AIRWORTHINESS DIRECTIVE

No F-2003-325 R1

Distribution:

A

Issue date:

May 12, 2004

Page :

1/3

This Airworthiness Directive is published by the DGAC:

X

on behalf of EASA, the Primary Airworthiness Authority for the 

affected product.

as the Registration Airworthiness Authority for the affected 

aircraft..

Direction 

générale

de 

l’aviation

civile

France

Translation of « Consigne de Navigabilité » of same 

number.

In case of difficulty, reference should be made to 

the French issue.

GSAC

publication

No person may operate an aircraft to which an Airworthiness Directive applies, 

except in accordance with the requirements of that Airworthiness Directive, 

unless otherwise agreed with the Authority of the State of Registry.

Corresponding foreign Airworthiness Directive(s):

Not applicable

Airworthiness Directive(s) replaced:

2003-325 original issue

Person in charge of airworthiness:

EUROCOPTER

Type certificate(s) No. 189

TCDS No 189

Type(s):

EC 120 helicopters

ATA chapter:

63, 05, 71

Subject:

Rotor drive - Engine mount and engine-to-main gear box (MGB) coupling 

tube assembly

1. EFFECTIVITY:

EC 120 B helicopters

- fitted with engine-to-MGB coupling tube assembly P/N C631A1101101,

- fitted with the engine mount comprising the parts specified in § 1.A. of referenced EUROCOPTER

EC 120 Alert Service Bulletin (ASB) No. 04A005.

2. REASONS:

This Airworthiness Directive (AD) is issued following a case of cracking detected on a reinforced coupling 

tube, which may lead to engine-to-MGB coupling failure and subsequently to autorotation.

This AD covers the requirements of AD 2000-176-004, which is cancelled by its Revision 3.

In addition, this AD incorporates the inspection intervals and service life limit of the coupling tubes 

introduced by Revision 2 of ASB No. 05A003. It also renders the engine mount described in § 1above as 

unfit for flight, in compliance with ASB No. 04A005.

Revision 1 of this AD takes into account Revision 3 of ASB No. 05A003 by incorporating the consequences 

of compliance, if applicable, with EUROCOPTER EC 120 Service Bulletins (SB) No. 71.003 (Improvement of 

the Engine Mount) and/or No. 71.005 (Installation of a New Spring-Loaded Engine Suspension).

3. MANDATORY ACTIONS AND COMPLIANCE TIMES:

3.1. Aircraft fitted with an engine mount block NOT modified as per EUROCOPTER EC 120 SB No. 71.003 

and with serial numbers lower than 1170 AND which have not been modified in compliance with

EUROCOPTER EC 120 Service Bulletin (SB) No. 71.005:

 n/DJ
AIRWORTHINESS DIRECTIVE

No F-2003-325 R1

Distribution:

A

Issue date:

May 12, 2004

Page:

2/3

3.1.1. Reminder of the actions required for compliance with AD 2000-176-004 R2:

Unless already accomplished, the following actions were rendered mandatory from the

effective date of the original issue of Airworthiness Directive 2000-176-004 i.e. on receipt of the 

“telegraphic” AD issued on April 21, 2000:

a) Prior to the next flight, perform a visual crack detection inspection on the cylindrical body of 

the coupling tube on both sides of the MGB coupling tube attachment fitting, in compliance 

with the instructions specified in paragraph 2.B. of referenced EUROCOPTER ASB

No. 05A003.

b) Immediately remove and replace any coupling tube which has one or more cracks.

c) At each check after the last flight of the day, without exceeding 5 flight hours, repeat the 

operations described in § a) and b) above.

Note that, for aircraft not modified as per SB No. 71.003 or SB No. 71.005, the service life limit 

of the coupling tubes specified in § 1 above is 1,000 flight hours.

3.1.2. Actions required for compliance with the original issue of this AD:

The following actions were rendered mandatory from the effective date of the original issue of 

this AD:

a) From June 30, 2004, the parts referenced in § 1.A of referenced EC 120 ASB No. 04A005 

will be unfit for flight.

b) In the next scheduled inspection and at the latest by June 30, 2004, the engine mountbase 

must be checked as per the instructions given in § 2.B of referenced EUROCOPTER EC 

120 ASB No. 04A005.

3.2. Aircraft fitted with an engine mount block modified in compliance with EUROCOPTER EC 120 SB

No. 71.003 or with serial numbers equal to or higher than 1170 AND that have not be modified in 

compliance with EUROCOPTER EC 120 SB No. 71.005:

The following operations were rendered mandatory from the effective date of the original issue of

this AD:

3.2.1. Within 25 flight hours, then at intervals of no more than 25 flight hours, visually check the 

condition of the coupling tube in compliance with the instructions described in § 2.B. of

referenced EUROCOPTER EC 120 ASB No. 05A003 R3.

3.2.2. Immediately remove and replace any coupling tube which has one or more cracks.

3.2.3. In this case, the service life limit of the coupling tubes referenced in § 1 above is 20,000 flight 

hours.

3.3. Aircraft that have been modified in compliance with EUROCOPTER EC 120 SB No. 71.005:

(Spring-Loaded Suspension Engine Mount)

From the effective date of Revision 1 of this AD:

3.3.1. The service life limit for the coupling tube referenced in § 1 above is extended to 20,000 flight 

hours.

3.3.2. The inspections of the coupling tube every 5 hours/at each flight related check or every

25 flight hours are cancelled.
AIRWORTHINESS DIRECTIVE

No F-2003-325 R1

Distribution:

A

Issue date:

May 12, 2004

Page:

3/3

3.4. Spare Parts:

From the effective date of Revision 1 of this AD:

3.4.1. Coupling tubes specified in § 1, held as spares AND having flown on an aircraft "prior to 

compliance with SB No. 71.005", must undergo a dye penetrant crack detection inspection in 

accordance with the instructions specified in § 2.B of referenced SB No. 71.005 before they are 

re-installed on aircraft "after compliance with SB No. 71.005".

3.4.2. After installing on an aircraft a coupling tube specified in paragraph 1, held as spares, comply 

with the instructions described in § 3.1. or in 3.2. or in 3.3. above, depending on whether the 

aircraft has not been fitted or has been fitted with an engine mount block modified in

compliance with SB No. 71.003 and depending on whether the aircraft has been modified in 

compliance with SB No. 71.005 for installing a spring-loaded engine suspension.

4. REFERENCE PUBLICATIONS:

EUROCOPTER EC 120 Alert Service Bulletins No. 05A003 R3 and No. 04A005,

EUROCOPTER EC 120 Service Bulletins No. 71.003 and No. 71.005.

(Any subsequent approved revision to the Alert Service Bulletins and Service Bulletins is acceptable).

5. EFFECTIVE DATES:

Original issue : Upon receipt, from September 13, 2003

Revision 1 : May 22, 2004.

6. REMARK:

For any questions concerning the technical content of the requirements in this AD, please contact:

EUROCOPTER (STXI) - Aéroport de Marseille Provence, 13725 Marignane Cedex - France

Phone: +33 (0)4 42 85 97 97 - Fax: +33 (0)4 42 85 99 46

E-mail: Directive.technical-support@eurocopter.com

7. APPROVAL:

This AD is approved under EASA reference No 2004-4810 of May 05, 2004.