Source: https://www.federalregister.gov/documents/2014/07/31/2014-18074/special-conditions-snecma-silvercrest-2-sc-2d-rated-10-minute-one-engine-inoperative-takeoff-thrust
Timestamp: 2017-08-19 02:24:50
Document Index: 756710230

Matched Legal Cases: ['art 1', '§\u200921', 'art 34', 'art 36', 'art 33', 'art 33', 'art 33', 'art 1', '§\u200933', '§\u200933', '§\u200933', 'art 33', '§\u200933', '§\u200933', '§\u200933', '§\u200933', '§\u200933', '§\u200933']

44321-44324 (4 pages)
Docket No.FAA-2014-0376
1. Part 1.1 Definitions.
https://www.federalregister.gov/d/2014-18074 https://www.federalregister.gov/d/2014-18074
Send comments identified by docket number [FAA-2014-0376] using any of the following methods:
For technical questions concerning this proposed rule, contact Tara Fitzgerald, ANE-111, Engine and Propeller Directorate, Aircraft Certification Service, 12 New England Executive Park, Burlington, Massachusetts, 01803-5213; telephone (781) 238-7130; facsimile (781) 238-7199. For legal questions concerning this proposed rule, contact Vincent Bennett, ANE-7, Engine and Propeller Directorate, Aircraft Certification Service, 12 New England Executive Park, Burlington, Massachusetts, 01803-5299; telephone (781) 238-7044; facsimile (781) 238-7055; email vincent.bennett@faa.gov.
We invite interested persons to participate in this rulemaking by submitting written comments, data, or views. The agency also invites comments relating to the economic, environmental, energy, or federalism impacts that might result from adopting the proposals in this document. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data. To ensure the docket does not contain duplicate comments, commenters should send only one copy of written comments, or if comments are filed electronically, commenters should submit only one time.
On April 19, 2011, SNECMA applied for a new type certificate (TC) for the Silvercrest-2 SC-2D engine model. On April 30, 2014, SNECMA requested an extension to their original TC application, which the FAA granted through June 30, 2015.
For their Silvercrest-2 SC-2D engine model, SNECMA requests an additional takeoff rating to maintain takeoff thrust in certain high ambient temperature conditions with OEI. Therefore, the Silvercrest-2 SC-2D engine model would have two different takeoff ratings. The first rating corresponds with the rated takeoff thrust of the engine. The second takeoff rating maintains the takeoff thrust in certain high ambient temperature conditions for a maximum of 10 minutes. This additional takeoff rating is named, “Rated 10-Minute OEI Takeoff Thrust at High Ambient Temperature” (Rated 10-minute OEI TOTHAT).
These special conditions are necessary because the applicable airworthiness regulations do not contain adequate or appropriate safety standards for the additional takeoff rating.
If the FAA finds that the regulations in effect on the date of the application for the change do not provide adequate or appropriate safety standards for the Start Printed Page 44322Silvercrest-2 SC-2D because of a novel or unusual design feature, special conditions are prescribed under the provisions of § 21.16.
In addition to complying with the applicable product airworthiness regulations and the requirements of these special conditions, the Silvercrest-2 SC-2D engine model must also comply with the fuel vent and exhaust emission requirements of 14 CFR part 34 and the noise certification requirements of 14 CFR part 36 in accordance with the “Noise Control Act of 1972.”
The Silvercrest-2 SC-2D engine model will incorporate the following novel or unusual design feature:
These proposed special conditions are necessary because current part 33 regulations do not contain airworthiness standards for airplane applications of OEI ratings. For an airplane application, the OEI rating is the same as the rated thrust of the engine. All OEI ratings in current part 33 regulations are only applicable to rotorcraft applications.
These proposed special conditions were modeled based on the rotorcraft requirements for the 30-second and 2-minute OEI ratings, and modified to represent the airplane application. The Rated 10-minute OEI TOTHAT is similar to the 30-second and 2-minute OEI ratings available in part 33 for rotorcraft engines. The Rated 10-minute OEI TOTHAT shares common features, such as the need to notify the pilot and maintenance personnel about the rating's use, provides data needed for power assurance check, and continued validation of the related maintenance procedures.
The Rated 10-minute OEI TOTHAT is for use during OEI events that occur during takeoff in high ambient temperature conditions, up to 5 degrees Celsius hotter than the rated takeoff thrust corner point. Under these unique conditions (extreme hot day and OEI), the Rated 10-minute OEI TOTHAT leads to an increase in EGT to maintain the takeoff thrust of the engine. These proposed special conditions contain additional mandatory post-flight inspection and maintenance action requirements associated with any use of the Rated 10-minute OEI TOTHAT. These requirements add a rating definition in part 1.1 and mandates mandatory inspections in the ICA; instructions for installing and operating the engine; engine rating and operating limitations; instrument connection; and endurance testing.
The current requirements of the endurance test under § 33.87 represent a typical airplane flight profile and the severity of the takeoff rating. Therefore, the endurance test under § 33.87 covers normal all-engines-operating takeoff conditions for which the engine control system limits the engine to the takeoff thrust rating. The proposed special conditions for the endurance testing requirements are intended to represent the airplane flight profile when an OEI event occurs during takeoff under specified ambient temperatures, and until the mandatory inspection and maintenance actions can be performed. These proposed special conditions require endurance testing that is not less than 135 minutes in duration and demonstrates the engine is capable of the additional Rated 10-minute OEI TOTHAT rating at the higher EGT limit following completion of the tests required by § 33.87(b), without disassembly or modification.
As discussed above, these special conditions are applicable to the Silvercrest-2 SC-2D engine model. Should SNECMA apply at a later date for a change to the type certificate to include another engine model incorporating the same novel or unusual design feature, these special conditions would apply to that model as well.
This action affects only the Rated 10-minute OEI TOTHAT features on the Silvercrest-2 SC-2D engine model. It is not a rule of general applicability and applies only to SNECMA, who requested FAA approval of this engine feature.
Accordingly, the FAA proposes the following special conditions as part of the type certification basis for the SNECMA Silvercrest-2 SC-2D engine model.
“Rated 10-Minute One Engine Inoperative Take-off Thrust at High Ambient Temperature” (Rated 10-minute OEI TOTHAT) means the approved engine thrust developed under specified altitudes and temperatures within the operating limitations established for the engine, and for continuation of flight operation after failure or shutdown of one engine in a multi-engine airplane during takeoff operation. Use is limited to two periods, no longer than 10 minutes each in any one flight, and followed by mandatory inspection and maintenance actions.
In addition to the airworthiness standards in 14 CFR part 33, effective Start Printed Page 44323February 1, 1965, Amendments 33-1 through 33-31 applicable to the engine and the Rated 10-minute OEI TOTHAT, the following special conditions apply:
(2) As required by § 33.5(b), Operating instructions, include a note stating that “Rated 10-Minute One Engine Inoperative Take-off Thrust at High Ambient Temperature” (Rated 10-minute OEI TOTHAT) means the approved engine thrust developed under specified altitudes and temperatures within the operating limitations established for the engine, and for continuation of flight operation after failure or shutdown of one engine in multi-engine airplane during takeoff operation. Use is limited to two periods, no longer than 10 minutes each in any one flight, and followed by mandatory inspection and maintenance actions.
(a) The engine must incorporate a means, or a provision for a means, for automatic availability and automatic control of the Rated 10-minute OEI TOTHAT.
(b) The engine controls managing the OEI takeoff thrust for all ambient conditions must assure that:
(1) The approved rated takeoff thrust is available to the pilot at all times by throttle selection, and
(2) The Rated 10-minute OEI TOTHAT is only available in an OEI condition at specified altitudes and temperatures.
(1) Have means or provisions for means, to alert the pilot when the Rated 10-minute OEI TOTHAT is in use, when the event begins, and when the time interval expires.
(iii) Have means, or provision for means, to enable routine verification of the proper operation of the means in §§ 33.29(1) and (2) of these special conditions.
(a) Following completion of the tests required by § 33.87(b), and without intervening disassembly, except as needed to replace those parts described as consumables in the ICA, the applicant must conduct the following test sequence for a total time of not less than 135 minutes:
(2) Sixty-five minutes at maximum continuous thrust,
(3) One minute at 50 percent of takeoff thrust,
(7) Five minutes at maximum continuous thrust,
(8) One minute at 50 percent of takeoff thrust,
(12) Five minutes at maximum continuous thrust,
(13) One minute at 50 percent of takeoff thrust,
(b) The test sequence of §§ 33.87(a)(1) through (a)(15) of these special conditions must be run continuously. If a stop occurs during these tests, the interrupted sequence must be repeated unless the applicant shows that the severity of the test would not be reduced if the current tests were continued.
(c) Where the engine characteristics are such that acceleration to the Rated Start Printed Page 4432410-minute OEI TOTHAT results in a transient overtemperature in excess of the steady-state temperature limit identified in § 33.7(a)(3) of these special conditions, the transient gas overtemperature must be applied to each acceleration to the Rated 10-minute OEI TOTHAT of the test sequence in § 33.87(a) of these special conditions.
Issued in Burlington, Massachusetts, on July 11, 2014.
[FR Doc. 2014-18074 Filed 7-30-14; 8:45 am]