# SERVICE BULLETIN TRANSMITTAL SHEET

Service Bulletin No.: V 3 /00 02 Date of Original Issue: 22

- September

- 201 0

Revision No.: Revision C Date of Issue: 30

- April

- 2014



### DHC

- 3 COMPLETE WING BOX INSPECTION

– BORESCOPE AND VISUAL

Viking has received SDRs related to cracking of the DHC

- 3 wing upper skin corrugations as well as
cracks in the m ain spar lower cap

. The intent of this S ervice Bulletin is to detect and repair these cracks and to obtain as much information as possible from operators to evaluate the overall condition of the fleet to assess if further action is required

.

NOTE 1: NO RETROACTIVE THRESHOLD INSPECTION IS REQUIRED IF THRESHOLD INSPECTION FROM SB V3/0002 REVISION A OR B HAS BEEN COMPLETED

– CONTINUE WITH REPEAT INSPECTIONS IN ACCORDANCE WITH SB V3/0002 REVISION C AT APPROPRIATE REPEAT INSPECTION SCHEDULE.

NOTE 2: ALL OTHER AIRCRAFT MUST INCORPORATE APPLICABLE INSPECTIONS IN ACCOR DANCE WITH SB V3/0002 REVISION C.
NOTE 3: This revision supersedes the previous revision of this Service Bulletin.

NOTE 4: Revision bars in the left margin of this Service Bulletin denote changes from the previous revision.

This page transmits Revision ‘ C ’ of Service Bulletin V 3 /00 02 , pages 1 thru 12 , dated 30 April 2014

.

Service Bulletin re

- issued to include incorporation of MOD 3/1005 (MOD for inspection access holes )
and detailed compliance and accomplishment instructions for the inspection of the entire wing box assembly

.

Remove Service Bulletin V 3 /00 0 2 Revision ‘ B ’ dated 03 July 2013 and replace with attached.

Previous issues of Service Bulletin V 3/0002 :

Initial Issue

– (22

- Sep

- 2010)

- effectivity

– All DHC

- 3 aircraft

Rev ision A

– (22

- Feb

- 2013)

- effectivity

– All DHC

- 3 aircraft

Revision B

– (03

- Jul

- 2013)

- effectivity

- All DHC

- 3 aircraft

Page 1 of 2 ATA Ref: 57

- 00

30

- April

- 2014 Service Bulletin V 3 /00 02THIS PAGE INTENTIONALLY LEFT BLANK

Page 2 of 2 ATA Ref: 57

- 00

30

- April

- 2014 Service Bulletin V 3 /00 021959 De Havilland Way Sidney, B.C. Canada
V8L 5V5 Tel: (250) 656

- 7227



# SERVICE BULLETIN

ATA SYSTEM: 5700 NUMBER: V3/0002

SUBJECT: DHC

- 3 Complete Wing Box Inspection

– Borescope and Visual



## I. PLANNING INFORMATION

A. Effectivity
The complete wing box inspection requirement laid out herein, has an effectiv ity of

A LL DHC

- 3 aircraft

. NOTES: To perform this inspection , improved access is required. Refer to Section II.A. of this Service Bulletin for details. Before you do this Service Bulletin, read ALL Section s of the bulletin and examine all Supplemental Type Certificate (STC) or equivalent action changes to make sure this Service Bulletin can be completed

. FOR AIRCRAFT EQUIPED WITH STCs or EQUIVALENT CHANGES,
THE OPERATOR MUST CONTACT THE STC HOLDER TO EVALUATE
CONFLICT POSSIBILITIES.

B. Reason Viking has received Service Difficulty Reports (SDR’s) related to cracking of the DHC

- 3 wing upper skin corrugations as well as cracks in the main spar lower cap. The intent of this Service Bulletin is to detect and repair these cracks and to obtain as much information as possible from operators to evaluate the overall condition of the fleet and assess if further action is required. All wings require internal inspections in order to maintain long term s tructural integrity.

The purpose of incorporating additional inspection openings is to provide sufficient access to complete a thorough inspection of the DHC

- 3 wing

.
C. Description

Inspections are required to identify possible cracking, co rrosion or any other damage of the wing box assembly

. To accommodate these inspections

, access panels are incorporated in the wing lower

skin in accordance with MOD 3/1005 ( MOD Kit DWG C3MK100 5 ; MOD Kit
C3MK1005

- 1 )

. 

# DHC

-

3 

# OTTER

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Revision ‘ C ’ Page 1 of 12

### SERVICE BULLETIN V3/0002

The purpose of this Service Bulletin is to:

1. Borescope inspect and visual ly inspect the wing box for cracks and corrosion.

2. As soon as possible following the f irst inspection accomplished in accordance

with Rev ision C of the Service Bulletin

, complete the Operator Reply Form
included with this Ser vi ce Bulletin e ven if no cracks or damage is found.

3. Repair damage prior to next flight.

D. Compliance

The compliance time for actions associated with this Service Bulletin is listed in

Table 1 below

. NOTE 1: To accompli sh inspection (action) from Table 1 below, incorporate lower wing skin access openings as defined in Section II.A. of this Service Bulletin

. NOTE 2: If actual flight hours of wing are not known, contact Tec hnical Support at Viking Air L imited (see Sec. I.J for contact information) to assist in the determination

. NOTE 3 : If SB V3/0002 Rev A or B has been complied with prior to the issue date of SB V3/0002 Rev C, continue with the repeat inspection s, in accordance with Table 1 below, from the last completed inspection in accordance with SB V3/0002 Rev A or B

. NOTE 4 : Damage shall be repaired prior to next flight in accordance with accepted data ( such as PSM1

- 3

- 3 ) or other approved data

.

T ABLE 1

– W ING BOX I NSPECTION

- C OMPLIANCE D ETAILS

Action Action Detail Effectivity Threshold Inspection Repeat Inspection

Complete wing box inspection Do a bor e scope and visual inspection on ALL areas of the Wing Box in accordance with (Sec. II). a. <31,200 wing flight hours Within 800 wing flight hours or within 6 months of issue date of this SB (whichever occurs first) Also see note 3 Every 1600 wing flight hours or 2100

flight cycles (whichever occurs first) b. 31,200≤ wing flight hours <31,600 Before accumulating 32,000 wing flight hours or within 6 months of issue date of this SB (whichever occurs first)

c. ≥ 31,600 wing flight hours Within 400 wing flight hours or 3 months of the issue date of this

SB (whichever occurs first)



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

- V

- 02.

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Revision ‘ C ’ Page 2 of 12

### SERVICE BULLETIN V3/0002

F. Manpower

An estimated 36 man

- hours per wing will be required to complete this Service Bulletin (16 man hours to install access panels and 20 hours to inspect the wing components).

All costs to complete the inspection of the wing components are the responsibility of the Operator.

G. Weight and Balance

FOR MOD 3/1005 (Current) FOR MOD 3/1002 (Original)

AIRCRAFT STATION WEIGHT AIRCRAFT STATION WEIGHT

STA 1 39.25 +1.58 lbs STA 134.15 +1.58 lbs

STA 159.63 +0.60 lbs STA 159.63 +0.60 lbs

H. Electrical Load Data

Not affected.

I. Publications Affected

None.

J. References
This Service Bulletin contains a Survey to be completed and returned to Viking. The following drawings have been provided with this Service Bulletin to illustrate the

technical activities: C3MK100 5
, C3Z1001 , and C3Z1002 . For more information please contact:

Viking Air Limited Technical Support 1959 De Havilland Way Sidney, British Columbia

V8L 5V5 technical.support@vikingair.com

FAX: 250

- 656

- 0673 Telephone Numbers: Regional: 250

- 656

- 7227
North Am erica: 1

- 800

- 663

- 8444
International: 1

- 800

- 6727

- 6727

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Revision ‘ C ’ Page 3 of 12

### SERVICE BULLETIN V3/0002



## II. ACCOMPLISHMENT INSTRUCTIONS

A. INTRODUCTION OF NEW ACCESS HOLES IN THE LOWER WING SKIN

1. To perform this inspection, Viking is providing MOD 3/1005 (MOD KIT DWG C3MK1005) for the incorporation of access holes which is only suitable for incorporation on OEM wings used on OEM aircraft

. NOTE 1 : (a) If MOD 3/1002 (MOD Kit DWG C3MK1002) has been incorporated in accordance with SB V 3/0002 Revision A or B, the incorporation of MOD 3/1005 (MOD Kit DWG C3MK1005) is not required in order to accomplish the inspection requirements of this Service Bulletin

. (b) If the inspection opening at wing station 53.75 has been incorporated in accordance with SB V3/0002 Revision NC, no change is required at this location, but the remaining inspection openings specified in MOD 3/1005 (MOD Kit DWG C3MK1005) are required unless MOD 3/1002 (MOD Kit DWG C3MK1002 ) was also incorporated

. NOTE 2 : MOD 3/1005 (MOD Kit DWG C3MK1005) is compatible for wings fitted with STC SA94

- 114 (or US STC SA00287NY) STOL Kit

. NOTE 3 : For aircraft fitted with Viking STC SA03

- 50, refer to Service Bulletin SB 3

- STC(03

- 50)

- 001 for applicable access instructions.

NOTE 4 : 

### For Wings / Aircraft equipped with STCs or equivalent changes, other than mentioned in Section II.A.1. above, th e operator must contact the STC holder to evaluate conflict possibilities

.

2. Add applicable new access holes in accordance with MOD Kit C3MK1005

- 1 on both Left Hand (LH) Wing and Right Hand (RH) Wing

.
3. Parts can be fabricated by qualified individuals or purchased from Viking Product Support

.

B. COMPLETE WING BOX INSPECTION



### Th e Lef t Hand (LH) Wing :
1. Remove all inspection access panels / plugs between wing root and wing tip, including those for the access holes incorporated in Section II.A. above, and remove wing tip in accordance with PSM1

- 3

- 2 Section 2.15.1.

2. Using a flexible borescope, inspect for cracks, corrosion, missing /smoking /working /broken fasteners or other damage on the entire internal structure of wing between wing root and wing tip, upper/lower skins, ribs (webs, upper/lower flanges), fore and aft surfaces of nose spar, main spar and re ar spar (including caps and webs)

. Pay particular attention to the following areas for cracks in fastener holes and open holes:
(a.) Skin splice;
(b.) Spar Web splice;
(c.) Spar cap splice;

30

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Revision ‘ C ’ Page 4 of 12

### SERVICE BULLETIN V3/0002

(d.) Hinge attachments on rib and rear spar;
(e.) F astener holes on skin (especially those common to the inboard/outboard

end

- row of fastener holes on the reinforcement doublers);
(f.) Access cutouts and lightening holes on spar/rib webs;
(g.) Rib attachment to the webs and caps of the nose spar, main spar, and rear spar, looking for cracks in flanges, bending radii and at fastener heads;
(h.) Corrugations at rib attachments (both forward and aft of the main spar ) . See Figure 1A and 1B for typical corrugation cracks;
(i.) All fastener holes on the lower spar caps (main and rear spar), lower stringers and lower skins between wing root and wing tip. Note that fatigue prone areas may be located between Sta 135 and 185. See Figure 1C for example of cracks on main spar lower c ap.

3. Carry out a detailed inspection of the exterior surface of the wing for cracks, corrosion, missing/ smoking/ working/ broken fasteners or other damage. Pay particular attention to skin splice, and access cutouts.

4. Do a visual i nspection around doub ler area of inspection holes at every repeat inspection.

5. Document all findings and cracks (noting length, direction, wing station position, smoking fasteners, oversized or broken fasteners, etc.); include pictures identifying the location (use station n umber) and orientation of all findings.

6. Complete the attached Post Inspection Survey Report Form (even if no damage was found) and forward to Technical Support as soon as possible (see Sec. I.J for contact information).

7. Repair damage prior to next fligh t.

NOTE : Repairs shall be in accordance with accepted data such as PSM1

- 3

- 3 or other approved data.

8. Re

- install inspection panels and wing tip in accordance with PSM1

- 3

- 2 Section

2.15.2.



### The Right Hand (RH) Wing :

9. Repea t Step II.B.1 to Step II.B.8 on the RH wing

.

D. RECORDING

1. Make an entry in the aircraft flight log book upon completion of access hole incorporation associated with MOD 3/1005: “INCORPORATION OF MOD 3/1005
ACCESS HOLE S COMPLETED IN ACCORDANCE WITH SECTION II.A OF SB
V3/0002 Re v ision C AT XX,XXX WING FLIGHT HOURS FOR WING S/N XXX. ”



### 2. Complete Operator R eply Form attached following the first inspection incorporated

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Revision ‘ C ’ Page 5 of 12

### SERVICE BULLETIN V3/0002

in accordance with Revision C of Service Bulletin V3/0002 , and send it to Viking Air Limited Technical Support

. 3. Make an entry in the aircraft flight log book upon completion of Section II.B of this
Service Bulletin: “ INSPECTIONS COMPLETED IN ACCORDANCE WITH
SECTION II.B OF SB V3/0002 Revis i on C AT XX,XXX FLIGHT HOURS FOR WING S/N XXX; INSPECTIONS RESULTS SENT TO VIKING AIR LIMITED .”



## III. MATERIAL INFORMATION AND TOOLING

A. Material

• Modification Kit C3MK1005

- 1 (includes MOD Kit DWG C3MK1005 and DWGs
C3Z1001 & C3Z1002 )

B. Tooling

– Price and Availability

(a) Flexible Borescope Kit with light

(b) Flashlight and mirror

(c) Wing Support Stand

(d) Standard AME hand tools

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Revision ‘ C ’ Page 6 of 12

### SERVICE BULLETIN V3/0002



## IV. FIGURES AND TABLES

F IGURE 

### 1A

– T YPICAL 

### C ORRUGATION 

### C RACKS



### F IGURE 

### 1B

– C ORRUGATION 

### C RACKS ON ONE OF THE WING 

### SDR Typical Corrugation Cracks

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Revision ‘ C ’ Page 7 of 12

### SERVICE BULLETIN V3/0002



### F IGURE 

### 1C

– C RACKS ON 

### M AIN 

### S PAR 

### L OWER 

### C AP FROM ONE OF THE W ING INSPECTION 

### SDR

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Revision ‘ C ’ Page 8 of 12

### SERVICE BULLETIN V3/0002

Service Bulletin V3/0002

– Operator Reply Form (Left Hand Wing)



### Operator Name:

Contact Person:

Contact Phone/Email :

A

/C Serial Number:

Wing S/N: Total Time on Wing (in hrs):

Inspection Findings (use Figure 2 diagram below to indicate location of findings):



### Additional Comments:

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

- 656

- 0673

30

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- 201 4 S.B. V3/0002

Revision ‘ C ’ Page 9 of 12

### SERVICE BULLETIN V3/0002



## 4 3 2 1 37.15



## 8 7 6 5 47.5



## 11 10 9 60



## 14 13 12 72.5



## 17 16 15 85



## 20 19 18 97.5



## 23 22 21 110



## 26 25 24 122.5



## 29 28 27 135



## 32 31 30 147.5



## 35 34 33 160



## 38 37 36 172.5



## 41 40 39 185



## 44 43 42 197.5



## 47 46 45 210



## 50 49 48 222.5



## 53 52 51 235



## 56 55 54 247.5



## 59 58 57 260



## 62 61 60 272.5



## 65 64 63 285



## 68 67 66 297.5



## 71 70 69 310



## 74 73 72 322.5



### F IGURE 

### 2

– F INDING 

### L OCATION 

### D IAGRAM 335 Front Spar Main Spar Rear Spar Sta. No.NOTE:NOT TOSCALE–FORREFERENCEPURPOSESONLY

LEFT HAND WING

– LOOKING UP AT TOP SKIN Document all findings and crack locations on this page Noting length, WS position, rivet locations, loose, oversized or blind fasteners, etc. 30

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Revision ‘ C ’ Page 10 of 12

### SERVICE BULLETIN V3/0002



### Service Bulletin V3/0002

– Operator Reply Form (Right Hand Wing)
Operator Name:

Contact Person:

Contact Phone/Email :

A

/C Serial Number:

Wing S/N: Total Time on Wing (in hrs):

Inspection Findings (use Figure 3 diagram below to indicate location of findings):



### Additional Comments:

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

- 656

- 0673

30

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Revision ‘ C ’ Page 11 of 12

### SERVICE BULLETIN V3/0002



## 1 2 3 4 37.15



## 5 6 7 8 47.5



## 9 10 11 60



## 12 12 14 72.5



## 15 16 17 85



## 18 19 20 97.5



## 21 22 23 110



## 24 25 26 122.5



## 27 28 29 135



## 30 31 32 147.5



## 33 34 35 160



## 36 37 38 172.5



## 39 40 41 185



## 42 43 44 197.5



## 45 46 47 210



## 48 49 50 222.5



## 51 52 53 235



## 54 55 56 247.5



## 57 58 59 260



## 60 61 62 272.5



## 63 64 65 285



## 66 67 68 297.5



## 69 70 71 310



## 72 73 74 322.5



### F IGURE 

### 3

– F INDING 

### L OCATION 

### D IAGRAM Rear Spar Main Spar Front Spar Sta. No.

335

RIGHT HAND WING

– LOOKING UP AT TOP SKIN Document all findings and crack locations on this page Noting length, WS position, rivet locations, loose, oversized or blind fasteners, etc. 30

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Revision ‘ C ’ Page 12 of 12