A93H0023 - Flight Recorder Inadequacies
Concerning FDR AND CVR Inadequacies
Introduction
On 10 November 1993, a Hawker Siddeley Hs748 aircraft (C-GQTH) operated by Air Manitoba was taking off from Sandy Lake, Ontario, for a scheduled flight to Garden Hill, Manitoba, after off-loading 22 passengers. The aircraft crashed just after take-off; all occupants on board (three crew members and four passengers) were fatally injured (TSB file A93H0023 refers). The aircraft was destroyed, making determination of the accident's cause and contributing factors through examination of the wreckage extremely difficult. The investigation is ongoing.
FDR/CVR Serviceability
The cockpit voice recorder (CVR) and flight data recorder (FDR) were recovered from the wreckage. They had not been operating on the occurrence flight; the reason has yet to be determined. However, the recorders did contain information recorded during the preceding flight. Analysis of the CVR information revealed that, when the CVR was operating, it received input only from the cockpit area microphone. It appears that the CVR ad been in correctly installed, in that the intercom and other radio sources were not connected to the appropriate recording channels. At least three other Air Manitoba HS748 aircraft are reported to have CVRs installed this way (C-FGGE, C-FAGI, C-FFFS). Apparently, inspectors had not detected this configuration shortcoming in any of the aircraft. The company has been advised of this installation anomaly, and reportedly has taken corrected action. It is also understood that Transport Canada (TC) has found another Canadian HS748 operator with a similarly installed CVR.
In HS748 aircraft, cockpit area microphone information is, by itself, of little value because of the high level of background noise. Intercom, radio transmission, and navigation aid information which could have possibly provided insight into the accident's causation was not available. Of note, recording only the cockpit area microphone does not meet the current requirements in the TC Engineering and Inspection Manual.
A previous investigation into a 1989 occurrence involving a Fairchild Metro III found that an inappropriate FDR was installed in the aircraft and that it was not functioning properly. Since missing flight recorder information inhibits accident investigations and the determination of safety deficiencies, the Board recommended to the Minister of Transport in 1990 that: the Department of Transport validate its approval process for FDRs to ensure that current procedures are adequate to meet the Air Navigation Orders and Engineering and Inspection Manual requirements (TSB A90-93); and the Department of Transport ensure that companies have adequate maintenance plans and procedures for ensuring the continued serviceability of FDRs (TSB A90-94).
In its reply to these recommendations, the Department of Transport considered that the current procedures were sufficiently detailed and comprehensive to provide adequate guidance to air carriers and TC officials. Notwithstanding, in the spring of 1992, TC circulated for comment two draft Airworthiness Manual Advisories (AMAs) concerning the maintenance of CVRs and FDRs. In part, these draft AMAs deal with an integrated test to ensure the intelligibility of CVR information under operational conditions, and a correlation check on FDRs to ensure that recorded data derived from each system parameter were accurate and usable. Regrettably, these AMAs were not in effect at the time of this accident.
The history of occurrences in older Canadian commercial aircraft (such as the Fairchild Metro III, HS748, and Convair 580) where the flight information required has not been recorded, continues. In a number of recent investigations, recorder information that should have been available was not due to the following types of problems: foil-type recorder data extraction difficulties or complete failure, recorders having insufficient recording time or recorded parameters, recording tape capstans jamming, installation and approval process anomalies, inadequate maintenance and inspections, etc. For example, during an on-going investigation into a recent Convair 580 occurrence (TSB file A93H0008), two deficiencies in he CVR were discovered. A TSB Aviation Safety Advisory addressed two specific CVR shortcomings, namely vulnerability to recording "tape jam" and unreliability of approved test procedures.
Notwithstanding TC's intent as expressed in the draft AMAs, and considering that accident investigators frequently encounter flight data recorders (FDR) and cockpit voice recorder (CVR) which have not recorded the required information, the Board is not satisfied that current approval processes and maintenance procedures are adequate for flight recorders. Since the loss of information may preclude the timely identification of safety deficiencies, the Board recommends that:
The Department of Transport immediately verify through field audit that existing FDR and CVR installations meet current regulatory requirements, and make public its findings; and (TSB A94-01)
The Department of Transport revise its approval and monitoring process to ensure that all future FDR and CVR installations continue to meet regulatory requirements." (TSB A94-02)
Transport Canada Response:
Transport Canada supports these recommendations. Current requirements for installations and maintenance of Flight Data Recorders (FDR) and Cockpit Voice Recorders (CVR) are contained in the Department Engineer and Inspection (E&I) Manual, Part II, Chapter III, Sections 3.9 and 3.10. If an operator's approved maintenance programs adequately address these requirements, then installed recorders should maintain an acceptable serviceability rate.
However, in view of the TSB investigations which resulted in the above recommendations, the Department has initiated a program to review compliance with flight recorder requirements. Regional offices are being required to review air carrier's Maintenance Control Manuals (MCMs). The following categories of carriers will be required to confirm compliance of their flight recorder installation to approved data, and proper recording of all parameters:
- Those whose MCMs are found deficient regarding the maintenance program for flight recorders;
- Those who contract their recorder maintenance to other organizations; and
- Those operating aircraft with foil and wire type FDRs.
A sampling review of carriers identified above will be conducted by the regional offices. A summary of the results of the review will be made available to the TSB.
Should the review show that there are deficiencies, further measures will be undertaken to ensure compliance with flight recorder installations, maintenance and verification requirements, and consideration will be given of to revision of approval and monitoring procedures.
Legislation
The present Canadian regulations for flight recorders came into effect in 1969. Subsequently, only minor changes have been made. In 1985, the International Civil Aviation Organization (ICAO) issued new Standards and Recommended Practices (SARPs) for flight recorders. Canada endorsed the SARPs and formed a Flight Recorder Standards Review Group in 1986. Since the primary purpose of flight recorders is for occurrence investigations, in 1987 the Canadian Aviation Safety Board (CASB) forwarded to TC a Statement of Requirements (SOR) for FDRs and CVRs as perceived at that time.
Subsequently, after consultation with the Canadian aviation industry, TC stated its intention to issue new legislation which would closely correspond to new U.S. rules for flight recorders issued in July 1988.
In 1991, following the report of an investigation into an accident involving a Beechcraft King Air A-100 air ambulance (A88Ø0491), the underlying causes of which could not be determined, the TSB reviewed the Canadian flight recorder requirements. The Board noted that the U.S. rules and the planned Canadian legislation would meet neither the ICAO SARPs nor the CASB's Statement of Requirements. Nevertheless, the Board believed that new rules were needed in the near term to provide information necessary for occurrence investigations and effective corrective measures. Therefore, despite the limitations of the proposed legislation and the prospect of better hardware to come, the Board recommended that, as an interim measure, the Department of Transport expedite legislation for upgrading the flight recorder requirements for Canadian-registered aircraft (TSB A91-13).
TC responded that it had accorded the highest priority to the processing of the FDR/CVR Orders and had advised the Department of Justice of the importance of expediting the promulgation of these Orders. Two and one-half years have elapsed since Recommendation A91-13; new legislation for FDR/CVRs has not been promulgated.
Many aircraft that are involved, or are capable of being involved, in commercial passenger operations continue to be exempt from the requirement to install any recorders. The recent accident at Tuktoyaktuk, 03 December 1993, involving a Britten-Norman Islander (in which seven person were fatally injured) is an example of an aircraft capable of carrying 10 persons but which is not required by regulations to be outfitted with any type of flight recorder (TSB file A93W0204).
In summary, many Canadian commercial aircraft continue flight operations with inadequate or unserviceable flight recorders, or no flight recorders at all. Shortcomings in the current legislation, regulatory processes, and enforcement action for flight recorders continue to thwart efficient accident investigation. Since investigators are being deprived of critical safety information, thereby putting the aviation community and traveling public at risk, the Board recommends that:
The Department of Justice and Transport promulgate the new Orders on flight recorders without further delay. (A94-03)
Transport Canada Response :
Transport Canada Aviation (TCA) is rewriting the existing regulations, including the updating of the FDR/CVR Orders, into the Canadian Aviation Regulations on a priority basis as part of the Regulatory Renewal Project. The Project team includes Department of Justice lawyers on site to ensure timely that the new Regulations will come into law early in 1995.
While it is recognized that the industry will require a period of time to equip their aircraft with recorders, TCA will issue an Air Carrier Advisory Circular and an Aeronautical Information Circular informing the aviation industry of the implementing requirements and notification that industry will be required to comply within one year after promulgation.
Notwithstanding that the promulgation of the proposed legislation is of utmost importance, the TSB believes that Canadian flight recorder legislation must keep pace with advances in aircraft and recorder technology. This technology has progressed significantly since the CASB's 1987 SOR ad TC's decision to adopt the new U.S. based regulations. Modern aircraft incorporate computer technology for flight management systems (FMS) and data link communications; recorders offer expanded recording capability, and enhanced reliability and survivability. It is understood that the proposed TC legislation does not take into account such recent progress in technology; hence, investigations into occurrences involving the latest generation of aircraft registered in Canada may be denied time-critical evidence.
Recognizing a requirement for improved data collection to accommodate present and new generations of aircraft, the European Organization for Civil Aviation Electronics (EUROCAE) published a document (ED55) in May 1990 containing the data parameters considered to be essential for aeroplances and helicopters. The adoption of ED55 as a requirement has been proposed to member nations following the Joint Airworthiness Regulations. The International Society of Air Safety Investigators (ISASI) has proposed to ICAO that ED55 be considered when its SARPs are amended. Both TC and the TSB have participated in EUROCAE meetings; as well, the TSB is currently updating its SORs for recorders.
If the TSB is to adequately, investigate occurrences involving advanced technology aircraft, Canadian aircraft must incorporate flight recorders capable of providing investigators wit the pertinent information. Given that the proposed Canadian legislation does not yet provide for these latest generation of aircraft, and given Canada's history of delays in updating flight recorder legislation, the Board recommends that:
The Department of Transport streamline its processes to facilitate the timely Canadian implementation of updated flight recorder requirements. (A94-04)
Transport Canada Response :
The Regulatory Renewal Project is incorporating existing regulations in a new regulatory structure consisting of regulations with standards incorporated be reference. The intent is that the standards will be contained in an incorporated document that is much more easily amended than the regulation.
Concerning the revised recorder regulations, we have a consensus with industry that agrees to full harmonization with the Federal Aviation Regulations (FAR) of the U.S.A. hence, the draft regulations have been finalized. The regulation section will stipulate briefly which aircraft require FDRs and CVRs. The standards section will list parameters, operational requirements and other technical specifications.
A94C0034 - Pratt & Whitney JT8D-7B Engines - March 1994
On 5 March 1994, the crew of an Air Canada McDonnell -Douglas CD-9 experienced significant airframe vibration during a take-off roll at Regina, Saskatchewan. They rejected the take-off and stopped the aircraft on the runway. The left engine (Pratt & Whitney JT8D-7B) had sustained an uncontained failure. The investigation is still in progress and is identified as TSB A94C0034.
The combustion chamber outer case (CCOC) suffered an uncontained rupture during the initial stages of the take-off roll. It appears that the failure of the CCOC initiated in the area of the rear flange. Similar combustion chamber outer case failures prompted FAA Airworthiness Directive (AD) 87-11-07 R1, the last amendment effective in November 1989, based on a Pratt & Whitney Alert Service Bulletin. The AD addresses the methods of inspection time-frames dependent on the engine model, the CCOC component, the method of inspection, and whether there have been previous repairs. For the -7B model, the AD requires a 6000 cycle repetitive inspection process for CCOC bosses. The process for the CCOC rear flange requires either a 3000 or 12000 cycle repetitive inspection. More rigid inspection time-frames are to be applied for outer cases that have been weld repaired or operated in more than one JT8D engine model. Additionally, the AD states that the CCOC bosses and rear flanges are to be inspected at each engine "shop visit".
The initial review of the maintenance records pertaining to the failed engine indicates that the CCOC failed with 4499 cycles of a 12000-cycle repetitive inspection period remaining. The records do not clearly reflect completion of the CCOC boss and rear flange inspections during two previous interim shop visits. At this point in the investigation, it appears that the requirements of the AD may not have been satisfied due to a misinterpretation of what constitutes a "shop visit". In fact, exactly how the AD should be interpreted has yet to be clearly established. Pratt & Whitney and a Minister's representative from Transport Canada have been in attendance at the engine investigation to help resolve the problem. In the meantime, Air Canada is actively searching all of their JT8D maintenance and overhaul records to ensure that any and all engines possibly affected will be re-inspection. As a result, nine additional engines were inspected, and one of these may require the CCOC to be replaced.
The JT8D engine is fitted in many models of large air carrier aircraft, and as such, this engine is in widespread use throughout the world. Given that one large safety-conscious operator appears to have incorrectly applied the shop visit inspection requirement of AD 87-11-07 R1, the potential exists that other operators may have done likewise. In view of the serious consequence of combustion chamber outer case rupture on JT8D engines, the Board recommends that the Department of Transport:
Require that the maintenance records for all in-service JT8D engines used by Canadian operators be reviewed with respect to compliance with the intent of AD 87-11-07 R1; and that, where applicable, the combustion chamber outer cases be re-inspected; (TSB A94-05); and
use appropriate channels to advise other operators of the JT8D engine internationally of the potential for misinterpretation of AD 87-11-07 R1. (TSB A94)
Transport Canada's Response :
Transport Canada (TC) shares the Transportation Safety Board’s concern that operators comply with the FAA Airworthiness Directive 87-11-07 R1. As the definition of “shop visit” is clearly stated in the AD, however, it is not considered appropriate, TC will issue a Service Difficulty Advisory to advise Canadian operators of JT8D engines to review their maintenance records with respect to compliance with the mandatory requirements and interpretation of AD 87-11-07 R1. A copy of the advisory will be passed to the FAA for their information and their discretion in informing international operators.
SA9401 - A Safety Study of Survivability in Seaplane Accidents
Introduction
The Transportation Safety Board (TSB) recently completed an analysis of seaplane accidents2 that occurred in Canada over the 15-year period from 1976 through 1990. During that period, there were 1,432 such accidents; and 452 people died in 234 of these accidents.
The TSB examined these 1,432 accidents in order to identify underlying safety deficiencies in seaplane operations. Using this database, the Board recently completed a safety study addressing shortcomings in piloting skills, abilities and knowledge.3 This second study deals with occupant survivability in seaplane accidents.
Of the 234 fatal accidents examined, 96 (41%) occurred during the take-off phase, and 87 (37%) occurred during the approach and landing phase.4 In 48% (103) of the 216 fatal accidents where the accident site was described fully in the occurrence records, the aircraft terminated in the water. Less than 10% of the 276 occupants involved in these 103 accidents escaped unhampered from these aircraft.
Objective
This study aims to advance aviation safety by identifying factors affecting occupant survivability in seaplane accidents that terminate in the water.
Scope
Information from the 103 fatal accidents that terminated in the water (resulting in 168 deaths) was examined from the point of view of impact survivability and post-impact survival.
A myriad of issues pertaining to post-crash survivability arose that could only be examined through a file-by-file examination of accident and autopsy data. Did the deaths occur predominantly as a result of impact-related forces, or as a result of post-impact drowning? To what extent were lap belts and shoulder harnesses used? Did the drowning occur in the cabin as a result of egress difficulties or did they occur outside the aircraft? Were personal flotation devices available to the occupants? If so, were they used and were they effective?
The study examines the potential for egress of the occupants in the 103 fatal accidents, the causes of death, and the use of personal restraint systems and flotation devices.
Personal Flotation Devices
In view of the continuing vulnerability of the occupants of seaplanes in accidents on the water to drowning, and since nearly four-fifths of fatal seaplane accidents which terminated in the water occurred during the take-off or the approach and landing phase, the Board, having considered advances in permanent wear, damage resistant, inflatable life-jackets, recommends that:
The Department of Transport require that all occupants of seaplanes wear a personal flotation device during the standing, taxiing, take-off, and approach and landing phases of flight. A94-07
Transport Canada's Response:
Transport Canada Aviation (TCA) has identified a requirement to update the Life Saving Equipment Order, (A.N.O., Series II, No.8) and to improve life preservers currently in use.
During consultation with industry, operators of floatplanes and amphibians pointed out that life preservers are not rugged enough for everyday wear, are unsuitable for frequent donning and doffing and are expensive. Continuing research and development is being conducted by TCA to improve life preserver design. In addition, TCA will present the proposal to make the wearing of such devices a regulatory requirement to the Work Group of the Canadian Aviation Regulation Advisory Council (CARAC) which is currently developing recommendations pertaining to Life Saving Equipment requirements. The Work Group will be asked to assess the safety implications of the proposal.
There is a widespread concern in the aviation industry regarding additional risks inherent in the wearing of the life vests during the standing, taxiing, take-off and landing phases of flight. It is claimed that marine cushions that are in wide-spread supplementary use are more likely to aid in water accidents.
TCA will not legislate that all occupants of seaplanes wear a personal flotation device during the standing, taxiing, take-off, and approach and landing phases of flight until clear safety benefits can be quantified. The revised legislation will require the life preservers to be within was reach of each seated passenger. This will increase their availability to all the occupants in the seaplane.
Personal Restraint Systems
Although the majority of fatal seaplane accidents in the water involve drowning, approximately one-tenth of these victims were incapacitated from non-fatal impact forces. The availability and use of personal restraint systems could have facilitated a successful egress for many of these victims.
The amendment to ANO Series II, No. 225, which would require the fitment of seat-belts and shoulder harnesses and their use by flight crews on board small commercial fixed wing aircraft, has not been promulgated. Consequently, a significant proportion of Canadian seaplanes (most of which were manufactured before 1978) continue to operate without shoulder harnesses available--even for the flight crew. Given that the 1990 Sypher: Mueller study26 estimated that the front seats of aeroplanes could be retrofitted with shoulder harnesses for approximately $2,000, the Board does not understand TC's apparent reluctance to require retrofit.
In view of the vulnerability of seaplane pilots to drowning following non-fatal accident impact forces, the Board recommends that:
The Department of Transport require the fitment of lap belts and shoulder harnesses in seaplanes and require their use by all pilots during take-offs and landings before the 1995 seaplane season begins. A94-08
Transport Canada's Response:
The new Canadian Aviation Regulations (CARs) will address the requirement to install seat belts and shoulder harnesses in aircraft. Some of the relevant text in section 605.24 of the proposed Canadian Aviation Regulations General Operating and Flight Rules stipulates the following as a minimum requirements to which all Canadian aircraft will have to conform, among other things:
- no person shall operate an aeroplane, other than a small aeroplane manufactured before July 18, 1978, unless each front seat or, if the aeroplane has a flight deck, each seat on the flight deck is equipped with a safety-belt that includes a shoulder harness;
- no person shall operate a small aeroplane manufactured after December 12, 1986, the initial type certificate of which provides for not more than nine passenger seats, excluding any pilot seats, unless each forward or aft-facing seat is equipped with a safety-belt that includes a shoulder harness;
and - no person shall operate a rotorcraft manufactured after September 16, 1992, the initial type certificate of which specifies that the rotorcraft is certified as belonging to the normal or transport category, unless each seat is equipped with a safety-belt that includes a shoulder harness.
Canadian commercially registered aircraft will have to conform to these regulations as a minimum requirement. Section 602.116 paragraph (a) of the proposed Canadian Aviation Regulations General Operating and Flight Rules states:
"No person shall operate an aircraft unless; the crew members are seated at their stations with their safety-belts fastened during take-off and landing, and at any other time the pilot-in-command so directs;...."
Compliance
The accident record seriously draws into question the attitude of some seaplane pilots towards basic safety measures. Even when shoulder harnesses were fitted in the aircraft, two-thirds of the accident pilots were not using them; some of them did not even secure the lap belt. Only half of the accident passengers who had shoulder harnesses available wore them--perhaps a reflection of the example set by their pilots. Similarly, despite the availability of life jackets on many of the accident aircraft, apparently few occupants wore them, or had a personal flotation device sufficiently close to use.
The Board recognizes that more stringent regulations alone will not alter current behaviour patterns which exacerbate the fatality rate. Furthermore, enforcement of regulations pertaining to seaplane operations in Canada presents a formidable challenge on a day-to-day basis. Nevertheless, in view of the continuing disregard of basic safety provisions by many pilots and operators in seaplane operations, the Board recommends that:
The Department of Transport implement a national safety awareness program, promoting the use of personal restraint systems and personal flotation devices in seaplane operations as soon as practicable; and (A94-09)
The Department of Transport investigate options for imposing strong sanctions on owners and operators who flagrantly disregard the basic tenets of safety in seaplane operations, and make public its findings within one year of the receipt of these recommendations. A94-10
Transport Canada's Response A94-09:
Transport Canada Aviation (TCA) concurs with the intent of this recommendation. A National Safety Awareness Program which focuses on the use of personal restraint systems and personal flotation devices will be developed.
This program will build on current initiatives under way in the Ontario and Pacific Regions which are aimed at ad dressing safety in seaplane operations.
Transport Canada Response A94-10:
Transport Canada Aviation (TCA) concurs with the current of this recommendation. It is TCA's current policy to take strong enforcement action against any operator who flagrantly violates the aviation safety rules. In addition, the Legislation and Compliance Branch publishes annual statistics on national compliance activities. Regional Compliance Offices pay particular attention to seaplane operations every year in their annual surveillance activities.
The authorities to impose strong sanctions for violations of the aviation safety rules are provided in the Aeronautics Act and the Criminal Code. These authorities must be exercised equitably and fairly in respect to all operators, regardless of the nature and location of their business.
To target any specific member of the aviation community for higher sanctions or penalties, may be considered contrary to the intend and spirit of the Charter of Rights.
Passenger Briefings
Many of the occupants of the accident aircraft were not experienced in seaplane operations. Often they were fare-paying passengers who were unfamiliar with the aircraft, its personal restraint systems, its life-support equipment, emergency egress routes, etc. These passengers could have benefited from a pre-flight briefing prior to the take-off or landing on water. The provision of such safety briefings was recommended in the 1988 CASB study;27 but regrettably, the recommendation has not been satisfactorily implemented.
In order to improve the survival of passengers in the event of a seaplane accident, the Board recommends that:
The Department of Transport establish and promote specific pre-flight briefing requirements for passengers for commercial seaplane operations from or to water. A94-11
Transport Canada's Response:
Amendments to regulations are being made requiring safety briefings for all passengers on commercial air carrier operations.
The Life-Saving Equipment Order (A.N.O., Series II, No.8) requires the carriage of life preservers on all aircraft taking off from or landing on water for each person on board. The Order also requires the passengers to be informed of the location and method of use of the life-saving equipment carried for their use.
Proposed amendments to the Order Respecting Air Carrier Using Large Aeroplanes, (A.N.O., Series VII, No.2), the Order Respecting Air Carriers Using Small Aeroplanes, (A.N.O., Series VII, No.3), and the Order Respecting Rotorcraft Transport Operations, (A.N.O., Series VII, No.6), were published in the Canada Gazette, Part 1 on April 23, 1994. Comments have been received and the Canada Gazette, Part 2 is being prepared for publishing. The proposed amendments will require the provisions of "standard safety briefings" on all commercial flights and among the briefings required are those to be delivered before each take-off. One of the requirements of the pre-flight safety briefing is the location and use of life preservers including a demonstration of their location, and use of life preservers including a demonstration of their location, method of donning and inflation for aircraft being operated in accordance with the Life-Saving Equipment Order.
Again, the Board recognizes the difficulty of enforcing such a requirement. Whereas a TC inspector cannot be omni-present, perhaps the fare-paying passengers themselves can be better informed regarding seaplane safety and encouraged to report unsafe practices to TC; e.g. inadequacy of passenger briefing, non-availability of personal restraint systems and personal flotation devices, excessive or improperly secured cargo, etc. Therefore, the Board recommends that:
The Department of Transport provide all commercial seaplane operators with safety information brochures, including procedures for reporting unsafe operating practices, to be made available to all fare-paying passengers. A94-12
Transport Canada's Response:
Transport Canada Aviation (TCA) concurs with the intent of this recommendation. The Department currently publishes two brochures, TP 5584 Flying With Floats, and TP 7087E A Safety Guide for Aircraft Charter Passengers, which in a generic sense provide safety-related information to seaplane passengers. Notwithstanding, TCA will publish a new safety information brochure, to be carried on all commercial seaplanes, which will specifically address the concerns of Recommendation A94-12.
TCA will ensure the dissemination of this brochure and the requirement to make it available to passengers, to all commercial seaplane operators though an Air Carrier Circular.
A92C0048 - Norontair De Havilland DHC-6-300 Twin Otter C-GQKZ - Red Lake, Ontario 19 March 1992
Synopsis
The aircraft became airborne after a take-off ground roll of approximately 300 feet. Initially the aircraft climbed, and then it began to descend. The aircraft then climbed again, more steeply than before, then suddenly descended in a steep nose-down attitude, crashing half-way down the runway. The captain received minor injuries; the first officer was seriously injured. The aircraft sustained substantial damage.
The Board determined that inappropriate short take-off and landing (STOL) take-off procedures were applied, which placed the aircraft in a flight regime outside of the aircraft performance envelope for sustained flight. The aircraft stalled at an altitude from which recovery was not possible.
Contributing to the occurrence was the general acceptance of the use of STOL techniques as an approved procedure.
Safety Action Taken
Air Carrier's Actions
Following this occurrence, the air carrier conducted an internal review of its policies, procedures, and training practices to assure their correctness. Also, the company pilots were directed not to use STOL procedures on the Twin Otter aircraft.
Transport Canada's Actions
Based on the information gathered during the initial stages of the investigation, Transport Canada advised its regional offices that all Twin Otter operators should be made aware that STOL operations outlined in the Supplemental Operating Procedures are not authorized in commercial operations.
Safety Action Required
Knowledge of Aircraft Flight Manuals
A single binder was used by the air carrier to hold the approved Aircraft Flight Manual (PSM 1-63-1A) and the non-approved Supplementary Operating Data Manual (PSM 1-63-1). This is an accepted practice in the aviation industry, and the combination binder is commonly referred to as the "Aircraft Flight Manual." Generally, a tab divider separates the two portions of the binder; in practice, little distinction is made between the "approved" and "non-approved" contents. It is not uncommon to find flight manual binders with the two categories of information inter-mixed, most likely as a result of years of local reproduction of the original manuals.
The mandatory or "approved" portion of the flight manual binder is generally comprised of the aircraft certification information relating to airspeeds, power plant and weight limitations, normal and emergency operating procedures, aircraft performance data, and loading parameters. The flight manual binder may contain supplemental operating procedures. Since this additional material has not necessarily been reviewed by the certification authority, it is referred to as "non-approved" information. Typically, this section includes acceleration-stop distances, specific range and cruise power charts, some climb and descent performance, system descriptions, maintenance procedures, and other handling characteristics. It often holds manufacturer-issued safety bulletins or communiqués covering topics from product enhancements to revised recommended operating procedures. However, at times, this "non-approved" information from the manufacturer goes beyond the "nice-to-know" category, by providing information essential for flight safety.
"Non-approved" material can generally be divided into two types: information which was not required for the certification of the aircraft, and information that did not meet the safety/performance level required during certification of the aircraft. The STOL procedures for the Twin Otter aircraft belong to the latter category.
The operator involved in this occurrence had separated the two categories of information in the flight manual binder. The company SOPs included duties for a 20-degree STOL take-off based on the "non-approved" procedure. Apparently, the company pilots considered this procedure as a "normal" training sequence, most likely unaware that the STOL procedure did not meet the safety criteria for commercial flight operations.
While there are guidelines on the use of "approved" information, there is no direction as to how the "non-approved" portion of the flight manual binder may be used by pilots and operators. Explanation of the differences between "approved" and "non-approved" information in flight manual binders is not required in initial or recurrent pilot training, nor is it found in commonly used flight publications. Hence, many in the aviation community are unaware of the differences. This lack of understanding regarding the proper use of the "non-approved" information contained in aircraft flight manual binders could result in pilots employing unsafe procedures. Therefore, the Board recommends that:
The Department of Transport promulgate guidelines regarding the use of "non-approved" material contained in aircraft flight manuals, including related operational information issued by aircraft manufacturers; and (A94-13)
The Department of Transport incorporate the subject of "approved" and "non-approved" aircraft flight information in the syllabus for initial pilot training. (A94-14)
Transport Canada's Response - A94-13:
Transport Canada Aviation agrees with this recommendation. An Aeronautical Information Circular (AIC) will be issued with the earliest available amendment cycle of the Aeronautical Information Publication (AIP) Canada. This AIC will go to all pilots and will explain the differences in the basis and use of approved and unapproved information.
Transport Canada's Response - A94-14:
Transport Canada Aviation agrees with this recommendation. The aforementioned AIC will be incorporated in the training for Private, Commercial and Airline Transport Pilot License candidates. In addition, questions concerning this material will appear in the applicable examinations.
DHC-6 (Twin Otter) STOL Performance
The Twin Otter aircraft has an international reputation as a STOL aircraft, and it is often employed in operations demanding short field operations. However, to indicate that the maximum performance STOL configuration of the Twin Otter does not meet certification standards, the manufacturer has provided a "NOTE" in the "Normal Operating Procedures" section of the Supplementary Operating Data Manual.
International aircraft publication standards of the General Aviation Manufacturers' Association and the Air Transport Association promote the use of a system of NOTES, CAUTIONS, and WARNINGS in flight manuals. A "NOTE" is meant to expand further on a topic; a "CAUTION" deals with matters that, if not strictly observed, could result in damage or destruction of equipment; and a "WARNING" directs attention to potentially critical information that, if disregarded, could lead to personal injury or loss of life. Although air crew may not know the exact definitions of NOTES, CAUTIONS, and WARNINGS, they are generally familiar with their relative importance through frequent exposure to them; that is, NOTES receive less attention than CAUTIONS and WARNINGS.
The use of the word "Normal" in the Twin Otter Supplementary Operating Data Manual to describe STOL procedures that do not provide the level of safety required by regulations for Normal Category Operations is misleading. Further, the message contained in the associated NOTE is more in line with what air crew would expect to be labeled as a WARNING.
As evidenced by this occurrence, the limitations of operating the Twin Otter in the maximum performance STOL configuration were not fully recognized by at least one Canadian operator. Consequently, Transport Canada issued a memorandum to its Regional Directors General on "the widespread use of unauthorized STOL procedures" for the DHC-6, alerting TC officials "to the hazards inherent in these procedures." The memorandum indicated "that operators should be made aware that the use of these procedures are not permitted" and "inspectors should ensure that these unapproved STOL operations are not being utilized by operators." Except for the internal Transport Canada memorandum, the Board is not aware of any formal communication or direction being given to Canadian operators regarding "non-approved" STOL procedures for the DHC-6. In March 1994, four randomly chosen DHC-6 operators in different regions across Canada indicated that Transport Canada had not contacted them regarding STOL procedures, and that STOL take-offs were being employed. Furthermore, given that the DHC-6 is widely used throughout the world, there does not appear to have been any related correspondence to international agencies responsible for foreign DHC-6 operators.
Since the DHC-6 Twin Otter is marketed as a STOL aircraft, since the information provided by the manufacturer regarding limitations on the "non-approved" procedures for maximum performance STOL take-offs is misleading, and since Transport Canada has advised its Regional Directors General that "the use of these procedures are not permitted," there is room for considerable misunderstanding in the global aviation community regarding the safe operation of this aircraft in the STOL configuration. Therefore, the Board recommends that:
The Department of Transport define, through a program of flight testing, the aircraft configuration and operating conditions under which "maximum performance" STOL take-offs are authorized; and A94-15
The Department of Transport take the necessary measures to advise all DHC-6 operators on a global basis of the operating limitations for these "authorized maximum performance" STOL procedures; and A94-16
Transport Canada's Response - A94-15:
Transport Canada Aviation is preparing an Air Carrier Advisory Circular (ACAC) which will further define the operating conditions for use of Maximum Performance STOL procedures. Only operators who have been authorized by an Operations Specification will be permitted to conduct STOL take-offs. Flight testing is not required to verify the aircraft configuration or operating conditions as testing was done by the manufacturer.
Transport Canada's Response - A94-16:
The DHC-6 Twin Otter certification basis, US Civil Aviation Regulations (CAR) 3, does not address Short Take-Off and Landing. As there is no domestic or international standard against which to qualify them, Maximum Performance - STOL procedures are not certified by the Department. They are published by the manufacturer in the unapproved section of the Aircraft Flight Manual (AFM). The approved AFM is clearly identified and separated from the unapproved or manufacturer provided Supplementary Operating Data. The manufacturer provided a clear note at the beginning of the section stating that since STOL capabilities “do not provide the level of safety required that since STOL capabilities “do not provide the level of safety required by CAR 3, Normal Category Operations, they must be used only when specifically authorized by the local regulating authority”.
Because DHC-6 STOL operations do not confirm to any internationally recognized standards, it is the prerogative of the aviation regulatory authority in each foreign state where the aircraft is operated to decide whether, and under what conditions, STOL operation will be permitted. It would not be appropriate for the Department to interfere in the jurisdiction of other states by communicating with foreign operators concerning these matters. However, the Department will send a letter to aviation authorities in foreign countries where the DHC-6 is operated to advise them of the circumstances of the accident and the measures that are being taken in Canada to improve regulation of DHC-6 STOL operations.
A94H0001 - Flight into Terrain Westland Helicopters Inc. - Bell 206 BIII JetRanger (Helicopter) C-GRAH - Houston, British Columbia - 29 January 1994
Synopsis
The helicopter, a Bell 206 BIII, with the pilot and four passengers on board, was on a charter flight from Houston, British Columbia, to a ski cabin on Mount Morice, 10 miles to the south of Houston. The helicopter crashed approximately 2.5 miles to the north of its departure point. The helicopter was destroyed, and the pilot and passengers sustained fatal injuries.
The Board determined that the pilot, while attempting to climb through a fog layer by using rising terrain as a visual reference, most likely lost the visual cues required for flight in visual meteorological conditions (VMC). The helicopter struck a ridge, probably while the pilot attempted to regain his visual reference with the ground.
The pilot's decision to use the rising terrain as a visual reference under the existing visibility conditions was a contributing factor to this accident.
Safety Action Taken
Hydraulic Servo Contamination
On 15 December 1994, Transport Canada (TC) advised the Federal Aviation Administration (FAA) of the metallic contamination found in the helicopter's collective servo actuator. In their correspondence, TC suggested that the FAA ensure that the servo manufacturer takes appropriate quality control/assurance actions.
Interim TSB Aviation Safety Recommendations
Based on information compiled during this investigation, and frequent evidence of a lack of appreciation on the part of helicopter operators/pilots of the risks involved in conducting VFR flights into adverse weather, especially in mountainous terrain, the Board notified the Minister of Transport in August 1994 of three interim Safety Recommendations.
Flight Into Adverse Weather - Risk Awareness
A TSB safety study on VFR into adverse weather found that VFR-into-instrument-meteorological-conditions (IMC) accidents accounted for only 6% of the total number of aircraft accidents in Canada; yet, they involved 23% of all fatal accidents and took the lives of 418 persons between 1976 and 1985. Half of the VFR-into-IMC accidents had occurred in mountainous or hilly terrain; approximately 10% of VFR-into-IMC accidents involved helicopters, and one third of these were fatal. Since the release of the safety study and its associated recommendations in December 1990, there have been 10 commercial helicopter accidents in Canada involving VFR flight in adverse weather, resulting in six fatalities. The Board believes that some VFR-rated helicopter pilots, especially those operating in mountainous areas, have adopted the practice of intentionally penetrating localized areas of extremely reduced visibility in order to reach areas of better weather.
Commercial helicopter accidents in adverse weather continue, despite frequent emphasis in TC safety newsletters and presentations on the importance of adhering to established VFR limits. The Board believes that proper training and education are important in the prevention of adverse weather accidents; however, the Board was not aware of any substantial measures in this vein being taken by TC or the helicopter industry following the recommendations of its 1990 study. Therefore, the Board recommended that:
The Department of Transport, in consultation with the aviation industry, implement a special safety campaign to inform the helicopter community of the inherent risks involved in the ad hoc practice of penetrating cloud/fog in VFR operations, particularly in mountainous regions. (A94-18, issued August 1994)
Transport Canada Response:
Transport Canada Aviation (TCA) agrees with the concerns of the Transportation Safety Board regarding the inherent risks involved in the ad hoc practice of penetrating cloud/fog in VFR operations, particularly in mountainous regions. In this regard, TCA regularly stresses in its safety newsletters and presentations across the country the importance of adhering to establish VFR limits and the practice of good airmanship while flying in areas of adverse weather.
TCA will promote the Board’s concerns in a feature article in the specialized helicopter safety newsletter, the Aviation Safety Vortex, which is distributed free of charge to all holders of a valid Canadian helicopter pilot license. In addition to the Vortex feature article, and after the release of the Board’s Final Report into the Houston accident, the Regional Aviation Safety Officers (RASOs) across the country will be provided with a special promotional package concerning this accident and the practice of voluntarily penetrating cloud/fog in VFR operations, so that they may distribute it to the helicopter industry during their regional visits. In the meantime, the RASOs have been provided with copies of the Board’s Communiqué and background information on the three recommendations.
Regulatory Compliance & Industry Self-Regulation
ANO V, No. 3, Para 6 does not permit VFR flight in cloud. The Board believes that the extent to which the unsafe practice of cloud penetration is prevalent might suggest a lack of respect for the need for regulatory compliance; operators/pilots may feel that there is only a remote possibility of being found in violation of the ANO. In a 1991 TSB survey of commercial pilots, 38% of respondents stated that TC's inspections of company facilities are not sufficiently frequent to ensure that regulations are respected. It is understood that Transport Canada has not recorded any violations under ANO V, No. 3, Para 6 in the mountainous regions of western Canada in the last ten years.
The Board is well aware that climatic conditions in many locations prevent some VFR-only operators from conducting their business at certain times of the year. However, if these operators ignore the weather limits in the ANO, they negate the safety buffer provided by the regulation, and put themselves and their passengers at risk. Furthermore, the Board believes that within the helicopter industry in general, the practice of "pressing-the-weather" is tacitly accepted and is viewed as a part of doing business. There does not appear to be self-regulation through condemnation by peers in this regard within the industry.
The Board believes that neither the regulator nor the commercial helicopter industry are effectively ensuring compliance with established weather limits. Therefore, the Board recommended that:
The Department of Transport place increased emphasis on achieving compliance with respect to VFR weather limits for commercial helicopter operations; and (A94-19, issued August 1994)
The Department of Transport, in conjunction with industry, explore measures to counter attitudes that "pressing-the-weather" is an acceptable practice in commercial VFR helicopter operations.(A94-20,issued August 1994)
Transport Canada Response - A94-19
Transport Canada Aviation (TCA) agrees with the requirement to achieve compliance with the respect to VFR weather limits for commercial helicopter operations. Compliance is achieved through education, training, inspections and surveillance. Regional air carrier branches will be tasked to place increased emphasis on commercial helicopter operations in adverse weather conditions. As well, an Air Carrier Advisory Circular (ACAC) will be issued to address the risks involved in conducting VFR flight into adverse weather, especially in mountainous terrain. This Circular will emphasize the hazards of the practice adopted by some helicopter pilots, of intentionally penetrating localized areas of reduced visibility to reach areas of better weather.
Transport Canada Response - A94-20
Transport Canada Aviation (TCA) agrees with the intent of this recommendation and will send a letter to the major helicopter associations across Canada which will reflect the Board’s concerns and to ask them to impress upon their members that “pressing-the-weather” is not an acceptable practice in commercial VFR helicopter operations. The letter will stress, among other things, the importance of risk awareness, regulatory compliance, industry self-regulation, various types of pressures and respect for the weather. TCA believes that this letter, in addition to the actions described in response to the Board’s recommendations A94-18 and A94-19, will satisfy the intent of this recommendation.
A93A0223 - Loss of Separation Between - Lufthansa German Airlines Airbus A310 D-AIAF and American Airlines Boeing 767-300 N354AA - Goose Bay, Labrador 68 nm E - 06 October 1993
Synopsis
Lufthansa flight 408 (DLH 408) and American flight 79 (AAL 79) were both westbound over Labrador. DLH 408 was at flight level 330 and AAL 79 was at flight level 350. DLH 408 was one minute ahead of AAL 79 when they progressed by SCROD intersection proceeding along the same track to FRAZR intersection. The loss of separation occurred when DLH 408 was cleared to climb through the flight level of AAL 79.
The Board determined that the loss of separation occurred because the controller on-the-job instructor (OJI) failed to adequately monitor the controller trainee and both the controller OJI and the controller trainee forgot about AAL 79. Contributing to this occurrence was the fact that the radar target of AAL 79 was not displayed on the radar indicator module (IM) for several minutes prior to the loss of separation.
Safety Action Taken
Dissemination of Fact Finding Board Findings
During the investigation, it was learned that Transport Canada (TC) limits the dissemination of the findings from Fact Finding Boards in order to protect controller confidentiality. This practice reduces the opportunities for controllers to learn from the experiences of others. An Aviation Safety Information Letter was sent to TC pointing out that, considering the commonality of procedures and equipment at ATS facilities across Canada, a potential safety deficiency exists--that is, other occurrences could be waiting to happen for reasons already identified by a Fact Finding Board.
Safety Action Required
SSR Transponder Replies - Synchronous Garble
It is understood that the Goose Bay radar has been modified and now operates like other RAMP secondary surveillance radar (SSR) systems. Thus, the potential for the Goose Bay radar to disregard a transponder reply has been reduced; as with all SSRs, though, it has not been eliminated.
When two aircraft are approximately the same slant range distance from an SSR, the aircraft transponder replies to SSR interrogation can be synchronous. In such situations, the SSR digitizer attempts to ungarble the replies; however, any information that remains garbled will be disregarded. This results in a loss of radar target data from the radar display.
The probability of synchronous garble occurring depends upon the capability of an SSR to identify the specific block of airspace from which a transponder reply was emitted. These specific blocks of airspace (defined by azimuth, height, and distance) are referred to as extractor bins. State-of-the-art SSR technology has reduced bin size, thus reducing the chance of transponder replies being received simultaneously from the same bin; however, further significant reductions to bin size are not likely due to physical constraints. In addition, modern flight management systems facilitate precise track navigation, thereby increasing the potential for no lateral displacement from the centre line for two aircraft following a common track. This eliminates differences in azimuth from the extractor bin equation, making it more difficult for the SSR to determine the location of the transponder reply. Thus, synchronous garble will continue to exist with the type of SSRs presently in use in Canada's air navigation system.
Synchronous garble can be avoided by ensuring that individual aircraft transponder replies are either unique to individual aircraft by using Mode Select SSR or are transmitted by data link. TC's current plans for surveillance systems do not include Mode Select but do include data link. However, the use of data link for ATS will not be widely available before 1998, at the earliest.
As previously mentioned, some controllers at the Moncton ACC had developed a procedure to preclude the possibility of not all radar targets being properly displayed when conditions conducive to synchronous garble existed. For example, aircraft were being deviated slightly from cleared routes to create lateral displacement between the aircraft involved before a clearance was given to climb one aircraft through an altitude assigned to another aircraft. While this ad hoc procedure appeared to be acceptable, there was no evidence that management had participated in the procedure's development or approval prior to this occurrence. (The Board understands that, since the occurrence, local ATC management has approved such a procedure for use at Moncton ACC.)
The measures implemented at Moncton ACC should assist in mitigating losses of separation there due to synchronous garble. Although the Board has not investigated other occurrences involving synchronous garble, the Board is concerned that other SSRs are prone to target data degradation due to synchronous garble, with a continuing potential for risk of a collision. Therefore, the Board recommends that:
The Department of Transport implement procedures to reduce the possibility of radar target loss due to synchronous garble. A94-21
Transport Canada Response:
The loss of a Radar target due to synchronous garble is considered to be an extremely remote possibility with the Monopulse Secondary Radar (SSR) technology incorporated in the new RAMP radar system. All SSR target returns in Canada (including the Goose Bay Radar) are now secured by the monopulse method and processed by the RAMP Radar Data Processing System (RDPS).
The Goose Bay radar data being received and displayed in the Moncton Area Control Centre on the date of the loss of separation was downgraded due to the interference restrictions imposed while transitioning to the new RAMP Radar Data Processing System. This transition was completed on January 24, 1994, and the precision of the radar data now being received and processed is the most accurate possible in a any radar system.
The Air Traffic Control Manual of Operations provides direction to controllers to follow in the event of the loss of radar data. These procedures would be applicable to any situation where radar data is lost, including synchronous garble. The retention of all flight data manually on the flight data strip is a redundancy feature which is in place to ensure a safe operation can be maintained, using non-radar separation techniques, in the event of any loss of radar data or radar failure.
A93C0130 - Loss of Separation Between Air Canada Airbus Industrie A320-211 Airbus C-FDRP and Perimeter Airlines Inland (Ltd) Swearingen SA226-TC Metroliner C-FKEX Winnipeg, Manitoba 20 nm SE 30 July 1993
Synopsis
The arriving aircraft, whose air traffic control target on the radar display disappeared after being radar identified, was overlooked by the air traffic controller. The arriving aircraft continued inbound with no separation standard applied and passed in proximity to a departing aircraft.
The Board determined that loss of separation occurred when an operational deficiency in the radar system known as the "Secondary Surveillance Radar Monopulse Plot Extractor Missing Target Phenomenon" occurred and the en route air traffic controller forgot about the arriving aircraft. Contributing factors were: the lack of a warning of the phenomenon occurring, a misapplied corrective procedure, reduced availability of technical staff, atmospheric effects, and an improperly positioned primary radar filter switch.
Safety Action Taken
SMPE Software
The Board understands that Transport Canada (TC) has installed software to advise when the SMPE missing target phenomenon has possibly occurred. The software continually monitors the SMPE's track file capacity and causes error messages to be sent to technical and operational staff when a discrepancy exists. The effectiveness of the software cannot be validated through simulation, and since this software was installed, the phenomenon has apparently not reappeared. The Board further understands that TC is continuing its efforts with the manufacturer of the SSR to eliminate the deficiency that causes the phenomenon.
Safety Action Required
Interim Safeguards
The Winnipeg RAMP radar was certified for operational use with the SMPE missing target deficiency known, and measures were put in place to safeguard against risks of collision resulting from losses of targets. However, this investigation identified shortcomings with the existing defence mechanisms.
In the event of SSR target loss, a radar technician is required to reset the SMPE and regain SSR targets quickly. Part of the original measures to cope with the known deficiency included radar technician support over the midnight shift; however, some time prior to this occurrence, radar technician support during the night shift was eliminated. The elimination of the continuous technician support also necessitated that the "P" switch be turned on by the DSC prior to the midnight shift. As seen in this investigation, there was no procedure to safeguard against a failure of the day shift DSC to turn the "P" switch off. Moreover, the design of the SMPE reset procedure could allow errors to go undetected during the reset process.
The Board believes that there may still be latent, unsafe conditions within the measures and procedures that were designed to cope with the SMPE deficiency. If so, these conditions could again contribute to a risk of, or actual, collision of aircraft. Therefore, until the SMPE deficiency is corrected, the Board recommends that:
The Department of Transport reconsider the technical procedures and equipment associated with operating the radar with the SMPE deficiency. (A94-22)
Transport Canada's Response:
Transport Canada recognized the problem with the RAMP Radar Site Equipment (RSE) radars, characterized as ‘The SMPE Missing Target Phenomenon’ and has taken action to comply with Transportation Safety Board recommendation A94-22.
The following actions have been taken which have a direct effect on the significant contributing factors that were identified by the Safety Board.
A. SSR Monopulse Extractor (SMPE) Software Updates:
Software upgrades were made to the SMPE in late 1993. The modified software monitors the SMPE for missing the target condition. When the condition is detected, a forced switchcover to the standby SMPE unit occurs. This switchover is transparent to the ATS operation. Transport Canada considers the SMPE Missing Target Phenomenon to have been corrected.
B. Use of Primary Radar Filter ('P') Switch:
The Radar Data Processing System (RDPS) R500 series software release, which sent into use in late 1993, contains enhancements that obviate the need for daily manipulation of the primary radar inhibit switch. The procedures of enabling the primary radar inhibit switch during the midnight shift is no longer practised by the Winnipeg Data Systems Coordinators (DSCs). Therefore the daily procedure of cycling the ‘P’ switch, which was identified by the TSB as a contributing factor in the occurrence, has been removed from the operational milieu.
C. Re-enforced indication of ‘P’ Switch Selection:
An RDPS Change Proposal (CP 94-001) which provides a positive indication of the setting of the ‘P’ switch at each affected controller’s display has been approved by the Configuration Control Board. Current plans are to have this enhancement delivered in the R800 series release, which should be in mid to late 1995. When implemented, this change will reduce, to absolute minimums, the possibility of a “P” switch being inadvertently activated.
The Air Traffic Control Manual of Operations provides direction to controllers to follow in the event of the loss of radar data. These procedures would be applicable to any situation where radar data is lost. The retention of al flight data manually on the flight data strip is a redundancy feature which is in place to ensure a safe operation can be maintained, using non-radar separation techniques, in the event of any loss of radar data or radar failure.
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
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.
Safety Action Taken con'td
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)
Transport Canada Response:
The Manual of Regulatory Audits (MRA) already defines an audit as “an in-depth review of the activities of an organization to verify conformance with the current regulatory standards”. While the Transportation Safety Board (TSB) report suggests that Transport Canada Aviation (TCA) may on occasion conduct less than comprehensive audits, this is not TCA’s present policy.
As a result of the Moshansky Inquiry and the Air Carrier Inspection Task Force, the MRA is in the process of being amended to further improve the audit process. TCA will take into consideration recommendation A94-23 in the MRA amendement.
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)
Transport Canada Response:
The Manual of Regulatory Audits (MRA) provides direction on the application of risk management indicators to determine the frequency of audits. The Transportation Safety Board (TSB) report indicates that, based on interviews with Transport Canada Aviation (TCA) regional staff, consistency in the application of risk assessment criteria was lacking. It should be noted that managers in the regions are responsible for the establishment of the regional audit program and it would not be expected that a working level Inspector be fully aware of the process. The Air Carrier Inspection Task Force has recommended that TCA “expand and develop the explanation and guidance provided on risk indicators.” TCA has accepted this recommendation. Action on this recommendation will be taken in the revision to the MRA to be issued in draft by February 1995.
The Audit Procedures training program for inspectors was revised during the period September 1993 to February 1994. The first course was given in March 1994 and since that date training has been provided to 68 TCA personnel.
TCA has introduced improvements to the training of those involved in the audit process which includes the principles of risk management. TCA will ensure that the training takes into account the TSB recommendation so that risk management methods are clearly understood and applied.
The Department of Transport develop, as a priority, a system to track audit follow-up actions; and (A94-25, issued December 1994)
Transport Canada Response:
The Manual of Regulatory Audits (MRA) requires that a system be in place for follow-up. Transport Canada Aviation will review the MRA to ensure clear policy direction is given to ensure effective systems are in place.
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)
Transport Canada Response:
The Manual of Regulatory Audits (MRA) states that “managers assigned responsibility for follow-up must ensure that a formal system is in place to track and verify the progress of the company’s approved Corrective Action Plan.” Regions have each developed their own system to ensure that follow-up is complete. Transport Canada Aviation (TCA) is enhancing the National Aviation Company Information System (NACIS) to include a module that will track audit follow-up on a national basis.The contract has been awarded and the NACIS system should be operational by September 1995.
In the interim, TCA will issue a policy directive to regions to require a review of their respective regional system to ensure its effectiveness.
TCA’s Quality Assurance Review Program has been strengthened to verify that audit follow-up and appropriate enforcement action has been taking place after audits follow-up and appropriate enforcement action has been taking place after audits. In the long term, NACIS will provide for an automated national audit follow-up tracking system.
TCA will be conducting a thorough review of the audit program implementation and the audit follow-up process.
A93C0208 - Risk of Collision Between Air Canada A320 211 Airbus C-FDRP and Canadian Airlines International A320 211 Airbus C-FLSS - Thunder Bay, Ontario 40 nm NW - 03 December 1993
Synopsis
An Air Canada A320 was en route from Montreal, Quebec, to Vancouver, British Columbia, at flight level 370 and a Canadian Airlines International A320 was en route from Edmonton, Alberta, to Toronto, Ontario, at the same altitude. In the vicinity of Thunder Bay, Ontario, a risk of collision occurred. The aircraft passed each other within two miles horizontally and 1,800 feet vertically.
The Board determined that the controller did not recognize the developing traffic conflict between Air Canada 111 and Canadian 952 and did not maintain the required separation criteria for the two aircraft. Contributing to the occurrence was the lack of adequate supervision of the controller's technique, staffing shortfalls, and the absence of a traffic conflict warning system.
Safety Action Taken
Since the occurrence, shift scheduling for the Winnipeg ACC has been revised. Controllers are now scheduled so that supervisors can conduct "standback" supervision from 0800 to 1630 local on weekdays.
Provision of Standback Supervision
The CASB's Report on a Special Investigation into Air Traffic Control Services in Canada (March 1990) found, inter alia, that supervisors had been working at control positions when many of the loss-of-separation incidents had occurred. The report recommended that operational restrictions be placed on supervisors performing in direct control positions to provide a more effective supervisory presence (CASB 90-28). In response, Transport Canada (TC) indicated acceptance of the recommendation and agreed to implement it with the proviso that, due to staff shortages, supervisors would be required to work control positions occasionally.
Since making that recommendation in 1990, the TSB has investigated eight occurrences2, including this one, in which the lack of standback supervision was a factor. In its final reports on two of these occurrences3, the Board expressed concern that supervisors were still working at direct control positions and were not available to provide standback supervision during busy traffic periods.
The Board recognizes the difference between the role of a supervisor to schedule the work and relief of controllers assigned to sectors under his responsibility and the requirement to maintain situational awareness of overall traffic levels and workloads at these sectors. When a supervisor is working at a control position, the operational supervision of controllers and the maintenance of an overall awareness of the evolving air traffic situation will suffer.
TC has developed new target staffing levels for controllers, partially as a result of the aforementioned recommendation for standback supervision. Reportedly, the TC Resource Alignment Process visited the Winnipeg Area Control Centre (ACC) in July 1993, and provided the ACC with adequate staffing numbers to reduce the need for supervisors to work control positions during the core hours of 0800 to 2400 local. However, as TC has acknowledged, due to financial and staffing constraints, full time direct supervision is not always possible. (As indicated in section 4.1 of this report, the shift schedule at Winnipeg has been revised to provide "standback" supervision from 0800 to 1630 hours local on weekdays.)
Supervisory presence to oversee operations is not in itself a guarantee against occurrences. However, in view of the frequency of serious loss-of-separation incidents in which lack of supervision continues to be a contributing factor, the Board recommends that:
The Department of Transport conduct risk assessments by ATC unit to confirm that currently available controller forces are optimally deployed. A94-27
Transport Canada Response:
Transport Canada Aviation (TCA) supports this recommendation. The Air Traffic Services Branch has already initiated a "Resource Utilization Assessment" of all Area Control Centres and major Control Towers. A risk assessment of the supervision and deployment of staff will also be completed.
Once the reviews are completed, a national comparison report will be prepared with recommendations to ensure that the best operating practices are identified and implemented at all units.
In addition to the above, longer term initiatives include the Instrument Flight Rules (IFR) Workload Measurement Project and the Scheduling Project. These projects involve the development and implementation of an automated system to determine the controller requirements during a given time frame at specific workstations, and an automated system for the optimum scheduling of staff to meet identified systems requirement.
Situational Awareness
A high degree of vigilance is essential for sustaining awareness of developments in dynamic situations. In this investigation, it was found that the controller did not effectively monitor the traffic, nor take timely action to resolve the conflict. The manner in which the controller planned, executed, and monitored the air traffic was not conducive to maintaining good situational awareness, particularly during periods of light traffic. Several studies of operational errors, including a study of operational irregularities in the Canadian air traffic system (Stager and Hameluck, 1990), identified that a failure to maintain adequate situational awareness was the likely cause of most errors.
In its Report on a Special Investigation into the Risk of Collision Involving Aircraft On or Near the Ground (August 1987), the CASB noted that vigilance is the key to collision avoidance. Yet, the methods for stimulating and maintaining the high levels of vigilance requisite for collision avoidance are not well understood. Therefore, it was recommended that the Department of Transport initiate a multi-disciplinary study on the most effective means for sustaining vigilance, particularly for controllers under periods of low activity rates (CASB 87-41). In the subsequent Report on a Special Investigation into Air Traffic Control Services in Canada (March 1990), the CASB noted that TC was only planning to take action to determine the methodology and personnel requirements to conduct an analysis of means of sustaining vigilance. It was then further recommended that the Department of Transport accelerate all technical initiatives with a potential for providing controllers with automated conflict prediction and alerting (CASB 90-36).
A traffic conflict warning system is being included in the Radar Modernization Project (RAMP), but it is not yet functional. However, automated systems still require high levels of operator vigilance to monitor the effective performance of the systems. The Board is concerned that the RAMP warning system may create a false sense of security, lessening the perceived need for continued high controller vigilance. Analysis of flight crew performance in highly automated cockpits has shown that inadequate monitoring of automated flight management systems has resulted in loss of situational awareness; in such cases, considerable time is required for the operator to get "back into the loop" and revert to backup procedures should the "system" fail. The aviation industry continues to grapple with the issue of sustained vigilance and maintenance of situational awareness in automated cockpits. The Board believes that a thorough understanding of the mechanics of sustaining vigilance in an automated ATC environment will also be critical for the maintenance of a safe air transportation system.
Controller inattention, lack of vigilance, or loss of situational awareness continue to be major factors in loss of separation occurrences. Therefore, the Board recommends that:
The Department of Transport sponsor research into methods for maintaining reliable controller vigilance in an increasingly automated ATC work environment. A94-28
Transport Canada Response:
Transport Canada Aviation (TCA) agrees with this recommendation and will conduct research on the most effective communication, focusing and distraction control techniques for air traffic controllers and implement relevant training programs. TCA has started doing research on other areas that impact on controller vigilance, e.g., workload and traffic levels, more effective scheduling tools, the effects of shift work and overtime on the health and performance of controllers. TCA has also implemented the following preventive and facilitative programs designed to optimize air traffic controllers health and performance: "Air Traffic Controller Chemical Critical Incident Stress Education and Peer Support Program", and the "Air Traffic Controller Occupational Health Program". Air traffic controller ab initio trainees at the Transport Canada training Institute (TCTI) are given a module called "Mental Control" which teaches trainees focusing, distraction control and visualization techniques to optimize their performance.
In the meantime, given that an operational overview by standback supervisors may not always be available, the Board believes that immediate measures must be taken to enhance the skill required by controllers for maintaining situational awareness.
Maintaining situational awareness is one of the key skills developed in crew resource management (CRM) programs. The Board understands that the concept of CRM training for flight crews is being adapted for controllers, and situational awareness training specific to air traffic control is being developed in other countries. Therefore, to assist controllers in their maintenance of situational awareness, the Board recommends that:
The Department of Transport provide training for Canadian controllers similar to CRM training for pilots. A94-29
Transport Canada Response:
Transport Canada Aviation (TCA) does not feel that the Crew Resource Management (CRM) training designed for pilots is applicable to the controllers. A decision making course similar to the Pilot Decision Making course is felt to be more relevant. This type of training will be researched and an appropriate training course developed. Action has already been initiated to implement a system safety awareness program. A position for an Air Traffic Services (ATS) controller has been established within the Safety Programs Branch and an ATS Safety Newsletter was published recently. These Newsletters will be published on a regular basis. Safety awareness training will also be pursued for introduction at TCTI.
Footnotes
2 TSB occurrences A90P0347, A90H0008, A92H0003, A92H0028, A92H0035, A93O0203, A93A0118
3 TSB occurrences A90P0347 and A90H0008
Should you require further information, please contact Aviation Safety Analysis at asi-rsa@tc.gc.ca