55228 Federal Register / Vol. 80, No. 178 / Tuesday, September 15, 2015 / Rules and Regulations 

Issued in Renton, Washington, on 

September 9, 2015. 

Michael Kaszycki, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2015–23099 Filed 9–14–15; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2015–1483; Special 

Conditions No. 25–598–SC] 

Special Conditions: Gulfstream 

Aerospace Corporation Model GVII– 

G500 Airplanes; Limit Engine Torque 

Loads 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final special conditions; request 

for comments. 

SUMMARY: These special conditions are 

issued for the Gulfstream Model GVII– 

G500 airplane. These airplanes have a 

novel or unusual design feature as 

compared to the state of technology 

envisioned in the airworthiness 

standards for transport category 

airplanes. This design feature includes 

engine size and the potential torque 

loads imposed by sudden engine 

stoppage. The applicable airworthiness 

regulations do not contain adequate or 

appropriate safety standards for this 

design feature. 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: The effective date of these 

special conditions is September 15, 

2015. We must receive your comments 

by October 30, 2015. 

ADDRESSES: Send comments identified 

by docket number FAA–2015–1483 

using any of the following methods: 

• Federal eRegulations Portal: Go to 

http://www.regulations.gov/ and follow 

the online instructions for sending your 

comments electronically. 

• Mail: Send comments to Docket 

Operations, M–30, U.S. Department of 

Transportation (DOT), 1200 New Jersey 

Avenue SE., Room W12–140, West 

Building Ground Floor, Washington, DC 

20590–0001. 

• Hand Delivery or Courier: Take 

comments to Docket Operations in 

Room W12–140 of the West Building 

Ground Floor at 1200 New Jersey 

Avenue SE., Washington, DC, between 9 

a.m. and 5 p.m., Monday through 

Friday, except Federal holidays. 

• Fax: Fax comments to Docket 

Operations at 202–493–2251. 

Privacy: The FAA will post all 

comments it receives, without change, 

to http://www.regulations.gov/, 

including any personal information the 

commenter provides. Using the search 

function of the docket Web site, anyone 

can find and read the electronic form of 

all comments received into any FAA 

docket, including the name of the 

individual sending the comment (or 

signing the comment for an association, 

business, labor union, etc.). DOT’s 

complete Privacy Act Statement can be 

found in the Federal Register published 

on April 11, 2000 (65 FR 19477–19478), 

as well as at http://DocketsInfo.dot 

.gov/. 

Docket: Background documents or 

comments received may be read at 

http://www.regulations.gov/ at any time. 

Follow the online instructions for 

accessing the docket or go to Docket 

Operations in Room W12–140 of the 

West Building Ground Floor at 1200 

New Jersey Avenue SE., Washington, 

DC, between 9 a.m. and 5 p.m., Monday 

through Friday, except Federal holidays. 

FOR FURTHER INFORMATION CONTACT: Walt 

Sippel, FAA, Airframe and Cabin Safety 

Branch, ANM–115, Transport Airplane 

Directorate, Aircraft Certification 

Service, 1601 Lind Avenue SW., 

Renton, Washington 98057–3356; 

telephone 425–227–2774; facsimile 

425–227–1232. 

SUPPLEMENTARY INFORMATION: The FAA 

has determined that notice of, and 

opportunity for, prior public comment 

on these special conditions are 

impracticable because these procedures 

would significantly delay issuance of 

the design approval and thus delivery of 

the affected airplane. 

In addition, the substance of these 

special conditions has been subject to 

the public-comment process in several 

prior instances with no substantive 

comments received. The FAA therefore 

finds that good cause exists for making 

these special conditions effective upon 

issuance. 

Comments Invited 

We invite interested people to take 

part in this rulemaking by sending 

written comments, data, or views. The 

most helpful comments reference a 

specific portion of the special 

conditions, explain the reason for any 

recommended change, and include 

supporting data. 

We will consider all comments we 

receive on or before the closing date for 

comments. We may change these special 

conditions based on the comments we 

receive. 

Background 

On March 29, 2012, Gulfstream 

Aerospace Corporation applied for a 

type certificate for their new Model 

GVII–G500 airplane. 

The GVII airplane is a large-cabin 

business jet with seating for 19 

passengers. It incorporates a low, sweptwing design with winglets and a T-tail. 

The Model GVII–G500 airplane is 

powered by two aft-fuselage-mounted 

Pratt & Whitney turbofan engines. 

Avionics will include four primary 

display units and multiple touchscreen 

controllers. The flight-control system is 

a three-axis fly-by-wire system 

controlled by active control/coupled 

side sticks. 

The Model GVII–G500 airplane 

wingspan is approximately 87 ft with a 

length of just over 91 ft. Maximum 

takeoff weight will be approximately 

76,850 lbs and maximum takeoff thrust 

will be approximately 15,135 lbs. 

Maximum range will be approximately 

5,000 nm and maximum operating 

altitude will be 51,000 ft. 

Type Certification Basis 

Under the provisions of Title 14, Code 

of Federal Regulations (14 CFR) 21.17, 

Gulfstream Aerospace Corporation must 

show that the Model GVII–500 airplane 

meets the applicable provisions of part 

25, as amended by Amendments 25–1 

through 25–137 thereto. 

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 Model GVII–G500 airplane 

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 or similar novel 

or unusual design feature, the special 

conditions would also apply to the other 

model under § 21.101. 

In addition to the applicable 

airworthiness regulations and special 

conditions, the Model GVII–G500 

airplane must comply with the fuel-vent 

and exhaust-emission requirements of 

14 CFR part 34 and the noisecertification requirements of 14 CFR 

part 36. 

The FAA issues special conditions, as 

defined in 14 CFR 11.19, in accordance 

with § 11.38, and they become part of 

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Federal Register / Vol. 80, No. 178 / Tuesday, September 15, 2015 / Rules and Regulations 55229 

the type-certification basis under 

§ 21.17(a)(2). 

Novel or Unusual Design Features 

The Model GVII–G500 airplane will 

incorporate the following novel or 

unusual design features: Large-bypass 

engines capable of larger and more 

complex dynamic loads than were 

envisioned when the 14 CFR 25.361(b) 

rule was developed in 1957, thereby 

requiring issuance of special conditions 

to establish appropriate design 

standards for the Model GVII–G500 

airplane. 

Discussion 

The limit engine torque load imposed 

by sudden engine stoppage due to 

malfunction or structural failure (such 

as a compressor jamming) has been a 

specific requirement for transportcategory airplanes since 1957. In the 

past, the design torque loads associated 

with typical failure scenarios have been 

estimated by the engine manufacturer 

and were provided to the airframe 

manufacturer as limit loads. These limit 

loads were considered simple, puretorque static loads. 

It is evident from service history that 

the engine-failure events that tend to 

cause the most severe loads are fanblade failures, and these events occur 

much less frequently than the typical 

‘‘limit’’ load condition. 

To maintain the level of safety 

envisioned by § 25.361(b), more 

comprehensive criteria are required for 

the new generation of high-bypass 

engines. These special conditions 

distinguish between the more common 

engine-failure events and those rare 

events resulting from structural failures. 

The more-common events are regarded 

as static torque limit load conditions. 

The more-severe events resulting from 

extreme engine-failure conditions (such 

as loss of a full fan blade at redline 

speed) are regarded as full dynamic load 

conditions. These are considered 

ultimate loads, and include all transient 

loads associated with the event. An 

additional safety factor is applied to the 

more-critical airframe supporting 

structure. 

Applicability 

As discussed above, these special 

conditions are applicable to the Model 

GVII–G500 airplane. Should Gulfstream 

Aerospace apply at a later date for a 

change to the type certificate to include 

another model incorporating the same 

novel or unusual design feature, the 

special conditions would apply to that 

model as well. 

Conclusion 

This action affects only certain novel 

or unusual design features on one model 

series of airplane. 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 the Gulfstream 

Aerospace Corporation Model GVII– 

G500 airplane. 

In lieu of § 25.361(b) the following 

special conditions apply: 

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 that could result in a 

temporary loss of power or thrust, and 

b. The maximum acceleration of the 

engine. 

2. For auxiliary power unit (APU) 

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 APU deceleration due to 

malfunction or structural failure; and 

b. The maximum acceleration of the 

APU. 

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 separately, 

b. 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 special 

conditions 3(a) and 3(b), above, 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 

special condition 3, above, must not 

prevent continued safe flight and 

landing. 

Issued in Renton, Washington, on 

September 1, 2015. 

Michael Kaszycki, 

Acting Manager, Transport Airplane 

Directorate, Aircraft Certification Service. 

[FR Doc. 2015–23100 Filed 9–14–15; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2015–0926; Directorate 

Identifier 2014–NM–121–AD; Amendment 

39–18263; AD 2015–18–05] 

RIN 2120–AA64 

Airworthiness Directives; Airbus 

Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Final rule. 

SUMMARY: We are superseding 

Airworthiness Directive (AD) 97–07–14, 

for certain Airbus Model A320–111, 

–211, and –231 airplanes. AD 97–07–14 

required modification of an area on the 

front spar of the wing center section by 

installing shims and new fasteners to 

reinforce pressure floor fittings. This 

new AD continues to require modifying 

the rib flange on the front spar of the 

wing center section by installing shims 

and new fasteners to reinforce pressure 

floor fittings; and requires repetitive 

high frequency eddy current inspections 

for cracking of the radius of the rib 

flanges and vertical stiffener at frame 36, 

a rototest inspection for cracking of the 

fastener holes of the rib flanges, repair 

if needed, and adding additional 

airplanes to the applicability. This AD 

was prompted by the need for repetitive 

inspections on airplanes on which the 

modification of the rib flange on the 

front spar of the wing center section has 

been done. We are issuing this AD to 

prevent fatigue cracking on the rib 

flange area of the front spar of the wing 

center section, which can reduce the 

structural integrity of fuselage frame 36 

and the wing center section. 

DATES: This AD becomes effective 

October 20, 2015. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in this AD 

as of October 20, 2015. 

The Director of the Federal Register 

approved the incorporation by reference 

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