~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 of Transportation 

Docket Operations M-30 

1200 New Jersey Avenue, SE 

Room W12-140, West Bldg. Ground Floor 

Washington DC 20590-0001 

FAA Transport Airplane Directorate 

The Boeing Company 

Boeing Commercial Airplanes 

Southern California Engineering Design Center 

2401 E. Wardlow Road 

MIC D800-00 18 

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 of affected airplanes 

(B) Versatile Integrated Avionics (VIA) Block Diagram 

(C) Boeing 60 Month Software (S/W) Change Timeline 

FAA Exemption No. 10611,Regulatory Document No.: FAA-2012-0429 

On behalf of all affected Boeing 717-200 U.S. operators, Boeing hereby petitions for exemption 

from 14 CFR §121.344(e)(l) and (f)(1) Amendment 121-338, parameter 46 (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 may take as long as 60 months to accomplish and 

implement in the affected fleet. However, Boeing requests immediate approval of relief for affected 

Boeing 717 operators, identified in Enclosure A, for an interim period of twenty-four (24) months. 

Within twenty-four (24) months from the date of this grant of exemption, Boeing will provide the 

FAA with detailed results of the efforts to define the scope of work, 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) month period will also provide time to develop an application for 

exemption to allow for the activities of accomplishing the changes, making them available, fleet 

implementation, as well as time for the FAA to consider this adherent second exemption. 
~BEING 

Background 

CP-L4L-14-00312 

September 2, 2014 

Page 2 of 5 

During a routine check of system function, one 717 operator noted that a portion of the data 

required by 14 CFR §121.344(a)(46), for Nav 1 and Nav 2 selected frequency parameter was not 

being recorded correctly by the Digital Flight Data Recorder (DFDR). 

As part of parameter 46, the 717-200 airplane's DFDR is intended to record ADF (if equipped), 

VOR, and ILS frequency selected. 

Further investigation indicated that Nav 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 being properly recorded on 717 airplanes 

There are eighty-four (84) U.S. registered 717 airplanes subject to regulations are requiring 

recording of parameter (46). There are an additional thirty-nine (39) foreign registered 717 

airplanes manufactured within the date range requiring parameter 46. 

The 717 has two interchangeable VIA units that supplies specified central computer functions for 

the airplane (see Enclosure B). The cause of the 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 behalf of all affected 717 operators since Boeing's 

requirement to comply with 14 CFR part 25.1459, Flight data recorders, supports compliance to 

various 14 CFR part 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 DFDR parameter 46 (ILS frequency) has no direct impact on safety of daily flight 

operations ofthe 717 fleet. 

Public Interest 

The public interest is benefitted by the granting of this petition because it allows continued 

operation in revenue service of the affected worldwide fleet of one 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 of this Exemption would prevent severe economic impact to scheduled commercial operators 

with 717 airplanes if operations were required to cease until this issue is corrected on each airplane. 

Justification for Exemption: 

The unreadable DFDR parameter (ILS frequency) presents no additional hazard to daily fleet 

operations of 717-200 airplanes. 

DFDR data is a post accident/event investigative tool. 
rtJ.-aoEING 

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 parameter to the 717 VIA 

airplane system, including collaboration with the VIA software supplier, related certification efforts 

with publication of the service action for the 717 fleet, make the corrective action available to the 

fleet and eventual incorporation of these software changes by the operators could require as long as 

60 months to complete. 

A timeline addressing aspects of our planning and coordination with Honeywell (VIA Supplier) are 

provided with Enclosure C. A review of this process flow would substantiate our requested 

exemption time period. 

The 717 has been out of production 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 of this function on flight operations. 

With consideration to the above, Boeing has accumulated a significant number of VIA 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 of change 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 of the schedule for certification since it is 

complicated by Boeing's need to contract use of an 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 of Exemption has been issued by the FAA to another 

transport category aircraft manufacturer for a unreadable parameter required under 14 CFR 

§ 121.344, in order to continue operation of affected airplanes until such time as the corrective 

action can be implemented. 

Mitigating Factors 

Other DFDR Data 

The 717 DFDR records Localizer (Parameter 27) and Glide Slope (Parameter 28) tracking data. 

The Localizer and Glide Slope data, combined with radar tracking data and/or other physical data 

will provide post event investigative evidence of proper/improper ILS frequency selection. 

717 Design Features- Auto Tuning 
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September 2, 20 14 

Page 4 of 5 

In addition to conventionally tuning navaids, including those navaids associated with specific 

Instrument Approach Procedures (lAPs), the 717 Flight Management System (FMS) has an 

automatic navaid tuning function which retrieves navaid frequencies from the NavDataBase 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 of the ILS transmitter ( ~ 25 NM). This tuned 

digital frequency is initially displayed on the lower left of the Primary Flight Display (PFD) as well 

as the lower left of the Nav Display (ND). The automatic navaid tuning feature reduces the 

probability of a tuning error by allowing this task to become part of pre-approach planning and is 

keyed to the flight plan arrival runway/approach selected from within the NavDataBase. 

Alpha Decoding of Morse Code NA V station identifier 

The 717 Flight Management System (FMS) has an automatic decoding function from Morse Code 

to alpha character for navaid station station identifiers. Upon decoding of the 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 "Accident Database & Synopsis" was searched for all 14 

CFR § 121 operations of all makes and models where ILS was mentioned in the event. The search 

included approximately 15 years of event data beginning in September 1999 to the present, which 

also encompasses the 71 7 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 %) of the average of approximately 

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 Fact Books). 

Public Comment 

Boeing requests a waiver for the publication and public comment period of this request in order to 

provide immediate, interim, regulatory coverage ofthe Boeing 717-200 fleet, which is now out of 

compliance. Similar grants ofExemption to 121.344 have established that public impact would be 

minimal if this Exemption were granted without public comment. 

Operations Outside of the United States 

If granted, Boeing 717 operators may exercise the privileges of this exemption, both inside and 

outside of the United States, due to the global nature of the Boeing 717-200 fleet operations. 

Additionally, foreign operators may use the FAA exemption as a basis of application to their 

authority for continuing operation of affected 717 airplanes. 

Summary for Federal Register 

It was determined that parameter 46 (Nav 1 and Nav 2 selected frequency) was: validated readable 

and correct for ADF and VOR frequencies, and unreadable for the ILS frequency. The unreadable 

ILS frequency has no direct impact on safety in daily flight operations of the 717 fleet. This 

parameter is a post accident/event investigative tool. 
~OEIND CP-L4L-14-00312 

September 2, 2014 

Page 5 of 5 

On behalf of all affected Boeing 717-200 U.S. operators, Boeing hereby petitions for exemption 

from 14 CFR §121.344(e)(l) and (f)(1) Amendment 121-338, parameter 46 (Nav 1 and Nav 2 

selected frequency), for all717-200 airplanes listed in Type Certificate Data Sheet (TCDS) A6WE. 

Boeing anticipates the corrective actions may take as long as 60 months to complete. A time line 

addressing all aspects of our planning and coordination with the VIA Supplier has been provided to 

the FAA to substantiate our requested exemption time period. 

With the consideration to the information above, Boeing requests immediate approval of relief for 

affected Boeing 717 operators for an interim period of at least 24 months to prevent severe 

economic hardship and interruption of service to the public. 

Within this 24 month period, Boeing estimates that sufficient data will be available to request a final 

exemption that provides fmal action which will correct the non-compliance by the recording of 

parameter 46 to the DFDR for those affected 717 aircraft. 

There are mitigating factors for the 717-200: 

• The 717 DFDR records Localizer (Parameter 27) and Glide Slope (Parameter 28) tracking 

data. This, combined with radar tracking data and/or other physical data, will provide post 

event investigative evidence of proper/improper ILS frequency selection. 

• The 717 has auto tuning of navigation frequencies from a database for activated flight plans 

within the flight management system 

• The 717 has auto decoding of tuned 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 of all 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 %) of the total §121 operating airplanes. 

Grant of this Exemption would prevent severe economic impact to scheduled commercial operators 

with affected 717 airplanes, as well as preventing interruption of service to the public, if operations 

were required to cease until this issue is corrected on affected airplanes. 

Sincerely, 

Tim Hendrix 

Manager, Certification & Airworthiness 

Southern California Engineering Design Center 

Boeing Commercial Airplanes 

CH/DP:ap 

Enclosure A