Page 1 of 2 ATA Ref: 54-13 14 December 2012 Service Bulletin V7-54-02 

# SERVICE BULLETIN TRANSMITTAL SHEET

CRACKS IN ENGINE OUTBOARD NACELLES UPPER LONGERONS


### Service Bulletin No.: V7-54-02 Date of Original I ssue: 14 December 2012 Revision No.: Revision NC Date of Issue: 14 December 2012

Cracks were reported in outboard nacelles upper longeron channels and angles at about Station XN 1 78. The cracks in part were hidden by bearing blocks(Part 75410096) at the nacelle latch locations. They were roughly orientated in the longitudinal direction in a quarter elliptic shapes. A one time visual inspection of the outboard nacelles upper longeron channels and angles at about Station XN 1 78 is required and results must be sent to Viking Air Limited.Page 2 of 2 ATA Ref: 54-13 14 December 2012 Service Bulletin V7-54-02 THIS PAGE INTENTIONALLY LEFT BLANK

### 14 December 2012 S.B. V7-54-02 Revision ‘NC’ Page 1 of 6 1959 de Havilland Way Sidney, B.C. Canada V8L 5V5 Tel.: (250) 656-7227 

# DASH7
SERVICE BULLETIN ATA SYSTEM: 54-13 Number: V7-54-02

I. PLANNING INFORMATION A. Effectivity Aircraft Affected: All DHC-7 Aircraft. 

### B. Reason Cracks were reported in outboard nacelles upper longeron channels and angles at about Station XN 1 78. The cracks in part were hidden by bearing blocks (Part 75420978) at the nacelle latch locations. They were roughly orientated in the longitudinal direction. 

### C. Description A one time visual inspection of the outboard nacelles upper longeron channels and angles at about Station XN 1 78 is required and inspection report must be sent to Viking Air Limited. 

### D. Compliance This visual inspection must be done within six months of this Service Bulletin issue date. 

### E. Approval The technical content of this Service Bulletin has been approved under the authority of the Transport Canada Civil Aviation (TCCA) De sign Approval Organization (DAO) 04-V-02. 

### F. Manpower It is estimated that it will take 2 to 3 man-h ours to complete the instructions on this Service Bulletin on the two outboard nacelles. 

### G. Weight and Balance Not affected. 

### H. Electrical Load Data Not affected. SUBJECT: CRACKS IN ENGINE OUTBOARD NACELLES UPPER LONGERONS.

### SERVICE BULLETIN V7-54-02

14 December 2012 S.B. V7-54-02 Revision ‘NC’ Page 2 of 6 I. Publications Affected Not affected. 

### J. References Note: This Service Bulletin is self-contained. No drawings are supplied. For more information please contact: Viking Air Limited FAX: 250-656-0673 Technical Support Telephone Numbers: 1959 de Havilland Way Regional: 250-656-7227 Sidney, British Columbia North America: 1-866-49-ATLAS Canada, V8L 5V5 International: 1-800-6727-6727 technical.support@vikingair.com 

### II. ACCOMPLISHMENT INSTRUCTIONS A. 

### Preparation 1. Gain access to the left and right outboard nacelles upper longeron channels and angles as follows: (a) For the left outboard nacelle: (1) Remove cowlings 415AL and 414AR. (b) For the right outboard nacelle: (1) Remove cowlings 445AL and 444AR. 2. For each outboard nacelle, at station XN 1 78, remove the bearing block as follows: (Refer to Figure 1, detail A) (a) Remove the two nuts (1), two washers (2), two bolts (3). (b) Remove the bearing plate and bearing block (4) from the longeron assembly. 

### B. Inspection 

### Procedure (Refer to Figure 1) 1. Do a detailed visual inspection of the upper longeron channels and angles as follows: (a) Look for cracks or signs of fati gue material on the channels and angles. Note: If cracks are found, contact Technical Support at Viking Air Limited before further flight. (b) Fill out inspection report and send to Technical Support at Viking Air Limited (refer to Section I, Para J. for contact information). 

### C. Close-out 1. For each outboard nacelle, at station XN 1 78, re-install the bearing block as follows: (Refer to Figure 1, detail A). Note: Apply Boeshield T9 or equivalent co rrosion protection to shank and under bolt head on installation.

### SERVICE BULLETIN V7-54-02

14 December 2012 S.B. V7-54-02 Revision ‘NC’ Page 3 of 6 (a) Place the bearing plate and bearing block (4) on the longeron assembly. (b) Install the two bolts (3), two washers (2) and two nuts (1) 2. Clean the inspection area of unwanted material and remove all tools. 3. Close access to the left and right outboard nacelle upper longeron channels and angles as follows: (a) For the left outboard nacelle: (1) Install cowlings 415AL and 414AR. (b) For the right outboard nacelle: (1) Install cowlings 445AL and 444AR. 

### D. Recording On completion of this Service Bulletin, make the following entry in the aircraft log book: “Service Bulletin No. V7-54-02 - CRAC KS IN ENGINE OUTBOARD NACELLES UPPER LONGERONS has been incorporated”. 

### III. MATERIAL INFORMATION AND TOOLING A. Material Information (Parts Required Per Aircraft) • None. 

### B. Tooling – Price and Availability • Standard mechanic’s tools. 

### C. Material Information • Boeshield T9 or equivalent.

### SERVICE BULLETIN V7-54-02

14 December 2012 S.B. V7-54-02 Revision ‘NC’ Page 4 of 6 IV. TABLES AND FIGURES

Figure 1

### SERVICE BULLETIN V7-54-02

14 December 2012 S.B. V7-54-02 Revision ‘NC’ Page 5 of 6 

## Service Bulletin V7-54- 02 - Inspection Report Operator: _________________

____________________________ __________________ Contact Person: ____

_________________________________ ____________________ Contact Phone/Email: ___________________________ _________________________ Inspection Findings:

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### Please return fo rm via email to technical.support@vikingair.comor via fax to 250-656-0673

### SERVICE BULLETIN V7-54-02

14 December 2012 S.B. V7-54-02 Revision ‘NC’ Page 6 of 6 THIS PAGE INTENTIONALLY LEFT BLANK