EASA AD No.: 2010-0213 

EASA Form 110 Page 1/3

EASA AIRWORTHINESS DIRECTIVE 

AD No.: 2010-0213 

[Corrected: 03 December 2010] 

Date: 14 October 2010 

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 and EC 635 helicopters 

TCDS Number : EASA.R.009 

Foreign AD : Not applicable 

Supersedure : None 

ATA 63 Main Rotor Drive – Main Transmission Housing Upper Part – 

Modification 

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

Applicability: EC 135 P1(CDS), EC 135 P1(CPDS), EC 135 P2(CPDS), EC 135 P2+, 

EC 135 T1(CDS), EC 135 T1(CPDS), EC 135 T2(CPDS), EC 135 T2+, 

EC 635 T1(CPDS), EC 635 P2+ and EC 635 T2+ helicopters, all serial 

numbers, if equipped with a Main Transmission FS108 housing upper part, 

Part Number (P/N) 4649 301 034. 

Reason: A recent inspection has shown that, on some of the housing upper parts for 

the main transmission FS108, the bypass inlet in the oil filter area has not 

been manufactured in accordance with the applicable design specifications. 

This condition, if not corrected, could adversely affect the oil-filter bypass 

function, which is essential for continued safe flight. 

For the reason described above, this AD requires a temporary modification of 

each affected P/N 4649 301 034 main transmission upper part by installing a 

corrugated washer, which will establish an equivalent structural design for the 

oil supply to the bypass. This AD also requires rework of the oil filter area to 

bring the affected parts (back) within the applicable design specifications. 

This AD has been republished to remove a part serial number (1028) from 

Appendix 1 of this AD and to correct paragraphs (2) and (3) for consistency. 

Effective Date: 28 October 2010 
EASA AD No.: 2010-0213 

EASA Form 110 Page 2/3

Required Action(s) 

and Compliance 

Time(s): 

Required as indicated, unless accomplished previously: 

(1) Within 3 months after the effective date of this AD, identify the serial 

number (s/n) of the P/N 4649 301 034 main transmission upper part 

installed on the helicopter and, if the s/n is listed in Appendix 1 of this AD, 

modify the filter housing of the housing upper part of the main 

transmission in accordance with the instructions of paragraph 3.B.2 (a) of 

ECD Alert Service Bulletin (ASB) EC135-63A-017. 

(2) From the effective date of this AD, do not install a P/N 4649 301 034 main 

transmission upper part with a s/n as listed in Appendix 1 of this AD on 

any helicopter, unless it has been modified as required by paragraph (1) 

of this AD, or reworked as required by paragraph (3) of this AD. 

(3) Within 4 000 flight hours, or at the next main transmission repair or 

overhaul, whichever occurs first after the effective date of this AD, rework 

each main transmission housing upper part with a s/n as listed in 

Appendix 1 of this AD in accordance with the instructions of paragraph 

3.B.2 (b) of the ECD ASB EC135-63A-017. 

Ref. Publications: ECD ASB EC135-63A-017 original issue dated 11 October 2010. 

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. 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 Airworthiness 

Directives, Safety Management & Research Section, Certification 

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. 
EASA AD No.: 2010-0213 

EASA Form 110 Page 3/3

APPENDIX 1 

List of affected P/N 4649 301 034 

Main Transmission Housing Upper Parts 

serial numbers

111 263 1066 through 1100 

115 265 1102 through 1120 

119 267 through 269 1122 through 1147 

127 271 through 274 1149 through 1197 

130 276 1199 through 1214 

136 277 1216 through 1243 

137 279 through 281 1245 through 1265 

144 289 1267 through 1294 

151 through 153 292 1296 through 1305 

155 294 1307 through 1313 

156 through 159 295 through 297 1315 through 1359 

161 through 163 300 1361 through 1373 

165 through 168 302 1375 through 1410 

170 304 1412 through 1417 

171 305 1419 through 1428 

173 307 1430 through 1447 

175 through 179 309 1449 through 1462 

181 310 1464 through 1472 

183 through 190 313 1478 through 1500 

193 316 1502 through 1536 

195 318 1538 

200 through 203 319 1540 through 1555 

209 322 1557 through 1565 

215 323 1567 through 1584 

217 329 through 333 1586 through 1604 

218 335 through 339 1606 through 1633 

220 341 through 343 1635 through 1643 

223 345 through 349 1645 

224 351 1646 

227 355 1649 through 1656 

242 357 1658 through 1682 

244 358 1684 through 1709 

249 360 1711 through 1714 

250 363 1716 through 1718 

245 through 248 364 1720 through 1730 

251 366 1732 

254 1000 through 1006 1733 

255 1008 through 1027 1735 

257 1029 through 1032 1736 

259 1034 through 1037 1742 

260 1039 through 1048 

262 1050 through 1064