EASA AD No.: 2011-0111R1 

EASA Form 110 Page 1/2 

EASA AIRWORTHINESS DIRECTIVE 

AD No.: 2011-0111R1 

Date: 22 September 2011 

Note: This Airworthiness Directive (AD) is issued by EASA, acting in accordance with 

Regulation (EC) No 216/2008 on behalf of the European Community, 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 EC 1702/2003, Part 21A.3B. In accordance with EC 2042/2003 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 

[EC 2042/2003 Annex I, Part M.A.303] or agreed with the Authority of the State of Registry [EC 216/2008, Article 14(4) exemption]. 

Type Approval Holder’s Name : 

Eurocopter Deutschland GmbH 

Type/Model designation(s) : 

EC 135 helicopters 

TCDS Number: EASA.R.009 

Foreign AD: Not applicable 

Revision: This AD revises EASA AD 2011-0111 dated 10 June 2011. 

ATA 21 Air Conditioning – Mechanical Air Conditioning System – 

Inspection / Deactivation 

Manufacturer(s): Eurocopter Deutschland GmbH, Eurocopter España S.A., Eurocopter S.A. 

Applicability: EC 135 P2+ and EC 135 T2+ helicopters, serial numbers 870, 872, 873, 

879, 883, 884, 888, 893, 900, 905, 911, 914, 916, 917, 923 and 926, which 

are equipped with a mechanical air condition system with compressor 

bearing block Part Number (P/N) L210M1872105. 

Reason: During a recent pre-flight check of an EC 135 P2+ helicopter, metallic parts 

were found within the area of the air inlets of both engines. Subsequent 

inspection identified the debris as parts of the bearing cage of one of the ball 

bearings of the air conditioning compressor bearing block. Loose parts of 

the bearing cage damaged the compressor stage of one of the two engines 

to such an extent that a basic overhaul was necessary. 

As the affected mechanical air conditioning system was only recently 

introduced on the production line, only a limited number of helicopters are 

affected. No P/N L210M1872105 compressor bearing blocks have been 

supplied as spares. 

This situation, if not detected and corrected, could lead to further cases of 

bearing case failure, possibly resulting in loss of engine power and reduced 

control of the helicopter. 

To address this potential unsafe condition, EASA issued AD 2011-0111 to 

require repetitive inspections of the affected ball bearing and, depending on 

findings, deactivation of the mechanical air conditioning system. 

This AD has been revised to allow replacement of the affected compressor 

bearing block with an improved block, which constitutes an optional 

terminating action for the repetitive inspections required by this AD. 
EASA AD No.: 2011-0111R1 

EASA Form 110 Page 2/2 

Effective Date: Revision 1: 29 September 2011 

Original issue: 24 June 2011 

Required Action(s) 

and Compliance 

Time(s): 

Required as indicated, unless accomplished previously: 

(1) Within 25 flight hours (FH) or 14 days, whichever occurs first after 

24 June 2011 [the effective date of the original issue of this AD], inspect 

the mechanical air conditioning system compressor bearing block upper 

bearing, in accordance with the instructions of Eurocopter Deutschland 

(ECD) Alert Service Bulletin (ASB) EC135-21A-013. 

(2) Thereafter, within the applicable intervals specified in Table 1 of this 

AD, depending on the results of the inspection as required by 

paragraph (1) of this AD, inspect the mechanical air conditioning 

system compressor bearing block upper bearing, in accordance with 

the instructions of the ECD ASB EC135-21A-013. 

Table 1 

Inspection results: Repeat Inspection Interval 

(+10% tolerance), whichever 

occurs first 

No detection of water, corrosion 

or leaking grease 

Not to exceed 100 FH or 3 months 

Detection of condensation 

water (small amounts of 

humidity) only 

Not to exceed 25 FH or 28 days 

(3) If, during an inspection as required by paragraph (1) or (2) of this AD, 

water, corrosion or leaking grease is detected, before next flight, 

deactivate the air conditioning system in accordance with the 

instructions of ECD ASB EC135-21A-013. 

(4) Modification of a helicopter by replacing the mechanical air conditioning 

system compressor bearing block, P/N L210M1872105, with an 

improved block, P/N L210M1872107 or P/N L210M1872886, in 

accordance with the instructions of ECD Service Bulletin (SB) EC135-

21-015, constitutes terminating action for the repetitive inspections 

required by this AD for that helicopter. 

Ref. Publications: ECD ASB EC135-21A-013 original issue, dated 06 June 2011. 

ECD SB EC135-021-015 original issue, dated 12 July 2011. 

The use of later approved revisions of these documents 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. The required actions and the risk allowance have granted the issuance 

of a Final AD with Request for Comments, postponing the public 

consultation process after publication. 

3. Enquiries regarding this AD should be referred to the Safety Information 

Section, Executive Directorate, EASA. E-mail ADs@easa.europa.eu 

4. For any question concerning the technical content of the requirements in 

this AD, please contact: 

Eurocopter Deutschland GmbH, Industriestrasse 4, 

86607 Donauwörth, Federal Republic of Germany 

Telephone: + 49 (0)151-1422 8976; Facsimile: + 49 (0)906-71 4111.