Special Conditions: Gulfstream Model GVI Airplane; Limit Engine Torque Loads for Sudden Engine Stoppage, 44245-44246 [2011-18654]

Download as PDF 44245 Rules and Regulations Federal Register Vol. 76, No. 142 Monday, July 25, 2011 This section of the FEDERAL REGISTER contains regulatory documents having general applicability and legal effect, most of which are keyed to and codified in the Code of Federal Regulations, which is published under 50 titles pursuant to 44 U.S.C. 1510. The Code of Federal Regulations is sold by the Superintendent of Documents. Prices of new books are listed in the first FEDERAL REGISTER issue of each week. DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 25 [Docket No. NM454 Special Conditions No. 25–441–SC] Special Conditions: Gulfstream Model GVI Airplane; Limit Engine Torque Loads for Sudden Engine Stoppage AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final special conditions. SUMMARY: These special conditions are for the Gulfstream GVI airplane. This airplane has novel or unusual design features when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. These design features include engine size and the potential torque load imposed by sudden engine stoppage. These special conditions pertain to their effects on the structural performance of the airplane. The applicable airworthiness regulations do not contain adequate or appropriate safety standards for these design features. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards. rmajette on DSK89S0YB1PROD with RULES DATES: Effective Date: August 24, 2011. FOR FURTHER INFORMATION CONTACT: Carl Niedermeyer, FAA, Airframe/Cabin Safety Branch, ANM–115, Transport Standards Staff, Transport Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 227–2279; electronic mail Carl.Niedermeyer@faa.gov. SUPPLEMENTARY INFORMATION: VerDate Mar<15>2010 14:55 Jul 22, 2011 Jkt 223001 Background On March 29, 2005, Gulfstream Aerospace Corporation (hereafter referred to as ‘‘Gulfstream’’) applied for an FAA type certificate for its new Gulfstream Model GVI passenger airplane. Gulfstream later applied for, and was granted, an extension of time for the type certificate, which changed the effective application date to September 28, 2006. The Gulfstream Model GVI airplane will be an all-new, two-engine jet transport airplane with an executive cabin interior. The maximum takeoff weight will be 99,600 pounds, with a maximum passenger count of 19 passengers. Type Certification Basis Under provisions of Title 14, Code of Federal Regulations (14 CFR) 21.17, Gulfstream must show that the Gulfstream Model GVI airplane (hereafter referred to as ‘‘the GVI’’) meets the applicable provisions of 14 CFR part 25, as amended by Amendments 25–1 through 25–119, 25– 122, and 25–124. If the Administrator finds that the applicable airworthiness regulations (i.e., 14 CFR part 25) do not contain adequate or appropriate safety standards for the GVI because of a novel or unusual design feature, special conditions are prescribed under the provisions of § 21.16. Special conditions are initially applicable to the model for which they are issued. Should the type certificate for that model be amended later to include any other model that incorporates the same novel or unusual design features, the special conditions would also apply to the other model under provisions of § 21.101. In addition to complying with the applicable airworthiness regulations and special conditions, the GVI must comply with the fuel vent and exhaust emission requirements of 14 CFR part 34 and the noise certification requirements of 14 CFR part 36. The FAA must also issue a finding of regulatory adequacy pursuant to section 611 of Public Law 92–574, the ‘‘Noise Control Act of 1972.’’ The FAA issues special conditions, as defined in 14 CFR 11.19, in accordance with § 11.38, and they become part of the type certification basis under § 21.17(a)(2). PO 00000 Frm 00001 Fmt 4700 Sfmt 4700 Novel or Unusual Design Features The GVI will have high bypass engines. Engines of this size, configuration, and failure modes were not envisioned when § 25.361, which addresses loads imposed by engine seizure, was adopted in 1965. Worst case engine seizure events have become increasingly more severe with increasing engine size because of the higher inertia of the rotating components. The GVI engines are sufficiently different and novel to justify issuance of a special condition to establish appropriate design standards. Discussion of Special Conditions Section 25.361(b)(1) requires that for turbine engine installations, the engine mounts and the supporting structures must be designed to withstand a ‘‘limit engine torque load imposed by sudden engine stoppage due to malfunction or structural failure.’’ Limit loads are expected to occur about once in the lifetime of any airplane. Section 25.305 requires that supporting structures be able to support limit loads without detrimental permanent deformation, meaning that supporting structures should remain serviceable after a limit load event. Since adoption of § 25.361(b)(1), the size, configuration, and failure modes of jet engines have changed considerably. Current engines are much larger and are designed with large bypass fans. In the event of a structural failure, these engines are capable of producing much higher transient loads on the engine mounts and supporting structures. As a result, modern high bypass engines are subject to certain rare-butsevere engine seizure events. Service history shows that such events occur far less frequently than limit load events. Although it is important for the airplane to be able to support such rare loads safely without failure, it is unrealistic to expect that no permanent deformation will occur. Given this situation, the Aviation Rulemaking Advisory Committee (ARAC) has proposed a design standard for today’s large engines. For the commonly-occurring deceleration events, the proposed standard would require engine mounts and structures to support maximum torques without detrimental permanent deformation. For the rare-but-severe engine seizure events such as loss of any fan, compressor, or E:\FR\FM\25JYR1.SGM 25JYR1 44246 Federal Register / Vol. 76, No. 142 / Monday, July 25, 2011 / Rules and Regulations turbine blade, the proposed standard would require engine mounts and structures to support maximum torques without failure, but allows for some deformation in the structure. The FAA concludes that modern large engines, including those on the GVI, are novel and unusual compared to those envisioned when § 25.361(b)(1) was adopted and thus warrant special conditions. The special conditions contain design criteria recommended by ARAC. The special conditions also clarify the design criteria that apply to auxiliary power units. Discussion of Comments Notice of proposed special conditions No. 25–11–11–SC for Gulfstream GVI airplanes was published in the Federal Register on May 5, 2011 (76 FR 25648). One supportive comment was received and the special conditions are adopted as proposed. Applicability As discussed above, these special conditions are applicable to the GVI. Should Gulfstream apply at a later date for a change to the type certificate to include another model incorporating the same novel or unusual design features, these special conditions would apply to that model as well. Conclusion This action affects only certain novel or unusual design features of the GVI. It is not a rule of general applicability. List of Subjects in 14 CFR Part 25 Aircraft, Aviation safety, Reporting and recordkeeping requirements. The authority citation for these special conditions is as follows: BILLING CODE 4910–13–P rmajette on DSK89S0YB1PROD with RULES Jkt 223001 Federal Aviation Administration 14 CFR Part 25 [Docket No. NM456; Special Conditions No. 25–442–SC] Special Conditions: Boeing Model 747– 8 Series Airplanes; Overhead Flight Attendant Rest Compartment AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final special conditions. SUMMARY: These special conditions are issued for Boeing Model 747–8 series airplanes. These airplanes will have novel or unusual design features associated with the installation of an overhead flight attendant rest compartment. The applicable airworthiness regulations do not contain adequate or appropriate safety standards PO 00000 Frm 00002 Fmt 4700 for these design features. These special conditions contain the additional safety standards that the Administrator considers necessary to establish a level of safety equivalent to that established by the existing airworthiness standards. Additional special conditions will be issued for other novel or unusual design features of Boeing 747–8 airplanes. DATES: Effective Date: August 24, 2011. FOR FURTHER INFORMATION CONTACT: Jayson Claar, FAA, Airframe/Cabin Safety Branch, ANM–115, Transport Standards Staff, Transport Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue, SW., Renton, Washington 98055–4056; telephone (425) 227–2194; facsimile (425) 227–1149. SUPPLEMENTARY INFORMATION: Background On November 4, 2005, The Boeing Company, P.O. Box 3707, Seattle, WA 98124, applied for an amendment to Type Certificate Number A20WE to include the new Model 747–8 passenger airplane. Boeing later applied for, and was granted, an extension of time for the amended type certificate, which changed the effective application date to December 31, 2006. The Model 747–8 is a derivative of the 747–400. The Model 747–8 is a four-engine jet transport airplane that will have a maximum takeoff weight of 975,000 pounds and new General Electric GEnx–2B67 engines. The Model 747–8 will have two flight crew and the capacity to carry 605 passengers. Type Certification Basis DEPARTMENT OF TRANSPORTATION The Special Conditions Accordingly, pursuant to the authority delegated to me by the Administrator, the following special conditions are issued as part of the type certification basis for Gulfstream GVI airplanes. The following special conditions are in lieu of § 25.361(b): 1. For turbine engine installations, the engine mounts, pylons and adjacent supporting airframe structure must be designed to withstand 1g level flight loads acting simultaneously with the maximum limit torque loads imposed by each of the following: (a) Sudden engine deceleration due to a malfunction which could result in a temporary loss of power or thrust; and (b) The maximum acceleration of the engine. 14:55 Jul 22, 2011 Issued in Renton, Washington, on July 18, 2011. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 2011–18654 Filed 7–22–11; 8:45 am] Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704. VerDate Mar<15>2010 2. For auxiliary power unit installations, the power unit mounts and adjacent supporting airframe structure must be designed to withstand 1g level flight loads acting simultaneously with the maximum limit torque loads imposed by each of the following: (a) Sudden auxiliary power unit deceleration due to malfunction or structural failure; and (b) The maximum acceleration of the power unit. 3. For engine supporting structure, an ultimate loading condition must be considered that combines 1g flight loads with the transient dynamic loads resulting from: (a) The loss of any fan, compressor, or turbine blade; and (b) Separately, where applicable to a specific engine design, any other engine structural failure that results in higher loads. 4. The ultimate loads developed from the conditions specified in paragraphs 3(a) and 3(b) are to be multiplied by a factor of 1.0 when applied to engine mounts and pylons and multiplied by a factor of 1.25 when applied to adjacent supporting airframe structure. 5. Any permanent deformation that results from the conditions specified in paragraph 3 must not prevent continued safe flight and landing. Sfmt 4700 Under the provisions of Title 14, Code of Federal Regulations (14 CFR) 21.101, Boeing must show that the Model 747– 8 meets the applicable provisions of part 25, as amended by Amendments 25–1 through 25–120, plus amendment 25– 127 for § 25.795(a), except for earlier amendments as agreed upon by the FAA. These regulations will be incorporated into Type Certificate No. A20WE after type certification approval of the 747–8. In addition, the certification basis includes other regulations, special conditions and exemptions that are not relevant to these special conditions. Type Certificate No. A20WE will be updated to include a complete description of the certification basis for these airplanes. If the Administrator finds that the applicable airworthiness regulations (i.e., 14 CFR part 25) do not contain adequate or appropriate safety standards for the 747–8 because of a novel or unusual design feature, special E:\FR\FM\25JYR1.SGM 25JYR1

Agencies

[Federal Register Volume 76, Number 142 (Monday, July 25, 2011)]
[Rules and Regulations]
[Pages 44245-44246]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-18654]





========================================================================

Rules and Regulations

                                                Federal Register

________________________________________________________________________



This section of the FEDERAL REGISTER contains regulatory documents 

having general applicability and legal effect, most of which are keyed 

to and codified in the Code of Federal Regulations, which is published 

under 50 titles pursuant to 44 U.S.C. 1510.



The Code of Federal Regulations is sold by the Superintendent of Documents. 

Prices of new books are listed in the first FEDERAL REGISTER issue of each 

week.



========================================================================





Federal Register / Vol. 76, No. 142 / Monday, July 25, 2011 / Rules 

and Regulations



[[Page 44245]]







DEPARTMENT OF TRANSPORTATION



Federal Aviation Administration



14 CFR Part 25



[Docket No. NM454 Special Conditions No. 25-441-SC]




Special Conditions: Gulfstream Model GVI Airplane; Limit Engine 

Torque Loads for Sudden Engine Stoppage



AGENCY: Federal Aviation Administration (FAA), DOT.



ACTION: Final special conditions.



-----------------------------------------------------------------------



SUMMARY: These special conditions are for the Gulfstream GVI airplane. 

This airplane has novel or unusual design features when compared to the 

state of technology envisioned in the airworthiness standards for 

transport category airplanes. These design features include engine size 

and the potential torque load imposed by sudden engine stoppage. These 

special conditions pertain to their effects on the structural 

performance of the airplane. The applicable airworthiness regulations 

do not contain adequate or appropriate safety standards for these 

design features. These special conditions contain the additional safety 

standards that the Administrator considers necessary to establish a 

level of safety equivalent to that established by the existing 

airworthiness standards.



DATES: Effective Date: August 24, 2011.



FOR FURTHER INFORMATION CONTACT: Carl Niedermeyer, FAA, Airframe/Cabin 

Safety Branch, ANM-115, Transport Standards Staff, Transport Airplane 

Directorate, Aircraft Certification Service, 1601 Lind Avenue, SW., 

Renton, Washington 98057-3356; telephone (425) 227-2279; electronic 

mail Carl.Niedermeyer@faa.gov.



SUPPLEMENTARY INFORMATION:



Background



    On March 29, 2005, Gulfstream Aerospace Corporation (hereafter 

referred to as ``Gulfstream'') applied for an FAA type certificate for 

its new Gulfstream Model GVI passenger airplane. Gulfstream later 

applied for, and was granted, an extension of time for the type 

certificate, which changed the effective application date to September 

28, 2006. The Gulfstream Model GVI airplane will be an all-new, two-

engine jet transport airplane with an executive cabin interior. The 

maximum takeoff weight will be 99,600 pounds, with a maximum passenger 

count of 19 passengers.



Type Certification Basis



    Under provisions of Title 14, Code of Federal Regulations (14 CFR) 

21.17, Gulfstream must show that the Gulfstream Model GVI airplane 

(hereafter referred to as ``the GVI'') meets the applicable provisions 

of 14 CFR part 25, as amended by Amendments 25-1 through 25-119, 25-

122, and 25-124. If the Administrator finds that the applicable 

airworthiness regulations (i.e., 14 CFR part 25) do not contain 

adequate or appropriate safety standards for the GVI because of a novel 

or unusual design feature, special conditions are prescribed under the 

provisions of Sec.  21.16.

    Special conditions are initially applicable to the model for which 

they are issued. Should the type certificate for that model be amended 

later to include any other model that incorporates the same novel or 

unusual design features, the special conditions would also apply to the 

other model under provisions of Sec.  21.101.

    In addition to complying with the applicable airworthiness 

regulations and special conditions, the GVI must comply with the fuel 

vent and exhaust emission requirements of 14 CFR part 34 and the noise 

certification requirements of 14 CFR part 36. The FAA must also issue a 

finding of regulatory adequacy pursuant to section 611 of Public Law 

92-574, the ``Noise Control Act of 1972.''

    The FAA issues special conditions, as defined in 14 CFR 11.19, in 

accordance with Sec.  11.38, and they become part of the type 

certification basis under Sec.  21.17(a)(2).



Novel or Unusual Design Features



    The GVI will have high bypass engines. Engines of this size, 

configuration, and failure modes were not envisioned when Sec.  25.361, 

which addresses loads imposed by engine seizure, was adopted in 1965. 

Worst case engine seizure events have become increasingly more severe 

with increasing engine size because of the higher inertia of the 

rotating components. The GVI engines are sufficiently different and 

novel to justify issuance of a special condition to establish 

appropriate design standards.



Discussion of Special Conditions



    Section 25.361(b)(1) requires that for turbine engine 

installations, the engine mounts and the supporting structures must be 

designed to withstand a ``limit engine torque load imposed by sudden 

engine stoppage due to malfunction or structural failure.'' Limit loads 

are expected to occur about once in the lifetime of any airplane. 

Section 25.305 requires that supporting structures be able to support 

limit loads without detrimental permanent deformation, meaning that 

supporting structures should remain serviceable after a limit load 

event.

    Since adoption of Sec.  25.361(b)(1), the size, configuration, and 

failure modes of jet engines have changed considerably. Current engines 

are much larger and are designed with large bypass fans. In the event 

of a structural failure, these engines are capable of producing much 

higher transient loads on the engine mounts and supporting structures.

    As a result, modern high bypass engines are subject to certain 

rare-but-severe engine seizure events. Service history shows that such 

events occur far less frequently than limit load events. Although it is 

important for the airplane to be able to support such rare loads safely 

without failure, it is unrealistic to expect that no permanent 

deformation will occur.

    Given this situation, the Aviation Rulemaking Advisory Committee 

(ARAC) has proposed a design standard for today's large engines. For 

the commonly-occurring deceleration events, the proposed standard would 

require engine mounts and structures to support maximum torques without 

detrimental permanent deformation. For the rare-but-severe engine 

seizure events such as loss of any fan, compressor, or



[[Page 44246]]



turbine blade, the proposed standard would require engine mounts and 

structures to support maximum torques without failure, but allows for 

some deformation in the structure.

    The FAA concludes that modern large engines, including those on the 

GVI, are novel and unusual compared to those envisioned when Sec.  

25.361(b)(1) was adopted and thus warrant special conditions. The 

special conditions contain design criteria recommended by ARAC. The 

special conditions also clarify the design criteria that apply to 

auxiliary power units.



Discussion of Comments



    Notice of proposed special conditions No. 25-11-11-SC for 

Gulfstream GVI airplanes was published in the Federal Register on May 

5, 2011 (76 FR 25648). One supportive comment was received and the 

special conditions are adopted as proposed.



Applicability



    As discussed above, these special conditions are applicable to the 

GVI. Should Gulfstream apply at a later date for a change to the type 

certificate to include another model incorporating the same novel or 

unusual design features, these special conditions would apply to that 

model as well.



Conclusion



    This action affects only certain novel or unusual design features 

of the GVI. It is not a rule of general applicability.



List of Subjects in 14 CFR Part 25



    Aircraft, Aviation safety, Reporting and recordkeeping 

requirements.



    The authority citation for these special conditions is as follows:



    Authority:  49 U.S.C. 106(g), 40113, 44701, 44702, 44704.



The Special Conditions



    Accordingly, pursuant to the authority delegated to me by the 

Administrator, the following special conditions are issued as part of 

the type certification basis for Gulfstream GVI airplanes.

    The following special conditions are in lieu of Sec.  25.361(b):

    1. For turbine engine installations, the engine mounts, pylons and 

adjacent supporting airframe structure must be designed to withstand 1g 

level flight loads acting simultaneously with the maximum limit torque 

loads imposed by each of the following:

    (a) Sudden engine deceleration due to a malfunction which could 

result in a temporary loss of power or thrust; and

    (b) The maximum acceleration of the engine.

    2. For auxiliary power unit installations, the power unit mounts 

and adjacent supporting airframe structure must be designed to 

withstand 1g level flight loads acting simultaneously with the maximum 

limit torque loads imposed by each of the following:

    (a) Sudden auxiliary power unit deceleration due to malfunction or 

structural failure; and

    (b) The maximum acceleration of the power unit.

    3. For engine supporting structure, an ultimate loading condition 

must be considered that combines 1g flight loads with the transient 

dynamic loads resulting from:

    (a) The loss of any fan, compressor, or turbine blade; and

    (b) Separately, where applicable to a specific engine design, any 

other engine structural failure that results in higher loads.

    4. The ultimate loads developed from the conditions specified in 

paragraphs 3(a) and 3(b) are to be multiplied by a factor of 1.0 when 

applied to engine mounts and pylons and multiplied by a factor of 1.25 

when applied to adjacent supporting airframe structure.

    5. Any permanent deformation that results from the conditions 

specified in paragraph 3 must not prevent continued safe flight and 

landing.



    Issued in Renton, Washington, on July 18, 2011.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification 

Service.

[FR Doc. 2011-18654 Filed 7-22-11; 8:45 am]

BILLING CODE 4910-13-P