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Airbus Helicopters

DIRECTION TECHNIQUE SUPPORT

13725 MARIGNANE CEDEX FRANCE

EMERGENCY

ALERT SERVICE BULLETIN

DAUPHIN NUMBER VERSIONS

AS365 05.00.57 Civil: N, N1, N2, N3

Military: F, Fs, Fi, K

AS565 05.00.25 Military: MA, MB, SA, SB, UB

SA366 05.39 Civil: G1

Military: GA

SUBJECT: TIME LIMITS / MAINTENANCE CHECKS

Check of the lateral parts of the 9° frame

ATA: 53

REVISION No. DATE OF APPROVAL DATE OF ISSUE

Revision 0 On: June 12, 2009 2009.06.12

Revision 1 On: March 30, 2010 2010.03.31

Revision 2 On: April 03, 2014 2014.04.07

This document is available on the internet: www.airbushelicopters.com/techpub
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1. PLANNING INFORMATION

1.A. EFFECTIVITY

1.A.1. Helicopters/installed equipment

Helicopters equipped with a 9° frame, all part numbers.

1.A.2. Non-installed equipment

Not applicable.

1.B. ASSOCIATED REQUIREMENTS

Not applicable.

1.C. REASON

To check at regular intervals that there is no crack in the areas of the inner angles and flanges of 

the 9° frame, on the RH side and LH side, near the splice.

This ALERT SERVICE BULLETIN formed the subject of EASA Airworthiness Directive 

No. 2009-0125-E.

The purpose of Revision 1 of this ALERT SERVICE BULLETIN was to modify the time limit for first 

compliance with paragraph 1.E.2.a. according to the aircraft versions.

Revision 1 of this ALERT SERVICE BULLETIN formed the subject of an EASA Airworthiness 

Directive.

Revision 1 of this ALERT SERVICE BULLETIN affected compliance with Revision 0.

The purpose of Revision 2 of this ALERT SERVICE BULLETIN is:

- to reevaluate the inspection thresholds as defined in paragraph 1.E.2.

These thresholds are now defined either in flying hours or in take-off/landing cycles.

- to extend the inspection areas up to the junction with the upper part of the 9° frame (refer 

to Figure 1).

Revision 2 of this ALERT SERVICE BULLETIN affects compliance with Revision 1.
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1.D. DESCRIPTION

Revision 0:

EUROCOPTER was informed of a crack which was discovered in the 9° frame of an AS365 N2 

helicopter which had logged a total of 10,786 flying hours.

The crack which was located 230 mm above the cabin floor and which had grown over a large section 

of the 9° frame, on the RH side, was discovered during the Major Inspection of the helicopter.

If it had not been discovered early, this crack, over time, could have led to the failure of the 9° frame.

Pending the results of the analyses that are currently being conducted to establish the cause of this 

crack, EUROCOPTER rendered the instructions given in this ALERT SERVICE BULLETIN mandatory.

Revision 1:

The examinations and analyses performed since Revision 0 was issued showed that the time required 

for initiation of a crack in this area varied a lot according to the weight and balance data of the different 

aircraft versions. Consequently, these studies compelled EUROCOPTER to define the time limit for 

the initial check according to the helicopter version.

EUROCOPTER informed you that an improvement was currently being studied and would be 

proposed to you by a Service Bulletin. The checks required by this ALERT SERVICE BULLETIN will 

be nullified following the embodiment of this reinforcement.

Pending the availability of this improvement, EUROCOPTER rendered compliance with Revision 1 of 

this ALERT SERVICE BULLETIN mandatory.

Revision 2:

Airbus Helicopters has carried out new studies on the strength of the 9° frame and has reevaluated 

the inspection thresholds defined in Revision 1 of this ALERT SERVICE BULLETIN.

In addition, Airbus Helicopters has decided to extend the inspection areas up to the junction with the 

upper part of the 9° frame.

Consequently, Airbus Helicopters makes compliance with Revision 2 of this ALERT SERVICE 

BULLETIN mandatory.
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1.E. COMPLIANCE

Airbus Helicopters renders compliance with this ALERT SERVICE BULLETIN mandatory.

1.E.1. Compliance at the works

1.E.1.a. On helicopters/installed equipment

Not applicable.

1.E.1.b. On non-installed equipment

Not applicable.

1.E.2. Compliance in service: By the operator:

1.E.2.a. On helicopters/installed equipment

ANY ALTERATION OF THE 9° FRAME DUE TO 

THE INSTALLATION OF AN STC 

(SUPPLEMENTAL TYPE CERTIFICATE) CAN 

AFFECT THE INSTRUCTIONS GIVEN IN THIS 

ALERT SERVICE BULLETIN.

For helicopters which have not reached the inspection threshold defined in the table below, on 

receipt of Revision 2 of this ALERT SERVICE BULLETIN, issued on the date indicated at the foot 

of the page:

- Comply with paragraph 2. of this ALERT SERVICE BULLETIN within 110 flying hours after 

having reached the threshold.

Then, 

- Comply with paragraph 2. at intervals not exceeding 110 flying hours.

For helicopters which have reached or exceeded the inspection threshold defined in the table 

below, on receipt of Revision 2 of this ALERT SERVICE BULLETIN, issued on the date indicated at 

the foot of the page:

- Comply with paragraph 2. of this ALERT SERVICE BULLETIN at the latest upon reaching

110 flying hours following the latest inspection or within 110 flying hours following receipt of 

Revision 2 of this ALERT SERVICE BULLETIN (the first limit reached is applicable).

Then,

- Comply with paragraph 2. at intervals not exceeding 110 flying hours.

WARNING
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Helicopter 

types/versions

Inspection thresholds

(the first limit reached is applicable)

Thresholds in number of 

take-off/landing cycles 

Thresholds in number of 

flying hours

AS365 N, Fs 22980 11490

AS365 N1, F, Fi, K 20980 10490

AS365 N2 18280 9140

AS365 N3 17480 8740

AS565 MB, SB, UB 14780 7390

AS366 G1, GA 16780 8390

AS565 MA, SA 15580 7790

NOTE 1

Helicopters which have exceeded the inspection 

thresholds defined in Revision 1 of this ALERT 

SERVICE BULLETIN shall require compliance with 

Revision 2 of this ALERT SERVICE BULLETIN upon 

reaching the thresholds defined above.

1.E.2.a.1. Interpretation of the results:

a) If there is no crack in the 9° frame:

Leave as is and resume flights.

b) If a crack is found in the 9° frame, in the inspected areas on the lateral parts:

1) If the length of the crack is strictly less than 33 mm (1.3 in.):

- Contact the Airbus Helicopters Customer Service Technical Support Department to 

request a “Repair Design Approval Sheet” (RDAS), in accordance with the conditions 

described in NOTE 2. 

- Comply with this “Repair Design Approval Sheet” (RDAS) no later than within 660 flying 

hours or 1 year (the first limit reached is applicable):

. Pending compliance with the RDAS, comply with paragraph 2. at intervals not 

exceeding 10 flying hours.

2) If the length of the crack is equal to or more than 33 mm (1.3 in.):

Contact the Airbus Helicopters Customer Service Technical Support Department to request 

a “Repair Design Approval Sheet” (RDAS), to be complied with before resuming flights, 

in accordance with the conditions described in the NOTE below.
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NOTE 2

Airbus Helicopters remains at your disposal for any further 

information or support you may require to comply with the 

instructions given in this ALERT SERVICE BULLETIN:

Contact the Airbus Helicopters Customer Service Technical 

Support Department

By: Phone: +33 (0)4.42.85.97.10

Fax: +33 (0)4.42.85.99.66

Email: Airframe.technical-support@eurocopter.com

1.E.2.b. On non-installed equipment

Not applicable.

1.F. APPROVAL

1.F.1. Approval of modifications

Not applicable.

1.F.2. Approval of the Service Bulletin

The technical information given in this ALERT SERVICE BULLETIN Revision 0 was approved 

on June 12, 2009 under the authority of EASA Design Organisation Approval No. 21J.056 for civil 

version helicopters subject to an Airworthiness Certificate.

The technical information given in this ALERT SERVICE BULLETIN Revision 0 was approved 

on June 12, 2009 by the EUROCOPTER Airworthiness department for military version helicopters.

The technical information given in this ALERT SERVICE BULLETIN Revision 1 was approved 

on March 30, 2010 under the authority of EASA Design Organisation Approval No. 21J.056 for civil 

version helicopters subject to an Airworthiness Certificate.

The technical information given in this ALERT SERVICE BULLETIN Revision 1 was approved 

on March 30, 2010 by the EUROCOPTER Airworthiness department for military version helicopters.

The technical information contained in this ALERT SERVICE BULLETIN Revision 2 was approved 

on April 03, 2014 under the authority of EASA Design Organization Approval No. 21J.056 for 

helicopters of civil versions subject to an Airworthiness Certificate.

The technical information contained in this ALERT SERVICE BULLETIN Revision 2 was approved 

on April 03, 2014 under the prerogatives of the recognition of design capability FRA21J-002-DGA for 

French Government helicopters.

The technical information contained in this ALERT SERVICE BULLETIN Revision 2 was approved 

on April 03, 2014 by the Airbus Helicopters Airworthiness Department for export military versions.
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1.G. MANPOWER

1.G.1. Qualification

Mechanic or Structural Technician.

1.G.2. Time for the operations

Approximately 3 hours for compliance with paragraph 2. (excluding customization).

1.H. WEIGHT AND BALANCE

Not applicable.

1.I. EFFECT ON ELECTRICAL LOADS

Not applicable.

1.J. SOFTWARE MODIFICATION EMBODIMENT RECORD

Not applicable.

1.K. REFERENCES

Not applicable.

1.L. OTHER DOCUMENTS AFFECTED

Not applicable.

1.M. TOOLING AFFECTED

Not applicable.

1.N. INTERCHANGEABILITY OR MIXABILITY OF PARTS

Not applicable.
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2. ACCOMPLISHMENT INSTRUCTIONS

2.A. GENERAL

Not applicable.

2.B. OPERATIONAL PROCEDURE

The operational procedure must be complied with on the LH and RH sides of the 9° frame.

2.B.1. Preliminary steps

Remove the coverings from the 9° frame.

2.B.2. Visual check to ensure that there are no cracks in the 9° frame

As per Figure 1 to 3:

Using a magnifying glass and a light source:

- Check that there are no cracks (See Details B, C, D and E) in the 9° frame.

NOTE

In Revision 2 of this ALERT SERVICE BULLETIN, the 

inspection area has been extended to a width of 

20mm (.79in.) (see Section A-A and Detail B, 

Figure 2) at the “H” splice.

Then,

- Interpret the results as per paragraph 1.E.2.a.1.

2.B.3. Final steps

- Install the coverings on the 9° frame.

- Resume flights.

2.C. IDENTIFICATION

Record first compliance with this ALERT SERVICE BULLETIN, with the revision number, in the 

helicopter documents.

And, if necessary,

Record compliance with the repair solution (RDAS), with its number, in the helicopter documents.

2.D. OPERATING AND MAINTENANCE INSTRUCTIONS

Not applicable.
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Figure 1: Inspection areas on the lateral parts of the 9° frame

Areas to be inspected

A

A

B

B

See Figure 2

See Figure 3

See Figure 3

See Figure 2
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Figure 2: Details of the inspection areas

See Figure 1

Covering support base

SECTION B-B

Internal plate of the 

9° frame

Angle

”H” splice

See Figure 1

Areas to be inspected

20 mm

.79 in.

Cabin floor

Upper limit of the 

covering support base 

of the 9° frame

20 mm

.79 in.

SECTION A-A

“H” splice

Angle

Internal plate of 

the 9° frame
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Figure 3: Examples of cracks on the lateral parts of the 9° frame

See Figure 1

9° frame viewed from the rear

Crack

See Figure 1

Cracks

9° frame viewed from the front
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3. MATERIAL INFORMATION

3.A. MATERIAL: PRICE AND AVAILABILITY

Not applicable.

3.B. INFORMATION CONCERNING INDUSTRIAL SUPPORT

Not applicable.

3.C. MATERIAL REQUIRED FOR EACH HELICOPTER/ENGINE/COMPONENT

Not applicable.

3.D. PROCUREMENT CONDITIONS

Not applicable.

4. APPENDIX

Not applicable.