[Federal Register Volume 82, Number 122 (Tuesday, June 27, 2017)]
[Rules and Regulations]
[Pages 28993-28994]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-12937]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 33

[Docket No. FAA-2014-0376; Notice No. 33-014-01-SC]


Special Conditions: SNECMA, Silvercrest-2 SC-2D; Rated 10-Minute 
One Engine Inoperative Takeoff Thrust at High Ambient Temperature; 
Withdrawal

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; withdrawal.

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

SUMMARY: The FAA is withdrawing previously published special conditions 
for the Silvercrest-2 SC-2D engine model. We are requesting the 
withdrawal because the ``Rated 10-Minute One Engine Inoperative Takeoff 
Thrust at High Ambient Temperature (Rated 10-Minute OEI TOTHAT) is not 
needed.

[[Page 28994]]


DATES: As of June 27, 2017, the special conditions published on October 
31, 2014, at 79 FR 64666, are withdrawn.

FOR FURTHER INFORMATION CONTACT: Tara Fitzgerald, ANE-112, Engine and 
Propeller Directorate, Aircraft Certification Service, 1200 District 
Avenue, Burlington, Massachusetts, 01803-5213; telephone (781) 238-
7130; facsimile (781) 238-7199; email [email protected].

SUPPLEMENTARY INFORMATION: 

Background

    On April 19, 2011, SNECMA, now known as Safran Aircraft Engines 
(SAE) applied for a new type certificate for the Silvercrest-2 SC-2D 
engine model. At that time, the Silvercrest-2 SC-2D engine model was to 
have a novel or unusual design feature when compared to the state of 
technology described in the airworthiness standards for aircraft 
engines. The design feature included an additional takeoff rating for 
the Silvercrest-2 SC-2D engine model, named ``Rated 10-Minute One 
Engine Inoperative Takeoff Thrust at High Ambient Temperature'' (Rated 
10-Minute OEI TOTHAT). It was intended to maintain the takeoff thrust 
in certain high ambient temperature conditions for a maximum of 10 
minutes with one engine inoperative (OEI).

Reason for Withdrawal

    The FAA is withdrawing Notice No. 33-014-01-SC because of concerns 
raised over the sufficiency of the ``Rated 10-Minute OEI TOTHAT'' 
special condition to meet the Automatic Takeoff Thrust Control System 
(ATTCS) design requirement specified in Title 14, Code of Federal 
Regulations (14 CFR) part 25, section I25.5(b)(2).
    The proposed takeoff rating was for use during OEI events that 
occur during takeoff in high ambient temperature conditions, up to 5 
degrees Celsius hotter than the rated takeoff corner point. The 
assumptions for this rating are no longer valid and the ``Rated 10-
Minute OEI TOTHAT'' is not needed.

Conclusion

    This withdrawal does not preclude the FAA from issuing another 
notice on the subject matter in the future or committing the agency to 
any future course of action.

    Issued in Burlington, Massachusetts, on June 13, 2017.
Carlos A. Pestana,
Acting Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2017-12937 Filed 6-26-17; 8:45 am]
BILLING CODE 4910-13-P