Petition for Extension of Limitation from Exemption No. 10267, 10267A, and 10267B

The Boeing Company 

Douglas M. Lane, ODA Deputy Lead Administrator 

The Boeing Company 

PO Box 3707 

Seattle, Washington, 98124 

Section of the Code of Federal Regulations (CFRs) that are affected

Regulation At

Amendment

Which Requires

14 CFR 

25.1305(c)(6) 

120 (c) For turbine engine-powered airplanes. In addition 

to the powerplant instruments required by paragraph 

(a) of this section, the following powerplant 

instruments are required: 

(6) An indicator for the fuel strainer or filter required by 

§25.997 to indicate the occurrence of contamination of 

the strainer or filter before it reaches the capacity 

established in accordance with §25.997(d). 

14 CFR 

25.1309(c) 

120 (c) Warning information must be provided to alert the 

crew to unsafe system operating conditions, and to 

enable them to take appropriate corrective action. 

Systems, controls, and associated monitoring and 

warning means must be designed to minimize crew 

errors which could create additional hazards. 

Enclosure 

RA-14-03862 

Page 1 of 5
The Original Extent of Relief Sought and Reason(s):

Regulation Requires: Relief is necessary because:

14 CFR 

25.1305(c)(6) 

and 

25.1309(c) 

Amendment 

120 

For the GEnx-2B fuel 

system to comply 

with § 25.1309(c), an 

unambiguous and 

timely indication to 

the flight crew is 

required to alert them 

of an anticipated fuel 

system contamination

that could clog the 

fuel system, or could 

significantly delay the 

indication required by 

§ 25.1305(c)(6) 

during gross 

contamination of the 

airplane fuel system. 

The purpose of this 

indication is to enable 

the flight crew to take

appropriate corrective

action. 

The 747-8 and 747-8F / GEnx-2B engines will 

be some of the first General Electric engines 

to incorporate a method to detect gross fuel 

system contamination. The FAA only recently 

provided guidance regarding what is needed 

to show compliance to §25.1305(c)(6) and 

§25.1309(c) for indication of gross fuel 

contamination. Therefore, it would create a 

significant burden if Boeing were now required 

to incorporate this new gross fuel system 

contamination indication(s) on the first 

production 747-8/-8F airplanes prior to Type 

Certification. 

For the 747-8/-8F fuel systems to comply with 

§25.1309(c), an unambiguous and timely 

indication to the flight crew is required in the 

event that multiple engines on the same flight 

are subjected to a fuel filter impending bypass 

condition. Further, to comply with §25.1309(c),

the flight crew must be alerted of anticipated 

fuel system contamination that could clog the 

fuel system ahead of the engine fuel filter, or 

that could significantly delay the indication 

required by §25.1305(c)(6) during gross 

contamination of the airplane fuel system. 

The purpose of this indication is to enable the 

flight crew to take appropriate corrective 

action. 

With this Petition for Exemption, Boeing is 

requesting relief for a limited number of 747-

8F and 747-8 airplanes to allow sufficient 

time to develop, validate, certify and 

incorporate into production a new compliant 

gross fuel system contamination 

indication(s). Following incorporation of the 

compliant indication into production 

airplanes, Boeing will issue a service bulletin 

that recommends all airplanes delivered 

under this Time-Limited Exemption be 

retrofitted. 

Enclosure 

RA-14-03862 

Page 2 of 5
Description of relief sought: The requested 

Time-Limited Exemption will allow the Boeing 

Models 747-8F and 747-8 relief from the 

requirement of §25.1305(c)(6) and 25.1309(c) 

for an unambiguous and timely indication to the 

flight crew of gross fuel system contamination. 

The relief sought is limited to those 747-8F and 

747-8 aircraft completed prior to the 

production incorporation of the compliant 

message. The production incorporation of 

the compliant message will first be 

accomplished by 30 June 2014. A service 

bulletin will be available no later than 30 

June 2014 such that all 747-8F and 747-8 

airplanes delivered under this Exemption can 

order parts and install a compliant 

configuration. The Boeing service bulletin will 

recommend that all airplanes be retrofitted 

by 31 December 2016.

Description of Issue

On 7 June 2013, FAA Time-Limited Exemption No. 10267B was published (as amended from 

the original issuance on 19 May 2011, and Revision A on 5 August 2011) granting operators 

of the Boeing Model 747-8F and 747-8 airplanes powered by General Electric GEnx-2B 

engines temporary relief from the flight deck indication requirements for indicating fuel system 

contamination. The grant of Exemption was from the requirements of §25.1305(c)(6) and 

§25.1309(c) at Amendment 25-120, for airplanes for which an application for an airworthiness 

certificate is made prior to 30 June 2014. 

Boeing seeks an extension to the time-limited relief from full compliance to §25.1305(c)(6) and 

§25.1309(c) for the GEnx-2B powered 747-8 and 747-8F production airplanes, for the 

unambiguous and timely indication to the flight crew to alert them of an anticipated fuel 

system contamination event. If granted, this extension will allow sufficient time for Boeing to 

complete modifications of the new Main Fuel-Oil Heat Exchanger differential pressure sensing 

system, which has demonstrated less than desired reliability on production airplanes. The 

extension would allow relief for airplanes for which an application for an airworthiness 

certificate is made prior to 31 March 2015 and 30 September 2017 for retrofit of the 747-8 and 

747-8F fleet. 

Enclosure 

RA-14-03862 

Page 3 of 5
Relief from the original schedule is necessary because:

Boeing and GE worked together to design and certify a gross fuel contamination indicating 

system compliant to §25.1305(c)(6) and §25.1309(c), under ODA Project Number PS13-

0049. On 25 June 2014, 747-8 airplane RC035 was the first production delivery of the 

compliant design. GE Service Bulletin GEnx-2B S/B 79-0017 (18 June 2014) and Boeing 

Service Bulletin 747-73-2082 (13 June 2014) provide retrofit instruction to the operators. 

However, findings during production engine pass-off testing at GE and pre-delivery 

production airplane testing at Boeing has shown that the new Main Fuel-Oil Heat Exchanger 

differential pressure sensing system is demonstrating less than desired reliability. The root 

cause process will identify necessary hardware and/or software modifications to improve 

system reliability. Until this design is available, Boeing desires to limit the number of 

airplanes in the fleet with this unreliable sensing system. The granting of the Exemption 

extension will allow time for Boeing and GE to develop, validate, and certify a reliable Main 

Fuel-Oil Heat Exchanger differential pressure sensing system for production and in-service 

airplanes. 

Statement of No Adverse Affect on Safety Due to Schedule Extension 

Boeing contends that the safety rationale provided in the original Petition for Exemption is 

not compromised by this extension. Additionally, the unambiguous EICAS Caution 

message (ENG FL FILT MULT) is provided to the flight crew in the event that multiple 

engines on the same flight subjected to a fuel filter impending bypass condition remains 

active. 

Statement of Public Interest

Boeing asserts that the public interest stated in the original Petition for Exemption is still 

applicable to the requested extension. 

Request to Waive Publication and Comment

Boeing requests that the revision to the original Time-Limited Exemption not be delayed by 

the public process including publication of the subject petition as there were no previous 

public comments, and the conditions for grant of the original Exemption remain the same. 

Privileges of this Exemption Outside the United States 

Per §11.81(h), Boeing requests that the privileges of this Exemption be extended outside the 

United States. 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. The 747-8F and 747-8 are 

intended for the global market place with a launch customer based in a country utilizing the 

United States airworthiness standards. 

Enclosure 

RA-14-03862 

Page 4 of 5
Conclusion

Boeing requests an additional nine (9) month extension to allow sufficient time for Boeing 

to complete modifications of the new Main Fuel-Oil Heat Exchanger differential pressure 

sensing system, which has demonstrated less than desired reliability on production 

airplanes. This would result in an Exemption termination date of 31 March 2015 for 

airplanes that have not been issued an original airworthiness certificate prior to this date 

and 30 September 2017 for retrofit of the 747-8 and 747-8F fleet. 

Summary to be Published in the Federal Register 

PETITIONER: Boeing Commercial Airplanes 

SECTION OF 14 CFR AFFECTED: §25.1305(c)(6) and §25.1309(c) 

DESCRIPTION OF RELIEF SOUGHT: The Boeing Company has requested additional 

compliance time until 31 March 2015 (an additional 9 months) for airplanes that have not 

been issued an original airworthiness certificate prior to this date and 30 September 

2017 for retrofit of the 747-8 and 747-8F fleet. This nine (9) month extension is 

requested in order to complete modifications of the new Main Fuel-Oil Heat Exchanger 

differential pressure sensing system to improve system reliability, compliant with 

§25.1305(c)(6) and §25.1309(c), for GEnx-2B powered 747-8/8F airplanes. 

Enclosure 

RA-14-03862 

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