Voglio sapere a riguardo di…

lotter on DSK11XQN23PROD with RULES3

53512

Federal Register / Vol. 86, No. 184 / Monday, September 27, 2021 / Rules and Regulations
Special Condition No. 3, Materials The FAA proposed that Special Condition no. 3 would require the design of these engines to comply with 14 CFR 33.15, which sets requirements for the suitability and durability of materials used in the engine, and which would otherwise be applicable only to reciprocating and turbine aircraft engines.
Comment Summary: Textron highlighted the potential hazards from certain electronic components, such as aging electrolytic capacitors. Textron recommended that the FAA require periodic testing of electrolytic capacitors to determine an appropriate replacement interval to avoid hazardous effects at altitude such as breakdown, corona, flashover, creep, strike distance, and cooling.
FAA Response: These special conditions address the hazards that may result from failure or malfunction of electronic components. Special Condition no. 27 System and component tests is a performance-based requirement in which the applicant must show that systems and components will perform their intended functions in all declared environmental and operating conditions. This requirement addresses all types of component failures, including those referenced in Textrons comment.
Special Condition no. 13 Critical and life-limited parts requires the applicant to show, by a safety analysis or means acceptable to the Administrator, whether rotating or moving components, bearings, shafts, static parts, and non-redundant mount components should be classified, designed, manufactured, and managed throughout their service life as critical or life-limited parts, including electronic parts and components.
Special Condition no. 10g Engine control systems requires the applicant to conduct a control system safety assessment to identify the hazards resulting from control system failures and malfunctions, such as those in Textrons comment. The FAA made no changes to these special conditions as a result of this comment.
Comment Summary: TCCA
recommended that these special conditions address the potential for manufacturing errors by appending the following text: In addition, manufacturing methods and processes must be such as to produce sound structure and mechanisms, and electrical systems that retain the design properties under assumed service conditions declared in the engine installation manual. This includes the
VerDate Sep<11>2014

19:16 Sep 24, 2021

Jkt 253001

effects of deterioration over time, e.g., corrosion.
FAA Response: The 14 CFR part 33
airworthiness requirement for materials 33.15 applies to these engines. The existing part 33 materials requirement is adequate and appropriate for the certification basis for these engines. The FAA made no changes to the special condition as a result of the comment.
Special Condition No. 4, Fire Protection The FAA proposed that Special Condition no. 4 would require the design of these engines to comply with 14 CFR 33.17, which sets requirements to protect the engine and certain parts and components of the airplane against fire, and which would otherwise be applicable only to reciprocating and turbine aircraft engines. Additionally, this special condition proposed to require magniX to ensure the highvoltage electrical wiring interconnect systems that connect the controller to the motor are protected against arc faults. An arc fault is a high power discharge of electricity between two or more conductors. This discharge generates heat, which can break down the wires insulation and trigger an electrical fire. Arc faults can range in power from a few amps to thousands of amps and are highly variable in strength and duration.
Comment Summary: GE proposed that the special conditions include a provision for non-protected electrical wiring interconnects that requires the applicant to conduct an analysis to show that arc faults do not cause hazardous engine effects. GE stated that if electrical wiring interfaces with aircraft parts or components, the potential for arc faults should be communicated to the aircraft manufacturer. In addition, GE
recommended that the FAA require the applicant to declare potential arc faults in the engine installation manual.
FAA Response: This special condition has provisions to prevent arc faults in high-voltage wire interconnecting systems from causing hazardous engine effects. Additionally, Special Condition no. 17 Safety analysis will have the effect of requiring magniX to account for the intended aircraft application in the engine installation manual. 14 CFR
33.5c, Instruction manual for installing and operating the engine, applies to the two magniX engines.
These requirements will generate the recommended documentation, such as installation instructions. The FAA made no changes to the special condition as a result of the comment.
Comment Summary: TCCA stated that no special conditions provide standards
PO 00000

Frm 00006

Fmt 4701

Sfmt 4700

for the electrical connectors supplied with the motor. TCCA requested clarification of the FAAs intent.
FAA Response: The special condition is a performance-based requirement, which allows flexibility for magniX to design and substantiate components such as connectors that they use in their engine design. The FAA made no changes to the special condition as a result of the comment.
Special Condition No. 5, Durability The FAA proposed that Special Condition no. 5 would require the engine design and construction to ensure safe engine operation between maintenance intervals, overhaul periods, and mandatory actions described in the applicable ICA.
Comment Summary: Textron noted that the proposed wording of Special Condition no. 5 matched the intent of 14
CFR 33.19a but omitted the requirements of 33.19b. Textron suggested that Special Condition no. 5
include the following: Each component of the propeller-blade pitch control system which is part of the engine type design must meet the requirements of 35.21, 35.23, 35.42 and 35.43.
TCCA provided a similar comment, asking why 33.19b was omitted and seeking its inclusion in Special Condition no. 5.
FAA Response: These special conditions apply only to the two magniX engine designs, which do not include a propeller-blade pitch control system. The FAA made no changes to the special condition as a result of the comments.
Comment Summary: TCCA
recommended that the FAA include the requirements from 14 CFR 33.5b into these special conditions, as the controller may include propeller control functions.
FAA Response: These special conditions apply only to the proposed magniX engine designs, which do not include propeller controls and controllers. In addition, Special Condition no. 1 mandates compliance with 33.5b, Instruction manual for installing and operating the engine, which addresses this comment. The FAA made no changes to the special condition as a result of the comment.
Comment Summary: TCCA stated the requirements from 14 CFR 33.4 are missing from these special conditions, but noted that including all instructions for off-wing maintenance that were contained in the ICA, would not be appropriate.
FAA Response: These special conditions are not intended for all electric engine certification projects. As
E:FRFM27SER3.SGM

27SER3