PO Box 31,Derby DE24 8BJ,England

Telephone: +44 (0) 1332 249292 Fax: +44 (0) 01332 245328

January 21

, 2014

U

. S

. Department of Transportation Docket Management Facility 1200 New Jersey Avenue, SE West Building Ground Floor Room W12

- 140 Washington, DC 20590

Subject: Petition for exemption from § 33.27(f)(6) of Title 14, Code of Fed eral Regulatio n s

(14 C

. F

. R

. ) ; Docket No. FAA

- 2013

- 1049

Dear Sir or Madam :

Attached please find a revised petition providing the additional information in support of the petition presented in our letter to the FAA dated December 9, 201 3 . This submission specifically responds to

a letter we received from the FAA, Aircraft and Propeller Directorate, Aircraft Certification Service, dated December 31, 2013. The first three items identified in the FAA’s December 31, 2013

, letter are address ed in the following parts of the revised petition:

Extent of the exemption : Section C of the petition. Extended justification to address § 11.81(d) : Section D of the petition. Extended justification to address § 11 .81(e) : Section E of the petition.

In a ddition, the FAA ’s December 31, 2013

, letter requested copies of the relevant reference s listed in the substantiating report, DNS192492

. These documents were supplied on a confidential basis as proprietary information to Mr Robert Green

, the FAA Engineer ing Certification Office focal point

, on January 14, 2014

.

Rolls

- Royce would appreciate the FAA’s consideration of this revised petition on an expedited basis, to the extent consistent with its internal processes

. T he exemption, if granted, will facilitat e completion of cross

- validation of the Trent 1000 engine models identified in the petition

, which is necessary to support introduction of the Boeing 787

- 9

.

S incerely

,

Iain Park

Airworthiness Specialist Tel

. (+44) 1332 2 49292 F ax (+44) 1332 2 45328

cc: Colleen M. D’Alessandro, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service

Tara Fitzgerald, Project Officer, Engine and Propeller Directorate, Aircraft Certification Service

Robert Gree n, Engineering Certification Office Focal Point, Engine and Propeller Directorate, Aircraft Certification Service

### Revised Petition for Exemption from 14 C

. F

. R

. § 33.27(f)(6)
, amendment 31

A. Name, A ddress and Contact I nformation of the Petitione r

Iain Park Airworthiness Specialist ML

- 52 Rolls

- Royce plc PO Box 31 Derby DE24 8BJ England Tel (+44) 1332 249292 Iain.Park@rolls

- royce.com

B. Pertinent S ection of the Code of Federal Regulation s

Rolls

- Royce hereby petitions for an exemption from 14 C

. F

. R

. § 33.27(f)(6). This exemption is requested for the HP shaft system only, for the Trent 1000 engine models identified in Section C below

.

The pertinent provisions of 14 C

. F

. R

. § 33.27 are :

14 C

. F

. R

. § 33.27 Turbine, compressor, fan, and turbosuperch arger rotor overspeed.

(f) Failure of a shaft section may be excluded from consideration in determining the highest overspeed that would result from a complete loss of load on a turbine rotor if the applicant:

(6) Does not exclude the entire shaft.

C. The Exemption Being S ought

Rolls

- Royce requests an exemption from 14 C

. F

. R

. § 33.27(f)(6) for the HP s haft s ystem of the following Trent 1000 engine models:



### Model Rating x 1000 lbs.

Trent 1000

- K2 74 Hot and High Trent 1000

- J2 74 Trent 1000

- L2 70 Hot and H igh + 

### 24°C Kink point

Trent 1000

- D2 70 Hot and High + 

### 20°C Kink point Trent 1000

- C2 70 Trent 1000

- G2 67 Trent 1000

- A2 64 Trent 1000

- H2 58 Trent 1000

- E 2 53

No exemption is sought for other shaft systems on these, or any other, engine models. The HP s haft

s ystem will c ompl y with § 33.27

, subject to the granting of the exemption from § 33.27(f)(6) requested herein

.Relief from § 33.27(f)(6) is sought bec ause analysis has failed to show that failure of the HP shaft

system can never result in overspeed to burst. The design of the HP shaft system is not amenable to analysis by shaft section. Rolls

- Royce therefore seeks an exemption from § 33.27(f)(6) to exclude the entire HP shaft system from consideration in determining the highest overspeed that would result from a complete loss of load on a turbine rotor

. However, as demonstrated in Section E below , the level of safety afforded by compliance with § 33.27 for the HP shaft system will be unaffected by the granting of an exemption from § 33.27(f)(6).

In sum , Rolls

- Royce is requesting this exemption because compliance with § 33.27 cannot be shown absent an exemption from § 33.27(f)(6) . However, compliance can be shown, with at least an equal level of safety to that required to meet § 33.27, if the exempti on is granted.

D. Statement of Public Interest

Granting this exemption will promote and serve the public interest because:

 The state

- of

- the

- art engine models (and the HP shaft system) at issue in this petition represent the latest generation of engines and engine technology from the Trent engine family. The Trent line of engines has established an outstanding track record of p erformance and safety over 41 years and more than 228 million service flight hours. Thus, the engine models and shaft system at issue in this petition are based on proven expertise and in

service

- verified design styles and practices. This experience and track record helps to ensure the reliability and safety of the product. As explained further in the points immediately below, the intro duction of these engine models into service will generate valuable public benefits.

 The granting of the requested exemption will expedite the entry into service of superior engines and engi ne technology that will enhance the safety and reliability of airli ne operations, and increase the efficiency of aircraft performance, thereby promoting U.S. economic interests (including those of Boeing, U.S. airlines, and their employees and shareholders) as well as those of the traveling public, while also reducing adv erse effects on the environment. All of these enhancements constitute substantial public benefits.

 These state

- of

- the

- art engine models will reduce the operating costs of aircraft, and the airlines that operate them, relative to costs associated with aircr aft that are currently in service. Such a reduction in operating costs will benefit U.S. and international airlines, their employees and shareholders. Moreover, such reduced operating costs provide the opportunity for airlines to offer more and less expens ive air service options to the traveling public.

 Certification of state

- of

- the

- art engine models, when operated in the Boeing 787, will reduce fuel burn, thereby reducing harmful emissions such as carbon dioxide (CO2) and NOx from levels experienced with engines currently in service.

 The Trent 1000 models are installed on the Boeing 787

- 9 which has customers outside the United States

. Sales of the engine contribute to the U.S. economy, support U.S. jobs, and enhance the U.S. balance of trade and gross dome stic product

— all of which promote the U.S. public interest.

E. Statement of No Adverse Effect on Safety

The FAA’s grant of this requested exemption will have no adverse effect on safety. Compliance with § 33.27 is significant for safety purposes because it demonstrates that an engine’s rotors will not fail under a varying range of potential operating conditions. The requirements contained in § 33.27(f) are significant for safety because this subsection allows failures of shaft sections to be excluded from th e range of conditions considered under § 33.27, but only if a design organization can demonstrate thatthe risk of such shaft section failures is sufficiently remote. Subsection 33.27(f)(6) does not in itself

impose any additional safety requirement. Clear ly

, if risk of failure of the whole shaft system is considered and shown to be at least as remote as is acceptable for “shaft sections,” then the overall level of safety must be at least equal to circumstances in which only “shaft sections” are considered, as provided for under § 33.27(f). Subsection 33.27(f)(6) was included in Section 33.27 based on a history of failures associated with conventional shaft systems, which raised doubt about the ability of design organizations to fully assess the potential fa ilure modes (and failure rate) of an entire shaft system. However, for the HP shaft system of the Trent 1000 (and indeed for other Rolls

- Royce modern 3 shaft engines), this analysis can be carried out with high fidelity because:

1. The HP shaft system design utilized across the Trent engine family differs significantly from conventional shaft systems

. For example, it features no bearings or oil system components, has high stiffness and significant clearance relative to other shafts; consequently, the threats associated with the features of a conventional shaft do not apply. A Failure Mode and Effect Analysis has determined that there are no known or potential environmental threats to the integrity of the HP shaft system components that could lead to a loss of load failure.

2. In order to ensure a high level of integrity, the special controls applied to the torque

transmitting components (i.e., the HP Compressor Rear Drum and the HP Turbine disc of the HP shaft system) are of a higher standard than those of many o ther shaft systems in the past. These mandated controls address, but are not limited to:

 Material specifications;

 Material properties (e.g., low cycle fatigue, high cycle fatigue, creep);

 Manufacturing induced anomalies;

 Service induced damage tolerance a ssessment;

 Safe life mandatory inspections; and

 Mandatory cycle life limitation.

3. The theoretical assessment of points 1) and 2) above is supported by the service experience of the Rolls

- Royce three shaft family of engines, all of which incorporate the sam e design style for the HP shaft system as the Trent 1000 engine models that are the subject of this petition. Over the course of more than 228 million service flight hours, there have been no failures of the HP shaft system torque path on the Trent family of engines. This performance reflects an extremely remote potential failure rate of less than 3.1 x 10

- 9 failures per flight hour.

In sum, there is ample evidence that analysis of the complete HP shaft system on the Trent 1000 models at issue achieves the level of fidelity required for failures of shaft sections under § 33.27(f)

. Therefore, the level of safety under the requested exemption will be at least equal to that otherwise provided by § 33.27, thereby assuring that no adverse effect on safety will r esult from a grant of the requested exemption.

F. Summary for Federal R egister

In accordance with § 11.81(f), Rolls

- Royce offers the following summary suitable for publication in the Federal Register.

Petitioner: Rolls

- Royce plc

Section of 14 C

. F

. R

. A f fected : 14 C.F.R. § 33.27(f)(6)

Description of Relief S ought:

Rolls

- Royce requests an e xemption from 14 C.F.R

. § 33.27(f)(6) to be applied to Rolls

- Royce Trent1000 engine

, models Trent 100 0

- A2, Trent 1000

- C2, Trent 1000

- D2, Trent 1000

- E2,Tre nt 1000

- G2, Trent 1000

- H2, Trent 1000

- J2, Trent 1000

- K2

, and Trent 1000

- L2

. Rolls

- Royce

seeks to exclude the entire HP shaft system from consideration in determining the highest overspeed that would result from a complete loss of load on a turbine rotor

.

G

. Additional Supporting Information

EASA Certificatio n requirements CS

- E 84 0 and CS

- E 850 are similar requirements to those of § 33.27. The Trent 1000 engine models at issue have been certified by EASA under Type Certificate E.036 issue 4 , which was relea sed on September 10, 2013. To meet the requirements of CS

- E 840 and CS

- 3 850

, EASA grant ed an Equivalent Safety Finding. The evidence provided to support this Equivalent Safety Finding was similar to that provided in this petition for exemption. The Equiva lent Safety Finding was accepted by EASA on August 27

, 2013

.

H

. Privileges of this Exemption O utside the United States

Per 14 C

. F

. R

. § 11.81(h), Rolls

- Royce reques ts that the privileges of this e xemption be extended outside the United States. This extens ion of privileges is necessary for operations based within foreign countries having bilateral agreements with the United States accepting FAA 14 C

. F

. R

. Part 33 as their airworthiness standards for transport category aircraft. The Trent 1000 is intended for the global marketplace

, with customers based in countries utili z ing the U

. S

. airworthiness s tandards.

I

. Good Cause Exists to Issue the Exemption without Notice and Comment

P ursuant to 14 C.F.R. § 11.87, Rolls

- Royce requests that this petition be proc essed without publication in the Federal Register for notice and comment

, as may otherwise be required. Rolls

Royce believes that good cause exists to not delay this action because : a) granting of this petition will not set a precedent; b) the relief reque sted is effectively identical an Equivalent Safety Finding previously accepted by EA S A (c) delaying the action would adversely affect Rolls

- Royce because t he Trent 1000 engine models covered by this petition are currently undergoing cross

- validation with th e FAA , the timing of which is aimed at meeting Boeing requirements for entry into service of the Boeing 787

- 9 , and significant delays in engin e validation would im pact the Boeing program; and (d) this petition is timely filed.

Respectfully s ubmitted,

Iain Park Airworthiness Specialist Rolls

- Royce p lc

Date: January 21

, 2014