国空機第131号 整理番号TCD-10485-2025
耐 空 性 改 善 通 報
令和7年6月3日
適用航空機の所有者各位
国土交通省航空局長 平岡 成哲
（公印省略）
1. 第2項の航空機又はその装備品等の安全性又は環境適合性を確保するため、第3項の整備又は改造作業等の実施が必要であると認められますので通報します。
なお、本通報による作業が実施されないときは、航空法第14条の3第1項に基づく整備改造命令を発出し、又は同法第134条第2項に規定された立入検査を実施のうえ、同法第14条の3第2項の規定により耐空証明の効力を停止し、若しくは有効期間を短縮し、若しくは同法第10条第3項（同法第10条の2第2項において準用する場合を含む。）の規定により指定した事項を変更する場合があります。
また、本通報により実施した作業については、同法第58条第2項に定めるとおり航空日誌に記載することが求められます。
2. 適用航空機
エアバス式A350-941及びA350-1041型
3. 適用項目
エンジンの出力制限による離陸操作中、エンジン推力が左右非対称となることにより、乗員の負荷が増大し、機体の操縦性の喪失に至る不具合を防止するため、既に実施した場合を除き、別添EASA AD 2025-0105（以下「AD」という。）のDefinitions項及びRequired Action(s) and Compliance Time(s)項に従って、飛行規程の改訂を実施すること。
ただし、AD中「the effective date of this AD」とあるのは、「本通報発効日」（第4.1項による。）と読み替えるものとする。
なお、本通報による処置を他の同等な方法で実施する場合には、航空局長の承認が必要である。ただし、ADに係る同等な方法としてEASAの承認を受けているSB等に従って処置を実施する場合（運用限界の変更を伴う場合を除く。）には、航空局長への届出でよい。
4. 備考
4.1 本通報は、令和7年6月16日から発効する。
4.2 本通報は、EASA AD 2025-0105による。
4.3 本通報の送付を受けた者は、参考配布を除き、令和7年6月24日までに、適用項目に関する実施状況を記載した報告書を、先任航空機検査官又は駐在航空機検査長に提出すること。記載要領、様式及び提出先については、航空機検査業務サーキュラーNo.3-003に従うこと。
4.4 次に掲げる文書（その承認された改訂版を含む。）は、本件に関するものである。
・Airbus A350 AFM TR 137 Issue 1, EASA approval date 14 March 2025.
・Airbus A350 AFM TR 143 Issue 2, EASA approval date 28 March 2025.
・Airbus A350 AFM TR 139 Issue 1, EASA approval date 08 April 2025.
・Airbus A350 AFM TR 142 Issue 1, EASA approval date 14 March 2025.
耐空性改善通報ＴＣＤ－１０４８５－２０２５別添
EASA AD No.: 2025-0105
AD No.: 2025-0105
Issued: 07 May 2025
Design Approval Holder’s Name:AIRBUS S.A.S.
Type/Model designation(s):A350 aeroplanes
Effective Date: 21 May 2025
TCDS Number(s): EASA.A.151
Foreign AD: Not applicable
Supersedure: None
ATA – Aircraft Flight Manual – Derated Take-Off/Limitations – Amendment
Manufacturer(s):Airbus
Applicability:Airbus A350-941 and A350-1041 aeroplanes, all manufacturer serial numbers.
Definitions:For the purpose of this AD, the following definitions apply:
The AFM TR: Airbus A350 Airplane Flight Manual (AFM) Temporary Revision (TR) 137 issue 1 or
AFM TR 143 issue 2 or AFM TR 139 issue 1 or AFM TR 142 issue 1, as applicable to aeroplane model and configuration.
Reason:
During a design review, a potential thrust asymmetry condition has been identified during derated take-off operations when one engine is operating within a restricted N1 zone due to KOZ (Keep Out Zone) limitations.
Investigation revealed that the root cause lies in the interaction between derated logic and KOZ-limited engine control laws, which may result in significant thrust differences between engines.
This condition, if not corrected, could lead to increased flight crew workload during critical phases of flight, possibly resulting in reduced control of the aeroplane.
To address this potential unsafe condition, Airbus published the AFM TR, as defined in this AD, to implement limitations on the derated take-off limitation supplement.
For the reason described above, this AD requires amendment of the applicable AFM by incorporating the AFM TR.
Required Action(s) and Compliance Time(s):
Required as indicated by this AD, unless the action(s) required by this AD have been already accomplished:
AFM Amendment:
(1)Within 3 months after the effective date of this AD, amend the applicable AFM by incorporatingthe AFM TR, inform all flight crews, and, thereafter, operate the aeroplane accordingly.
(2)Amending the applicable AFM of an aeroplane by incorporating a later AFM revision, which
includes the same content as the AFM TR, is an acceptable method to comply with therequirements of paragraph (1) of this AD for that aeroplane.
Ref. Publications:
Airbus A350 AFM TR 137 Issue 1, EASA approval date 14 March 2025.
Airbus A350 AFM TR 143 Issue 2, EASA approval date 28 March 2025.
Airbus A350 AFM TR 139 Issue 1, EASA approval date 08 April 2025.
Airbus A350 AFM TR 142 Issue 1, EASA approval date 14 March 2025.
The use of later approved revisions of the above-mentioned documents is acceptable for compliance with the requirements of this AD.
Remarks:
1.If requested and appropriately substantiated, EASA can approve Alternative Methods ofCompliance for this AD.
2.Based on the required actions and the compliance time, EASA have decided to issue a Final ADwith Request for Comments, postponing the public consultation process until after publication.All interested persons may send their comments, referencing the AD Number, to the E-mailaddress specified in below Remark 3, prior to 04 June 2025. Only if any comment is receivedduring the consultation period, a Comment Response Document will be published in the EASASafety Publications Tool, in a compressed (‘zipped’) file, attached to the record for this AD.
3.Enquiries regarding this AD should be referred to the EASA Safety Information Section,Certification Directorate. E-mail: ADs@easa.europa.eu.
4.Information about any failures, malfunctions, defects or other occurrences, which may besimilar to the unsafe condition addressed by this AD, and which may occur, or have occurred ona product, part or appliance not affected by this AD, can be reported to the EU aviation safetyreporting system. This may include reporting on the same or similar components, other thanthose covered by the design to which this AD applies, if the same unsafe condition can exist ormay develop on an aircraft with those components installed. Such components may beinstalled under an FAA Parts Manufacturer Approval (PMA), Supplemental Type Certificate(STC) or other modification.
5.For any question concerning the technical content of the requirements in this AD, pleasecontact: AIRBUS S.A.S. A350 XWB (1IAK), E-mail: continued-airworthiness.a350@airbus.com.
 TCD-10485-2025.pdf |