rzJ-BDEING 

SEP 30 2016 

RA-16-01977 

U.S. Department of Transportation 

Docket Operations 

West Bldg. Ground Floor, Room W12-140 

1200 New Jersey Avenue, SE. 

Washington, DC 20590 

Dear Sir or Madam, 

Subject: 

Model: 

Response Due: 

Reference: 

Petition for an Extension to Time-Limited Partial Grant of Exemption 

10905- Exemption from 14 CFR 25.901(c) Amendment 25-126 and 

25.981 (a)(3) Amendment 102 or later Pertaining to Planned Changes 

to the 737-600/-700/-700C/-800/-900/-900ER Fuel Quantity Indication 

System (FQIS) 

737 -600/-700/-700C/-800/-900/-900ER 

December 31,2016 

Boeing Letter RA-16-01978, "Submittal of Petition for an Extension to 

Time-Limited Partial Grant of Exemption 10905- Exemption from 14 

CFR 25.901(c) Amendment 25-126 and 25.981(a)(3) Amendment 102 

or later Pertaining to Planned Changes to the 737-600/700/-700C/-

800/-900/-900ER Fuel Quantity Indication System (FQIS) and 

Additional Supporting Data", dated September 30, 2016 

This letter is to submit: 

Petition for an Extension to Time-Limited Partial Grant of Exemption 

The Boeing Company respectfully submits the petition for an extension to time-limited partial 

grant of Exemption 10905- exemption from 14 CFR 25.901(c) Amendment 25-126 and 

25.981(a)(3) Amendment 102 or later pertaining to planned changes to the 737-600/-700/-

700C/-800/-900/-900ER Fuel Quantity Indication System (FQIS). 

Additional proprietary information and data has been submitted directly to the cognizant FAA 

directorate in support of this petition via Boeing Letter RA-16-01978 dated September 30, 2016. 

Please contact this office or the following individuals if you have further questions: 

Certification Engineer: Matthew A. Henriksen at 425-234-5818 

Program Manager: Guillermo J. (Bill) Campisteguy at 425-237-1377 
~OEING 

Page 2 

RA-16-01977 

Your timely cooperation in these matters is greatly appreciated. 

Sincerely, 

G. 

~~ J. Campisteauv 

2016.09.30 

14:41 :22 -07'00' 

(for) Douglas M. Lane 

Director, Commercial Airplanes 

(425) 237-1383, MC 03-56 

FAX: (425) 294-9340 

MAH 

Enclosure: Petition for an Extension to Time-Limited Partial Grant of Exemption 1 0905 

cc 

Name --- Encl EDT Comments 

Mr. Jeff Duven X X Mgr., FAA TAD -- Mr. Victor Wicklund X X Mgr., FAA TAD- Propulsion 

Mr. John Piccola X X Mgr., FAA BASOO 

Mr. Patrice Adjibly X X FAA Program Mgr., 6Y-01 

Mr. J. Sutherland X X FAA Program Mgr., 6Y-01 

Mr. Tom Thorson X X FAA Propulsion TPM 
RA-16-01977 Enclosure. page 1 of5 

Petition for an Extension to Time-Limited Partial Grant of Exemption 10905 

Name and Address of the Petitioner 

Douglas M. Lane, 

Director 

Commercial Airplanes 

The Boeing Company 

PO Box 3707 MC 03-56 

Seattle, Washington, 98124-2207 

Section(s) of the Regulations from which Relief is sought: 

14 CFR 25.901(c) amendment 25-126 and 25.981 (a)(3) amendment 25-102 or later 

§25.901(c) Amendment 25-126: 

(c) For each powerplant and auxiliary power unit installation, it must be 

established that no single failure or malfunction or probable combination of 

failures will jeopardize the safe operation of the airplane except that the failure of 

structural elements need not be considered if the probability of such failure is 

extremely remote. 

§25.981(a)(3) Amendment 25-102 and 125: 

(a) No ignition source may be present at each point in the fuel tank or fuel tank 

system where catastrophic failure could occur due to ignition of fuel or vapors. 

This must be shown by: 

(3) Demonstrating that an ignition source could not result from each 

single failure, from each single failure in combination with each latent 

failure condition not shown to be extremely remote, and from all 

combinations of failures not shown to be extremely improbable. The 

effects of manufacturing variability, aging, wear, corrosion, and likely 

damage must be considered. 

The Original Extent of Relief Sought and Reason(s) 

Regulation Requires: Relief is Necessary because: 

§25.901(c) For each powerplant and Direct compliance would require 

Amendment 25-126 auxiliary power unit extensive airplane design changes for 

installation, it must be both new production and retrofit for inestablished that no single service airplanes. Changes include: 

failure or malfunction or 

probable combination of Redesign of the Airplane Wiring System 

failures will jeopardize the safe to ensure Fuel Quantity Indication System 

operation of the airplane (FQIS) wire separation for more than 100 

except that the failure of unique customer driven airplane 

structural elements need not configurations. 

be considered if the probability 

of such failure is extremely Make new main tank penetrations inremote. board of the struts and procure new intank wiring harnesses. 

Modify the Fuel Quantity Processor Unit 

(FQPU) mother board and associated 
RA-16-01977 Enclosure, page 2 of 5 

Regulation Requires: Relief is Necessary because: 

connectors. The solution would likely 

require the FQPU to grow in size. 

Relocate the FQPU from the forward 

equipment center to the forward cargo 

compartment to allow for a larger FQPU 

and enable a clear path for wire 

separation. 

In-tank Component Changes (new 

brackets, shorter probe, revised in-tank 

wire harness and retention means). 

Software changes related to Fuel Tank 

Gauging Function (to account for 

capacitance change due to in-tank 

component changes). 

§25.981 (a)(3) An ignition source could not Same as above. 

Amendment 25-102 result from each single failure, 

and 25-125 from each single failure in 

combination with each latent 

failure condition not shown to 

be extremely remote, and from 

all combinations of failures not 

shown to be extremely 

improbable. The effects of 

manufacturing variability, 

aging, wear, corrosion, and 

likely damage must be 

considered. 

Description of Issue 

Exist ing Grant of Exemption 

On December 18, 2013, Federal Aviation Administration (FAA) Time Limited Partial Grant of 

Exemption 1 0905 was published granting Boeing relief for up to 48 months after the effective 

date from §§25.901 (c), Amendment 25-126 and 25.981(a)(3), Amendment 25-102 or later, as 

they pertain to fuel tank ignition prevention associated with the following FQIS changes on inservice and newly-produced 737 -600/-700/-700C/-800/-900/-900ER airplanes: 

• Replacement of the Signal Conditioner Circuit Cards (SCCC) and the Aeronautical Radio 

Incorporated (ARINC) display card within the FQPU; and 

• Changed areas for the re-routing and separation of FQIS wires where the changed areas of 

the FQIS wire routing meet the installation requirements for separation and fault tolerance 

required to comply with § 25.981 (a)(3) as associated with the: 

o Semi-monolithic side-of-body change, and 

o Forward bulkhead relocation. 
RA-16-01977 Enclosure. page 3 of 5 

After expiration of this time-limited exemption, the FQIS on all newly-produced airplanes will 

need to be shown to comply with§§ 25.901(c), Amendment 25-46, and 25.981 (a)(3), 

Amendment 25-102, or later amendments. 

Note: For simplification, the 737-600/-700/-700C/-800/-900/-900ER airplane models will 

henceforth be referred to as 737NG. Likewise, the 737-7/-8/-9 airplane models will henceforth 

be referred to as 737MAX. 

Proposed Revision of Limitation 

Boeing is requesting that the original time limit of 48 months as approved in Exemption 1 0905 

be extended through December 17, 2025. The reasons that this extension is needed are 

summarized here: 

• Exemption 10905 will expire on December 18, 2017 which does not provide coverage for 

the production of the remaining commercial 737NG airplanes prior to transitioning fully to 

the 737MAX. The estimated number aircraft utilizing relief provided by Exemption 

10905, if the extension is granted, would be 4.4% greater than the projected number of 

airplanes requiring relief at the time of the issuance of Exemption 10905. Final 

production of 737NG airplanes for commercial customers will come to an end by 

December 18, 2019. 

• In order to support a United States military customer, Boeing will continue producing the 

737-7001GW military platform at a very low rate through December 17, 2025. 

• An improvement to the 737NG FQIS wire sleeving is planned which will improve the 

current level of protection. Additionally, producibility enhancements to the FQPU are 

planned. 

The proprietary data to describe these changes has been sent to the cognizant FAA Directorate 

via RA-16-01978. 

Statement of No Adverse Effect on Safety Accounting for the Extension of the Existing 

Exemption for the 737NG airplanes 

Boeing proposes that the safety position provided in the original request for an exemption is not 

compromised by this extension. 

Additional factors that will maintain or improve the safety position provided in the original 

request are listed below: 

• The extension does not significantly increase the quantity of aircraft that would be 

exempt under the grant of the exemption. The proprietary fleet data to support this 

petition has been sent to the cognizant FAA Directorate via RA-16-1978. 

• As a component, the redesigned FQPU was found to be fully compliant with 

§25.981(a)(3), Amendment 25-125 which represents an incremental improvement in 

system safety. 

• An additional sleeving improvement is planned to be implemented on the FQIS wiring 

pending acceptance of the petition for extension. 
RA-16-01977 Enclosure, page 4 of 5 

The proprietary data to describe these changes has been sent to the cognizant FAA Directorate 

via RA-16-01978. 

Statement of Public Interest Accounting for the Extension of the Existing Exemption for 

the 737NG airplanes 

Commercial Customers 

Boeing proposes that the public interest statement upon which the grant of exemption was 

based remains applicable as written in the original petition. This petition for extension of the time 

to comply does not alter the previously submitted statement of public interest. 

Military Customers (737-7001GW only) 

In addition to the rationale supporting the statement of public interest in the original petition, a 

variant of the 737 -7001GW is anticipated to be produced and delivered in limited quantities 

through December 17, 2025 to support unique US military operations. The US government is 

expected to replace aging military aircraft with commercial aircraft platforms that allow the US 

government more cost effective acquisition and operations to support military mission 

requirements. Approval of this extension would enable continued limited production of the 737-

7001GW specifically to support these US Military requirements and therefore supports the public 

interest. 

The projected increase in the 737-7001GW fleet size due to this requirement is minimal at less 

than 30 aircraft. Additional proprietary data has been provided to the cognizant FAA Directorate 

via RA-16-1978 to support the petition for extension of the time limit on the existing exemption 

for the 737-7001GW. The associated design proposal in support of this petition for exemption 

will include a fully compliant FQPU (at the component level) further providing enhancements to 

airplane safety. 

Design changes that would be required for full compliance would not provide a significant 

benefit or increased level of safety for new production airplanes which have the Nitrogen 

Generation System (NGS) installed. Additionally, the costs associated with these changes 

would not be commensurate with the increased level of safety and would be economically 

prohibitive given the relatively small number of additional production aircraft that would be 

burdened with these costs. 

Extending the time limit of the existing exemption for the 737 -7001GW is in the public interest for 

the aforementioned reasons and will promote continued production of the 737 -7001GW military 

airplane variants through December 17, 2025. 

Request to 'Waive Publication and Comment' 

The relief sought by this exemption does not result in any reduction in level of safety for a 

previously type certified product with a highly reliable system; rather, it allows for an additional 

incremental enhancement to the level of safety of the product. Boeing respectfully requests 

that, in order to expedite the exemption process, the FAA waive the requirement for publication 

and comment. 
RA-16-01977 Enclosure. page 5 of 5 

Privileges of the Exemption Outside the United States 

Because the 737NG is used by customers around the world, Boeing requests that the privileges 

of this exemption be extended outside the United States, per 14 CFR 11 .81 (h). This extension 

of privileges is necessary for operations based within foreign countries having bilateral 

agreements with the United States accepting FAA 14 CFR Part 25 as their airworthiness 

standards for transport category aircraft. 

Conclusio n 

Boeing is seeking an exemption time limit extension to the original 48 month grant of Exemption 

10905 from§§ 25.901(c), Amendment 25-126, and 25.981(a)(3), Amendment 25-102, or later. 

The time extension requested is through December 17, 2025. 

This extension is sought to allow for the full production transition from the commercial 737NG to 

the 737MAX airplanes by the end of 2019 and to enable Boeing to support a U.S. Military 

customer through the end of 2025 with a small number of 737-7001GW airplanes. This request 

will also enable the implementation of planned FQIS wiring improvements and other potential 

system modifications. 

The request is justifiable because the quantity of affected airplanes will not significantly 

increase, additional enhancements are being incorporated that increase the overall safety of the 

FQIS, and full compliance is not practical due to the timing of the transition to the 737MAX. 

These requests are justified based on the rationale provided in the original exemption petition, 

additional details provided in this petition and the additional proprietary data provided to the 

cognizant FAA Directorate via RA-16-1978. 

Summary to be Publ ished in the Federal Register 

PETITIONER: Boeing Commercial Airplanes 

SECTION OF 14 CFR AFFECTED: 14 CFR 25.981(a)(3) Amendment 25-125 and 

25.901(c) Amendment 25-126 

DESCRIPTION OF RELIEF SOUGHT: 

The Boeing Company, has requested a 96 month extension to the existing Time-Limited Partial 

Grant of Exemption 10905 to 14 CFR 25.901 (c), Amendment 25-126, and 25.981 (a)(3), 

Amendment 25-102, or later amendments for the FQIS on 737NG commercial airplanes, 

through 2019,and a small number of 737-7001GW military platforms for through 2025.