Federal Register - September 27, 2021
Versione di testo Cosa è?Dateas è un sito indipendente non affiliato a entità governative. La fonte dei documenti PDF che pubblichiamo qui è l'entità governativa indicata in ciascuno di essi. Le versioni in testo sono trascrizioni che realizziamo per facilitare l'accesso e la ricerca di informazioni, ma possono contenere errori o non essere complete.
Source: Federal Register
lotter on DSK11XQN23PROD with RULES3
53522
Federal Register / Vol. 86, No. 184 / Monday, September 27, 2021 / Rules and Regulations
necessary requirements to achieve the safety analysis goals. EASA provided a similar comment and recommendation.
FAA Response: In response to these comments, the FAA has changed final Special Condition no. 17b to ensure all the applicable integrity requirements are applied to magniX engine parts that can fail and are likely to result in hazardous engine effects.
Comment Summary: GE commented that the definitions of major and minor engine effects, as mentioned in Special Condition nos. 17d1, 17d2, and 17d3 are ambiguous, leaving a wide gap in the failure types that could be classified as hazardous or major engine effects. GE also commented that there is no probability requirement for major engine effects like there is in 14 CFR 33.75a4. GE
recommended that the FAA clarify the definitions of major and minor engine effects, and include a probability requirement to ensure a level of safety commensurate with the current regulations.
FAA Response: These special conditions are not generally applicable to all electric engines. They apply only to these proposed magniX engines. The FAA acknowledges many possible outcomes to the engine safety analysis, including the failure classifications.
Failure classification and probabilities for the engine and certain electronic components are still needed, but the failure classifications and reliability thresholds will account for the aircrafts capabilities. Special Condition no. 17
does not specify the engine failure effects that could be classified as major because aircrafts capabilities can affect the failure classification.
As a result of this comment, the FAA
modified final Special Condition nos.
17d1 and 17d3 to clarify the differences between major and minor engine failure effects. The FAA also added final Special Condition no. 17e to account for the potential influence aircraft capabilities may have on the engine safety analysis.
Comment Summary: Ampaire recommended adding criteria from the industry standard ASTM F333818, sections 5.18.1 through 5.18.6, to Special Condition no. 17.
FAA Response: ASTM F333818
contains technical criteria that the FAA
incorporated in these special conditions. It also contains information that the applicant can use to develop a means of compliance to these special conditions. The FAA did not change these special conditions as a result of this comment.
Comment Summary: Textron stated that electrical-component manufacturers
VerDate Sep<11>2014
19:16 Sep 24, 2021
Jkt 253001
typically do not know how their components will be used or the implications to safety when changes are made to the design and manufacturing process. Textron recommended modifying Special Condition no. 17c to state: In addition, if electrical components of a safety system are outside the control of the engine manufacturer, then the manufacturer must implement a component tracking system to monitor component revisions, change of manufacture, counterfeit parts, and component end of life EOL.
FAA Response: Textrons comment identified a need for engine-level configuration control. The FAA
acknowledges that a products end-user could affect the intended engine configuration through parts manufacturer approvals and supplemental type certificates.
However, the FAA imposed Special Condition no. 1, which mandates magniXs compliance with14 CFR
33.5a5, 33.5c, and 33.75 d to manage non-OEM engine configurations. The FAA made no changes to the special condition as a result of the comment.
Comment Summary: Safran noted that Special Condition no. 17a requires magniX to comply with 14 CFR
33.75a3, which establishes a fixed numerical value of 107 per flight hour for extremely remote; a number that might exceed the aircraft safety objectives. For example, extremely remote for a part 23/Level 1 aircraft application is rated at 105 per flight hour, not 107. EASA shared Safrans concern and recommended that the FAA use the EASA SC E18 9 to establish engine safety objectives that are proportional to the safety objectives of the intended aircraft when they are equipped with the magniX engines.
FAA Response: Both comments presume the general applicability of the proposed special conditions. These special conditions apply only to magniXs two proposed engine models.
The aircraft that will use the magniX
engines do not include Part 23/Level 1
aircraft. However, the FAA
acknowledges that acceptable engine failure rates could vary depending on the aircrafts configuration and capabilities. Therefore, the FAA
removed reference to 33.75a3 from Special Condition no. 17a. Also, The FAA changed final Special Condition no. 10g and added Special Condition 9 https www.easa.europa.eu/sites/default/files/
dfu/sc_e-18_electric_propulsion_units_for_cs-23_
normal-category_aeroplanes_u.pdf.
PO 00000
Frm 00016
Fmt 4701
Sfmt 4700
no. 17e to require magniX to account for the intended aircraft application.
Comment Summary: TCCA stated the term electrocution is defined as to kill with electricity and recommended that the FAA change the term electrocution in this special condition to electric shock or injury from electric shock.
FAA Response: The FAA does not agree with the comment. The term electrocution, as used in these special conditions, is consistent with the risk of serious injury or fatality caused by electric shock.
Comment Summary: TCCA asked the FAA to explain why proposed Special Condition no. 17 did not include the requirement for major failure rates in 14
CFR 33.75a4.
FAA Response: To account for the potential dependency between the electric engine safety analysis and the aircraft capabilities, the FAA did not prescribe failure rates for major engine failures. Special Condition no. 10g and Special Condition no. 17e require magniX to account for the intended aircraft application. magniX will still need to classify major failures for the engine and certain electronic components, but the failure rates will account for aircraft capabilities. The FAA has changed the special condition as a result of this comment.
Comment Summary: TCCA asked the FAA to consider requiring the applicants safety analysis to analyze uncontrollable high thrust and potential physical separation of the engine from the aircraft.
FAA Response: The FAA understands TCCAs reference to uncontrollable high thrust to mean a higher thrust than the commanded thrust or a thrust that is above a limit value. Special Condition no. 10f1 requires a maximum LOPC
rate for the intended aircraft that will use the magniX engines, and magniX
will need to show how they comply with those rates. Special Condition no.
17d2 requires magniX to comply with 14 CFR 33.75g2v, which addresses the physical separation of the engine from the aircraft. The FAA did not change this special condition as a result of this comment.
Comment Summary: TCCA suggested that the FAA require magniX to show that a cooling loss will not result in a hazardous engine effect or that blockage cannot lead to a cooling failure. TCCAs comment was directed to Special Condition no. 18 in the context of protecting the cooling inlet from ingestion.
FAA Response: In response to TCCAs comment, the FAA has included a requirement in Special Condition no.
E:FRFM27SER3.SGM
27SER3
