# ~DEING John A. Hamilton Lead Administrator Regulatory Administration Commercial Airplanes The Boeing Company P.O. Box 3707 MC 03-56 Seattle, WA 98124-2207



### NOV 

## 022012

RA-12-04226

U.S. Department ofTransportation Docket Operations, M-30 1200 NewJerseyAvenue, S.E. Room W12-140, West Bldg. Ground Floor Washington, DC 20590-0001


### Subject:

Model: RA Project No.: Request forAmendment to FAA Exemption No. 10267A Provision No. 1 Pertaining to Engine Fuel Strainer Inspections on 747-8/-8F Aircraft 747-8, 747-8F PS12-0815 l ()'1 ]>



### Reference(s): a) FAA Exemption No. 10267 (Regulatory Docket No. FAA-2010-1268), issued on May 19, 2011 b) FAA Exemption No. 10267A (Regulatory Docket No. FAA-2010-1268), issued on August 05, 2011

The Boeing Company respectfully requests an amendmentto provision #1 of Exemption 10267 

### A The FAA decision included the following provision in granting the Exemption:
"ForModei747-81-8Fairplanes granted

### a certificate ofairworthiness before June 30, 2014, the Airworthiness Limitations section ofthe Instructions for Continued Airworthiness mustinclude 

### a limitation that requires operators to verify that contaminants have notaccumulatedon the fuel strainerlocated upstream ofthe engine driven fuelpump. The limitation mustalso require an inspection ofthe fuel cooledoil coolerifthe fuel strainerhas bypassed fuel. The airworthiness limitation mustrequire these actions following anymaintenance action thatresultedin personnelentryinto the center wing fuel tank: 

### a. Afterthe first flight following tank entry, access andanalyze the messages frc

### m the engine indication andcrewalerting system andcentralmaintenance computerto detectanybypass orimpending bypass ofanyofthe. engine fuel strainers. b. Perform 

### a physicalinspection ofthe engine fuel strainerfrom one engine within 20 flight hours. c. Perform 

### a secondphysicalinspection ofthe engine fuel strainerfrom 

### a second engine within 40 flight hours."

# ~OEING.
U.S. Department ofTransportation RA-12-04226 Page 2

The current provision only allows 20 flight hours between fuel tank maintenance and engine fuel strainer inspection events. The amendment Boeing requests to this provision would allow for 20 flight hours or4 flight cycles (whichever comes later) between fuel tank maintenance events and the first physical engine fuel strainer inspection, and 40 flight hours or 8 flight cycles (whichever comes later) to accrue between fuel tank maintenance events and the second physical engine fuel strainer inspection.
This amended provision would be met by three separate inspections:

• Inspection ofthe Engine Indication and Crew Alerting System (EICAS) and Central Maintenance Computer (CMC) messages to detect any bypass or impending bypass at the fuel strainers afterthe first flight.

• Physical inspection ofthe engine fuel strainer for the first engine after 20 flight hours or4 flight cycles, whichever comes later.

• Physical inspection ofthe engine fuel strainer for the second engine after 40 hours or 8 flight cycles, whichever comes later.
The two engines selected will be those determined by analysis to be fed primarily from the center fuel tank; no inspection would be required for the othertwo engines after centertank maintenance activity. Additionally, Boeing is committing to similar inspections following inboard main fuel tank entry by maintenance personnel.
The rationale for requesting this amendment to add a flight cycles condition to 10267 A Provision No. 1 is to ensure the engines are operated on center tank fuel for sufficient time for any maintenance related contaminants to be captured by the engine fuel strainers, while allowing adherence to the best practices of avoiding maintenance on**multipl~** common engine fuel systems at the same maintenance opportunity. The addition offlight cycles in combination with the existing flight hour requirement is an effective common mode threat mitigation strategy and provides an allowance for one round trip flight in combination with an unplanned in-flight diversion between maintenance events.
This proposed amendment has been discussed and reviewed by Sue Lucier ofthe FAA-Seattle Aircraft Certification Office in July 2012 and Henk Pruis, Powerplant & Fuel Systems Expert ofthe European Aviation SafetyAgency in August 2012 at the request of Lufthansa German Airlines. The FAA and EASA evaluators had no technical objections to the proposed amendment.

# rfJ--IIDEING

U.S. Department ofTransportation RA-12-04226 Page 3



### This letter petitions: (X) An exemption amendment for operations inside and outside the United States.



### This letter is sent for: (X) Review and approval.
This petition reflects coordination between 747-8/8F air carriers and Boeing in the accumulation of more than 10,000 flight cycles of service. Therefore, Boeing respectfully requests waiving the open comment period so the public can benefit from the effects ofthis amendment as soon as possible. Boeing respectfully requests a response from the FAA by January 31,2013. 

### Please contact this office orthe following individuals ifyou have further questions: (X) Project Administrator (PA): Virinder Duggal at (425) 717-3446
The information being forwarded to the FAA by or with this correspondence is for the exclusive purpose ofsupport ofapplications for or amendments to Type Certificates, is considered proprietary to The Boeing Company and/or its suppliers, and is provided on a confidential basis.

Sincerely,

# ~**~** (_VIRIJVI>tEIL puG,.G/JL)

### ~Douglas M. Lane ODA Deputy Lead Administrator (425) 237-1383, MC 03-56 FAX: (425) 294-9340



### cc: Name 

### R. Reed (747-8/8F) G. Oltman (747-8/8F) 

### Sharepoint Comments Yes (FAA)6Y-01 Yes (FAA) 6Y-01