63822 Federal Register / Vol. 76, No. 199 / Friday, October 14, 2011 / Rules and Regulations 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. FAA–2011–1107; Special 

Conditions No. 25–447–SC] 

Special Conditions: Gulfstream 

Aerospace LP (GALP) Model G280 

Airplane, Limit Engine Torque Loads 

for Sudden Engine Stoppage 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final special conditions; request 

for comments. 

SUMMARY: These special conditions are 

issued for the Gulfstream Aerospace LP 

(GALP) model G280 airplane. This 

airplane will have a novel or unusual 

design feature associated with engine 

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 October 6, 2011. 

We must receive your comments by 

November 28, 2011. 

ADDRESSES: You must mail two copies 

of your comments to: Federal Aviation 

Administration, Transport Airplane 

Directorate, Attn: Rules Docket (ANM– 

113), Docket No. FAA–2011–1107, 1601 

Lind Avenue, SW., Renton, Washington 

98057–3356. You may deliver two 

copies to the Transport Airplane 

Directorate at the above address. You 

must mark your comments: Docket No. 

FAA–2011–1107. You can inspect 

comments in the Rules Docket 

weekdays, except Federal holidays, 

between 7:30 a.m. and 4 p.m. 

FOR FURTHER INFORMATION CONTACT: Carl 

Niedermeyer, Transport Airplane 

Directorate, Aircraft Certification 

Service, 1601 Lind Avenue, SW., 

Renton, Washington 98057–3356; 

telephone (425) 227–2279; facsimile 

(425) 227–1149. 

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 aircraft. 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 ask that you send 

us two copies of written comments. 

We will file in the docket all 

comments we receive, as well as a 

report summarizing each substantive 

public contact with FAA personnel 

about these special conditions. You can 

inspect the docket before and after the 

comment closing date. If you wish to 

review the docket in person, go to the 

address in the ADDRESSES section of this 

preamble between 7:30 a.m. and 4 p.m., 

Monday through Friday, except Federal 

holidays. 

We will consider all comments we 

receive by the closing date for 

comments. We may change these special 

conditions based on the comments we 

receive. 

If you want us to acknowledge receipt 

of your comments on these special 

conditions, include with your 

comments a self-addressed, stamped 

postcard on which you have written the 

docket number. We will stamp the date 

on the postcard and mail it back to you. 

Background 

On March 30, 2006, GALP applied for 

a type certificate for their new Model 

G280 airplane. The G280 is an 8- to 10- 

passenger (19 maximum), twin-engine 

airplane with a 41,000-foot cruise 

altitude, maximum operating altitude of 

45,000 feet, and a range of 

approximately 3,400 nautical miles. 

Type Certification Basis 

Under the provisions of 14 CFR 21.17, 

GALP must show that the Model G280 

airplane meets the applicable provisions 

of part 25 as amended by Amendments 

25–1 through 25–117. 

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 G280 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 novel or unusual 

design feature, the special conditions 

would also apply to the other model. 

In addition to the applicable 

airworthiness regulations and special 

conditions, the Model G280 airplane 

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; and the 

FAA must issue a finding of regulatory 

adequacy under § 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). 

Novel or Unusual Design Features 

The GALP Model G280 airplane 

incorporates a novel or unusual design 

feature involving engine size and related 

torque load that affect sudden enginestoppage conditions. 

Discussion 

The size, configuration, and failure 

modes of jet engines have changed 

considerably from those envisioned by 

14 CFR 25.361(b), when the engineseizure requirement was first adopted. 

Engines have become larger and are now 

designed with large bypass fans capable 

of producing much larger and more 

complex dynamic loads. Relative to the 

engine configurations that existed when 

the rule was developed in 1957, the 

present generation of engines is 

sufficiently different and novel to justify 

issuance of a special condition to 

establish appropriate design standards 

for the GALP Model G280 airplane type 

design. 

Consideration of the limit engine 

torque load imposed by sudden engine 

stoppage due to malfunction or 

structural failure (such as compressor 

jamming) has been a specific 

requirement for transport-category 

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 and pure 

torque static loads. 

It is evident from service history that 

the engine-failure events that tend to 

cause the most severe loads are fanblade failures, which occur much less 

frequently than the typical ‘‘limit’’ load 

condition. 

The regulatory authorities and 

industry have developed a standardized 

requirement in the Aviation Rulemaking 

Advisory Committee (ARAC) forum. 


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Federal Register / Vol. 76, No. 199 / Friday, October 14, 2011 / Rules and Regulations 63823 

The technical aspects of this 

requirement have been agreed upon and 

have been accepted by the ARAC Loads 

and Dynamics Harmonization Working 

Group, and incorporated in EASA CS– 

25. The proposed special conditions 

outlined below reflect the ARAC 

recommendation and CS–25. In 

addition, the ARAC recommendation 

includes corresponding advisory 

material that is considered an 

acceptable means of compliance to the 

proposed special conditions outlined 

below. 

To maintain the level of safety 

envisioned by § 25.361(b), more 

comprehensive criteria are needed for 

the new generation of high-bypass 

engines. These proposed special 

conditions would distinguish between 

the more-common engine-failure events 

and those rare events resulting from 

structural failures. The more-common 

events would continue to be treated 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), would be treated as full 

dynamic-load conditions. These would 

be considered ultimate loads, and 

include all transient loads associated 

with the event. An additional safety 

factor would be applied to the morecritical airframe supporting structure. 

Applicability 

As discussed above, these special 

conditions are applicable to the GALP 

Model G280 airplane. Should GALP 

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 

of airplane. It is not a rule of general 

applicability. 

Under standard practice, the effective 

date of final special conditions would 

be 30 days after the date of publication 

in the Federal Register. However, as the 

certification date for the GALP Model 

G280 airplane is imminent, the FAA 

finds that good cause exists to make 

these special conditions effective upon 

issuance. 

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 typecertification basis for GALP Model G280 

airplane. 

In lieu of 14 CFR 25.361(b), the 

following special conditions are 

proposed: 

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 (APU) 

installations, the APU 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 paragraphs 

3(a) and 3(b) of these special conditions 

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 of these special conditions 

must not prevent continued safe flight 

and landing. 

Issued in Renton, Washington, on October 

6, 2011. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. 2011–26557 Filed 10–13–11; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 25 

[Docket No. NM457; Notice No. 25–449–SC] 

Special Conditions: Gulfstream 

Aerospace LP (GALP) Model G280 

Airplane Pilot-Compartment View— 

Hydrophobic Coatings in Lieu of 

Windshield Wipers 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final special conditions. 

SUMMARY: These special conditions are 

issued for the Gulfstream Aerospace LP 

(GALP) Model G280 airplane. This 

airplane will have a novel or unusual 

design feature associated with the pilotcompartment view through a 

hydrophobic windshield coating, in lieu 

of windshield wipers. 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: Effective Date: November 14, 

2011. 

FOR FURTHER INFORMATION CONTACT: 

Loran Haworth, Transport Airplane 

Directorate, Aircraft Certification 

Service, 1601 Lind Avenue, SW., 

Renton, Washington 98057–3356; 

telephone (425) 227–1133; facsimile 

(425) 227–1149. 

SUPPLEMENTARY INFORMATION: 

Background 

On March 30, 2006, GALP applied for 

a type certificate for their new Model 

G280 airplane. The G280 is an 8–10 

passenger (19 maximum), twin-engine 

airplane with a 41,000-foot cruise 

altitude, a maximum operating altitude 

of 45,000 feet, and a range of 

approximately 3,400 nautical miles. 

Type Certification Basis 

Under the provisions of Title 14, Code 

of Federal Regulations (14 CFR) 21.17, 

GALP must show that the Model G280 

airplane meets the applicable provisions 

of part 25 as amended by Amendments 

25–1 through 25–117. 

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 G280 airplane because of 

a novel or unusual design feature, 

special conditions are prescribed under 

the provisions of § 21.16. 


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