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Supporting technical information A98H0003

In-flight entertainment network (IFEN) – Project history and responsibilities


The installation of the IFEN system into Swissair MD-11 aircraft was one element of a four-part aircraft interior reconfiguration project that Swissair referred to as Product 97.

The Product 97 initiative to create a new cabin configuration was undertaken in response to perceived market demands for more economy-class seating. Along with numerous changes to the cabin interior and the installation of the IFEN system, this project would reduce the number of first-class seats from 18 to 12, reduce the number of business-class seats from 72 to 49, and increase the number of economy-class seats from 153 to 196, for a total of 257 seats. The overall Product 97 project was the responsibility of SR Technics. The IFEN installation was done by HI under the SR Technics, Swiss FOCA-approved JAR 145 QA program.

Depending on Swissair's business requirements, the number of passenger seats in the MD-11 aircraft could vary between 239 and 257. At the time of the occurrence, HB-IWF (the occurrence aircraft) was configured with 241 passenger seats.

IFT marketing of IFEN system to Swissair

IFT had expertise in gaming machine technology, and in particular with connecting gaming machines through secure computer networks. IFT was looking to expand and saw an opportunity to use its technology to place highly advanced IFEN systems in commercial airline aircraft

IFT initially approached Swissair in 1994 with a proposal to install its IFE system in Swissair aircraft. The Swissair marketing department was enthusiastic about the potential for such a system, as they saw it as an opportunity to set Swissair apart from the competition in the area of customer service. They also saw the system as a generator of revenue, particularly through the gaming aspects of the technology.

IFT proposed to Swissair that they would install the systems in Swissair aircraft free of charge in exchange for a share of the gaming revenue. In 1994, the initial proposal from IFT was turned down by Swissair when SR Technics assessed the system as insufficiently developed and tested.

In 1995, IFT approached Swissair with a similar proposal. Again, the proposal was rejected, primarily because of SR Technics' concerns about the power requirements and weight of the system.

The marketing department at Swissair persuaded Swissair management to reconsider the option of installing IFE systems in Swissair aircraft. Integral to that decision was the fact that, by early 1996, IFT had installed its IFEN system on four MD-11 aircraft of another carrier. Subsequently, Swissair decided to issue a request for proposals, to which there were eight responses. Eventually, IFT was chosen, as they met the technical specifications and were judged to have offered a superior financial package (including free installation, and gaming revenue potential). The IFT system was also viewed as being the most "mature," in particular because the associated hardware was already developed and available.

Description of the IFT and Swissair IFEN project

In May 1996, IFT and Swissair signed a letter of intent to have the IFT IFEN system installed in Swissair's 16 MD-11s and 5 B-747s. The first MD-11 installation was to take place in October 1996.Footnote 1

In the agreement with Swissair, IFT was responsible for the integration of a new generation of its IFEN system into the Swissair aircraft. IFT responsibilities would include all aspects of the installation, including the system design, certification, the actual installation, ongoing support, training, and the continuing airworthiness of the system.

The Swissair-IFT plan for the MD-11 was to configure the IFEN system to allow passengers, including those in economy class, to access the system. Passengers were to be able to select, by touching the screen, on-demand movies, audio, interactive games, a moving map display, advertising, shopping, safety videos, news updates, and secure interactive gaming. These services were to be made available in five languages, and the menu was to be available in seven languages.

By April of 1997, with only four MD-11 aircraft in revenue service equipped with IFEN systems, it was apparent that the expected revenues were not forthcoming. For business reasons, IFT and Swissair decided to reduce the IFEN system configuration to accommodate only first- and business-class passengers. The original contract was changed in October of 1997. Only two MD-11 aircraft had the full 257-seat IFEN system installed. In the accident aircraft, the IFEN system was installed in 61 seats, in the first- and business-class seats only.

IFT history with IFEN system installations

IFT's specialty was the design and manufacture of the IFE system components. The company had started in this field in 1994, and had sold a first-generation version of their IFE system to an airline for installation on four MD-11 aircraft.

For IFT to enter into any contract that would include more than the design and manufacture of the IFEN system, IFT would have to subcontract additional expertise. For example, for the contract with their first customer, IFT had contracted Elsinore Aerospace to do the design, certification and installation work. (Elsinore was eventually purchased by HI's parent company, and employees from Elsinore were subsequently employed at both HI and SBA.)

Summary of the arrangement between IFT, HI and SBA

IFT did not have, from within the company, all of the expertise required to fulfill its Swissair IFEN system contract requirements. Therefore, IFT required the services of others who had expertise in integrating an IFE system into an aircraft design, certifying the system, and installing the system into the aircraft.

In July 1996, IFT entered into an agreement with HI, an FAA-certificated repair station, for the IFEN system design, integration, and installation functions. This included the development of all necessary engineering drawings and documents, and the manufacturing of wire bundles, equipment racks, and structural supports necessary for the installation of the IFEN system. Under the terms of the contract, HI was also responsible for the installation of the system into each aircraft (to be done at the SR Technics facilities in Zurich).

Only the FAA or a DAS can certify an STC (an STC is required for an IFE system). HI entered into an agreement with SBA to provide the certification services. Under the agreement between HI and SBA, SBA became responsible for the certification of the IFEN system, and for issuing the STC. SBA became the applicant and, therefore, in the eyes of the FAA, the owner of STC ST00236LA-D, and as such was responsible for the continuing airworthiness of the STC.

According to a separate contractual arrangement between IFT and SBA, although SBA remained the owner of the STC, IFT was given an exclusive license agreement for the rights to the STC in perpetuity. SBA provided experienced specialists, including DAS inspectors, who had the authority to work in areas such as electrical, avionics, structures, interior and crashworthiness, and flammability. Additionally, IFT contracted with SBA to review and approve test plans and results in support of environmental testing of the IFEN system components.

Statement of work to the agreement between IFT and HI

In order to satisfy their obligations to Swissair, IFT entered into an agreement with HI. Details of the required work were contained in a statement of work, which formed part of the formal agreement. Of interest to the SR 111 investigation was the section that dealt with cabling interfaces to the aircraft power:

3.1.8 Aircraft Power and Existing System Interface—System cabling interfaces to aircraft power and existing aircraft systems will be defined by the airline customer and will be communicated to HI.

Both IFT and HI indicated that they expected that Swissair would provide this information. However, the detailed specification produced by Swissair and appended to the Sales and Services Agreement did not include any reference regarding how the IFEN system was to be integrated into the MD-11 electrical system. Although certain technical information was requested by IFT and HI from Swissair, there is no record of a specific request relating to system cabling interfaces to aircraft power.

Among the documents received by the TSB from Swissair was an unsigned statement of work between HI and IFT. It appears that this was an early version of the final statement of work, which would later form part of the formal agreement between HI and IFT dated 30 July 1996. According to fax markings, the early version was faxed from HI on 24 May 1996 to an unknown recipient. Regardless, both versions of the statement of work contained the statement in Section 3.1.8 quoted above.

IFEN sales and services agreement

Paragraph 4.2.1 of the Sales and Services Agreement, dated 22 October 1996, contains the following statements under Section 4.2. (Installation), 4.2.1 (Responsibility: Anticipated Schedule):

…with the reasonable cooperation of Swissair, IFT shall be responsible for installation of the IFEN-2 Basic Shipsets….

…subject to timely approval by Swissair of the Specifications and acceptance by Swissair of the final IFEN-2 Basic Shipset design….

IFT was responsible for the installation of the IFEN system, but considered SR Technics, on behalf of Swissair, to be an active partner in the approval and acceptance of the IFEN system. IFT believed that the basic shipset design approval included both the design of the system and its integration into the aircraft.

Conversely, Swissair considered their approval of the final IFEN-2 basic shipset design to consist of ensuring that IFT's modification of IFT's existing IFEN-2 system design had been done in accordance with the Detailed-Specification as drafted by SR Technics.

FAA involvement – General description

The FAA was involved in the IFT IFEN system installation project in two ways:

Involvement of the Swiss FOCA

FOCA STC certification process

The FOCA certification process allows for two methods for STC certification: a Swiss STC can be approved by the FOCA under JAR 21, or an FAA-approved STC can be accepted by the FOCA.

FOCA involvement with the IFT IFEN STC

Before contracting with IFT, Swissair advised the FOCA that they were planning to use an FAA-approved STC to install the IFT IFEN system in their aircraft. Swissair was informed by the FOCA that in lieu of a formal Swiss STC, the installation would be allowed if it was based on an FAA-approved STC and was done in accordance with applicable regulatory requirements.

The actual IFEN system installation work was to be performed on Swissair aircraft at SR Technics facilities in Zurich, Switzerland, under the provisions of JAR 145. As per the terms of the contractual agreement between Swissair and IFT, the installation work was to be completed by IFT or its third-party subcontractors. In this case, IFT subcontracted HI to perform the installation work. The FOCA informed HI that their personnel were authorized to perform the IFEN system installation work only if it was accomplished under the SR Technics QA program, and in accordance with JAA Leaflet 3.Footnote 2 Accordingly, HI was required to submit FAA Form 337 to SR Technics, documenting that the system was installed in accordance with the certification requirements of STC ST00236LA-D.Footnote 3 Although FAA Form 337 was not typically used in Switzerland, this method was acceptable to the FOCA.

The FOCA accepted the FAA STC ST00236LA-D and did not perform any formal validation of the IFEN system. The FOCA did not assume any direct oversight responsibility for the IFT IFEN installations into the Swissair aircraft.

A FOCA memo entitled "MD-11 Product 97 Fact Sheet," dated 10 November 1998, records the results of FOCA inspections conducted on Swissair's MD-11 Product 97 installations. This memo states that the "FOCA discovered important deficiencies . . . ." While the IFEN system is listed as one of the installations inspected, no deficiencies were noted relating to the IFEN installation.

SR Technics involvement

In their capacity as a JAR/FAR 145 maintenance facility, SR Technics was the engineering authority for Swissair's fleet of MD-11 aircraft. In that capacity, they were responsible for the continuing airworthiness of these aircraft.

As part of the IFEN system Sales and Services Agreement between IFT and Swissair, SR Technics produced a document called Detail-IFEN Specification for the Interactive Inflight Entertainment & Cabin Management System (IFE) on Swissair's MD-11 and B-747, dated 22 July 1996. This specification was described by SR Technics as "the Specification for an interactive video/audio/cabin management system, manufactured by Interactive Flight Technologies Inc., (IFT), Type IFEN-2 for all our MD-11 and B-747 aircraft." SR Technics considered the intent of this document as being to provide IFT with "functional specifications" as to how the IFEN system was to perform in Swissair's MD-11 aircraft.

In order to provide Swissair with a level of confidence regarding the IFEN system installation project, and to comply with the FOCA-imposed conditions requiring the use of the SR Technics QA program for the use of STC ST00236LA-D, SR Technics agreed with Swissair marketing to

  1. participate in the commercial negotiations;
  2. work out the specifications required;
  3. provide detailed information on technical questions;
  4. provide documentation;
  5. provide project management meetings;
  6. coordinate the project work within SR Technics and with IFT;
  7. coordinate the work with Hollingsead;
  8. assist the modification crew;
  9. allow its infrastructure to be used for installation purposes; and
  10. provide QA by continuously monitoring HI's work to ensure it met regulations and standards set by the CAAs, the aircraft producers, and Swissair.

This agreement, known as the September 1996 Offer, described the scope of these duties, which included monitoring the quality of the work, defining specifications, and providing detailed information on technical questions.

IFT became a signatory to the agreement (September 1996 Offer) on 10 October 1996. IFT considered this to be a three-party agreement under which SR Technics oversight of HI's installation was also being done on behalf of IFT. IFT indicated that it was paying SR Technics for this service.

All IFEN installations were to be accomplished during regularly scheduled heavy maintenance or "D checks." SR Technics received a completed FAA Form 337 from HI after each installation. SR Technics used the FAA Form 337 to confirm that the IFEN system installation had been done in accordance with the FAA-approved STC and the FAR, Part 43. The FAA Form 337 was part of the supporting documentation used to return the aircraft to service.

STC no. ST00236LA-D – Application and approval


The modification of Swissair's fleet of MD-11s was accomplished through the STC process using SBA as the certifying agent under its authority as a DAS. In its capacity as a DAS, SBA was contracted by HI to perform the required certification services on behalf of the FAA. In particular, HI contracted SBA to provide the necessary certification services, such as approving data to show compliance with applicable regulations, test witnessing, drawing review, and parts and installation conformity. IFT also contracted SBA to review and approve test plans and results in support of environmental testing of IFE components. SBA did not perform any design or installation functions in support of the project. According to the LOI, SBA was the applicant and owner of the STC. However, according to the contractual arrangement between IFT and SBA, although SBA remained the owner of the STC, IFT was given an exclusive licence agreement for the rights to the STC in perpetuity. SBA was responsible for the continuing airworthiness of the STC.

Components such as wire bundles, equipment racks, and structural supports necessary for the installation of the IFEN system were manufactured by HI in Santa Fe Springs, California, while IFT manufactured the LRUs in Phoenix, Arizona. SBA, under its authority as a DAS, authorized HI and IFT to obtain statements of conformity for these components. SBA's DAS manual, Section 2.3 (f) allows "SBA to authorize, in writing a qualified representative of that facility or supplier to act as SBAs agent and execute an FAA Form 8130.9, Statement of Conformity."

According to the SBA DAS manual, Section 2.1 "Defining the Project," a DAS will initiate an STC project by submitting an LOI to the ACO along with the FAA STC application Form 8110-12. The SBA LOI and Form 8110-12 were forwarded to the LAACO on 19 August 1996 (SBA Document C-DAS14NM-1, Appendix 1). The LOI is required by FAA Order 8110.4A (and the DAS manual) to include a complete description of the system operation and installation, to complement the data that will show compliance. The SBA LOI contained the following information:

SBA's letter of intent

The LAACO received the SBA LOI, DAS Project DAS14NM97, and stamped it as "received" on 23 August 1996. The LAACO review of an LOI is performed in accordance with FAA Order 8110.4A by a team that typically consists of an aviation safety specialist, an airframe aerospace engineer, a system and equipment aerospace engineer, a propulsion aerospace engineer, a flight test pilot, a MIDO aviation safety inspector, and an AEG specialist. Accordingly, the SBA LOI documentation was circulated to the appropriate branches of the LAACO as well as the MIDO and AEG offices. LAACO records indicated that the propulsion and flight test branches, and the MIDO, did not sign the "coordination" sign-off stamp.

The FAA review of the LOI resulted in two additional requests of compliance, one with respect to the delethalization requirements of FAR 25.785, and one for the interior material flammability requirements of FAR 25.853. These two further requirements were handwritten on the front page of the LOI as follows: "Perform bowling ball test for existing and new food tray configurations" and "Flammability by test, and substantiation." The assigned FAA project manager reportedly contacted SBA by phone and advised SBA of the additional requirements. SBA submitted an amended LOI on 3 October 1996 incorporating the additional test requirements, added a flammability DAS specialist to the list of DAS staff, and amended the Certification checklist to include FAR 25.869(a), concerning fire protection systems. The FAA accepted the SBA LOI on 8 October 1996 and faxed the top sheet of the initial LOI with the handwritten FAA comments with "FAA Accepted" stamped on the document to confirm their acceptance.

Excerpts from the SBA LOI

In the original LOI, at Section, SBA had attempted to meet the requirement for head-strike testing by stating:

Head strike testing of the seat with tray/display stowed will be conducted in accordance with FAA Advisory material AND FAR 25.562 (HIC).

Although this statement was typical for air telephone installations in seat backs, it was not acceptable to the FAA LAACO for this project. The FAA requested an additional "bowling ball" head injury impact test. To comply with the additional FAA LAACO requests, SBA amended the LOI by adding the following to Section

The head strike tests will be conducted with the unmodified tray and the modified tray.

Under the Modification Description, Section 2.8 of the LOI stated the following:

there are no changes to the Pilot or Copilot's panels.

Under Aircraft Systems/Entertainment Interaction, Section 3.1 of the LOI stated the following:

the system to be installed is a "non-essential, non-required" passenger entertainment system. There is no single failure or latent multiple failure which would affect the ability of the aircraft to continue safe flight and landing, significantly increase flight crew work load, or require unusual strength.

The extent to which the LOI addressed the STC's impact on the operational characteristics of the MD-11 was stated in sections 2.8 and 3.1.

Section 6 of the LOI, "Certification Basis and Compliance Checklist," stated the following:

As specified in type certificate sheet A22WE for McDonnell Douglas MD-11 aircraft plus the attached compliance checklist applicable to the telephone installation to amendments effective August 19, 1996, date of application of this STC.

This statement was incorrect, as it described a telephone installation instead of an IFEN system installation and was never noted or corrected by either SBA or the FAA.

Also in Section 6 of the LOI, SBA outlined the electrical compliance checklist for the project, which included FAR 25.1309 (Equipment, Systems and Installations), sub-parts b, e, f, and g. Under the means of compliance, SBA indicated that sub-parts b, e, and f would be accomplished by analysis; sub-part g was left blank. Section 8 of the LOI detailed the schedule for the various activities as follows:

MD-11 Certification Basis

The MD-11 Type Certificate A22WE defines the certification basis of the aircraft and the regulations to which STCs must comply. The MD-11 was certified in compliance with Part 25 of the FARs by amendments 25-1 through 25-61, except for sections 25.607, 25.631(65), and 25.1309(66) as amended by Amendment 25-22; Section 25.109 as amended by Amendment 25-41; and sections 25.832(67) and 25.858. The MD-11 Type Certificate Note 66 indicated specifically that any "new systems and systems with major changes will comply with Amendment 25-61."

Along with the above type certificate requirements, the basis of certification as established by SBA in the LOI lists all the applicable FARs with which the IFEN system must comply, the means of compliance, and the applicable references.

Approval of STC no. ST00236LA-D

On 19 November 1996, STC ST00236LA-D was approved by SBA and issued as a "Provisions only installation of Interactive Flight Technologies Inc. Entertainment System per Hollingsead International Master Data List (MDL) 12003-511, Revision C." This installation was limited to aircraft SN 48445 (HB-IWC) only. The approved MDL contained six notes. Note 2 stated: "The maintenance instructions for continued airworthiness shall be reviewed by the FAA Flight Standards Aircraft Evaluation Group and are contained in Hollingsead International Document No. TBD." This document, 20091, was not identified until the fifth amendment. The maintenance instructions were a work-in-progress at that time and were eventually released in March 1997, two months after the issuance of the first operational IFEN STC installation approval. Note 6 stated:

The installation of the entertainment system defined herein requires that the aircraft interior be configured in accordance with FAA-Approved Swissair Layout of Passenger Accommodation (LOPA) 991056 (257 PAX) or 991057 (243 PAX) per STC (TBD).

The installation of the IFEN system was being accomplished during a regularly scheduled "D check," where the IFE STC was one of four STCs being incorporated into the aircraft. Swissair referred to the whole project as Product 97. According to the Product 97 modification, the cabin configuration of the MD-11 fleet had to be changed into two flexible configurations.

As a "Provisions Only" installation, the MDL approved by SBA on 19 November 1996 did not include any LRUs, as they were not yet available, and this resulted in only a partial installation of wiring and mounting hardware in HB-IWC. This first partial installation did include SBA-approved HI drawings 90049-511, "Overhead System Cable Routing Installation Kit Rev. A," dated 11 November 1996, and 90010-501, "System Circuit Breaker Installation Kit Rev. A," dated 14 November 1996. These drawings confirmed that four of the six PSU CBs were to be mounted in the lower avionics CB panel (also referred to as the observer's panel) located in the cockpit. The installation of CBs in the cockpit changed the scope of the project, in that the cockpit environment was altered. There is no indication that HI considered the operational impact of this change. SBA did not notify the LAACO to obtain its determination as to the significance of this change, nor did SBA submit an amended LOI.

The STC certificate incorrectly lists the Original Product – Type Certification Number as A22E and not A22WE for the MD-11. The STC date of application is shown as 9 August 1996, when the actual date on the application, FAA Form 8110-2, was 19 August 1996.

At the time the STC was issued on 19 November 1996, the following engineering drawings were not complete, and were dated "TBD."

Although MDL Document 20035 (Weight and Balance) was indicated as TBD, an FAA Form 337 had been completed by HI that indicated the weight and balance was "accomplished by actual weighing of the aircraft and is included in HI Weight and Balance Report No. 20035." This form also indicated that the system was deactivated.

Two "Statement of Compliance with the FAA Regulations" forms were provided by SBA and both were dated 19 November 1996. One statement identifies the approved data for seven of the documents referenced in the MDL 12003-511 (page 3 of 4), along with the "Structural Substantiation for Equipment Rack Installation for MD-11," Document ER134-1001. The structural substantiation was performed by Total Aircraft Services, Inc. of Chatsworth, California. This Statement of Compliance does not reference a particular configuration and, except for the date, it would not be possible to reference it to any particular configuration. Furthermore, two of the documents referenced in this statement of compliance, 90044-512 and 90046-512, have revision numbers different from those referenced in the MDL. Also, this particular document was not signed by the DAS Coordinator. The second statement of compliance does reference configuration 12003-511 Rev C and was signed by the DAS Coordinator.

STC no. ST00236LA-D amendments

First amendment

On 18 December 1996 the STC was amended to add provisions for another IFEN configuration as defined by HI MDL 12003-521 Rev C1, dated 17 December 1996. Under the Limitations and Conditions section of the STC, MDL 12003-511 Rev C was applicable to aircraft SN 48445 (HB-IWC) only, and this latest MDL 12003-521 Rev C1 was applicable to aircraft SN 48446 (HB-IWD) only. At this point, the two IFEN system configurations were applicable to two aircraft. In this amendment, in the Original Product – Type Certification Number section, the correct type certificate number was referenced as A22WE.

This first amendment also referenced the System ELA Document 20032 Rev N/C (initial release drawings). HI provided three versions of Document 20032 Rev N/C. One version was referenced by HI as an early development version that was not approved and not dated. A second version of 20032 N/C was stamped as "PRE RELEASE" and dated 16 January 1997, but it too was not approved or released. The third version of 20032 Rev N/C was dated 18 January 1997 and stamped "History Print for Reference Only." The latter two versions were dated after the first amendment was approved by SBA and, therefore, could not be the referenced documents. According to HI, the ELA for this first amendment should have read TBD, as it did for the issuance of the STC. There was no approved ELA N/C, and the change in this MDL to reflect this was a mistake. However, at that time no loads were physically attached to electrical buses in the aircraft.

Second amendment

On 24 January 1997, the STC was amended a second time, adding a new configuration according to HI MDL 12003-501 Rev D for 257 passengers. This configuration replaced both previous configurations: 12003-511 and 12003-521. At this point, the system was missing the left and right front row monitors in economy class and the first-class IFEN-equipped seats, as they were not available. The Limitations and Conditions section of the STC notes that the STC was applicable to SNs 48445, 48446, and 48452 only (HB-IWF was SN 48448). It also indicates:

[t]he installation of passenger seats and all other aspects of cabin interior arrangement are NOT approved by this STC, and must be approved separately. A copy of this STC must be included in the permanent records of the modified aircraft. All of the above interior furnishings have been demonstrated to meet the flammability requirements of FAR 25.853(B) (Amendment 25-32) and 25.1359(d) (Amendment 25-32).

This latter statement placed the burden on the seat manufacturers to ensure that the seat-mounted components were in compliance with the applicable certification requirements. ELA 20032 Rev N/C, was revised to 20032 Rev A, which is the first approved and released ELA.

Third amendment

The STC was amended a third time, on 3 February 1997, approving the same configuration as the second amendment, namely HI MDL 12003-501 Rev D. However, under the Limitations and Conditions section the specific MD-11 SN applicability was removed, resulting in the approval of the STC, configuration 12003-501 for 257 passengers, on all of Swissair's fleet of MD-11s.

Fourth amendment

The STC was amended a fourth time, on 11 March 1997, to add the words "or Subsequent FAA Approved Revisions" to the "Description of the Type Design Change". According to the FAA, this is a normal statement to include on an STC, and should have been accomplished at the third amendment level. The additional words allow the STC holder to obtain approval for minor design changes without having to amend the STC document each time a design change is FAA-approved.

Fifth amendment

The STC was amended a fifth time, on 7 August 1997, to approve a second IFEN configuration, 12003-503 Rev A, dated 28 July 1997, for 243 passengers. At this point, the STC approved two IFEN configurations: the -501 Rev D for 257 passengers and the -503 Rev A for 243 passengers, in accordance with FAA-approved Swissair LOPAs 991056 and 991057, respectively.

The ELA was also revised in the fifth amendment from 20032 Rev A to Rev B. ELA Rev B references two electrical summaries, one for 257 passengers and the other for 239 passengers. There is an apparent discrepancy between the referenced configuration, -503 for 243 passengers, and the ELA Rev B that references 257 and 239 passengers. There was no mention of an ELA for a 243-passenger configuration. According to HI, this was another mistake, in that ELA Rev B was not approved at that time, and was a work-in-progress. It should not have been referenced in this amendment to the STC. Also, released at this time was Drawing 20092, "Maintenance Instructions for Continued Airworthiness", dated 20 March 1997.

Additional SBA-approved HI MDL

On 22 October 1997, SBA approved another version of MDL 12003-503, revising the previous configuration, Rev A, to Rev B. The MDL can be revised without amending the STC, as previously stated, when the STC reads, "or Subsequent FAA Approved data." The MDL dated 22 October 1997 is DAS FAA-approved data. This revision added a provisions kit for first-class seats. The IFEN first-class seats became available on 10 October 1997. According to SBA, a second EMI/RF test plan, ground and flight, was conducted on 22 October 1997 when the IFEN- equipped first-class seats were first installed. However, the investigation could find no substantiating data to show that this test plan was conducted.

For the occurrence aircraft, the installation of the IFEN system was accomplished during a "D check" between 21 August and 9 September 1997, under MDL 12003-501 Rev D for 257 passengers. At this time, the IFEN-equipped first-class seats were not available. They were subsequently installed on 20 to 21 February 1998, when the first- and business-class sections of HB-IWF were re-configured as part of the Product 99 modification. HI provided an FAA Form 337, dated 21 February 1998, stating the work had been accomplished in accordance with HI MDL 12007. However, MDL 12007 is shown to be applicable to Boeing 747-300 aircraft only.

According to HI, MDL 12003-501 was revised to Rev E on 16 September 1997 and to Rev F on 8 January 1999. Both of these revisions reference 239 passengers. This change was based on the Swissair FAA-approved LOPA 991064 for 239 passengers. Although the IFEN system was now being installed in only 61 seats (first and business classes), ELA 20032 Rev A was not updated to reflect this change. The investigation revealed no SBA DAS-approved copies for these latest two changes to the MDL. Although the number of IFEN-equipped seats was substantially reduced, the documentation provided by HI that reflected these changes was not forwarded to, or approved by, the DAS.

For the accident aircraft, on 14 August 1998, SR Technics added two more seats to economy class, under EO 511648. The two seats were reserved for aircraft crew, bringing the HB-IWF seat count to 241. At this time, only the 12 first-class and 49 business-class seats were IFEN-equipped.

Location of IFEN power supply circuit breakers

The LOI described a system that would have no impact on the cockpit environment. A review of the HI ELA 20032 Rev A, approved by SBA on 24 January 1997, states on page 4, paragraph 2, that "the PSU (Power Supply Unit) inputs are protected by 3 phase, 15 Amp breakers located in the Cockpit Observers Station and LH Mid Circuit Breaker Panels." Furthermore, paragraph 4 states that "A 1 Amp, 28 V DC circuit breaker, located on the upper panel [upper panel refers to the avionics CB panel] of the cockpit observer's station provides power to the entertainment system Relay Box which is located above the G-8 Galley." Also, HI 90010 "System Circuit Breaker Installation Kit," issued in November 1996, stated that the 8 AWG main power supply cable was connected to the S3-600 terminal strip in the avionics compartment and routed to the cockpit lower avionics CB panel. The ELA and IFEN system installation drawings approved by SBA were in disagreement with the LOI.

Electrical load analysis

Prompted by the disagreement between the LOI and ELA 20032 Rev A over the CB locations, the various ELAs produced in support of Rev A were reviewed during the investigation. It is noted that the original Swissair MD-11 ELA was not available to HI until August 1996, when HI produced the fifth amendment of the IFEN-related ELA. During the investigation, HI provided an early development version of ELA 20032 Rev N/C, dated 28 August 1996. This version was neither released nor signed by HI. This early version did not mention the location of the IFEN CBs. However, of interest in this version were the following statements:

Each power supply, 200 V AC, 400 Hz 3 phase power input is fed from the AC Cabin Bus distribution system. The AC Cabin Bus distribution system is manually shed during abnormal operations and automatically shed during emergency operations.

This indicates that the initial intent of HI was to connect the IFEN PSUs to the cabin bus electrical system, and furthermore highlights the MD-11 load-shedding philosophy of the cabin buses for emergency operations. The cabin buses are shed via the activation of the cabin bus switch during emergency operations. HI personnel reportedly had no specific knowledge of the MD-11 electrical system, nor did they have any specific knowledge of the MD-11 abnormal or emergency checklist as it related to the aircraft electrical system. However, the above contradicts HI's assertion that they were not aware of the MD-11 cabin bus shedding philosophies, or of the specific emergency checklists. Once the ELA matured to the point that HI realized there was insufficient power available from the cabin buses to power the entire IFEN system, they moved four of the PSUs to the 115 V AC Bus 2. HI did not take into account the impact this would have on the aircraft's emergency procedures, specifically the use of the CABIN BUS switch.

The 28 August 1996 version of the ELA also indicated that "the DC power bus is not used for this modification and as such is unaffected."

This later changed—in future iterations of the ELA—as DC Bus 2 and the DC ground bus were used. Also of interest is the fact that the LOI was submitted on 19 August 1996, prior to any ELA being released. The analysis section includes the following statement:

For the purpose of this analysis, the IFT system is considered "Non-Essential" equipment with an operating time of 100% for loading, start, taxi, take-off and climb, cruise, descent, land and ground service.

This statement, which identifies the system as "non-essential," typically eliminates considerable time and effort in accomplishing the certification requirements for adding equipment to an aircraft.

The next version of the ELA was date stamped by HI as "JAN 97 PRE-RELEASE." This document was also unsigned. Section 3 of this ELA, "Configuration," states that six 48 V DC PSUs are fed from the AC Cabin Bus distribution system and, again, the shedding of these cabin buses during abnormal and emergency operations is mentioned. This ELA does indicate a DC power requirement for a relay box and a zone interface unit. Under Section 5.2 of this ELA, "AC Power Bus," four of the six PSUs are referenced as being powered by the Main AC Bus 2 and two PSUs are powered by the AC Ground Service Bus 2, Forward. There is no mention in this section of the cabin buses referenced in Section 3 of this same ELA. This version also does not mention the CB locations.

The third version of the ELA, 20032 Rev N/C, was dated and signed 1 January 1997 and appears to be the first version released. However, as mentioned, this N/C version was wrong, and was not released. This version was stamped by HI as a "History Print – For Reference Only." The "Configuration" section of this version was expanded and included the specific location of the 15 A CBs that protected the PSU inputs as "the Cockpit Observers Station and the LH Mid Circuit Breaker Panels." There was no mention of the cabin buses in either the Configuration or AC Power Bus sections of this version.

The fourth version of the ELA, 20032 Rev A, was dated 20 January 1997 and signed by HI as approved on 21 January 1997. This document was referenced in the HI MDL 12003-501 Rev D that was approved by SBA on 24 January 1997 in the second amendment of the STC. Again, in this version of the ELA there was no mention of cabin buses or the shedding of these buses during abnormal or emergency operation.

When the STC was amended a fifth time, on 7 August 1997, a second configuration, MDL 12003-503 Rev A, was added to the STC for 243 seats. This -503 configuration referenced ELA 20032 Rev B, which indicates that there were evidently two approved ELAs: ELA 20032 Rev A for the MDL -501 and ELA 20032 Rev B for the MDL -503.

As previously noted, the ELA Rev B was in error. This error was not identified by HI or SBA. According to HI, ELA Rev B was a work-in-progress at that time. However, ELA Rev B was approved on 22 October 1997 when MDL 12003-503 was changed from Rev A to Rev B, and the MDL references ELA Rev B. This latest ELA, Rev B, differed from the previous ELAs in that, for the first time, the actual Swissair MD-11 AC and DC electrical load analyses, along with specific Douglas MD-11 Wiring Diagrams, were mentioned.

Each of the HI ELAs included a statement as follows: "The total electrical loads presented in this ELA must be added by the customer to the original aircraft load analysis as supplied to the customer by Douglas Aircraft Company." Following the accident of aircraft HB-IWF, SR Technics noted that the HI ELA had not been provided to them, and requested the document from HI. An ELA should have formed part of the documentation required for SR Technics to return the aircraft to service.

According to the FAA Form 337 issued by HI after the installation of the IFEN in HB-IWF, the STC MDL approved was MDL 12003-501 Rev A for 257 passengers. At the time of the IFEN installation on HB-IWF (August and September 1997), the first-class IFEN-equipped seats were not available; they were only installed in February 1998. There were no recorded changes to the STC, nor were there amendments to reflect the reduction in IFEN-equipped seats from 257 to 61; the applicable ELA, 20032 Rev A, was not amended to address the IFEN change in seat count.

ON/OFF switch considerations

The "Detail-Specification" for the IFEN system, prepared for Swissair by SR Technics in mid-1996, stated that the IFEN system would have a lockable master ON/OFF switch at the cabin control station (M/C station). This switch was never installed in the IFE system. IFT wanted to control the system through software using a magnetic swipe card at the main terminals in the cabin. The business arrangements between IFT and Swissair were such that IFT would be financially penalized any time the system was not available for passenger use.

Documentation from September 1996 shows that SBA had concerns about the lack of a switch, which they thought might cause certification problems. However, no further follow-up in this regard was documented by SBA.

Swissair Operations insisted that a method be devised to allow the flight crew to shut down the system from the cockpit. This led to the use of the 28 V DC, 1 A CB in the F1 position of the lower avionics CB panel in the cockpit, which controlled a relay mounted in a panel above Galley 8. Pulling this CB would shut down the output from all four PSUs. As there was no switch, the only way for the IFEN system to be shut down was to pull the 1 A CB or pull all of the individual PSU CBs. Also, any time the IFEN system required a re-boot because of a system hang-up, a member of the cabin crew would have to go to the cockpit and request that a flight crew member cycle the IFEN F1 CB to reboot the entire IFEN system.

By October 1997, Swissair Operations was dissatisfied with the use of the F1 CB as a switch to control the IFEN system. They requested that IFT undertake a design change that would install a master ON/OFF switch at the M/C station to perform this function.

By early 1998 it was agreed that a master ON/OFF switch would be engineered by SR Technics and certified by HI. This work was not completed prior to the deactivation and removal of the system that followed from the SR 111 accident.

Placarding (labelling) of circuit breakers

The various CBs were labelled as to their function. Five IFEN-related CBs were installed in the cockpit. There were four 15 A, 115 V AC CBs. These controlled the four PSUs mounted in racks 1 and 2, and were grouped together and identified under one IFE/VES-specific label. Each CB was individually identified as to which PSU it controlled. The fifth CB was installed under the existing aircraft label "DC Bus 2," and identified as "IFE/VES 28 v."

The IFEN CB placarding did not conform to the original Douglas standard for CBs. The Douglas standard was to identify the electrical bus that was the originating source of power. The IFEN system placarding did not identify the actual electrical bus that was providing the power for the PSUs.

Weight and balance

After each IFEN system installation, the work was released by HI to SR Technics by issuing an FAA Form 337 and a weight and balance report (Document 20035). In HB-IWF, the IFEN system was installed, and the weight and balance recorded (Document 20035 Rev A), in accordance with MDL 12003-501.

A review of Document 20035 Rev A indicated a total IFEN weight of 1 723.7 lb. However, this document was stamped by HI as a "History Print for Reference Only;" therefore, the accuracy of the quoted weight was suspect. After the first-class seats were installed in HB-IWF in February 1998, the new weight and balance report from HI, Document 20035 Rev C, indicated an IFEN weight of 1 292 lb. However, the latest document, 20035 Rev E, indicated a total IFEN weight for first and business class of 1 862.69 lb.

SR Technics questioned HI about the actual weights, as they found discrepancies for the IFEN weight of up to 100% in some instances. HI and IFT were making errors in the total weights being used in the calculations. There was considerable ambiguity in the documents, providing basic aircraft weights that could lead to C of G mistakes.

In the fifth amendment to the STC, which approved MDL 12003-503 for the 243-passenger configuration, the weight and balance report document was changed to 20233 N/C.

The various versions of Document 20035 weight and balance referenced the 257- and 243-passenger configurations, but also referenced a 239-passenger configuration. According to the notes on the front of the approved MDLs, -501 and -503 required that the aircraft interior be configured in accordance with FAA-approved Swissair LOPAs for 257 and 243 passengers. It did not mention a configuration for 239 passengers. Nor did the certification documents reference the 241-seat configuration, which included 61 IFEN-equipped seats, as installed in the accident aircraft.

EMI/RF test

According to the EMI/RF Test Plan/Report Ground, and Flight MD-11 Swissair Document 20034 N/C, the required EMI/RF ground and flight tests were originally scheduled to be conducted on 18 November 1996. However, as a result of delays in obtaining equipment, the ground test was accomplished on 23 January 1997, and the flight test was conducted on 24 January 1997. This EMI/RF test was conducted on HB-IWG (SN 48452). For this test to be accomplished, an additional 18 economy-class video displays, used in the tray tables, had to be installed for the testing, and then removed as they were not certified as airworthy at that time. Furthermore, the first-class seats were not installed, as they were not available at that time. A single DAS specialist was on board to witness the testing; Swissair supplied the flight crew and other personnel to operate the IFEN system. According to the records, the EMI/RF tests were completed, and no EMI/EMC problems were evident during the testing.

When the first-class seats became available in October of 1997, SBA approved another MDL, dated 22 October 1997. This required that a second ground/flight EMI/RF test be accomplished. However, no records were located showing that this test was in fact accomplished.

Maintenance instructions for continuing airworthiness

The maintenance instructions for the IFEN system's continuing airworthiness were approved by SBA and issued by HI on 20 March 1997, two months after the first operational IFEN STC installation approval. The FAA certification process (FAA order 8110.4A and DAS Procedures Manual) requires that all STC design data be submitted to the ACO within 30 days of the STC being issued. The IFEN MM was completed for Swissair on 2 September 1997, in the format that had been required by SR Technics' system specification requirements.

SR Technics personnel were being trained by IFT for basic system trouble-shooting, and on system software update procedures. This training took place before the first system was in operation. Additional product support was provided in-situ by IFT personnel.

With respect to the actual maintenance instructions for the IFEN installation, the MDL 12003-501 Rev D is inconsistent. In Note 2 the maintenance instructions are indicated as "TBD," while in CSD 20091 they are "Rev N/C."

The FAA Flight Standards AEG, as part of its responsibilities, may review the maintenance manual. In each STC MDL release following the issuance of the STC in January 1997, it was indicated that the Maintenance Instructions "shall" be reviewed by the FAA AEG. SBA did not provide the Maintenance Instructions to the AEG for their review.

Aircraft return to service

Under its FAR 145, HI could not carry out maintenance work in the JAA territories; therefore, they could not release the aircraft to service after their IFEN installation work. The FOCA offered a viable alternative, which was to allow HI to perform the installations under the SR Technics quality system in accordance with JAA Leaflet No. 3 as detailed in SR Technics' MOE (3.12) and their Organisational Manual (P50.007). HI provided SR Technics with the necessary documentation on their technicians and inspectors, such as training records and technical background résumés, to qualify their personnel to work under the SR Technics quality system.

HI produced EO CSD 20016 for the installation of the IFT IFEN system. The EO provided instructions for the provisioning of, and modifications to, the aircraft structure, electrical system, and interior components. The EO included references to drawings and associated documents affected by this installation, including the ELA.

The EO controlled all of the installation and inspection activities. These activities included the following:

As indicated previously, FAA Form 337 was used by HI to assure SR Technics that all work performed by HI was performed in accordance with FAA regulations and was in compliance with the approved IFEN STC.

To release the aircraft to service, SR Technics required the issuance of FAA Form 337 by approved HI personnel. As a result of delays in acquiring certain components and seats, the first two MD-11 aircraft to be released to service under this arrangement (HB-IWC and HB-IWD) had only the system provisions installed. The IFEN system was not connected to aircraft electrical power. For each of these two aircraft, the FOCA issued a temporary authorization to allow them to be used in commercial operations. The FOCA eventually issued seven such authorizations, until the first-class seats became available in October 1997.

As part of the agreement between Swissair and SR Technics (the September 1996 Offer), the SR Technics Quality Assurance department inspected the installation work accomplished by HI. For the first three aircraft, more detailed QA inspections were accomplished in order to gain confidence in HI's work. As SR Technics became more comfortable with the quality of HI's work, normal "D check" QA procedures applied.