Petition for Extension to the Termination Date of March 31, 2017 for Exemption No. 12920 

from Title 14 Code of Federal Regulations sections 21.35(a), (b)(2), and (f)(2), Amendment 

21-95, Function and Reliability 

Name and Address of the Petitioner 

Douglas M. Lane, Director 

Commercial Airplanes 

The Boeing Company 

PO Box 3707 MC 03-56 

Seattle. WA 98124-2207 

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

Title 14 CFR 21.35(a) and (b)(2) at Amendment 21-95 requires the applicant to make all flight 

tests to assure that the aircraft, it components, and its equipment are reliable and function 

properly. 

§21.35 Flight tests. 

(a) Each applicant for an aircraft type certificate (other than under §§21.24 through 21.29) 

must make the tests listed in paragraph (b) of this section Before making the tests the 

applicant must show – 

(b) Upon showing compliance with paragraph (a) of this section, the applicant must make all 

flight tests that the FAA finds necessary 

(2) For aircraft to be certificated under this subchapter, except gliders and except 

reciprocating engine powered airplanes of 6,000 lbs. or less maximum certificated 

weight that are to be certificated under part 23 of this chapter, to determine whether 

there is reasonable assurance that the aircraft, its components, and its equipment are 

reliable and function properly. 

Title 14 CFR 21.35(f)(2) at Amendment 21-95 requires that the flight tests prescribed in 

paragraph (b)(2) for aircraft incorporating turbine engines of a type previously used in a type 

certificated aircraft must include at least 150 hours of operation. 

§21.35 Flight tests. 

(f) The flight tests prescribed in paragraph (b)(2) of this section must include – 

 (2) For all other aircraft, at least 150 hours of operation 

 

Enclosure to RA-17-00475 

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Original Extent of Relief Sought and Reason 

Boeing requests relief from certain aspects of §21.35(a), (b)(2) and (f)(2), specifically, the 

requirement to complete Function and Reliability (F&R) testing prior to receiving an Amended 

Type Certificate (ATC). Boeing requests to be able to defer the completion of Boeing Model 

767-2C F&R testing until after ATC approval of the 767-2C minor model, but prior to the 767-

2C being put into initial operational service. Boeing proposes to complete all required testing 

and incorporate any changes to the Type Design, required to comply with CFR part 21 

requirements, which the FAA deems necessary while all 767-2C aircraft remain under ownership 

and control of the Boeing Company. 

The 767-2C is being certified for use as a United States Air Force (USAF) KC-46 aerial 

refueling tanker (a public use aircraft), which will replace aging KC-10 and KC-135 tankers. The 

tanker configuration is comprised of the ATC configuration and the installation of an additional 

Supplemental Type Certificate (STC). The STC configuration is additive and will not impact 

F&R testing as applicable to the ATC configuration. 

This proposed relief will allow Boeing to be able to more fully evaluate the end-state KC-46 

tanker configuration (ATC plus STC) that will be operated by the USAF. Contractual 

requirements with the USAF require the conduct of extensive flight test hours in the KC-46 (i.e., 

ATC plus STC) configuration that are representative of tanker operations. These USAF flight 

test hours will be after FAA issuance of the ATC, but prior to initial entry into operational 

service. Boeing proposes to use these flight test hours to establish function and reliability rather 

than conduct redundant testing on the 767-2C configuration prior to issuance of the 767-2C 

ATC. Conducting redundant and dedicated testing on the 767-2C ATC configuration would 

delay aircraft delivery to the USAF. 

Regulation Requires: Relief (for a limited time) is necessary 

because: 

14 CFR 21.35(a) 

Amendment 21-95 

Each applicant for an 

aircraft type certificate 

(other than under 

§§21.24 through 21.29) 

must make the tests listed 

in paragraph (b) of this 

section 

Scheduling redundant Function and 

Reliability flight test hours prior to ATC 

approval would delay aircraft delivery to 

the USAF. Additionally, testing of the 

combined ATC and STC configuration is 

more representative of the USAF end state 

tanker aircraft and better supports the 

intent of function and reliability testing for 

this aircraft. 

14 CFR 21.35(b)(2) 

Amendment 21-95 

Flight tests to determine 

that there is reasonable 

assurance that the 

aircraft, its components, 

and its equipment are 

reliable and function 

properly. 

Enclosure to RA-17-00475 

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14 CFR 21.35(f)(2) 

Amendment 21-95 

At least 150 hours of 

operation for aircraft 

incorporating turbine 

engines previously used 

in a type certified 

aircraft. 

Boeing proposes a time limit in the Type Certification Data Sheet (TCDS) for the relief sought 

by this petition for exemption. The time limit proposed is shown; 

Time Limited Grant of Exemption § 21.35(a), (b)(2) and (f)(2), relief from the 

requirement that function and reliability testing be completed as a condition for obtaining 

an amended type certificate; Exemption No. 12920, month dd, yyyy (Relief expires at the 

time of aircraft delivery or ownership is transferred from the Boeing Company). 

Boeing also proposes to add the following to the Additional Design Requirements and 

Conditions (ADRC) of the Model 767 TCDS: 

14 CFR 21.35(a), (b)(2) and (f)(2) – Function and Reliability Testing 

Boeing may not transfer any ownership interest in any model 767-2C aircraft, and any 

such aircraft may only be flown by a Boeing pilot in command prior to the completion of 

that aircraft model’s Function and Reliability testing to the satisfaction of the FAA in 

accordance with 14 CFR Section 21.35 and Exemption No. 12920. Prior to any transfer 

of physical custody of any model 767-2C airplane not in compliance with Exemption No. 

12920 to any entity other than Boeing, Boeing must remove the data plate from that 

airplane. Additionally, the FAA would revoke the amendment to the TCDS that added 

the 767-2C model to the TCDS of the model 767. The text of this paragraph may only be 

removed from the TCDS of the Model 767 after such Function and Reliability testing is 

completed to the satisfaction of the FAA. 

All function and reliability testing per CFR 21.35 will be performed during ATC certification 

flight testing, STC certification flight testing, or USAF Pilot Training. USAF Pilot Training is 

provided by Boeing for USAF pilots. Training covers standard USAF aerial refueling operations, 

which is proposed as an ideal environment to evaluate function and reliability. During testing, 

the aircraft will be under Type Inspection Authorization as is routinely required for certification 

projects. Additionally, aircraft used during pilot training to support function and reliability 

compliance will be operated in accordance with § 21.191(f) and 21.195 while under a special 

(experimental) airworthiness certificate. Boeing will retain ownership, control, accountability 

and responsibility for the aircraft until successful completion of the function and reliability 

testing. 

Enclosure to RA-17-00475 

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All Part 21 findings of compliance are retained by the FAA. The FAA, at its discretion, may also 

rely on the US Government (USAF), and/or Boeing pilots to perform the FAA’s function for 

testing. Additionally, Boeing will provide status reports to the FAA for all test flights involving 

function and reliability. Any issues/squawks identified in testing are proposed to be captured per 

Boeing Commercial Aircraft (BCA) standard process. Issues are proposed to be tracked and 

resolved using the standard BCA Process Instructions to ensure closure and transparency. 

Description of Issue 

Existing Grant of Exemption 

On September 16, 2015, Federal Aviation Administration (FAA) Grant of Exemption 12920 was 

published granting Boeing relief from completing function and reliability (F&R) testing for the 

Model 767-2C prior to issuance of an amended type certificate (ATC). As published, Exemption 

12920 terminates on March 31, 2017, unless sooner superseded or rescinded. 

 Proposed Revision to Date of Termination 

Boeing is requesting that the original termination date of March 31, 2017 as published in 

Exemption 12920 be extended to October 24, 2017. Boeing is requesting an extension to the 

termination date due to a slide in the 767-2C program schedule which is extending the ATC date. 

Extending the termination date will allow Boeing to accumulate the required flight test hours 

after the issuance of the ATC that will better represent the aircrafts intended in-service 

configuration, capabilities and operation. 

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

Date of the Existing Exemption for the Model 767-2C Airplane 

The KC-46 tanker program has an extensive amount of testing requiring over 2000 flight test 

hours and 2500 ground test hours. This extensive testing encompasses both ATC and STC 

certification. All of this certification testing occurs prior to the proposed F&R testing and 

provides assurance that any safety issues are discovered and resolved. Therefore, deferring 

Function and Reliability testing will not result in any decrease in safety. 

Additionally, all necessary flight tests and any necessary change incorporation to support 14 

CFR Part 21 certification will be accomplished by Boeing before delivery to the USAF 

customer. The data gathered with the combined ATC and STC configuration will not invalidate 

the applicability of results to the ATC. Test operations of the airplanes are under conditions 

expected in service which will achieve the same level of safety as intended to ensure the aircraft, 

its components, and its equipment are reliable and function properly. As the requirements of 

§21.35(a), (b)(2) and (f)(2) will be substantiated prior to the 767-2C initial entry into operational 

service, granting of the exemption will not compromise safety. 

Enclosure to RA-17-00475 

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Statement of Public Interest 

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 March 

31, 2017 termination date to comply does not alter the previously submitted statement of public 

interest. 

Request to ‘Waive Publication and Comment’ 

The relief sought by this exemption extension does not result in any reduction in the level of 

safety upon which the grant of exemption was originally granted. Boeing respectfully requests 

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

and comment. 

Conclusion 

Boeing is seeking an extension to the termination date of March 31, 2017 as published in 

Exemption 12920 from §§ 21.35(a), (b)(2), and (f)(2) of Title 14 CFR. An extension of the 

termination date to April 24, 2018 is requested. 

Granting relief from 14 CFR 21.35(a) (b)(2) and (f)(2) for the requested date extension will 

allow Boeing, as provided in the original grant of exemption, to avoid duplicative testing while 

still accumulating the necessary test hours with intended in-service aircraft configuration, 

capabilities, and operations. Testing with the addition of the STC configuration is additive and 

does not invalidate test results as applied to the ATC. The public interest is served by supporting 

the earliest possible replacement of an aging fleet of public aircraft. The aging fleet has lower 

efficiency, higher maintenance costs and lesser operational capability. The approach to 

substantiate the function and reliability requirements will be completed prior to aircraft entry into 

service ensuring no decrease in safety. 

Privileges of this Exemption Outside the United States 

Boeing proposes to perform limited flights beyond U.S. Airspace in support of concurrent 

Function and Reliability testing. 

Summary to be Published in the Federal Register 

PETITIONER: Boeing Commercial Airplanes 

SECTION OF 14 CFR AFFECTED: 14 CFR 21.35(a), (b)(2) and (f)(2) Amendment 21-95 

Enclosure to RA-17-00475 

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DESCRIPTION OF RELIEF SOUGHT: To permit Boeing to accumulate additional flight test 

hours that represents the intended in-service aircraft configuration, capabilities, and operations 

after the approval of the ATC. These additional flight test hours will add assurance that the 767-

2C aircraft, its components, and its equipment are reliable and function properly in accordance 

with §21.35(b)(2). The exemption will allow relief from completing the tests required by 

§21.35(a), (b)(2) and (f)(2) prior to ATC; the relief to defer testing for the 767-2C aircraft would 

not exceed initial entry into operational service.

Enclosure to RA-17-00475 

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