Special Conditions: Mitsubishi Aircraft Corporation Model MRJ-200 Airplane; Use of Automatic Power Reserve for Go-Around Performance Credit, 15780-15784 [2021-06027]

Download as PDF 15780 Federal Register / Vol. 86, No. 56 / Thursday, March 25, 2021 / Rules and Regulations Amendment of the records could interfere with ongoing investigations and law enforcement activities and would impose an unreasonable administrative burden by requiring investigations to be continually reinvestigated. In addition, permitting access and amendment to such information could disclose security-sensitive information that could be detrimental to homeland security. (c) From subsection (e)(1) (Relevancy and Necessity of Information) because in the course of investigations into potential violations of federal law, the accuracy of information obtained or introduced occasionally may be unclear, or the information may not be strictly relevant or necessary to a specific investigation. In the interests of effective law enforcement, it is appropriate to retain all information that may aid in establishing patterns of unlawful activity. (d) From subsection (e)(2) (Collection of Information from Individuals) because requiring that information be collected from the subject of an investigation would alert the subject to the nature or existence of the investigation, thereby interfering with that investigation and related law enforcement activities. (e) From subsection (e)(3) (Notice to Subjects) because providing such detailed information could impede law enforcement by compromising the existence of a confidential investigation or reveal the identity of witnesses or confidential informants. (f) From subsections (e)(4)(G) through (I) (Agency Requirements) and (f) (Agency Rules), because portions of this system are exempt from the individual access provisions of subsection (d) for the reasons noted above, and therefore DHS is not required to establish requirements, rules, or procedures with respect to such access. Providing notice to individuals with respect to existence of records pertaining to them in the system of records or otherwise setting up procedures pursuant to which individuals may access and view records pertaining to themselves in the system would undermine investigative efforts and reveal the identities of witnesses, and potential witnesses, and confidential informants. (g) From subsection (e)(5) (Collection of Information) because with the collection of information for law enforcement purposes, it is impossible to determine in advance what information is accurate, relevant, timely, and complete. Compliance with subsection (e)(5) would preclude DHS agents from using their investigative training and exercise of good judgment to both conduct and report on investigations. (h) From subsection (e)(8) (Notice on Individuals) because compliance would interfere with DHS’s ability to obtain, serve, and issue subpoenas, warrants, and other law enforcement mechanisms that may be filed under seal and could result in disclosure of investigative techniques, procedures, and evidence. VerDate Sep<11>2014 16:53 Mar 24, 2021 Jkt 253001 (i) From subsection (g)(1) (Civil Remedies) to the extent that the system is exempt from other specific subsections of the Privacy Act. * * * * * James Holzer, Acting Chief Privacy Officer, U.S. Department of Homeland Security. [FR Doc. 2021–05941 Filed 3–24–21; 8:45 am] BILLING CODE 4410–10–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 25 [Docket No. FAA–2020–0721; Special Conditions No. 25–785–SC] Special Conditions: Mitsubishi Aircraft Corporation Model MRJ–200 Airplane; Use of Automatic Power Reserve for Go-Around Performance Credit Federal Aviation Administration (FAA), DOT. ACTION: Final special conditions; request for comments. AGENCY: These special conditions are issued for the Mitsubishi Aircraft Corporation (MITAC) Model MRJ–200 airplane. This airplane will have a novel or unusual design feature when compared to the state of technology envisioned in the airworthiness standards for transport-category airplanes. This design feature is an Automatic Takeoff Thrust Control System (ATTCS), referred to as an Automatic Power Reserve (APR), to set the performance level for approachclimb operation after an engine failure. 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: This action is effective on MITAC on March 25, 2021. Send comments on or before May 10, 2021. ADDRESSES: Send comments identified by Docket No. FAA–2020–0721 using any of the following methods: • Federal eRegulations Portal: Go to http://www.regulations.gov/ and follow the online instructions for sending your comments electronically. • Mail: Send comments to Docket Operations, M–30, U.S. Department of Transportation (DOT), 1200 New Jersey Avenue SE, Room W12–140, West Building Ground Floor, Washington, DC 20590–0001. SUMMARY: PO 00000 Frm 00002 Fmt 4700 Sfmt 4700 • Hand Delivery or Courier: Take comments to Docket Operations in Room W12–140 of the West Building Ground Floor at 1200 New Jersey Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. • Fax: Fax comments to Docket Operations at 202–493–2251. • Privacy: Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in 14 CFR 11.35, the FAA will post all comments received without change, to http:// www.regulations.gov/, including any personal information you provide. The FAA will also post a report summarizing each substantive verbal contact received about this proposal. • Confidential Business Information: Confidential Business Information (CBI) is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this Notice contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this Notice, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as ‘‘PROPIN.’’ The FAA will treat such marked submissions as confidential under the FOIA, and the indicated comments will not be placed in the public docket of this Notice. Send submissions containing CBI to the person indicated in the Contact section below. Comments the FAA receives, which are not specifically designated as CBI, will be placed in the public docket for this rulemaking. • Docket: Background documents or comments received may be read at http://www.regulations.gov/ at any time. Follow the online instructions for accessing the docket or go to Docket Operations in Room W12–140 of the West Building Ground Floor at 1200 New Jersey Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. FOR FURTHER INFORMATION CONTACT: Joe Jacobsen, Performance and Environment Section, AIR–625, Technical Innovation Policy Branch, Policy and Innovation Division, Aircraft Certification Service, Federal Aviation Administration, 2200 South 216th Street, Des Moines, Washington 98198; telephone and fax 206–231–3158; email joe.jacobsen@ faa.gov. E:\FR\FM\25MRR1.SGM 25MRR1 Federal Register / Vol. 86, No. 56 / Thursday, March 25, 2021 / Rules and Regulations The substance of these special conditions has been published in the Federal Register for public comment in several prior instances with no substantive comments received. Therefore, the FAA has determined that prior public notice and comment are unnecessary, and finds that, for the same reason, good cause exists for adopting these special conditions upon publication in the Federal Register. SUPPLEMENTARY INFORMATION: Comments Invited The FAA invites 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. The FAA will consider all comments received by the closing date for comments. The FAA may change these special conditions based on the comments received. Background On March 3, 2015, MITAC applied for a type certificate for their new Model MRJ–200 airplane. This airplane is a twin-engine, transport-category airplane with seating for 92 passengers and a maximum takeoff weight of 98,767 pounds. Type Certification Basis Under the provisions of title 14, Code of Federal Regulations (14 CFR) 21.17, the applicant must show that the airplane meets the applicable provisions of 14 CFR part 25, as amended by amendments 25–1 through 25–141. If the Administrator finds that the applicable airworthiness regulations (e.g., 14 CFR part 25) do not contain adequate or appropriate safety standards for the MITAC Model MRJ–200 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, these special conditions would also apply to the other model under § 21.101. In addition to the applicable airworthiness regulations and special conditions, the MITAC Model MRJ–200 airplane must comply with the fuel-vent and exhaust-emission requirements of 14 CFR part 34, and the noise- VerDate Sep<11>2014 16:53 Mar 24, 2021 Jkt 253001 certification requirements of 14 CFR part 36. 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 MITAC Model MRJ–200 airplane will incorporate the following novel or unusual design feature: An Automatic Takeoff Thrust Control System, referred to as an Automatic Power Reserve, to set the performance level for approach-climb operation after an engine failure. Discussion MITAC included an APR system (an ATTCS) in the Model MRJ–200 airplane and proposed using the APR function during go-around. They also requested approach-climb performance credit for the use of additional thrust set by the APR system. The MITAC Model MRJ– 200 powerplant control system comprises a Full Authority Digital Engine Control (FADEC) for the engine. The engine FADEC system utilizes the APR function during the takeoff and goaround phases of the flight when additional thrust is needed from an operating engine following a single engine failure. The APR system is available at all times, without any additional action from the pilot. It allows the pilot to use the same powersetting procedure during a go-around regardless of whether or not an engine fails. Because the APR system is always armed, it will function automatically following an engine failure, and advance the remaining engine to a higher thrust level. The part 25 standards for ATTCS, contained in § 25.904, and appendix I to part 25, specifically restrict performance credit for ATTCS to takeoff. Expanding the standards to include other phases of flight, including go-around, was considered at the time the standards were issued, but flightcrew workload issues precluded further consideration. As the preamble of amendment 25–62 states: In regard to ATTCS credit for approach-climb and go-around maneuvers, current regulations preclude a higher power for the approach climb (§ 25.121(d)) than for the landing climb (§ 25.119). The workload required for the flightcrew to monitor and select from multiple in-flight power settings in the event of an engine failure during a critical point in the approach, landing, or go-around operations is excessive. Therefore, the amendment should not PO 00000 Frm 00003 Fmt 4700 Sfmt 4700 15781 include the use of ATTCS for anything except the takeoff phase. Because the airworthiness regulations do not contain appropriate safety standards to allow approach-climb performance credit for ATTCS, special conditions are required to ensure a level of safety equivalent to that established in the regulations. The definition of a critical time interval for the approachclimb case, during which time it must be extremely improbable to violate a flight path based on the § 25.121(d) gradient requirement, is of primary importance. In the event of a simultaneous failure of both an engine and the APR function, falling below the minimum flight path defined by the 2.5degree approach, decision height, and climb gradient required by § 25.121(d) must be shown to be an extremely improbable event during this critical time interval. The § 25.121(d) gradient requirement implies a minimum oneengine-inoperative flight path capability with the airplane in the approach configuration. The engine may have been inoperative before initiating the goaround, or it may become inoperative during the go-around. The definition of the critical time interval must consider both possibilities. 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. Applicability As discussed above, these special conditions are applicable to the MITAC Model MRJ–200 airplane. Should MITAC apply at a later date for a change to the type certificate to include another model incorporating the same novel or unusual design feature, these special conditions would apply to that model as well. Conclusion This action affects only a certain novel or unusual design feature on one model of airplanes. It is not a rule of general applicability. List of Subjects in 14 CFR Part 25 Aircraft, Aviation safety, Reporting and recordkeeping requirements. Authority Citation The authority citation for these special conditions is as follows: Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701, 44702, 44704. The Special Conditions Accordingly, pursuant to the authority delegated to me by the E:\FR\FM\25MRR1.SGM 25MRR1 15782 Federal Register / Vol. 86, No. 56 / Thursday, March 25, 2021 / Rules and Regulations Administrator, the following special conditions are issued as part of the type certification basis for MITAC Model MRJ–200 airplanes. 1. The MITAC Model MRJ–200 airplane must comply with the requirements of 14 CFR 25.904, and appendix I, and the following requirements for the go-around phase of flight: 2. Definitions a. Takeoff/go-around (TOGA): Throttle lever in takeoff or go-around position. b. Automatic Takeoff Thrust Control System: The ATTCS in MITAC Model MRJ–200 airplanes is defined as the entire automatic system available during takeoff and in go-around mode, including all devices, both mechanical and electrical, that sense engine failure, transmit signals, actuate fuel controls or power levers (or increase engine power by other means on operating engines to achieve scheduled thrust or power increase), and furnish cockpit information on system operation. c. Critical time interval: VerDate Sep<11>2014 16:53 Mar 24, 2021 Jkt 253001 (1) When conducting an approach for landing using ATTCS, the critical time interval is defined as follows: (i) The critical time interval begins at a point on a 2.5-degree approach glide path from which, assuming a simultaneous engine and ATTCS failure, the resulting approach-climb flight path intersects a flight path originating at a later point on the same approach path that corresponds to the part 25 one-engine-inoperative approach-climb gradient. The period of time from the point of simultaneous engine and ATTCS failure, to the intersection of these flight paths, must be no shorter than the time interval used in evaluating the critical time interval for takeoff, beginning from the point of simultaneous engine and ATTCS failure and ending upon reaching a height of 400 feet. (ii) The critical time interval ends at the point on a minimum performance, all-engines-operating go-around flight path from which, assuming a simultaneous engine and ATTCS failure, the resulting minimum PO 00000 Frm 00004 Fmt 4700 Sfmt 4700 approach-climb flight path intersects a flight path corresponding to the part 25 minimum one-engine-inoperative approach-climb gradient. The allengines-operating go-around flight path, and the part 25 one-engine-inoperative approach-climb gradient flight path, originate from a common point on a 2.5degree approach path. The period of time from the point of simultaneous engine and ATTCS failure, to the intersection of these flight paths, must be no shorter than the time interval used in evaluating the critical time interval for the takeoff, beginning from the point of simultaneous engine and ATTCS failure and ending upon reaching a height of 400 feet. (2) The critical time interval must be determined at the altitude resulting in the longest critical time interval for which one-engine-inoperative approachclimb performance data are presented in the airplane flight manual. (3) The critical time interval is illustrated in Figure 1: BILLING CODE 4910–13–P E:\FR\FM\25MRR1.SGM 25MRR1 Federal Register / Vol. 86, No. 56 / Thursday, March 25, 2021 / Rules and Regulations 15783 ,.._____ •-------1~ Engine failed, ATTCS operating 25.121 (d) Gradient Requirement " The engine and ATTCS failed time Interval muat be no lhorter than the time lnteival from the point or simultaneous engine and ATTCS falure to a height or 400 feet used to comply with 125.2(b) fOr A TICS use during takeoff. Figure 1: Go-around ATTCS r 1 125,Z(b) Tim• Interval FG lleliht above nmway .urla«i (ft.) .• ..• . • • --.;1secr"'I:•. . .:• ..• Critical time bltenal BILLING CODE 4910–13–C The all-engines-operating go-around flight path, and the part 25 one-engineinoperative approach-climb gradient flight path (engine failed, ATTCS operating path in Figure 1), originate from a common point, point C, on a 2.5- VerDate Sep<11>2014 16:53 Mar 24, 2021 Jkt 253001 degree approach path. The period of time, ‘‘time interval DE,’’ from the point of simultaneous engine and ATTCS failure, point D, to the intersection of these flight paths, point E, must be no PO 00000 Frm 00005 Fmt 4700 Sfmt 4700 shorter than the corresponding time in Figure 2, above. d. The ‘‘critical time interval AD’’ is illustrated in Figure 1. 3. Performance and system reliability requirements: The applicant must comply with the performance and E:\FR\FM\25MRR1.SGM 25MRR1 ER25MR21.002</GPH> Figure 2: Appendix I25.2(b), "Critical Time Interval" (ATTCS takeoff) 15784 Federal Register / Vol. 86, No. 56 / Thursday, March 25, 2021 / Rules and Regulations ATTCS reliability requirements as follows: a. An ATTCS failure or a combination of failures in the ATTCS during the critical time interval (Figure 1): (1) Must not prevent the insertion of the maximum approved go-around thrust or power, or must be shown to be a remote event. (2) Must not result in a significant loss or reduction in thrust or power, or must be shown to be an extremely improbable event. b. The concurrent existence of an ATTCS failure and an engine failure during the critical time interval must be shown to be extremely improbable. c. All applicable performance requirements of part 25 must be met with an engine failure occurring at the most critical point during go-around with the ATTCS functioning. d. The probability analysis must include consideration of ATTCS failure occurring after the time at which the flightcrew last verifies that the ATTCS is in a condition to operate until the beginning of the critical time interval. e. The propulsive thrust obtained from the operating engine, after failure of the critical engine during a go-around used to show compliance with the oneengine-inoperative climb requirements of § 25.121(d), may not be greater than the lesser of: (1) The actual propulsive thrust resulting from the initial setting of power or thrust controls with the ATTCS functioning, or (2) 111 percent of the propulsive thrust resulting from the initial setting of power or thrust controls with the ATTCS failing to reset thrust or power, and without any action by the flightcrew to reset thrust or power. 4. Thrust setting a. The initial go-around thrust setting on each engine at the beginning of the go-around phase may not be less than any of the following: (1) That required to permit normal operation of all safety-related systems and equipment dependent upon engine thrust or power lever position; or (2) That are shown to be free of hazardous engine-response characteristics, and not to result in any unsafe airplane operating or handling characteristics when thrust or power is advanced from the initial go-around position to the maximum approved power setting. b. For approval to use an ATTCS for go-arounds, the thrust-setting procedure must be the same for go-arounds initiated with all engines operating as for go-around initiated with one engine inoperative. 5. Powerplant controls VerDate Sep<11>2014 16:53 Mar 24, 2021 Jkt 253001 a. In addition to the requirements of § 25.1141, no single failure or malfunction, or probable combination thereof, of the ATTCS, including associated systems, may cause the failure of any powerplant function necessary for safety. b. The ATTCS must be designed to: (1) Apply thrust or power to the operating engine(s), following any oneengine failure during a go-around, to achieve the maximum approved goaround thrust without exceeding the engine operating limits; (2) Permit manual decrease or increase in thrust or power up to the maximum go-around thrust approved for the airplane, under the existing conditions, through the use of the power lever. For airplanes equipped with limiters that automatically prevent the engine operating limits from being exceeded under existing ambient conditions, other means may be used to increase the thrust in the event of an ATTCS failure, provided that the means: (i) Is located on or forward of the power levers; (ii) Is easily identified and operated under all operating conditions by a single action of either pilot with the hand that is normally used to actuate the power levers; and (iii) Meets the requirements of § 25.777(a), (b), and (c). (3) Provide a means to verify to the flightcrew, before beginning an approach for landing, that the ATTCS is in a condition to operate (unless it can be demonstrated that an ATTCS failure, combined with an engine failure during an entire flight, is extremely improbable). 6. Powerplant instruments: In addition to the requirements of § 25.1305: a. A means must be provided to indicate when the ATTCS is in the armed or ready condition; and b. If the inherent flight characteristics of the airplane do not provide adequate warning that an engine has failed, a warning system that is independent of the ATTCS must be provided to give the pilot a clear warning of any engine failure during a go-around. DEPARTMENT OF TRANSPORTATION Issued in Kansas City, Missouri, on March 17, 2021. Patrick R. Mullen, Manager, Technical Innovation Policy Branch, Policy and Innovation Division, Aircraft Certification Service. You may examine the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA–2020–0710; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this final rule, any comments received, and [FR Doc. 2021–06027 Filed 3–24–21; 8:45 am] BILLING CODE 4910–13–P PO 00000 Frm 00006 Fmt 4700 Sfmt 4700 Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2020–0710; Project Identifier 2019–CE–037–AD; Amendment 39–21457; AD 2021–05–14] RIN 2120–AA64 Airworthiness Directives; Air Tractor, Inc., Airplanes Federal Aviation Administration (FAA), DOT. ACTION: Final rule. AGENCY: The FAA is adopting a new airworthiness directive (AD) for all Air Tractor, Inc., (Air Tractor) Models AT– 250, AT–300, AT–301, AT–302, AT– 400, AT–400A, AT–401, AT–401A, AT– 401B, AT–402, AT–402A, AT–402B, AT–501, AT–502, AT–502A, AT–502B, AT–503, AT–503A, AT–504, AT–602, AT–802, and AT–802A airplanes. This AD was prompted by reports of cracks in the flap torque tube actuator attachment brackets that may cause the flap actuator to detach from the flap torque tube. This AD requires repetitive visual and dye penetrant inspections of the flap actuator attachment bracket welds for cracks and replacement if cracks are identified. The FAA is issuing this AD to address the unsafe condition on these products. DATES: This AD is effective April 29, 2021. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of April 29, 2021. ADDRESSES: For service information identified in this final rule, contact Air Tractor, P.O. Box 485, Olney, TX 76374: phone: (940) 564–5616: email: info@ airtractor.com: website: https:// airtractor.com/. You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. For information on the availability of this material at the FAA, call 816–329–4148. It is also available at https://www.regulations.gov by searching for and locating Docket No. FAA–2020–0710. SUMMARY: Examining the AD Docket E:\FR\FM\25MRR1.SGM 25MRR1

Agencies

[Federal Register Volume 86, Number 56 (Thursday, March 25, 2021)]
[Rules and Regulations]
[Pages 15780-15784]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-06027]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2020-0721; Special Conditions No. 25-785-SC]


Special Conditions: Mitsubishi Aircraft Corporation Model MRJ-200 
Airplane; Use of Automatic Power Reserve for Go-Around Performance 
Credit

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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

SUMMARY: These special conditions are issued for the Mitsubishi 
Aircraft Corporation (MITAC) Model MRJ-200 airplane. This airplane will 
have a novel or unusual design feature when compared to the state of 
technology envisioned in the airworthiness standards for transport-
category airplanes. This design feature is an Automatic Takeoff Thrust 
Control System (ATTCS), referred to as an Automatic Power Reserve 
(APR), to set the performance level for approach-climb operation after 
an engine failure. 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: This action is effective on MITAC on March 25, 2021. Send 
comments on or before May 10, 2021.

ADDRESSES: Send comments identified by Docket No. FAA-2020-0721 using 
any of the following methods:
     Federal eRegulations Portal: Go to http://www.regulations.gov/ and follow the online instructions for sending 
your comments electronically.
     Mail: Send comments to Docket Operations, M-30, U.S. 
Department of Transportation (DOT), 1200 New Jersey Avenue SE, Room 
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery or Courier: Take comments to Docket 
Operations in Room W12-140 of the West Building Ground Floor at 1200 
New Jersey Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday 
through Friday, except Federal holidays.
     Fax: Fax comments to Docket Operations at 202-493-2251.
     Privacy: Except for Confidential Business Information 
(CBI) as described in the following paragraph, and other information as 
described in 14 CFR 11.35, the FAA will post all comments received 
without change, to http://www.regulations.gov/, including any personal 
information you provide. The FAA will also post a report summarizing 
each substantive verbal contact received about this proposal.
     Confidential Business Information: Confidential Business 
Information (CBI) is commercial or financial information that is both 
customarily and actually treated as private by its owner. Under the 
Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from 
public disclosure. If your comments responsive to this Notice contain 
commercial or financial information that is customarily treated as 
private, that you actually treat as private, and that is relevant or 
responsive to this Notice, it is important that you clearly designate 
the submitted comments as CBI. Please mark each page of your submission 
containing CBI as ``PROPIN.'' The FAA will treat such marked 
submissions as confidential under the FOIA, and the indicated comments 
will not be placed in the public docket of this Notice. Send 
submissions containing CBI to the person indicated in the Contact 
section below. Comments the FAA receives, which are not specifically 
designated as CBI, will be placed in the public docket for this 
rulemaking.
     Docket: Background documents or comments received may be 
read at http://www.regulations.gov/ at any time. Follow the online 
instructions for accessing the docket or go to Docket Operations in 
Room W12-140 of the West Building Ground Floor at 1200 New Jersey 
Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday through 
Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Joe Jacobsen, Performance and 
Environment Section, AIR-625, Technical Innovation Policy Branch, 
Policy and Innovation Division, Aircraft Certification Service, Federal 
Aviation Administration, 2200 South 216th Street, Des Moines, 
Washington 98198; telephone and fax 206-231-3158; email 
[email protected].

[[Page 15781]]


SUPPLEMENTARY INFORMATION: The substance of these special conditions 
has been published in the Federal Register for public comment in 
several prior instances with no substantive comments received. 
Therefore, the FAA has determined that prior public notice and comment 
are unnecessary, and finds that, for the same reason, good cause exists 
for adopting these special conditions upon publication in the Federal 
Register.

Comments Invited

    The FAA invites 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.
    The FAA will consider all comments received by the closing date for 
comments. The FAA may change these special conditions based on the 
comments received.

Background

    On March 3, 2015, MITAC applied for a type certificate for their 
new Model MRJ-200 airplane. This airplane is a twin-engine, transport-
category airplane with seating for 92 passengers and a maximum takeoff 
weight of 98,767 pounds.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.17, the applicant must show that the airplane meets the 
applicable provisions of 14 CFR part 25, as amended by amendments 25-1 
through 25-141.
    If the Administrator finds that the applicable airworthiness 
regulations (e.g., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the MITAC Model MRJ-200 airplane 
because of a novel or unusual design feature, special conditions are 
prescribed under the provisions of Sec.  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, these special conditions would also apply to 
the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the MITAC Model MRJ-200 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.
    The FAA issues special conditions, as defined in 14 CFR 11.19, in 
accordance with Sec.  11.38, and they become part of the type 
certification basis under Sec.  21.17(a)(2).

Novel or Unusual Design Features

    The MITAC Model MRJ-200 airplane will incorporate the following 
novel or unusual design feature:
    An Automatic Takeoff Thrust Control System, referred to as an 
Automatic Power Reserve, to set the performance level for approach-
climb operation after an engine failure.

Discussion

    MITAC included an APR system (an ATTCS) in the Model MRJ-200 
airplane and proposed using the APR function during go-around. They 
also requested approach-climb performance credit for the use of 
additional thrust set by the APR system. The MITAC Model MRJ-200 
powerplant control system comprises a Full Authority Digital Engine 
Control (FADEC) for the engine. The engine FADEC system utilizes the 
APR function during the takeoff and go-around phases of the flight when 
additional thrust is needed from an operating engine following a single 
engine failure. The APR system is available at all times, without any 
additional action from the pilot. It allows the pilot to use the same 
power-setting procedure during a go-around regardless of whether or not 
an engine fails. Because the APR system is always armed, it will 
function automatically following an engine failure, and advance the 
remaining engine to a higher thrust level.
    The part 25 standards for ATTCS, contained in Sec.  25.904, and 
appendix I to part 25, specifically restrict performance credit for 
ATTCS to takeoff. Expanding the standards to include other phases of 
flight, including go-around, was considered at the time the standards 
were issued, but flightcrew workload issues precluded further 
consideration. As the preamble of amendment 25-62 states:
    In regard to ATTCS credit for approach-climb and go-around 
maneuvers, current regulations preclude a higher power for the approach 
climb (Sec.  25.121(d)) than for the landing climb (Sec.  25.119). The 
workload required for the flightcrew to monitor and select from 
multiple in-flight power settings in the event of an engine failure 
during a critical point in the approach, landing, or go-around 
operations is excessive. Therefore, the amendment should not include 
the use of ATTCS for anything except the takeoff phase.
    Because the airworthiness regulations do not contain appropriate 
safety standards to allow approach-climb performance credit for ATTCS, 
special conditions are required to ensure a level of safety equivalent 
to that established in the regulations. The definition of a critical 
time interval for the approach-climb case, during which time it must be 
extremely improbable to violate a flight path based on the Sec.  
25.121(d) gradient requirement, is of primary importance. In the event 
of a simultaneous failure of both an engine and the APR function, 
falling below the minimum flight path defined by the 2.5-degree 
approach, decision height, and climb gradient required by Sec.  
25.121(d) must be shown to be an extremely improbable event during this 
critical time interval. The Sec.  25.121(d) gradient requirement 
implies a minimum one-engine-inoperative flight path capability with 
the airplane in the approach configuration. The engine may have been 
inoperative before initiating the go-around, or it may become 
inoperative during the go-around. The definition of the critical time 
interval must consider both possibilities.
    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.

Applicability

    As discussed above, these special conditions are applicable to the 
MITAC Model MRJ-200 airplane. Should MITAC apply at a later date for a 
change to the type certificate to include another model incorporating 
the same novel or unusual design feature, these special conditions 
would apply to that model as well.

Conclusion

    This action affects only a certain novel or unusual design feature 
on one model of airplanes. It is not a rule of general applicability.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

Authority Citation

    The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701, 44702, 44704.

The Special Conditions

    Accordingly, pursuant to the authority delegated to me by the

[[Page 15782]]

Administrator, the following special conditions are issued as part of 
the type certification basis for MITAC Model MRJ-200 airplanes.
    1. The MITAC Model MRJ-200 airplane must comply with the 
requirements of 14 CFR 25.904, and appendix I, and the following 
requirements for the go-around phase of flight:
    2. Definitions
    a. Takeoff/go-around (TOGA): Throttle lever in takeoff or go-around 
position.
    b. Automatic Takeoff Thrust Control System: The ATTCS in MITAC 
Model MRJ-200 airplanes is defined as the entire automatic system 
available during takeoff and in go-around mode, including all devices, 
both mechanical and electrical, that sense engine failure, transmit 
signals, actuate fuel controls or power levers (or increase engine 
power by other means on operating engines to achieve scheduled thrust 
or power increase), and furnish cockpit information on system 
operation.
    c. Critical time interval:
    (1) When conducting an approach for landing using ATTCS, the 
critical time interval is defined as follows:
    (i) The critical time interval begins at a point on a 2.5-degree 
approach glide path from which, assuming a simultaneous engine and 
ATTCS failure, the resulting approach-climb flight path intersects a 
flight path originating at a later point on the same approach path that 
corresponds to the part 25 one-engine-inoperative approach-climb 
gradient. The period of time from the point of simultaneous engine and 
ATTCS failure, to the intersection of these flight paths, must be no 
shorter than the time interval used in evaluating the critical time 
interval for takeoff, beginning from the point of simultaneous engine 
and ATTCS failure and ending upon reaching a height of 400 feet.
    (ii) The critical time interval ends at the point on a minimum 
performance, all-engines-operating go-around flight path from which, 
assuming a simultaneous engine and ATTCS failure, the resulting minimum 
approach-climb flight path intersects a flight path corresponding to 
the part 25 minimum one-engine-inoperative approach-climb gradient. The 
all-engines-operating go-around flight path, and the part 25 one-
engine-inoperative approach-climb gradient flight path, originate from 
a common point on a 2.5-degree approach path. The period of time from 
the point of simultaneous engine and ATTCS failure, to the intersection 
of these flight paths, must be no shorter than the time interval used 
in evaluating the critical time interval for the takeoff, beginning 
from the point of simultaneous engine and ATTCS failure and ending upon 
reaching a height of 400 feet.
    (2) The critical time interval must be determined at the altitude 
resulting in the longest critical time interval for which one-engine-
inoperative approach-climb performance data are presented in the 
airplane flight manual.
    (3) The critical time interval is illustrated in Figure 1:
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[GRAPHIC] [TIFF OMITTED] TR25MR21.002

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    The all-engines-operating go-around flight path, and the part 25 
one-engine-inoperative approach-climb gradient flight path (engine 
failed, ATTCS operating path in Figure 1), originate from a common 
point, point C, on a 2.5-degree approach path. The period of time, 
``time interval DE,'' from the point of simultaneous engine and ATTCS 
failure, point D, to the intersection of these flight paths, point E, 
must be no shorter than the corresponding time in Figure 2, above.
    d. The ``critical time interval AD'' is illustrated in Figure 1.
    3. Performance and system reliability requirements: The applicant 
must comply with the performance and

[[Page 15784]]

ATTCS reliability requirements as follows:
    a. An ATTCS failure or a combination of failures in the ATTCS 
during the critical time interval (Figure 1):
    (1) Must not prevent the insertion of the maximum approved go-
around thrust or power, or must be shown to be a remote event.
    (2) Must not result in a significant loss or reduction in thrust or 
power, or must be shown to be an extremely improbable event.
    b. The concurrent existence of an ATTCS failure and an engine 
failure during the critical time interval must be shown to be extremely 
improbable.
    c. All applicable performance requirements of part 25 must be met 
with an engine failure occurring at the most critical point during go-
around with the ATTCS functioning.
    d. The probability analysis must include consideration of ATTCS 
failure occurring after the time at which the flightcrew last verifies 
that the ATTCS is in a condition to operate until the beginning of the 
critical time interval.
    e. The propulsive thrust obtained from the operating engine, after 
failure of the critical engine during a go-around used to show 
compliance with the one-engine-inoperative climb requirements of Sec.  
25.121(d), may not be greater than the lesser of:
    (1) The actual propulsive thrust resulting from the initial setting 
of power or thrust controls with the ATTCS functioning, or
    (2) 111 percent of the propulsive thrust resulting from the initial 
setting of power or thrust controls with the ATTCS failing to reset 
thrust or power, and without any action by the flightcrew to reset 
thrust or power.
    4. Thrust setting
    a. The initial go-around thrust setting on each engine at the 
beginning of the go-around phase may not be less than any of the 
following:
    (1) That required to permit normal operation of all safety-related 
systems and equipment dependent upon engine thrust or power lever 
position; or
    (2) That are shown to be free of hazardous engine-response 
characteristics, and not to result in any unsafe airplane operating or 
handling characteristics when thrust or power is advanced from the 
initial go-around position to the maximum approved power setting.
    b. For approval to use an ATTCS for go-arounds, the thrust-setting 
procedure must be the same for go-arounds initiated with all engines 
operating as for go-around initiated with one engine inoperative.
    5. Powerplant controls
    a. In addition to the requirements of Sec.  25.1141, no single 
failure or malfunction, or probable combination thereof, of the ATTCS, 
including associated systems, may cause the failure of any powerplant 
function necessary for safety.
    b. The ATTCS must be designed to:
    (1) Apply thrust or power to the operating engine(s), following any 
one-engine failure during a go-around, to achieve the maximum approved 
go-around thrust without exceeding the engine operating limits;
    (2) Permit manual decrease or increase in thrust or power up to the 
maximum go-around thrust approved for the airplane, under the existing 
conditions, through the use of the power lever. For airplanes equipped 
with limiters that automatically prevent the engine operating limits 
from being exceeded under existing ambient conditions, other means may 
be used to increase the thrust in the event of an ATTCS failure, 
provided that the means:
    (i) Is located on or forward of the power levers;
    (ii) Is easily identified and operated under all operating 
conditions by a single action of either pilot with the hand that is 
normally used to actuate the power levers; and
    (iii) Meets the requirements of Sec.  25.777(a), (b), and (c).
    (3) Provide a means to verify to the flightcrew, before beginning 
an approach for landing, that the ATTCS is in a condition to operate 
(unless it can be demonstrated that an ATTCS failure, combined with an 
engine failure during an entire flight, is extremely improbable).
    6. Powerplant instruments: In addition to the requirements of Sec.  
25.1305:
    a. A means must be provided to indicate when the ATTCS is in the 
armed or ready condition; and
    b. If the inherent flight characteristics of the airplane do not 
provide adequate warning that an engine has failed, a warning system 
that is independent of the ATTCS must be provided to give the pilot a 
clear warning of any engine failure during a go-around.

    Issued in Kansas City, Missouri, on March 17, 2021.
Patrick R. Mullen,
Manager, Technical Innovation Policy Branch, Policy and Innovation 
Division, Aircraft Certification Service.
[FR Doc. 2021-06027 Filed 3-24-21; 8:45 am]
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