Federal Department of the Environment, Transport, Energy and

Communications DETEC

Federal Office of Civil Aviation FOCA

Safety Division

- Aircraft

Lufttüchtigkeitsanweisung (LTA)

Consigne de Navigabilité (CN)

Direttive sulla Navigabilit à (DN)

Airworthiness Directive (AD) FOCA AD



## HB

- 2012

- 009

Inkraftsetzung

Mise en vigueur

Entrata in vigore

Effective Date 03 January 201 3 

### Pilatus

– PC

- 7

FOCA TC/TCDS No: F 56

- 20

1 / 2

Rechtsgrundlage: Art. 26, 51 und 51A (Verordnu ng über die Lufttüchtigkeit von Luftfahrzeugen: SR 748.215.1)

Base juridique: Art. 26, 51 et 51A ( Ordonnance sur la navigabilité des aéronefs: SR 748.215.1)

Base giuridica: Art. 26, 51 e 51A ( Ordinanza concernente la navigabilità degli aeromobili: SR 748.2 15.1)

Legal base: Art. 26, 51 and 51A ( Ordinance on the airworthiness of aircraft: SR 748.215.1) Issue D ate: 20 December 20 12

ATA Chapter : ATA 53

– Fuselage

Su bject: Fuselage / Engine Mount Fittings

– Inspection

Su persedure / R e vi sed

AD(s): Not applicable

Type Certificate

Holder’s Name: Pilatus Aircraft Ltd.

Manufacturer(s): Pil atus Aircraft Ltd.

Applicability: Model PC

- 7 aircraft, Manufacturer Serial Number s (MSN) 101 through

MSN 618

.

Reason: This Airworthiness Directive (AD) is prompted due to the discovery of

cracks in the engine mount fittings. The cracks are caused b y stress co rrosion. It is possible for stress corrosion cracks to occur on engine mount

fittings in i tially made of aluminium alloy AA2024

- T351. Later in production,

the m a terial specification was changed to aluminium alloy AA2124

- T851

to d e crease the risk of stress corrosion. The Part Number (P/N) of the

engine mount fittings r e mained the same.

Such a condition, if left uncorrected, could lead to failure of the engine

mount fittings and po s sible failure of the engine attachment

.

In order to correct and co ntrol the situation, this AD requires a one

- time

check to identify the material specification and inspect those affected e ngine mount fittings that are made of aluminium alloy AA2024

- T351. Any

engine mount fittings found to be cracked must be reported to P ilatus

prior to fu r ther flight.

Required A c tion(s)

and Compliance

Time(s): Req uired as indicated below, unless already acco m plished:

(1) Within the next 90 days after the effective date of this AD, perform a

conductivity test to identify the material spec ification of the engine

mount fi t tings (P/N 112.35.07.152 ) as required by paragraph (§) 3.B.

of PIL A TUS PC

- 7 Service Bulletin No. 5 3

- 008

.Lufttüchtigkeitsanweisung (LTA)

Consigne de Navigabilité (CN)

Direttive sulla Navigabilità (DN)

Airworthiness Directive (AD) FOCA AD



## HB

- 2012

- 009

2 / 2

Rech tsgrundlage: Art. 26, 51 und 51A (Verordnung über die Lufttüchtigkeit von Luftfahrzeugen: SR 748.215.1)

Base juridique: Art. 26, 51 et 51A ( Ordonnance sur la navigabilité des aéronefs: SR 748.215.1)

Base giuridica: Art. 26, 51 e 51A ( Ordinanza concernente la navigabilità degli aeromobili: SR 748.215.1)

Legal base: Art. 26, 51 and 51A ( Ordinance on the airworthiness of aircraft: SR 748.215.1) (2) If during the condu c tivity test required by § (1) of this AD, engine

mount fittings made of aluminium alloy AA 2024

- T351 are found,

w ithin the next 90 days after the effective date of this AD , perform

the inspection in accordan ce with (§) 3.C. of PILATUS PC

- 7 Service

Bu l letin No. 53

- 008

.

Note 1: The Aircraft Maintenance Manual (AMM) will be updated to

inclu de r ep etitive inspection s of all engine mount fittings made of

aluminium alloy AA 2024

- T351.

(3) If during the inspection required by § (2) of this AD, cracks ar e found

in the engine mount fittings , prior to further f light, contact Pilatus Cu stomer Techn i cal Suppo rt (MCC) for further instructions

.

Ref. Public a tion(s): PILATUS PC

- 7 Service Bulletin No. 53

- 008 , initial issue.

The use of later approved revisions of this document is acceptable for

compliance with the r e quirements of this AD.

For further infor m a tion

co n tact: The applicable manufacturer’s documentation may be obtained directly

from:

PILATUS AIRCRAFT LTD.

Customer Technical Support (MCC)

P.O. Box 992

CH

- 6371 Stans, Switzerland

Tel.: +41 (0)41 619 67 74 Fax: +41 (0)41 619 6 7 7 3

E

- mail: Techsupport@pilatus

- aircraft.com

For further information contact:

FEDERAL OFFICE OF CIVIL AVIATION (FOCA)

Design and Production (STEH)

CH

- 3003 Bern, Switzerland

Fax: +41 (0) 31 322 59 18

E

- mail: airdir@bazl.admin.ch