September 12, 2013

SUBMITTED ELECTRONICALLY TO: Federal Docket Management System, 

www.regulations.gov

U.S. Department of Transportation

Docket Operations

West Building, Room W12-140

1200 New Jersey Avenue, SE

Washington, D.C. 20590-0001

RE: International Aero Engines, LLC Petition for Exemption from 14 CFR § 33.94(a)(1)

Dear Ladies and Gentlemen:

Pursuant to 14 CFR part 11,

1 International Aero Engines, LLC (IAE, LLC) hereby 

petitions for an exemption from § 33.94(a)(1) for the PW1100G-JM Series Turbofan 

Engine.

The exemption would allow IAE, LLC to show that its engine is capable of containing 

damage without catching fire and without failure of its mounting attachments where the 

most critical fan blade fails at the blade platform (as more particularly defined in 

technical specifications) rather than at the outermost retention groove. This would 

result in the liberation of more than 80% of the fan blade which is more material than 

required by § 33.94(a)(1) for the failure point in integrally-bladed rotors.

For the reasons described below, a grant of exemption would be in the public interest, 

would not adversely affect safety and would provide an equivalent level of safety to that 

provided by the rule.

Pertinent Regulation 

Section 21.21 requires an applicant for a Type Certificate for an aircraft engine to meet 

certain requirements specified in the Federal Aviation Regulations, including those 

found in part 33. In pertinent part, § 33.94(a)(1) requires the applicant to demonstrate 

by engine tests that --

(a) ... the engine is capable of containing damage without catching fire and 

 1 All citations are to 14 CFR unless otherwise noted.

117 North Henry Street, Alexandria, VA 22314–2903

Telephone 703.299.0784 Fax 703.299.0254

www.potomac-law.com

Marshall S. Filler Direct Dial - 703.451.7393

Admitted in the District of Columbia and Virginia E-Mail - marshall.filler@potomac-law.com
U.S. Department of Transportation

Docket Operations

September 12, 2013

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RE: International Aero Engines, LLC Petition for Exemption from 14 CFR § 33.94(a)(1)

without failure of its mounting attachments when operated for at least 15 

seconds, unless the resulting engine damage induces a self shutdown, after 

each of the following events: 

(1) Failure of the most critical compressor or fan blade while operating at 

maximum permissible r.p.m. The blade failure must occur at the 

outermost retention groove or, for integrally-bladed rotor discs, at least 

80 percent of the blade must fail.

Design Features and Safety Considerations

The PW1100G-JM Series Turbofan Engine employs geared turbofan technology, is 

manufactured with metallic, composite hybrid fan blades and contains additional 

strengthening at the fan blade attachment (i.e., fan blade root).

Fan blade containment is a function of fan rotational speed and fan blade weight.

The blade operating environment of the geared turbofan is substantially lower in 

rotational speed with a corresponding lower fan pressure ratio than conventional 

turbofans. The composite hybrid fan blade construction significantly reduces blade 

attachment load and is designed with significantly higher safety capability. It employs 

blade root surface treatments making it highly damage tolerant to service loads and 

wear. In addition, the root area is over-designed to drive any potential blade fracture to 

the blade airfoils section above the platform. The combination of these characteristics

enables IAE, LLC to demonstrate through analysis and test that the fan blade will not 

fail below the platform over the service life of the blade. 

Exhibit A, which contains IAE, LLC confidential and proprietary information and will 

therefore be submitted separately to the FAA, is an impact assessment of how the 

requested exemption would affect compliance with other airworthiness standards in part 

33.

2

 The design features of this engine described above, in combination with the impact 

assessment, conclusively demonstrates that granting an exemption would not adversely 

affect safety and would also provide a level of safety equivalent to that provided by the 

rule.

 2 The date of application for the PW1100G-JM type certificate was December 15, 2011. Therefore, the 

certification basis for the engine (part 33 as amended by Amendment 33-1 through Amendment 33-32) 

was used as the basis for the regulatory impact assessment. The assessment also considers the FAA 

Policy Statements included in the PW1100G-JM Compliance Plan PWA-9900, as well as a pending 

rulemaking proposal to amend, in pertinent part, the icing airworthiness standards for turbine engines.

See FAA docket 2010-0636; 75 FR 37311 (June 29, 2010).
U.S. Department of Transportation

Docket Operations

September 12, 2013

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RE: International Aero Engines, LLC Petition for Exemption from 14 CFR § 33.94(a)(1)

Public Interest 

Granting the petition is in the public interest because it would enable IAE, LLC to design 

and manufacture an engine with a lighter fan case and accessory attachments, and an

optimized flange joint design. This results in a lighter-weight engine relative to the 

engine thrust generated, which leads to (1) a lower fuel burn, and (2) reduced 

emissions. 

More specifically, the engine’s reduced weight decreases fuel burn by 26,000 gallons 

per year. IAE, LLC estimates that approximately 5,000 PW1100G-JM engines will enter 

into service between 2015 and 2035. Thus, fuel consumption will be reduced by 129.2 

million gallons over the 20 year period. This will lead to a savings of approximately

$517 million in lower fuel costs, and will reduce carbon dioxide emissions by 2.7 billion 

pounds over the 20 year period. The data supporting these substantial cost savings 

and emission reductions is found in the reference section of Exhibit A. These are 

significant, tangible benefits to the public as a whole. 

In addition, Congress has declared that encouraging and developing civil aeronautics, 

including new aviation technology, is in the public interest and should be considered by 

the FAA in carrying out its safety responsibilities under Title 49 U.S. Code.

3 As such, 

the FAA determined that the carbon fiber composite fan blades of certain GE engines4

were a novel and unusual design feature that justified the issuance of special 

conditions.5 Consequently, in addition to meeting certain other requirements, the 

special conditions authorized GE to perform a fan blade release test at the blade 

platform rather than the root. GE therefore enjoys the concomitant benefits, such as a 

lighter-weight fan case.

Conversely, the FAA determined that similar special conditions were inappropriate for 

the PW1100G-JM’s metallic composite hybrid fan blades. Nevertheless, the design 

characteristics of the PW1100G-JM geared turbofan engine are such that the most 

critical fan blade will not fail below the platform over the blade’s service life. The part 33 

impact assessment and associated engineering data clearly demonstrate that granting 

the exemption would not adversely affect safety and would also provide an equivalent 

level of safety to that provided by the rule. This data is similar to what the FAA required 

of GE to meet the special conditions.

In summary, granting this petition would allow the approval of a fan blade which results

in less fuel burn, lower operating costs and reduced emissions. It would be consistent 

 3 49 U.S.C. § 40101(d)(3) 4 GE90-75B/-85B/-76B and various GEnx-1B and -2B series turbofan engines 5 Special Conditions No. 33-006-SC, No. 33-007-SC and 33-ANE-08
U.S. Department of Transportation

Docket Operations

September 12, 2013

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RE: International Aero Engines, LLC Petition for Exemption from 14 CFR § 33.94(a)(1)

with Congress’ desire to encourage the development of new aviation technology which 

is clearly in the public interest.

Summary of Exemption Request

In accordance with § 11.81(f), IAE, LLC offers the following summary suitable for 

publication in the Federal Register.

IAE, LLC petitions the FAA for an exemption from § 33.94(a)(1) for its 

specific engine model PW1100G-JM to allow IAE, LLC to show that the 

PW110G-JM is capable of containing damage without catching fire and 

without failure of its mounting attachments where the most critical fan 

blade fails at the fan blade platform rather than at the outermost retention 

groove.

Respectfully submitted,

Marshall S. Filler

Counsel for International Aero Engines, LLC

Attachment (submitted separately to the FAA)