Maintenance and Records
SWR holds the following operating certificates:
The FOCA Certificate of Registration issued 5 August 1991 for HB-IWF Swissair lists the following information:
Registered owner's name and address
Blue Ridge Finance Ltd.
Registered operator's name and address
Additional aircraft information
Table: Aircraft Maintenance History
Table: Applicable Checks
A review of the maintenance records verified that all requirements of the approved maintenance program were completed on time or within the tolerance granted to Swissair by the FOCA.
The aircraft was delivered to Swissair with three Pratt & Whitney PW4460 model engines installed. McDonnell Douglas SB 72-001, to convert the PW4460 to the PW4462 model, was incorporated on 1 October 1997 under EO 069685.02. At the time of the accident the aircraft was equipped with three Pratt & Whitney PW4462 model engines.
The Engine Condition Trend Monitoring Reports from 16 June to 1 September 1998, and the Engine Trend Monitoring Watch-List of Swissair PW4462 engines were reviewed; there were no discrepancies directly pertinent to the investigation.
Engine 1 (SN P723896CN) was removed from aircraft HB-IWG (Swissair) on 2 February 1998, because of performance deterioration. The incoming inspection of the filter and magnetic plug revealed no deposits. Because of engine time accumulated, it was decided that the engine should be overhauled. Normal wear was indicated. High-pressure turbine T1 blades were excessively worn at the tips, and ceramic duct segments were spalled. The T2 rotating air seal was replaced because of a crack. Extensive overhaul maintenance was performed on all areas of the engine, and an engine test was performed in a test cell on 6 April 1998. A module analysis assessment was performed to evaluate performance standards. Total flight hours were 25 753 and total cycles were 4 290. The Engine Condition Report and Engine Test Summary Log were reviewed; there were no discrepancies directly pertinent to the investigation.
Engine 2 (SN P723856CN) was removed from aircraft HB-IWH (Swissair) on 12 June 1997, for modification. The incoming inspection of the filter and magnetic plug revealed no deposits. Normal wear was indicated. The T2 rotating air seal was replaced because of a crack, and standard overhaul maintenance was performed on other areas of the engine. An engine test was performed in a test cell on 11 August 1997, and a module analysis assessment was performed to evaluate performance standards. Total flight hours at this time were 24 770 and total cycles were 4 439. The Engine Condition Report and Engine Test Summary Log were reviewed; there were no discrepancies directly pertinent to the investigation.
Engine 3 (SN P733713) was removed from aircraft PH-MCS (Martinair) on 5 April 1996 as a result of an in-flight shutdown. The incoming inspection of the filter and magnetic plug revealed no deposits. The engine disassembly revealed that a fractured T2 blade caused heavy secondary damage to the high-pressure compressor, diffuser case assembly, high-pressure turbine, low-pressure turbine, and main gearbox. Extensive overhaul maintenance was performed on all areas of the engine and an engine test was performed in a test cell on 4 October 1996. A module analysis assessment was performed to evaluate performance standards. At the time of this maintenance, total flight hours were 4 735 and total cycles were 861. The Engine Condition Report and Engine Test Summary Log were reviewed; there were no discrepancies directly pertinent to the investigation.
SR Technics aircraft records indicated four STCs incorporated on HB-IWF:
The FOCA Maintenance System Approval Statement (AOC 1017) certified that Swissair was approved under JAR-OPS 1 Subpart M to manage the maintenance of the following aircraft:
Table: Approved Maintenance Programs
The SR Technics Engineering department was responsible for the maintenance programs for all Swissair aircraft, with the exception of the B747, which had been subcontracted to KLM.
The FOCA approved the Swissair maintenance program for MD-11 aircraft with the following conditions:
The FOCA authorized Swissair to participate in the SR Technics MD-11 Reliability Program (98-37146) under the condition that the SR Technics Reliability Program was considered part of the approved Swissair Maintenance Program.
SR Technics was composed of eight organization areas: Maintenance, Powerplant, Components, Materiel, Engineering and Quality, Finance, Human Resources, and Marketing and Sales. Each of these had a supporting structure to meet their specific business needs. For example, the supporting structure for Maintenance included the following:
SR Technics had the following certifications:
At the time of the accident, based on an authorization issued by the FOCA, SR Technics' Engineering department was authorized to release its own maintenance instructions and to amend maintenance instructions issued by the manufacturer of aircraft, engines, components, or both as described in the MOE. This particular Engineering approval was not applicable to SR Technics' FAA Repair Station certificate.
The FOCA Approval Certificate certified SR Technics as a JAR-145 maintenance organization approved to maintain the products listed in the Approval Schedule, issued 24 April 1998, expiry date 24 October 1998.
The extent of maintenance that can be performed is specific to aircraft type and series.
Table: Aircraft and Maintenance Type
The extent of maintenance that can be performed is specific to engine type and series.
Table: Engine Type and Maintenance
The FAA empowered SR Technics to operate an approved Repair Station with the following ratings:
Table: Repair Station Ratings
Delegated Authorities: None
Delegated Authorities: None
The purpose of the MOE manual (effective date 1 March 1997) was to describe the procedures and policies of SR Technics. Compliance with these procedures assures conformity with the applicable regulations, appropriate manufacturers' manuals, and other approved data, all of which are necessary to obtain and retain certificates and ratings. The MOE is a combined manual covering FOCA/JAA and FAA requirements, and cross-references subjects required by the FAA Foreign Repair Station Inspection Procedures Manual Guidance and Reference Material. The responsibility for compliance with the provisions of the MOE rested with the general managers of the different organizational areas.
An EO is the means by which the Engineering department provides instructions to the applicable work groups to perform specific work activities. EOs originate from an AD, manufacturers' recommendations (e.g., SBs, AOLs;), or from SR Technics internal decisions. An EO can also be generated to incorporate modifications, implement changes in the maintenance programs and fleet inspections, or both. They are published in written form, and compliance is mandatory. An EO deadline date is an agreed-upon date based on the requirements of the Engineering department and of other departments as deemed necessary. This date can be modified, unless the EO is related to an AD, upon approval by the Engineering department. Modifications to the deadline date can be attributed to a variety of reasons, such as availability of vendor-supplied parts.
The Technical Training Committee, training coordinators, supervisory personnel, QA departments, and the Personnel Development and Technical Training department worked together to ensure that there were appropriately qualified and trained personnel within SR Technics.
The Technical Training Committee was chaired by the head of the Personnel Development and Technical Training department and included representatives from all product areas. This committee was responsible for issues pertaining to overall training, including ensuring that the training corresponded with the objectives of SR Technics. Additionally, the committee provided information to managing personnel about the level of training in each product area.
Each assigned training coordinator was responsible for training issues, and for ensuring that decisions made by the Technical Training Committee were communicated within their specific product areas.
Within their specific work areas, the supervisory personnel were responsible for introducing a new employee to the workplace, establishing training requirements for each employee, providing on-the-job training, and keeping a training record for each employee.
Each QA department was responsible for controlling and approving the special procedures for certifying staff. These procedures included qualification profiles and training requirements.
The Personnel Development and Technical Training department was responsible for executing classroom and practical training and for keeping records of training that had been provided.
The MOE describes the training program as including:
Basic training mainly consisted of an introductory course, basic courses, and courses specific to aircraft types.
All new employees received an introductory course on their first day of employment. This included a general presentation of the company, personnel regulations, and a workshop tour in the maintenance base.
Basic courses provided general knowledge about aeronautical and technical subjects, selected English expressions, and practical instructions on the use of SR Technics work documents and the application of proper methods and routines for carrying out maintenance work. Additionally, these courses included instructions regarding QA, safety regulations, fire protection, and general familiarization with Swissair's documentation, policies and procedures.
The aircraft-type basic courses consisted of general information about each current aircraft type and supplementary information about the main aircraft sections or systems specific to the area where the employee was to work.
New employees who had completed their basic training and were working for the first time on an aircraft or in the workshop were to be accompanied and supervised by a qualified person until sufficient knowledge had been obtained.
System training, both theoretical and practical, provided the employee with the specific knowledge and skills needed to meet the requirements of an airframe, powerplant, and electric/avionics specialist, or both.
Special training provided the employee with the knowledge and skills to meet the requirements of each specific course, such as engine overhaul, run-up, and component overhaul. CAA regulation training was to be provided to supervisory and engineering personnel as well as to all certifying staff.
On-the-job training, as far as possible and practical, was to be prepared and carried out according to the same principles as basic and special training.
Each course was followed up with a test and, upon passing with a minimum of 70%, the employee was then permitted to work independently and to sign the work documents.
A continuous evaluation process was used to determine the training requirements beyond what was addressed in the Basic, System, Special, and on-the-job training. It was the responsibility of the head of each department to determine the type and extent of this continuation training.
Within the Engineering and Quality organization area there were three QA departments. QA Aircraft was assigned to the Aircraft Maintenance and Aircraft Overhaul organization areas, QA Components was assigned to the Components and Power Plant organization areas, and QA Services was assigned to the remaining organization areas. QA was responsible for the performance of required inspections and for planning and performing internal quality audits of the organizational procedures. These departments reported directly to the head of Engineering and Quality, who was responsible for ensuring adherence to the quality standards and requirements for the CAAs, and for ensuring the established quality system was reviewed for compliance with the quality standards, the government and CAA rules, and the company's regulations.
QA for SR Technics products, particularly the airworthiness of the aircraft and the use of aircraft parts, was the responsibility of the implementing departments, in accordance with relevant job descriptions and procedures.
Each employee was to be trained to be personally responsible for the quality of his or her work. The work was expected to be accomplished correctly, and the employee was required to perform a "self inspection" after each work step.
The supervisors of all individual departments were responsible for the following:
There were three levels of inspection: Self, Double, and Required. These inspection levels were determined by a team of specialists, based on two criteria: an analysis of the risk inherent in the performed work and an analysis of the probability and consequences of a failure. Double and Required inspections were only performed in production areas. In administrative areas the requirements for Double inspections were included in internal procedures, wherever appropriate.
The MOE defined Self, Double, and Required inspections in the following ways.
A Self inspection is required after each work step and is performed by the person who actually did the work. Personnel performing this work must be trained and qualified, and the work must be done in accordance with the applicable regulations, and instructions, procedures, or both.
A Double inspection may be required based on the probability of a failure during the execution of the work and the consequences thereupon. This inspection must always be carried out by a specially trained and qualified person who is not involved in the execution of the work to be inspected, and must be recorded on the applicable working paper. The Self inspection must be carried out prior to performing a Double inspection.
A Required inspection is to be performed if the probability of a failure during the execution of the work may consequently lead to unsafe operation of the aircraft. This inspection must always be carried out by a specially trained and qualified inspector from the QA department assigned to the product area, and must be recorded on the applicable working paper. The Self inspection must be carried out prior to performing a Required inspection.
In accordance with FAA AC 120-17A, administration of the Reliability Program can be assigned to an existing organizational element. In this case, the SR Technics engineering organization: CEA, CRE, or both.
Regular meetings were scheduled with the Engineering, Maintenance and Quality departments of SR Technics for the purpose of reviewing reliability aspects such as operating performance, airworthiness, and reliability in general.
The program's purpose was to establish a management and control system for optimizing aircraft, system, engine and component performance and service life, and to effectively adjust time limitations related to operating experience. The objective of the program was to control and maintain components, systems, and aircraft operated by customers within an acceptable level of airworthiness, reliability, and economics.
SR Technics and the subcontractors' reliability program obtained data from several sources (through the Technical Information System), and the development of this information provided the means for analysing operating experience and quality, and formulating projections. According to the SR Technics procedure manual applicable at the time of the accident, the customer airlines and SR Technics reported to each other all technical information necessary for control of the technical behaviour of the flight equipment. This information was sent to the CEA, which had the sole and exclusive responsibility for fulfilment of all engineering activities. Although the agency could partially delegate responsibilities to other parties, subject to SR Technics and subcontractors' Engineering Group approval, the overall responsibility still rested with the agency.
The CRE group was responsible for engineering activities related to components (including engines) within SR Technics and the subcontractors.
The responsible CEA/CRE group analyzed the collected data and made recommendations for time extensions, corrective actions, or additional investigations. The primary objective of these analyses and decisions was to maximize operational safety and airworthiness, and to optimize operational integrity and reliability.
All technical events that had a direct influence on flight safety or had negative operational consequences leading up to "emergency procedures" or abnormal operations were considered as incidents. Technical events or consequences that were not classified as incidents were considered occurrences.
SR Technics was required to report to the FOCA, the manufacturer, and, where applicable, the operator any un-airworthy condition found during maintenance that might have seriously compromised the airworthiness of the aircraft. The Engineering department would provide information to the liaison aviation authorities, who in turn were to submit the report to the FOCA. This information would be reported to the FOCA within three days, and submitted on special forms.
As an FAA-approved foreign repair station, SR Technics was required to report, with respect to United States-registered aircraft, any serious defect in, or other recurring un-airworthy condition of any aircraft, powerplant, propeller, or a component of any of them. These reports were to be submitted to a central collection point as specified by the FAA administrator, and in a format acceptable to the administrator. SR Technics used FAA Form 8010-4, Malfunction or Defect Report, for this purpose. The completed form was to be forwarded to the liaison aviation authorities who, in turn, were to submit the report to the FAA.
Although SR Technics did not differentiate between airlines in their treatment of these events, they did not, nor was there a need to, forward any reports to the FAA with respect to the Swissair fleet.
The 14 CFR, Part 129, did not require Swissair to provide mechanical reliability reports to the FAA.
The technical incident information was included in the MD-11 monthly reliability reports, which at the time of the accident included data for Swissair, KLM, Garuda, Thai International, Citybird and Martinair. This report was presented in such a manner that each airline had its own section, and each section contained reports titled Technical Incidents & Occurrences and Technical Incident Description.
The Technical Incidents & Occurrences report identified the number of incidents per month, the number of occurrences per month, and the consequences of these events per month. The categories for each of these sections are based on 14 CFR, Part 121.703, requirements.
The Technical Incident Description report included the following:
The following technical incidents, described in the MD-11 monthly reliability reports from September 1997 to September 1998, were reviewed:
A review of earlier technical incidents identified one that was considered potentially pertinent to the investigation:
The FAA's SDR system is designed to collect, analyse, record, and disseminate data concerning defects and malfunctions that have resulted in, or are likely to result in, a safety hazard to an aircraft or its occupants. The anticipated outcome of the system is to use the reported information to support regulatory activities required to improve the level of flight safety. At the time of the accident, the SDR database included reports for commercial and general aviation aircraft in the USA and Canada.
The SDR is a feedback system, which depends on a wide network of contributors. Due to the mandatory and seemingly consistent nature of SDR reporting, this data is considered to be the best available. Nevertheless, caution must be applied to the interpretation of the data as, for the most part, it contains unverified information whose quality is highly dependant on the reporter's knowledge, experience, and judgement.
Among the requirements for obtaining a Type Certificate in the USA, the applicant (manufacturer) must provide "Instructions for Continued Airworthiness," as defined in FAR 25.1529, and Part 25, Appendix H, in the form of a manual or manuals. These instructions must provide maintenance instructions that include (or refer to) scheduling information that provides the recommended periods for cleaning, inspecting, adjusting, testing, and lubrication, and the degree of inspection, the applicable wear tolerances, and work recommended at these periods. There must also be an inspection program that includes the frequency and extent of the inspections necessary to provide for the continued airworthiness of the aircraft. It is mandatory that applicants comply with the Instructions for Continued Airworthiness and all ADs in order to maintain the aircraft's Certificate of Airworthiness.
As described in SR Technics' MOE:
The SR Technics Status List of Engineering Orders is a record of EOs relating to a particular model of aircraft. The list includes
The Status List of Engineering Orders generated for HB-IWF (dated 5 October 1998) identified 2 597 entries:
Additionally, there were 699 entries for EOs produced by the SR Technics Engineering department for work that they deemed necessary. These EOs are not identified by a document type nor are they identified by publisher.
The investigation reviewed each entry. Pertinent EOs are discussed in the MD-11 Airworthiness Directives and Service Bulletins sections, which follow.
Although ADs issued after the date of the accident are not applicable to
The following ADs refer to SBs that were issued prior to 1 September 1998.
The following ADs refer to SBs, where applicable, issued after 1 September 1998.
SR Technics subsequently generated EOs to address each of these ADs.
A review of the SR Technics Status List of Engineering Orders identified
A review of the applicable Pratt & Whitney engine SBs did not identify any that were pertinent to the investigation.
A review of the aircraft manufacturer's issued MD-11 SBs up to the time of the accident identified 16 that were pertinent to the investigation (excluding those addressed in the discussion of Airworthiness Directives). Included in these were SBs related to events that could cause chafing, arcing, sparking, smoke, or all in the cabin or cockpit.
As described in the SR Technics Reliability Program, Daily Technical Reports show all initial flight interruptions attributed to cancellations or technical delays exceeding 15 minutes.
The Daily Technical Reports from 1 January 1997 to 3 September 1998 for HB-IWF were reviewed:
All complaints documented in the aircraft logbooks are considered "Pilot Complaints." Each of these entries are categorized by ATA chapter and recorded in a database. The information is then statistically reported in the Monthly Reliability Report and is described as a ratio: number of complaints/1000 FH. Below is a sample of what Swissair reported, from September 1997 to September 1998:
Table: Swissair Reports September 1997 to September 1998
Note: As there are no industry standards for reporting most complaints and reporting disciplines vary from airline to airline, the number of complaints cannot be considered indicative of product quality.
The non-routine structural discrepancies from the last "D check" were reviewed; none were directly pertinent to the investigation.
The Structural Significant Items from the last "D check" were reviewed; none were directly pertinent to the investigation.
The "Time-Controlled Components" inventory list, dated 3 September 1998, was reviewed; there was nothing noted that was directly pertinent to the investigation.
The "Limit Exceeded Components" MD-11 fleet reliability list, September 1997 to August 1998, was reviewed; no significant deviations were noted.
A list of components that had a shop visit, but did not have previously recorded maintenance, was reviewed; no significant events or maintenance actions were noted.
SR Technics provided the aircraft technical records, including such documents as the following:
These were reviewed by the investigation team.
Note: As there are no industry standards for reporting, most logbook entries and reporting disciplines vary from airline to airline, and the number of entries cannot be considered indicative of product quality.
The aircraft technical logbooks used by Swissair were designed such that there were 25 pages, each with four Complaint/Action cards, starting at Seq Number 00. From 10 September 1997 to 2 September 1998 there were 2 663 entries recorded, including 790 for pre-flight checks. Each entry was reviewed to determine whether it was related to events that could cause chafing, arcing, sparking, smoke, or all in the cabin or cockpit, or was in the area of interest (cockpit and forward cabin ceiling area). There were no trends evident.
The following information was reviewed:
There was one entry that referred to an electric smell, the first class Hot Cup electric socket had burnt. The part was replaced and there were no further discrepancies noted.
Although each "Complaint" had an "Action" recorded against it, there were a few entries that appeared to be outstanding. However, it was determined that this was attributable to discrepancies in the bookkeeping practices, rather than the entry not being rectified.
The last three "A checks" were reviewed to determine whether there were any maintenance activities directly pertinent to the investigation, such as events that could cause chafing, arcing, sparking, smoke, or all in the cabin or cockpit, and if any such event was in the area of priority (cockpit and forward cabin ceiling area). There were no activities identified in the "A06 check," 10 May 1998.
There was one scheduled activity identified in the "A07 check," 21 June 1998:
The air motor for the Left Forward (door 011) passenger door was changed, and to gain access to this motor the ceiling panel above the door must be moved prior to performing the maintenance activities.
There were two scheduled activities identified in the "A08 check," 9 August 1998:
The air motor for the Right Forward (door 021) passenger door was changed, and to gain access to this motor the ceiling panel above the door must be moved prior to performing the maintenance activities.
The cockpit zone temperature control sensor (ejector) was removed, cleaned and re-installed. This item is located above the ceiling, in the area adjacent to the cockpit entrance door. Access is through a ceiling panel.
There was one repair card generated and identified in the "A08 check," 9 August 1998:
A relay socket in the avionics compartment was changed as a result of damage.
The investigation team was also made aware of a report, by an M/C on an earlier HB-IWF flight, of an unusual smell. The accident aircraft's maintenance records were reviewed to confirm this report. Although not recorded in the aircraft technical logs, on 10 August 1998 the M/C reported to both the flight crew and ground crew that he noticed a burning/electrical smell specifically in the area around the 1.1 jumpseat (beside the L1 door), attached to the G1 galley. This report was made on the first flight following the completion of the "A08 check" in Zurich. A review of the "A08 check" maintenance requirements and of Bill Of Work 9838517, which was accomplished during the same maintenance period, did not reveal any maintenance activities that could be linked directly to a smell of this description.
The cargo for Hong Kong, located in compartment 2, included ethyl acetate solution, ethyl methyl ketone, printing ink, paint, and perfumery products. All of these items had Dangerous Goods declarations issued by the shipper, and there were no reported claims for damage.
All maintenance activities related to the IFEN installation were documented on a comprehensive database. There were 17 052 entries recorded for all the Swissair aircraft equipped with the IFEN system, covering the period from the first installation until system deactivation on 28 October 1998.
The collected data included, in part, aircraft registration, trouble, action, date A/C in, and date A/C out. "Action" was the maintenance activity that addressed the initial "trouble." For the purpose of evaluation, entries were grouped into the following four categories:
The following table shows a comparison between HB-IWF and a sampling of the other MD-11 aircraft with the same IFEN system configuration.
Table: IFEN System Configuration Comparison of HB-IWF with Other MD-11s
To ensure all elements of the MOE were audited at least once a year, each QA department was to establish an audit plan for their assigned area and these plans were to be based on the audit master-plan. The audit master-plan was established by QA for one year in advance and was to be forwarded to the FOCA for their approval. Each audit performed was to be documented in an audit report that included
Corrective actions were documented and their implementation was to be supervised by the relevant QA department. The audit reports were to be summarized and published in the company's quality report. QA also monitored trends in the field of QA and supported all departments in the development of measures to attain the required quality standards.
SR Technics provided a quarterly report summary of the results of 65 internal audits that were performed between 4 April 1997 and 13 July 1998. The main areas of discrepancies were summarized for each quarter and, although there were no specific findings, the summaries presented a pattern in which similar discrepancies were repeatedly identified. These included
A review of this internal audits summary did not identify any technical discrepancies that were considered directly pertinent to the investigation.
Prior to Swissair receiving its AOC on 31 March 1998, the FOCA ensured Swissair's compliance with the relevant regulations based on Swiss national law, using the internal directive "Rules Governing Flight Operation Inspections." The FOCA achieved this by conducting regularly scheduled meetings with various Swissair managers (e.g., flight operations, chief pilots, quality, flight safety), and by reviewing Swissair reports pertaining to flight safety and daily operations.
After 1 April 1998 the FOCA was to monitor Swissair's continued competence to conduct safe operations in compliance with JAR-OPS 1 regulation "Procedures for Assessing the Continued Competence of an AOC Holder." There is no record of the FOCA performing an audit of Swissair, in accordance with JAR-OPS 1 regulations, from 1 April to 2 September 1998.
SR Technics was a JAR-145-certified maintenance organization and the FOCA monitored it in accordance with the JAR requirements.
SR Technics' JAA and FAA approvals are based on compliance with regulatory requirements, and if procedures are not followed or standards upheld then both the FAA and the FOCA reserve the right to suspend, vary, or cancel their respective approvals of the organization.
To ensure SR Technics was in compliance with the JAR-145 maintenance organization requirements, the FOCA performed the following audits:
Table: FOCA Audits
A review of findings from these audits did not reveal any technical discrepancies directly pertinent to the investigation.
One of the purposes of an audit is to determine whether policies and procedures, directives, and specifications are properly implemented and maintained at all levels within the organization.
In accordance with the JAA requirements, SR Technics was to develop and put into effect a corrective action for each audit finding, and the FOCA was to assess the action and determine whether it was acceptable. The corrective actions undertaken by SR Technics, and accepted by the FOCA, focused on remedying the specific deficiency described in the finding. This pattern is apparent throughout subsequent audits, within various sections of SR Technics, in which similar deficiencies were repeatedly identified as findings. Examples include
 "A/C" means aircraft.
 "Reset" is defined as "causing a device to return to a former state." Therefore, when a tripped CB is pushed in, it is "reset." "Reboot" is defined as "to boot up a system again." Therefore, when a CB is deliberately pulled and then pushed in (i.e., cycled) it is done to "reboot" the system. Swissair and SR Technics personnel use the term "reboot" and "reset" interchangeably when they are referring to rebooting the IFEN system software. None of the "reboot" entries identified above are for a "reset" of a tripped CB.