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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 Issue: 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 XN178. 

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 XN178 is required and results must be sent to Viking Air Limited.
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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 XN178. 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 XN178 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) Design Approval Organization (DAO) 04-V-02.

F. Manpower

It is estimated that it will take 2 to 3 man-hours 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.
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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 XN178, 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 fatigue 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 XN178, re-install the bearing block as follows:

(Refer to Figure 1, detail A).

Note: Apply Boeshield T9 or equivalent corrosion protection to shank and under bolt

head on installation.
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(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 - CRACKS 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.
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IV. TABLES AND FIGURES

Figure 1
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Service Bulletin V7-54-02 - Inspection Report

Operator: _______________________________________________________________

Contact Person: _________________________________________________________

Contact Phone/Email: ____________________________________________________

Inspection Findings:

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

Please return form via email to technical.support@vikingair.com or via fax to 250-656-0673
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