# ~BEING The Boeing Company 2401 E. Wardlow Road

CP-L4L-14-00312 September 2, 2014
To:

CC: Applicant:

Contact:

Subject: Enclosure

Reference: U.S. Department ofTransportation Docket Operations M-30 1200New JerseyAvenue, SE Room W12-140, West Bldg. Ground Floor Washington DC 20590-0001
FAA TransportAirplane Directorate The Boeing Company Boeing Commercial Airplanes Southern CaliforniaEngineering Design Center 2401 E. Wardlow Road 

### MIC D800-0018 Long Beach, CA 90807-5309
Mr. Charles Heald Email: chuck.heald@boeing.com (562) 593-4892 Long Beach, CA go8o7-5309

Petition for Exemption from 14 CFR §121.344(e)(l) and (f)(l) Amendment 121-338 (A) Boeing 717-200 Fleet data ofaffected airplanes (B) Versatile Integrated Avionics (VIA) Block Diagram (C) Boeing 60 Month Software (S/W) Change Timeline
FAAExemptionNo. 10611,RegulatoryDocumentNo.: FAA-2012-0429

On behalfofall affected Boeing 717-200 U.S. operators, Boeinghereby petitions for exemption from 14 CFR §121.344(e)(l) and (f)(1) Amendment 121-338,parameter46 (Nav 1 and Nav 2 selected frequency), for all 717-200 airplanes listed in Type Certificate Data Sheet (TCDS) A6WE. Boeing anticipates the corrective actions maytake as long as 60 months to accomplish and implement in the affected fleet. However, Boeing requests immediate approval ofrelieffor affected Boeing 717 operators, identified in Enclosure A, for an interim period oftwenty-four (24) months. Within twenty-four (24) months from the date ofthis grant ofexemption, Boeing will provide the FAA with detailed results ofthe efforts to define the scope ofwork, secure contracts, and establish a schedule for accomplishing the tasks to develop the corrective actions and make them available to the fleet. This twenty-four (24) monthperiod will also provide time to develop an application for exemption to allowfor the activities ofaccomplishing the changes, makingthem available, fleet implementation, as well as time for the FAAto considerthis adherent second exemption.

# ~BEING

Background CP-L4L-14-00312 September 2, 2014 Page 2 of 5
Duringa routine check ofsystem function, one 717 operatornoted that a portion ofthe data required by 14 CFR §121.344(a)(46), for Nav 1 and Nav 2 selected frequency parameter was not beingrecorded correctly bythe Digital Flight DataRecorder (DFDR). As part ofparameter46, the 717-200 airplane's DFDR is intended to record ADF (ifequipped), VOR, and ILS frequency selected. Further investigation indicated thatNav 1 and Nav 2 VOR and ADF frequencies are being recorded correctly. ILS frequency is the only portion of 14 CFR §121.344(a)(46), forNav 1 and Nav 2 selected frequency, not beingproperlyrecorded on 717 airplanes There are eighty-four (84) U.S. registered 717 airplanes subject to regulations are requiring recording ofparameter (46). There are an additional thirty-nine (39) foreign registered 717 airplanes manufactured within the date range requiring parameter46. The 717 has two interchangeable VIA units that supplies specified central computer functions for the airplane (see Enclosure B). The cause ofthe issue was identified as a software coding error in the VIA which is sending unreadable data for ILS frequency selection from the Digital Flight Data Acquisition Unit (DFDAU) to the DFDR. Boeing is requesting this exemption on behalfofall affected 717 operators since Boeing's requirement to complywith 14 CFRpart 25.1459, Flight data recorders, supports compliance to various 14 CFRpart 121 requirements, including 121.344, and Boeing is responsible to provide the source parameters and/or signals to interface with a flight data recorder. The unreadable source data stream for this issue resides within the Boeing 717-200 Type Design VIA. Safety The unreadable DFDRparameter 46 (ILS frequency) has no direct impact on safety ofdaily flight operations ofthe 717 fleet.
Public Interest The public interest is benefitted by the granting ofthis petition because it allows continued operation in revenue service ofthe affected worldwide fleet ofone hundred-twenty-three (123) manufactured 717-200 airplanes, ofwhich eighty-four (84) are U.S. registered to three (3) operators, until such time that the unreadable recording parameter (ILS frequency) can be corrected by Boeing. Grant ofthis Exemption would prevent severe economic impact to scheduled commercial operators with 717 airplanes ifoperations were required to cease until this issue is corrected on each airplane.


### Justification for Exemption: The unreadable DFDRparameter (ILS frequency) presents no additional hazard to daily fleet operations of717-200 airplanes. DFDR data is a post accident/event investigative tool.

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CP-L4L-14-00312 September 2, 2014 Page 3 of 5

Other parameters required by 14 CFR §121.344(e)(l) and (f)(l) Amendment 121-338, as well as the cockpit voice recorder are functional in the approved Type Design. Boeing anticipates the investigation and actions to correct the unreadable parameterto the 717 VIA airplane system, including collaboration with the VIA software supplier, related certification efforts with publication ofthe service action for the 717 fleet, make the corrective action available to the fleet and eventual incorporation ofthese software changes by the operators could require as long as 60 months to complete. A timeline addressing aspects ofourplanning and coordination with Honeywell (VIA Supplier) are provided with Enclosure C. A review ofthis process flow would substantiate ourrequested exemption time period. The 717 has been out ofproduction for 8 years, therefore, the OEM VIA software supplier has no sustaining contract with Boeing. Changes to the existing VIA software require significant work scope and costs due to the criticality ofthis function on flight operations. With consideration to the above, Boeing has accumulated a significant number ofVIA software changes that are committed to the FAA for corrective action. In addition, 717 operators have requested new features which were planned to be included in this future change activity. Boeing will negotiate with the VIA supplier for these changes. Scheduling ofchange activity for VIA software is largely dependent on the VIA supplier's available work capacity. Once a contract is signed with both the VIA supplier and the 717 operators (for new features), changes made to the software will be developed and verified both at the supplier's and Boeing's facilities, followed by 717 Type Design compliance activities. Also, some customer desired features will require flight testing. This flight testing can contribute to the revision ofthe schedule for certification since it is complicatedbyBoeing's need to contract use ofan operator's aircraft for certification activity. Detailed data on the affected U.S. fleet is identified in the Enclosure A spreadsheet, along the affected foreign fleet. Public records indicate a similar grant ofExemption has been issued by the FAA to another transport category aircraft manufacturer for a unreadable parameterrequired under 14 CFR §121.344, in order to continue operation ofaffected airplanes until such time as the corrective action can be implemented. Mitigating Factors Other DFDRData The 717 DFDRrecords Localizer (Parameter 27) and Glide Slope (Parameter 28) tracking data. The Localizer and Glide Slope data, combined with radartracking data and/or otherphysical data will providepost event investigative evidence ofproper/improper ILS frequency selection. 717 Design Features- Auto TuningCP-L4L-14-00312 September 2, 2014 Page 4 of 5 In addition to conventionallytuningnavaids, includingthose navaids associated with specific Instrument Approach Procedures (lAPs), the 717 FlightManagement System (FMS) has an automatic navaid tuning function which retrieves navaid frequencies from theNavDataBase for selected approach procedures which have been activated in the FMS F-PLN. Automatic tuning of the ILS can occur once the, airplane is within range ofthe ILS transmitter (**~**25 NM). This tuned digital frequency is initially displayed on the lower left ofthe Primary Flight Display (PFD) as well as the lower left ofthe Nav Display (ND). The automatic navaid tuning feature reduces the probability ofa tuning errorby allowing this taskto becomepart ofpre-approach planning and is keyed to the flight plan arrival runway/approach selected from within the NavDataBase. AlphaDecoding ofMorse CodeNA V station identifier The 717 FlightManagement System (FMS) has an automatic decoding function from Morse Code to alpha characterfor navaid station station identifiers. Upon decoding ofthe Morse station identifier, the frequency displayed on the PFD and ND changes to the alpha character station identifier. Service History NTSB investigation historical data in the "AccidentDatabase & Synopsis" was searched for all 14 CFR 

### §121 operations ofall makes and models where ILS was mentioned in the event. The search included approximately 15 years ofevent data beginning in September 1999 to the present, which also encompasses the 717 introduction to present day. This review revealed no events where ILS frequency tuning errors were causal or contributed to the event. The U.S. registered 717 fleet of eighty-four (84) airplanes comprises slightly over one percent (1 %) ofthe average ofapproximately seven thousand (7000) domestic, flag, supplemental, scheduled cargo air carriers, and commercial operator airplanes that operated during the period the 717 has been in service (reference FAA Administrator's FactBooks).
Public Comment Boeing requests a waiver for the publication and public commentperiod ofthis request in order to provide immediate, interim, regulatory coverage ofthe Boeing 717-200 fleet, which is now out of compliance. Similar grants ofExemptionto 121.344 have established thatpublic impact would be minimal ifthis Exemption were granted without public comment. Operations Outside ofthe United States Ifgranted, Boeing 717 operators may exercise the privileges ofthis exemption, both inside and outside ofthe United States, due to the global nature ofthe Boeing 717-200 fleet operations. Additionally, foreign operators may use the FAA exemption as a basis ofapplication to their authority for continuing operation ofaffected 717 airplanes. Summary for Federal Register It was determined thatparameter46 (Nav 1 and Nav 2 selected frequency) was: validated readable and correct for ADF and VORfrequencies, and unreadable for the ILS frequency. The unreadable ILS frequency has no direct impact on safety in daily flight operations ofthe 717 fleet. This parameter is a post accident/event investigative tool.

# ~OEIND CP-L4L-14-00312 September 2, 2014 Page 5 of 5 On behalfofall affected Boeing 717-200 U.S. operators, Boeingherebypetitions for exemption from 14 CFR §121.344(e)(l) and (f)(1) Amendment 121-338, parameter46 (Nav 1 andNav 2 selected frequency), for all717-200 airplanes listed inType Certificate Data Sheet (TCDS) A6WE. Boeing anticipates the corrective actions maytake as long as 60 months to complete. A timeline addressing all aspects ofourplanning and coordination with the VIA Supplierhas beenprovidedto the FAAto substantiate ourrequested exemptiontimeperiod. Withthe considerationto the information above, Boeingrequests immediate approval ofrelieffor affected Boeing 717 operators for an interimperiod ofat least 24 months to prevent severe economic hardship and interruption ofservice to the public. Within this 24 monthperiod, Boeingestimates that sufficient data will be available to request a final exemption that provides fmal action which will correctthe non-compliance by the recording of parameter46 to the DFDRfor those affected 717 aircraft. There are mitigating factors for the 717-200:
• The 717 DFDRrecords Localizer (Parameter 27) and Glide Slope (Parameter 28) tracking data. This, combined with radartrackingdata and/or otherphysical data, will provide post event investigative evidence ofproper/improper ILS frequency selection.
• The 717 has auto tuning ofnavigation frequencies from a database for activated flight plans within the flight management system
• The 717 has auto decoding oftuned navigation station identifiers which is displayed to the pilots
• No accidents/incidents where ILS frequency tuning errors were causal or**contr~buted** in past 15 years ofall airplane types and models in§121 operations(NTSB data)
• The affected U.S. registered 717 fleet is relatively small at eighty-four (84) airplanes or approximately one percent (1%) ofthe total §121 operating airplanes.

Grant ofthis Exemption would prevent severe economic impactto scheduled commercial operators with affected 717 airplanes, as well as preventing interruption ofservice to the public, ifoperations were required to cease until this issue is corrected on affected airplanes. Sincerely,

Tim Hendrix Manager, Certification & Airworthiness Southern CaliforniaEngineering Design Center Boeing Commercial Airplanes CH/DP:ap Enclosure A