AIRBUS HELICOPTERS DEUTSCHLANDMBB-BK 117

ID: 2017-0193
Issue date: 2017-09-29
Effective date: 2017-10-13  
Source: EASA
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Main Rotor Drive – Main Rotor Mast – Inspection

EASA AD No.: 2017-0193


Airworthiness Directive
AD No.: 2017-0193
Issued: 29 September 2017
Note: This Airworthiness Directive (AD) is issued by EASA, acting in accordance with Regulation
(EC) 216/2008 on behalf of the European Union, its Member States and of the European third
countries that participate in the activities of EASA under Article 66 of that Regulation.

This AD is issued in accordance with Regulation (EU) 748/2012, Part 21.A.3B. In accordance with Regulation (EU) 1321/2014 Annex I, Part M.A.301, the
continuing airworthiness of an aircraft shall be ensured by accomplishing any applicable ADs. Consequently, no person may operate an aircraft to which
an AD applies, except in accordance with the requirements of that AD, unless otherwise specified by the Agency [Regulation (EU) 1321/2014 Annex I,
Part M.A.303] or agreed with the Authority of the State of Registry [Regulation (EC) 216/2008, Article 14(4) exemption].


Design Approval Holder’s Name: Type/Model designation(s):
AIRBUS HELICOPTERS DEUTSCHLAND GmbH MBB-BK117 helicopters

Effective Date:
13 October 2017
TCDS Number(s): EASA.R.010
Foreign AD: Not applicable
Supersedure: This AD supersedes Luftfahrt-Bundesamt (LBA) AD 97-276 dated 25 September
1997.


ATA 63 – Main Rotor Drive – Main Rotor Mast – Inspection


Manufacturer(s):

Eurocopter Deutschland GmbH, Eurocopter Hubschrauber GmbH, Messerschmitt-Bölkow-Blohm
GmbH

Applicability:

MBB-BK117 A-1, MBB-BK117 A-3, MBB-BK117 A-4, MBB-BK117 B-1, MBB-BK117 B-2 and
MBB-BK117 C-1 helicopters, all serial numbers (s/n).

Reason:

Cracks were detected in the rotor mast flange of a BO105 helicopter. It was determined that, due to
similarity of design, the same defect could develop on MBB-BK117 helicopters.

This condition, if not detected and corrected, could lead to failure of the rotor mast flange, possibly
resulting in loss of control of the helicopter.

To address this unsafe condition, Eurocopter Deutschland (ECD) issued Alert Service Bulletin (ASB)
ASB-MBB-BK 117-10-114, providing inspection instructions, and LBA issued AD 97-276 requiring
repetitive inspections.




TE.CAP.00110-006 © European Aviation Safety Agency. All rights reserved. ISO9001 Certified. Page 1 of 3
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EASA AD No.: 2017-0193

Since that AD was issued, Airbus Helicopters (AH) determined that the reinforced rotor mast part
number (P/N) 4639 305 095 (which is part of rotor mast assembly P/N 4639 205 016) is not affected
by this unsafe condition, and revised ASB-MBB-BK 117-10-114 accordingly.

For the reason described above, this AD partially retains the requirements of LBA AD 97-276, which
is superseded, and requires repetitive inspections only for helicopters equipped with rotor mast
P/N 4639 305 002, which is part of rotor mast assembly P/N 4639 205 011.

Required Action(s) and Compliance Time(s):

Required as indicated, unless accomplished previously:

Note 1: For the purpose of this AD, Group 1 helicopters are equipped with a rotor mast assembly
having P/N 4639 205 011 (including rotor mast P/N 4639 305 002). Group 2 helicopters are not
equipped with a rotor mast assembly having P/N 4639 205 011.

Repetitive Inspection:
(1) For Group 1 helicopters: Before next flight after 25 September 1997 [the effective date of LBA
AD 97-276] and, thereafter, at intervals not exceeding 100 flight hours, visually inspect the
rotor mast flange in accordance with the instructions of AH ASB-MBB-BK 117-10-114 Revision 1.

Corrective Action(s):
(2) If, during any inspection as required by paragraph (1) of this AD, as applicable, any crack is
found, before next flight, contact AHD for applicable instructions and accomplish those
instructions accordingly.

Credit:
(3) Inspection(s) and corrective action(s), accomplished on a helicopter before the effective date of
this AD in accordance with the instructions of the original issue of ASB-MBB-BK 117-10-114, are
acceptable to comply with the initial requirements of paragraphs (1) and (2) of this AD for that
helicopter.

Terminating Action:
(4) None.

Parts Installation:
(5) For Group 1 and Group 2 helicopters: From the effective date of this AD, it is allowed to install
(see Note 2 of this AD) on any helicopter a rotor mast assembly P/N 4639 205 011, or a main
gearbox (MGB) equipped with a rotor mast assembly P/N 4639 205 011, provided the rotor
mast is new, or provided that, before installation, the rotor mast flange passes an inspection in
accordance with the instructions of AH ASB-MBB-BK 117-10-114 Revision 1. Following
installation, the rotor mast flange must be inspected as required by paragraph (1) of this AD.

Note 2: For the purpose of this AD, removing a rotor mast assembly or MGB from a helicopter and
re-installing that rotor mast assembly or MGB on the same helicopter does not constitute
‘installation’.




TE.CAP.00110-006 © European Aviation Safety Agency. All rights reserved. ISO9001 Certified. Page 2 of 3
Proprietary document. Copies are not controlled. Confirm revision status through the EASA-Internet/Intranet.
An agency of the European Union
EASA AD No.: 2017-0193

Ref. Publications:

ECD ASB-MBB-BK 117-10-114 original issue dated 27 August 1997, or AH ASB MBB-BK117-10-114
Revision 1 dated 28 July 2017.

The use of later approved revisions of this document is acceptable for compliance with the
requirements of this AD.

Remarks:
1. If requested and appropriately substantiated, EASA can approve Alternative Methods of
Compliance for this AD.

2. This AD was posted on 29 August 2017 as PAD 17-118 for consultation until 26 September
2017. No comments were received during the consultation period.

3. Enquiries regarding this AD should be referred to the EASA Safety Information Section,
Certification Directorate. E-mail: ADs@easa.europa.eu.

4. For any question concerning the technical content of the requirements in this AD, please
contact:
Airbus Helicopters Deutschland GmbH, Industriestrasse 4,
86607 Donauwörth, Federal Republic of Germany
Telephone: + 49 (0)151 1422 8976; Facsimile: + 49 (0)906 71 4111.
Web portal: https://keycopter.airbushelicopters.com > Technical Requests Management
E-mail: customersupport.helicopters@airbus.com




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This is a partial extract of the full document - please refer to the actual report for full information.
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