aeroplanes certified to Federal Aviation Regulation (FAR, Part 24 or equivalent). This amendment will require the HS 748 to be so equipped. The CARs are scheduled to be published in Part I of the Canada Gazette in the Fall of 1995.
This requirement does include all airline turbine aircraft, but not all commuter aircraft in the 10-19 passenger seat range. Transport Canada Aviation will refer the recommendation to the Canadian Aviation Regulation Advisory Council, Part VII Technical Committee for analysis, including cost/benefit, to determine if the regulations should be expanded to include all commuter aircraft.
Ground Proximity Warning Systems (GPWS)
Within the global aviation community, GPWS has been recognized for its potential to prevent CFIT accidents. In Canada, GPWS has shown its effectiveness on at least two occasions. In 1987, the crew of a Boeing 737 carrying 96 people were warned of the aircraft's proximity to the ground on two separate occasions by GPWS while on approach at Prince George, British Columbia (A87P4128). Similarly, in 1990, the pilots of a Dash-8 on approach into Charlo, New Brunswick, were warned by their GPWS of inadequate ground clearance caused by a 1,000-foot altimeter error. There were 32 souls on board this Dash-8 aircraft (A90A0256). (Of note, the installation of the GPWS on this turbo-prop aircraft was not required by regulations).
In an effort to reduce CFIT accidents in commercial operations, the FAA in the United States made GPWS mandatory on all turbine-powered (i.e. both turbo-jet and turbo-prop) aircraft capable of carrying 10 or more passengers, effective 20 April 199415. It is understood that similar measures are not being contemplated at this time for Canadian-registered turbo-prop aircraft.
As previously stated, over the preceding 11 years, 68 commercially operated aircraft were involved in CFIT accidents; 13 of these were turbo-prop aircraft. The Board believes that the increased level of safety provided by GPWS should not be related to an aircraft's type of propulsion. Rather, GPWS installation should be based on the role of the aircraft and its passenger-carrying capacity. The Board commends the initiative of some operators to install GPWS in their aircraft--even though it is not required by Canadian regulations. However, most turbo-prop aircraft, some carrying dozens of passengers, continue to operate without the added safety protection of GPWS. Therefore, the Board recommends that:
The Department of Transport require the installation of GPWS on all turbine-powered IFR- approved commuter and airline aircraft capable of carrying 10 or more passengers. (A95-10)
Transport Canada's Response:
The current Canadian regulations with respect to GPWS, state that no person shall operate a turbo-jet powered aeroplane that has a maximum certificated take-off weight of more than 15,000 kg. (33,069 pounds) or for which a type certificate has been issued authorizing the carriage of 10 or more passengers unless the aircraft is equipped with GPWS. These provisions are continued in the draft Canadian Aviation Regulations (CARs).
This regulatory requirement does not include all turbine-powered aeroplanes in the commuter and airline category. Transport Canada Aviation will refer the recommendation to the Canadian Aviation Regulation Advisory Council (CARAC), Part VII Technical Committee for analysis. The CARAC Regulatory Committee will review the analysis prior to making a decision on whether the regulations should be expanded to include all commuter and airline aircraft.
14 Federal Aviation Regulation (FAR) 14, CFR Part 121
Safety Concern
Monitoring of Pilot Flying Performance
In occurrence investigations, the flying history and records of the involved aircrew are routinely reviewed in detail. Analysis of recurring shortcomings in a pilot's flying performance may provide insight into the factors contributing to an occurrence, especially if the circumstances of the occurrence are similar to those in which the pilot had previously shown weaknesses.
There are no requirements for company check pilots and air carrier inspectors to look for adverse trends in a pilot's performance on flight tests. Indeed, it is understood that TC discourages such practice with a view to maintaining objectivity in testing. Nor is there a tracking system within TC to identify individuals repeatedly experiencing particular difficulties during flight tests.
A pilot can achieve an overall satisfactory rating on a flying proficiency check even though a critical sequence on the test may have been performed marginally. The overall pass on the test suggests that the pilot is competent to handle all the challenges associated with the flying privileges of his/her licence. However, this may not be the case, in that the pilot may have a history of problems in that specific aspect of flying.
The Board found no link between the flight crew's performance and this accident. Nevertheless, the Board is concerned that, without a formal procedure in place to review past flight test results, pilots with fundamental weaknesses in flying performance may be permitted to continue flight operations. Therefore, the TSB will continue, through its investigations, to analyze any correlation between aircrews experiencing repeated flying performance difficulties, the circumstances of the occurrences in which they are involved, and the flight test standards as established by Transport Canada
A93P0131 - Runway Excursion - Canair Cargo Ltd. Convair 580 C-GQHB Tofino, British Columbia - 21 July 1993
Synopsis
The aircraft, a Convair 580, was on a flight from Vancouver, British Columbia, to Tofino with four crew members and 47 passengers on board. When the aircraft landed at Tofino, it touched down about midway down the 5,000-foot runway. The aircraft ran off the end of the runway and came to rest 150 feet past the runway end. There were no injuries; however, the aircraft sustained substantial damage.
The Board determined that the descent profile flown during the approach procedure resulted in the aircraft not being in a position to land safely; the captain elected to continue rather than conduct a missed approach, and the aircraft touched down with insufficient runway remaining in which to stop. Contributing to the occurrence were inadequate monitoring, by both the air carrier and Transport Canada, of aircraft operations remote from the company's main base.
Safety Action Taken
(as presented in the TSB Report)
Regulatory Audits and Surveillance
Analysis and information from this investigation and 18 others led to the identification of shortcomings in the regulatory audit process of air carriers. In particular, it was found that Transport Canada's (TC) audits lacked depth, and that the verification of corrective action following the audits was inadequate. Therefore, the Board recommended that:
The Department of Transport amend the Manual of Regulatory Audits to provide for more in-depth audits of those air carriers demonstrating an adverse trend in its risk management indicators; (A94-23, issued December 1994)
The Department of Transport ensure that its inspectors involved in the audit process are able to apply risk management methods in identifying carriers warranting increased audit attention; (A94-24, issued December 1994)
The Department of Transport develop, as a priority, a system to track audit follow-up actions; and (A94-25, issued December 1994)
The Department of Transport implement both short and long term actions to place greater emphasis on verification of required audit follow-up action and on enforcement action in cases of non-compliance. (A94-26, issued December 1994)
Flight Recorder Legislation
Over the years, the Board has made several recommendations concerning deficiencies in the retrieval and quality of flight recorded data and in the lengthy process required to update flight recorder legislation. Notwithstanding the emphasis that the Board has put on the importance of flight recorders for investigation and accident prevention purposes, there has not been significant progress in addressing these flight recorder deficiencies. Therefore, the Board recommended, inter alia, that:
The Departments of Justice and Transport promulgate the new Orders on flight recorders without further delay; and (A94-03, issued January 1994)
The Department of Transport streamline its processes to facilitate the timely Canadian implementation of updated flight recorder requirements. (A94-04, issued January 1994)
In response, TC has indicated that it intends to issue two interim circulars to facilitate industry adjustment to the new flight recorder regulation expected to come into law in early 1995. Also, TC stated that new regulations will refer to associated standards, which should facilitate amendment action in a timely way. The Department of Justice has advised that it is prepared to carry out its regulatory functions as quickly as possible to ensure that the regulations proposed by TC can be promulgated with the least possible delay.
Safety Action Required
(as presented in the TSB Report)
Crew Resource Management and Decision Making
Several factors led to the accident aircraft not being in the required position on final approach from which a safe landing could be executed. However, the accident could have been prevented if a decision had been made to discontinue the landing.
The Board has investigated several recent occurrences where inappropriate decisions have been made by aircrew, although cues were available which should have alerted them to potentially dangerous situations. While this occurrence at Tofino hinged upon a pilot decision at a critical point in the approach and landing phase, inappropriate decisions occur in almost all aspects of flight operations. See Appendix D (HTML or PDF ) for some examples of aviation occurrences with probable decision-making implications.
The Board recognizes that there are pressures in commercial aviation to "get the job done" and that these pressures undoubtedly affect decision making. Nevertheless, informed operators and trained aircrew should be able to handle these day-to-day operational decisions safely. In this vein, it is understood that crew training under real-world decision-making situations increases the likelihood of safe operational decisions. Subsequent to a DC-8 runway excursion at Moncton, New Brunswick (A91A0198), the involved carrier undertook several corrective measures, including the use of simulator training to assist crews in the decision-making process during approaches in reduced visibilities (such as the conditions encountered in the occurrence). In its final report on the occurrence, the Board encouraged such preventive action taken by the aviation community independent of regulatory requirements. However, the Board also expressed concern that other operators and aircrew without benefit of similar training programs and guidelines on the handling of critical decisions might continue to place their aircraft in unsafe situations.
Safety Action Required
(as presented in the TSB Report)
Like the Convair 580 aircrew involved in the Tofino occurrence, most of the aircrew involved in the other incidents/accidents had not received formal crew resource management (CRM) or pilot decision-making (PDM) training. (The operators and aircrew involved in the occurrences listed in Appendix D may have subsequently taken action with respect to CRM and PDM training.) In its Commercial Pilot Survey (1991), Levels III to VI Air Carrier Operations, the TSB found that only 22 per cent of the respondents indicated that CRM training was provided by their employer and that decision-making training was available to only 27 per cent. Other countries have recognized the merits of this type of training; reportedly, the Federal Aviation Administration in the United States will require, by late 1995, resource management training for airlines to improve communication and co-ordination among crew members.
In its Safety Study of VFR Flight into Adverse Weather (1990), the Board supported TC's initiative to evaluate pilot decision-making skills in the Private Pilot Licence flight test, and recommended that the Minister of Transport devise and implement a means of regularly evaluating the practical decision-making skills of commercially employed pilots in small air carrier operations (TSB A90-86). TC responded that Pilot Proficiency Checks would provide an assessment of a pilot's ability to make reasoned and timely decisions when faced with a simulated emergency situation. TC also indicated that it would keep abreast of developments in the field of decision-making training and assessment, and would not hesitate to introduce improvements.
The eight referenced occurrences and the one at Tofino involved a total of 188 crew and passengers on board nine aircraft; eighteen fatalities resulted. The potential for more serious consequences was high. All of these occurrences were after the issuance of TSB recommendation A90-86 and for the most part involved small air carriers. The "inappropriate decisions" taken in these occurrences were not linked to emergency situations that would normally be tested on Pilot Proficiency Checks. Furthermore, the Board understands that there are still no requirements or established guidelines for ongoing training and evaluation of decision-making skills in the routine situations that commercial pilots face day-to-day.
While the commercial aviation community has broadly embraced the concepts of CRM and PDM training, formal programs are only being administered on a voluntary, ad hoc basis. Consequently, ineffective resource management and faulty decision making continue to contribute to unsafe situations in commercial air transportation. Notwithstanding the many pressures in the commercial flying environment that come to bear on operators and aircrew, the Board believes that, with the correct tools and skills, the likelihood of inappropriate decisions can be reduced. While some large air carriers can develop the necessary training on their own, other operators will require direction and assistance in setting up meaningful training programs. Therefore, to ensure that all operators and aircrew involved in commercial aviation have access to training for better coping with day-to-day operating decisions, the Board recommends that:
The Department of Transport establish guidelines for crew resource management (CRM) and decision- making training for all operators and aircrew involved in commercial aviation; and (A95-11)
Transport Canada's Response:
Crew resource management (CRM) and decision making training will be mandated for all air operators who are required to adhere to the Airline Operations regulations. A standard has been developed and forms part of the Commercial Air Services Standard (CASS) incorporated by reference by the Canadian Aviaiton Regulations (CARs). The CARs will appear in the Canada Gazette Part I during the summer of 1995 and be promulgated later in the year. The CASS will allow initial CRM training to be conducted separately for pilots and cabin safety personnel, however recurrent training will be conducted annually in a joint training environment. In addition, guidance material has been developed to support the regulation and standard.
The Department of Transport establish procedures for evaluating crew resource management (CRM) and pilot decision-making (PDM) skills on a recurrent basis for all aircrew involved in commercial aviation. (A95-12)
Transport Canada's Response:
Transport Canada Aviation (TCA) has developed guidance material to assist air operators in the development of a Crew resource management (CRM) program that meets the Commercial Air Services Standard. Evaluation of CRM skills will be accomplished by way of a debriefing session involving all participants following the joint recurrent training. This, in addition to normal monitoring of air carrier training programs by TCA Air Carrier Inspectors will serve to evaluate the effectiveness of an air carrier’s CRM training program.
TCA is currently in the process of developing three human factors handbooks; one at the basic level, one at the advanced level, and one for flight instructors. In the advanced and flight instructor handbooks, there will be tools to evaluate attitudes, knowledge and skills for PDM. These handbooks will also include CRM measurement tools.
Appendix D - Some Occurrences in which Decision Making was a Factor
A90P0337: It was found that the crew of a B-737 attempted a second approach in marginal weather at an intended destination prior to proceeding to an alternate airport even though the fuel for the second approach had not been calculated in the fuel load.
A91C0083: Although there were several pre-flight indications of a hydraulic system malfunction on a HS 748, the captain elected to conduct the flight.
A91A0198: The crew of a DC-8 continued with a landing in marginal weather, although adequate visual references had not been acquired by the pilot flying.
A92P0015: The operator scheduled a flight of a float-equipped Beech 18 in unfavourable conditions and an inexperienced pilot attempted a heavy weight take-off in the marginal weather.
A93H0023: A night flight in a HS-748 with electrical problems was initiated from Sandy Lake, Ontario, and the aircraft struck the ground shortly after take-off.
A94H0001 (investigation ongoing): A VFR chartered helicopter struck a ridge in mountainous terrain during a flight in known poor weather.
A94W0026 (investigation ongoing): At Calgary, Alberta, the take-off of a charter DC-8 with 83 persons on board was continued with two failed tires.
A94A0078 (investigation ongoing): The crew of a Swearingen SA226-AT on a courier flight nearly collided with a building while on approach for landing at Sydney, Nova Scotia.
A93C0169 - Controlled Flight into Terrain - Athabaska Airways Limited Cessna 310R C-GILR Sandy Bay, Saskatchewan 1 mi NE - 12 October 1993
Synopsis
The aircraft departed Sandy Bay, Saskatchewan, on a chartered night flight to La Ronge. Shortly after take-off, the aircraft struck trees and crashed on the rocky shoreline of the Churchill River. All four occupants of the aircraft were fatally injured.
The Board determined that the pilot established, and the aircraft remained in, a very shallow climb after take-off and struck trees during the initial departure, while in controlled flight prior to reaching cruise climb speed.
Other factors that may have contributed to the accident were the poor ground and sky illumination, the absence of illumination from the landing lights, and the deviation from the recommended night departure profile.
Safety Action Taken
(as presented in the TSB Report)
Accidents Involving Controlled Flight into Terrain
This occurrence is classified as a Controlled Flight into Terrain (CFIT) accident. CFIT occurrences are those in which an aircraft, under the control of the crew, is flown into terrain (or water) with no prior awareness on the part of the crew of the impending disaster. The Board notes with concern that, over the 11-year period from 01 January 1984 to 31 December 1994, 68 commercially operated aircraft (not including those conducting low-level special operations) were involved in CFIT accidents. In view of the frequency and severity of such accidents, the Board is conducting a study of CFIT accidents to identify related systemic deficiencies. The study includes, inter alia, an examination of CFIT data on VFR operations at night and on contributing factors such as somatogravic illusions.
Safety Action Required
(as presented in the TSB Report)
Pilot Licence Restrictions - Practical Flight Tests
The pilot's vision had been considered by an Aviation Medical Review Board (AMRB). Following a practical flight test, the pilot had been issued a commercial licence in accordance with medical standards allowing the option of flexibility for vision; his licence indicated that he was required to wear prescription bifocal glasses while flying. The practical flight test had been conducted during daylight hours in visual meteorological conditions (VMC); the pilot's duties at the time of the occurrence required that he fly at night and in instrument meteorological conditions (IMC). The flight test environment was not typical of the most difficult conditions in which the pilot was expected to fly.
In the spring of 1990, the TSB investigated another occurrence in which the validity of an AMRB-requested practical flight test was also brought into question (TSB A90Q0090). In this accident, the TSB determined that, because the pilot had only limited use of his right leg, he was unable to recover from a spin in the ultralight he was flying. The flight test was conducted in a category of aircraft different from that which the pilot was licensed to fly, and the in-flight exercises apparently did not include manoeuvres which typically would have placed the greatest demands on the pilot's right leg.
Neither the content of the flight tests nor the environment in which they were conducted was representative of the challenges that these pilots might encounter while exercising the privileges of their respective licences; nor had the pilots' actual licences been annotated to indicate limitations to any operational aspects of flying associated with their category of licence.
The Board accepts the principle of issuing licences with a flexibility for various medical conditions. It is also recognized that it may be impractical on AMRB flight tests to cover all aspects of the flying environment. However, based on these two occurrences, there appear to be inconsistencies between the flying abilities actually being verified on the flight tests and the follow-on restrictions being placed on licence privileges. Consequently, pilots with licences issued under the medical flexibility option may be flying in aircraft or environments beyond their demonstrated abilities. In this occurrence, fare-paying passengers were relying on a pilot to safely fly in conditions in which his vision may have hampered his ability to maintain adequate visual reference with the ground and avoid obstacles.
To reduce the likelihood of other pilots with licences issued under the medical flexibility option inadvertently operating aircraft in conditions beyond their demonstrated ability, the Board recommends that:
The Department of Transport review all pilot licences issued under the medical flexibility option to ensure compatibility of verif ied pilot abilities and licence privileges. (A95-13)
Transport Canada's Response:
Transport Canada Aviation (TCA) share the Board’s concern that a practical flight test should verify a pilot’s ability under the conditions in which he/she will be flying. As the Board pointed out "... it may be impractical on AMRB flight tests to cover all aspects of the flying environment"; however, TCA agrees that the applicant should be tested under conditions representative of the most difficult conditions in which he/she will be expected to fly.
The question of how a practical flight test under flexibility should be carried out is a subject which is under constant review. The vision standards under flexibility were addressed at the Visual Standards conference in June 1990 and again at the Visual Standards Conference in May 1995. In addition the subject is reviewed whenever there is any new information or new grounds for challenging the existing standard. For example applications for Licence Validation Certificates where the applicant does not meet the medical standard have also been made on the grounds of Human Rights. These applications provide another trigger for review and refinement of the standards and procedures of TCA for issuing Licence Validation Certificates under the "flexibility" provisions.
As a result of the Board’s recommendation, TCA will review the practical flight test procedures for future tests with the view of ensuring that the abilities being tested and the privileges being granted are compatible.
A93Q0242 - Cabin Fire - Northwest Airlines - Boeing 727-200 N278US Montreal International (Dorval) Airport, Quebec - 28 November 1993
Synopsis
Immediately after push-back, a fire was noticed in an overhead stowage bin in the aft portion of the cabin. The fire was extinguished by the crew and the aircraft was evacuated. Some passengers sustained minor injuries.
The Board could not determine the cause of the fire; however, all evidence indicates that the fire was not accidental.
Safety Action Taken
(as presented in the TSB Report)
Joint Pilot/Cabin Crew Emergency Training
Northwest Airlines has indicated that, beginning in January 1995, joint training for pilots and flight attendants will be conducted during annual recurrent training. The training will focus on communications between the flight deck and cabin, and will include in-flight fire scenarios.
911 Communications During Airport Emergency Responses
Subsequent to this occurrence, the Centre d'Urgence established a new method of operation. Specifically, 911 operators have received directions on the amount and type of information to be collected prior to initiating emergency responses to local airports.
Unilingual Evacuation Instructions
Although not required by regulation, most Canadian air carriers endeavour to provide safety briefings in both official languages. Also, some foreign carriers routinely ensure that bilingual flight attendants are on aircraft serving Quebec airports to provide bilingual safety briefings during these flights.
In July 1994, the TSB forwarded an Aviation Safety Advisory to Transport Canada (TC) highlighting the potential for delayed and/or adverse reactions to unilingual emergency instructions by passengers who do not comprehend the language of instruction. In its response, TC indicated that, with the rewriting of the Canadian Aviation Regulations, safety briefings in both official languages will become a requirement under specified circumstances. Also, since the International Civil Aviation Organization (ICAO) has no established standard regarding the language of safety announcements, TC will address this issue with ICAO.
Safety Action Required
(as presented in the TSB Report)
Passenger Service Blanket Flammability
Passenger service blankets are carried on most large air carrier aircraft and are usually stored in the overhead bins in the cabin. In addition to using the blankets for passenger comfort, several Canadian air carrier Flight Attendant Manuals instruct flight attendants to use the blankets for smothering flames on a person's clothing or seat. As demonstrated by this incident and in TSB tests, some passenger service blankets have adverse flammability characteristics even though the blanket material passed the flammability test prescribed for cabin interior materials.
In May 1994, the TSB forwarded an Aviation Safety Advisory to TC and the Cabin Safety Standards section of the FAA indicating that passenger service blankets should meet an appropriate flammability standard and that TC might wish to advise Canadian air carriers that passenger service blankets may present a fire hazard. In July 1994, using TSB information from this occurrence, the National Transportation Safety Board (NTSB) recommended that the FAA develop a fire performance test method and performance criteria (standard) for blankets supplied to commercial operators, then require those operators to use only those blankets that meet the standard (NTSB-A-94-131). At the same time, the NTSB also recommended that the Air Transport Association of America (ATA) warn association members about the flammability of blankets used for passenger comfort and urge members to replace these blankets with blankets containing more fire-resistant materials (NTSB-A-94-132).
In August 1994, the ATA response to the NTSB recommendation indicated that ATA had advised its members about the flammability of passenger service blankets. In January 1995, in response to the TSB Advisory, TC indicated that they would be reviewing the issue of blanket and pillow flammability with the FAA via an international working group and that it would be premature to advise carriers of the potential fire hazard prior to the completion of the working group's activities.
The Board understands that the international working group is considering issues such as types of fabric and flammability protection processes, effects of in-service use, and appropriateness of flammability standards. It is recognized that it may not be practical to disseminate information on these issues until discussed by the working group. However, considering how easily the folded blankets ignited and developed a molten polyester pool fire in both the occurrence and post-incident test, Canadian air carriers may wish to take interim measures based on their assessment of the hazard. Therefore, the Board recommends that:
The Department of Transport immediately advise Canadian air carriers about the potential flammability of some passenger service blankets. (A95-14)
Transport Canada's Response:
Transport Canada Aviation has developed an Air Carrier Advisory Circular (ACAC) which advises all commercial air carriers of the potential flammability of service blankets. The ACAC will be distributed to all commercial air carriers once finalized.
A94C0088 - Controlled Flight into Obstacle and Terrain - Keewatin Air Limited Swearingen Merlin II C-FFYC - Thompson, Manitoba - 01 June 1994
Synopsis
The Swearingen Merlin II was returning to Thompson after having completed a MEDEVAC flight between Coral Harbour, Northwest Territories, and Churchill, Manitoba. After being cleared for a localizer back course approach to the Thompson Airport, the aircraft descended below the minimum beacon-crossing altitude, struck the Hotel non-directional beacon tower in a wings-level attitude, and crashed. Both crew members were fatally injured, and the flight nurse was seriously injured.
The Board determined that the flight crew lost altitude awareness during the localizer back course approach and allowed the aircraft to descend below a mandatory level-off altitude. Contributing factors to this occurrence were the crew's deviation from a published approach procedure, ineffective in-flight monitoring of the approach, rapidly developing localized fog conditions, and, probably, pilot fatigue.
Safety Action Taken
(as presented in the TSB Report)
Operator Action
The operator indicated that, subsequent to the accident, the chief pilot has taken steps to ensure that all standard procedures are adhered to. Also, a designated flight examiner was retained to act as an independent auditor of ongoing training, reporting any concerns directly to the chief pilot and the operations manager.
Revised Flight and Duty Time Regulations
The Canadian Aviation Regulation Advisory Council (CARAC) proposed regulations which deal with some of the fatigue issues raised in this report. Comments on these regulations were solicited in the Canada Gazette, Part 1 , on 12 August 1995. The proposed regulations address the following issues:
Flight Duty Time - Definition: "flight duty time" will start when the pilot reports for flight duty, is on stand-by with a reporting time of one hour or less, or reports for any duty assigned by the air carrier prior to flight duty.
Flight Duty Time - Extensions: Extensions will be limited to unforeseeable operational circumstances and be permitted only if no reasonable alternative is available. The extension is limited to a maximum of 3 hours and the subsequent rest period will be extended by an amount equal to the flight duty time extension.
Flight Duty Time - Positioning: Positioning flights (non-revenue) will now contribute towards maximum flight and duty times.
Predictable and Protected Rest Periods: When a pilot is on reserve or stand-by with more than one hour reporting time, the air carrier will be required to either provide the pilot with a daily predictable and protected rest period, or apply more restrictive flight duty times and/or extended rest periods.
If implemented, these proposed revisions should help aircrew to plan rest periods, eliminate the long periods of on-call or duty time, and provide for reasonable amounts of scheduled stand-by time.
In addition, Transport Canada intends to publish an Air Carrier Advisory Circular concerning fatigue and fatigue countermeasures.
Controlled Flight into Terrain (CFIT)
The circumstances of this occurrence are typical of a CFIT incident. CFIT occurrences are those in which an aircraft, under the control of the crew, is flown into terrain (or water) with no prior awareness on the part of the crew of the impending disaster. Over the eleven-year period from 01 January 1984 to 31 December 1994, 70 commercially operated aircraft not conducting low-level special operations were involved in CFIT accidents in Canada. In view of the frequency and severity of such accidents, the Board is conducting a study of CFIT accidents to identify systemic deficiencies. The study will include, inter alia, an examination of CFIT data involving aircraft altimeter displays, altitude alerting systems, radar altimeter systems, use of ground proximity warning systems (GPWS), and MEDEVAC flights.
Transport Canada has recently produced a video about CFIT to increase pilot and operator awareness of those factors which can contribute to CFIT accidents.
Safety Action Required
(as presented in the TSB Report)
Audio Warning Systems
The aircraft's radar altimeter was found to be serviceable and set to the MDA for the approach. However, because the audio output signal from the radar altimeter could not be directed to the crew's headsets, the pilots may not have heard the audio warning that the aircraft had descended to the MDA.
On 31 May 1994, a risk of collision occurred between two ATR-42-300 aircraft (TSB report A94O0137 refers). Although both aircraft were equipped with traffic alert and collision avoidance systems (TCAS), one of the flight crews did not hear their TCAS warning. The investigation determined that the audio signals from the TCAS equipment were not routed through the crew's headsets, and it is likely that the ambient noise levels and radio chatter obscured the audio warning.
Pilots may receive audio warnings from many aircraft systems, including stall, over speed, landing gear, and configuration warnings systems, as well as from altitude alerters, radar altimeters, TCAS, and GPWS. The audio warnings provided by these systems are meant to draw the pilot's attention to a situation which, if left unattended, could endanger the flight. However, many of these systems are not capable of directing audio signals to the audio system in use by the pilot (i.e., cockpit speaker or headsets), and there is no Federal Aviation Regulation (FAR) requirement for these systems to do so. If pilots are using noise-attenuating or noise-canceling headsets, they may not be able to hear audio warnings that are not directed through the headsets.
The TSB is aware of several accidents which occurred because audio warnings were not heard. To help prevent such accidents, the TSB recommends that:
The Department of Transport advocate the provision of audio warnings which can be heard by pilots through whichever audio system they have selected for use.
(A95-15)
Transport Canada's Response:
Transport Canada agrees that when equipment that provides audio warnings is installed in aircraft, the warnings must be audible to the flight crew in flight. In many cases, this goal may be achieved by enabling the audio signals to be directed through cockpit speaker or headsets, whichever audio system is in use by the pilot. Transport Canada, however, would not advocate regulations which require that as the only permissible design. Manufacturers must have the flexibility to produce the best design for each particular installation.
During the flight test and approval of new designs, Transport Canada assesses the proper integration of audio warning equipment including the evaluation of audio levels for acceptable volume and intelligibility during high cockpit noise levels. It is also our policy to encourage modifiers to perform similar evaluations during modifications of aircraft to install audio warning equipment. This policy will be highlighted to Regional staff by the issue of guidance material to emphasize the need to consider and assess the audibility of audio warnings when such equipment is installed.
Safety Concern
(as presented in the TSB Report)
CFIT Accidents Involving MEDEVAC Flights
The accident aircraft was returning from a MEDEVAC flight when it was flown, under control, into terrain. The TSB has identified several other CFIT accidents involving MEDEVAC flights, and notes that a disproportionately high number of CFIT accidents have involved MEDEVAC flights.
The Board is concerned that current operating procedures and practices may be contributing to many of these MEDEVAC accidents. Therefore, the TSB is further analyzing recent MEDEVAC occurrence data to identify any underlying systemic deficiencies.
A93W0204 - Marine Power Loss/Loss of Control - Arctic Wings and Rotors - Pilatus Britten-Norman BN2A-20 Islander C-GMOP Tuktoyaktuk, Northwest Territories 7.7 mi SE - 03 December 1993
Synopsis
The pilot and passengers on board the Britten-Norman Islander were on a scheduled night visual flight rules flight from Tuktoyaktuk to Inuvik, Northwest Territories. Approximately four minutes after take-off, the pilot reported to the Tuktoyaktuk Flight Service Station that he had an engine problem and was returning to the airport. When the aircraft did not arrive, an air and ground search was initiated. The wreckage was located three hours later, on an ice-covered lake approximately eight miles southeast of the airport. There were no survivors.
The Board determined that a magneto impulse coupling, worn beyond the prescribed limits, resulted in the failure of the right engine. Following the engine failure, the pilot mistrimmed the rudder and was unable to maintain control of the aircraft.
Safety Action Taken
(as presented in the TSB Report)
Magneto Inspection
In March 1994, the TSB forwarded an Aviation Safety Advisory to TC regarding magneto inspection and maintenance requirements. In response, TC sent a letter to the FAA querying whether AD 78-09-07 R3 would be amended to include the more stringent periodic inspection requirement of SB 599D. There has been no reply to date. This matter was also featured in TC's Aviation Safety Maintainer newsletter, issues 3/94 and 1/95.
Mandatory Service Bulletin MS645
On 04 April 1994, Teledyne Continental issued Mandatory Service Bulletin MSB 645, which superseded SB599D. The reason for the bulletin was to decrease operational wear rates on impulse couplings and to prevent engine stoppage. The bulletin requires 100-hour inspections of riveted impulse couplings. Couplings which do not meet the detailed coupling inspection criteria are to be replaced with new snap ring assemblies.
Regulatory Audits and Surveillance
Analysis and information from this and 18 other accidents led to the identification of shortcomings in the regulatory overview process of air carriers. In particular, it was found that TC's audits sometimes lacked depth, and that the verification of corrective action following the audits was sometimes inadequate. Therefore, the Board recommended that:
The Department of Transport amend the Manual of Regulatory Audits (MRA) to provide for more in-depth audits of those air carriers demonstrating an adverse trend in its risk management indicators; (A94-23, issued December 1994)
The Department of Transport ensure that its inspectors involved in the audit process are able to apply risk management methods in identifying carriers warranting increased audit attention; (A94-24, issued December 1994)
The Department of Transport develop, as a priority, a system to track audit follow-up actions; and (A94-25, issued December 1994)
The Department of Transport implement both short and long term actions to place greater emphasis on verification of required audit follow-up action and on enforcement action in cases of non-compliance. (A94-26, issued December 1994)
In response to these recommendations, TC has indicated that both recommendations A94-23 and A94-24 will be taken into consideration during amendments to the MRA. Also, TC will ensure that the Audit Procedures training program for inspectors takes into account recommendation A94-24 so that risk management methods are clearly understood and applied.
TC's reply to recommendations A94-25 and A94-26 indicates that the MRA will be reviewed to ensure that clear policy direction is given to ensure that effective audit follow-up systems are in place. Furthermore, TC intends to have an enhanced National Aviation Company Information System (NACIS) operational soon to track audit follow-up on a national basis. In the interim, a policy directive will be issued to regions to require a review of respective regional follow-up systems.
Safety Action Taken (as presented in the TSB Report)
Night VFR Commercial Operations
Commercial flights for aircraft of 12,500 pounds or less conducted under IFR are required to have either a crew of two pilots, or one pilot and a two-axis autopilot. These requirements recognize the demanding nature of maintaining aircraft control and situational awareness with reference to instruments only.
Night VFR flights over featureless terrain and without a visible horizon also demand instrument flying skills. As such, the regulatory requirements for commercial night VFR operations contain some safeguards; e.g., in consideration that the flight may temporarily encounter instrument meteorological conditions or poor ambient lighting, the pilot must be instrument rated; and to minimize the risk of collisions with terrain or obstacles, the flights must be conducted along airways, air routes, or approved company routes. However, these requirements do not address the added pressures placed on aircrew in severely deteriorated flight conditions or emergency situations.
Legally, night VFR commercial flights may be conducted with only one pilot and with no autopilot. The aircraft in this occurrence was certified for single pilot use in VFR operations, day or night; yet, this same aircraft used for commercial flight operations under IFR would have required two pilots. In the Board's view, coping single-handedly with weather diversions or an emergency during a dark night VFR flight would be very demanding, comparable to trying to handle these situations single-handedly on an IFR flight. However, on an IFR flight, another pilot would provide an added safety factor.
The differences in dispatching requirements for crew and in equipment requirements between commercial VFR and IFR flights are an economic consideration for operators. With VFR single-pilot crewing, manpower costs are lower; and the "nil" requirement for an autopilot reduces equipment and servicing expenses. Also, with VFR flight planning requirements for alternate airports and fuel reserves being less restrictive than the IFR requirements, the operator could have greater flexibility in meeting the routing and scheduling demands of his customers.
Although economic pressures are a factor to be considered by operators in the passenger-carrying business, from the fare-paying public's point of view, the level of safety should not be a function of the type of operation (i.e., VFR or IFR) or the time of day.
Aircrew in single-pilot commercial night VFR operations do not have the same level of safety back-up as their IFR counterparts in terms of equipment and crew requirements to safely cope with unforeseen situations. The Board is concerned that such night VFR flights do not afford the fare-paying public a level of safety equivalent to that on similar flights under IFR. Therefore, the Board recommends that:
The Department of Transport raise the regulatory requirements for the conduct of commercial passenger-carrying night VFR flights to provide a level of safety comparable to that provided on IFR flights with similar aircraft. (A95-16)
Training - Night Training
In order to carry passengers at night on multi-engine aircraft, an operator is required to provide specific on-type night training for company pilots. The pilot in this occurrence had not received this training; nor had this shortcoming been detected by Transport Canada inspectors during the audit of the company's operation one month prior to the accident.
In January 1993, following the investigation of a twin-engine turbo-prop aircraft accident at Moosonee (TSB report A90H0002) in which neither of the pilots involved had received the required night training and the regional Transport Canada inspectors had not observed that the training had not been conducted, the Board recommended that:
The Department of Transport validate its current procedures for checking that air carriers provide the required multi-engine night training. (A93-05, issued January 1993)
TC responded in August 1993 that the Manual of Regulatory Audits (MRA) (published since occurrence A90H0002) directed the audit staff to check the companies' flight training programmes. In addition, TC notified the regional Air Carrier staff of this matter and instructed its Quality Assurance Review team to ensure that the verification of night training did occur.
This occurrence is another example of a night accident in which the pilot had not received the required night training. Notwithstanding Transport Canada's continuing efforts to strengthen its processes for regulatory audit and surveillance, some commercial pilots are still not receiving the required night training. Since the skills required for safe night operations require reinforcement through periodic night training, the Board recommends that:
The Department of Transport conduct a special one-time audit to confirm that commercial pilots involved in night multi-engine operations are receiving the required night training. (A95-17)
While TC audit procedures continue to miss inadequacies in the night training of commercial pilots, it is recognized that TC inspectors cannot be continuously on site to ensure that operators are providing this training. Individual operators must be held accountable for any failure to provide mandatory training. Therefore, the Board recommends that:
The Department of Transport evaluate the effectiveness of its current practices for dealing with those operators who are not providing mandatory training for pilots. (A95-18)
Transport Canada's Response: A95-16, A95-17, A95-18
Transport Canada, in reviewing this accident report along with other recent fatal accidents in air taxi operations, has set up a Task Force to review the safety of air taxi operations, including night VRF. The Safety of Air Taxi Operations Task Force (SATOPS) will commence early in 1996 and will examine all aspects of this aviation environment, including the effectiveness of surveillance and inspection by Transport Canada, the regulatory setting, pilot licensing, training and checking requirements, and human factors such as company management attitudes toward safety. An Air Carrier Advisory Circular will be released to advise industry about SATOPS.
Safety Action Required
(as presented in the TSB Report)
Aircraft Grouping for Pilot Proficiency Checks (PPC)
TC had authorized the grouping of the Islander and the Navajo aircraft for PPCs for this operator. (The grouping of these two aircraft has reportedly been authorized at other carriers as well.) The policy regarding the grouping of aircraft for PPCs requires only that the aircraft be grouped according to performance and handling characteristics. However, significant differences apparently exist in both the handling characteristics and performance of the Navajo and Islander aircraft. Differences in the direction of application of the rudder trim between the two aircraft may have been critical in this accident.
The Board understands the desirability for operators to group aircraft for the conduct of PPCs. However, the Board believes that guidelines for the grouping of aircraft must ensure that a proficiency check on one aircraft of a group will consistently be an accurate indicator of pilot proficiency on other aircraft in the same group. Inappropriate groupings may lead the pilot, operator, and flight examiner to believe that the pilot's ability to handle all aircraft in the group is better than it actually is; such pilots will be vulnerable to encountering situations beyond their demonstrated capabilities. Therefore, the Board recommends that:
The Department of Transport confirm the suitability of all existing PPC aircraft groupings such that proficiency on one type is truly representative of all aircraft in the grouping. (A95-19)
A pilot who is current on several aircraft types is prone to applying the specific procedures or practices for one type to another; this includes the possible incorrect operation of controls if the control functions are significantly different from one aircraft to another. Such errors in the performance of an operation or procedure are known as "transfer errors." Individuals are more susceptible to transfer errors during periods of stress caused by high workloads. The incorrect application of rudder trim during an engine failure in a multi-engine aircraft would be a typical transfer error if the procedure to apply the trim varied significantly between different aircraft on which the pilot was current. Differences in cockpit layout, in the operation of flight and engine controls, in the major aircraft systems, and in the critical emergency procedures could promote transfer errors. To minimize aircrew susceptibility to making transfer errors, aircraft groupings should be based on more than general similarities in aircraft handling and performance. Therefore, the Board recommends that:
The Department of Transport revise the guidelines for grouping aircraft for PPCs to take into account the susceptibility to transfer errors by aircrew. (A95-20)
Transport Canada has established an approved list of groups of aircraft for aircraft above 7,000 pounds Maximum Certified Take-Off Weight (MCTOW). It is understood that a comprehensive analysis of the differences and similarities between the aircraft in each group was conducted to ensure the compatibility of aircraft. Such an approved list is not available for commercial aircraft below 7,000 pounds MCTOW. Ad hoc groupings of aircraft based on superficial similarities between aircraft can lead to fundamentally dissimilar aircraft being grouped together (e.g., Navajo and Islander), creating conditions conducive to transfer errors under high cockpit stress. Therefore, the Board recommends that:
The Department of Transport, where practicable, establish an approved list of aircraft groupings for PPCs of aircraft having a Maximum Certified Take-Off Weight (MCTOW) of under 7,000 pounds. (A95-21)
Transport Canada's Response: A95-19, A95-20, A95-21
Transport Canada agrees that the grouping of these types of aircraft needs to be reviewed. A review of the suitability of current groupings for aeroplanes will be included in the Terms of Referece (TOR) of the Safety of Air Taxi Operations Task Force.
Should you require further information, please contact Aviation Safety Analysis at asi-rsa@tc.gc.ca