Feb 12/2013

KELOWNA Flightcraft Ltd. CONVAIR® DIVISION

SERVICE BULLETIN SB 340-57-001

Page 1 of 5

INSPECTION OF LOWER WING SKIN FOR CRACKS BETWEEN WS 5 AND WS 6

1. Summary

This service bulletin gives the following:

• Planning information containing effectivity, reason, description, compliance, manpower and 

references; and

• accomplishment instructions containing the detailed procedures for incorporating the service 

bulletin on the aircraft.

2. Planning Information

A. Effectivity

• CV340, CV440 and C-131 (Military) series airplanes.

• CV580 (CV340/440 aircraft modified by TCCA STC SA00-140) airplanes.

• CV5800 (CV340/440 aircraft modified by TCCA STC SA93-208) airplanes.

• CV640 (CV340/440 aircraft modified by TCCA STC SA00-135) airplanes.

B. Concurrent Requirements

Not applicable.

C. Reason

An operator has found a crack in the wing lower surface skin from a fastener location 

attaching the wing access door doubler finger to the skin. The crack was found during a 

general internal inspection for corrosion.

General Dynamics Convair Division Report No. ZS-340-1000 Revision 1 Addendum I, II and 

IV, Structurally Significant Detail (SSD) 57-1-4 provides instructions to inspect the lower 

surface skin at the end rivets attaching the access door doubler fingers to the lower surface 

skin. SSD 57-1-4 instructs to accomplish external visual or dye penetrant inspections of the 

skin. The inspections per Report ZS-340-1000 are mandated by AD 92-06-06.

The external inspection of the wing lower surface skin specified by SSD 57-1-4 in the area of 

the access door doubler finger attachment located between WS 5 and WS 6 is not effective. 

The lower surface skin at this location is covered by the nacelle drag angle. 

D. Description

This service bulletin describes how to inspect the wing lower surface skin between WS 5 and 

WS 6 at the WS 6-7 access door doubler fingers.
Feb 12/2013

KELOWNA Flightcraft Ltd. CONVAIR® DIVISION

SERVICE BULLETIN SB 340-57-001

Page 2 of 5

E. Compliance

A visual inspection must be done within 20 hours, and a high frequency eddy current (HFEC) 

inspection within 100 hours after receiving this service bulletin.

These service bulletin inspections must be repeated every 1000 hours after the initial 

inspection has been completed. 

Operators with a Damage Rate Factor (DRF) must divide 1000 hours by their DRF to get the 

next inspection interval. For example:

• Inspection interval = 1000 / 7 = 142 Hours 

F. Approval

This service bulletin has been reviewed by Transport Canada Civil Aviation and the 

inspection herein complies with the applicable Aviation Regulations and is APPROVED.

The service bulletin is approved as an alternate means of compliance to AD 92-06-06 for 

SSD item number 57-1-4 and is specific to the area of the LH and RH lower wing skin surface 

between WS 5 and WS 6.

This Service Bulletin and it’s approval is based on the configurations listed in Paragraph 2., 

A. Effectivity. If the airplane has a modification or repair done to the area of the structure 

inspected, the operator is responsible for obtaining the appropriate regulatory agency 

approval.

G. Manpower

AME – 6 hours.

Aircraft downtime up to 6 hours.

H. Weight and Balance

Not affected.

I. Electrical Load Data

Not affected.

J. Software Accomplishment Survey

Not applicable.

K. References

1CC2-1, Allison Prop-jet Convair Maintenance Manual, dated 1 March 1984 or latest 

revision.

Kelowna Flightcraft NDT Technique 5-0201 (General HFEC Inspection of Metallic Structures 

or equivalent).
Feb 12/2013

KELOWNA Flightcraft Ltd. CONVAIR® DIVISION

SERVICE BULLETIN SB 340-57-001

Page 3 of 5

L. Other Publications Affected

Not applicable.

M. Interchangeability or Intermixability of Parts

Not applicable.

3. Material Information

A. Material

None.

B. Industry Support Information

Inform Kelowna Flightcraft Ltd. when this service bulletin has been incorporated:

Kelowna Flightcraft Ltd. Engineering Department

5655 Airport Way

Kelowna, BC

V1V 1S1

Canada

Phone: (250) 807-5416

FAX: (250) 765-7140

E-mail: kflengineering@flightcraft.ca

C. Material Necessary for Each Aircraft

Not applicable.

D. Material Necessary for Each Spare

Not applicable.

E. Re-identified Parts

Not applicable.

F. Tooling

Not applicable.
Feb 12/2013

KELOWNA Flightcraft Ltd. CONVAIR® DIVISION

SERVICE BULLETIN SB 340-57-001

Page 4 of 5

4. Accomplishment Instructions.

Refer to Figure 1.

A. Do an inspection on both the LH and RH wing as follows:

(1) Remove the No. 2 dry bay access panels.

(2) Get access to the No. 2 dry bay wing interior.

(3) Do a detailed visual inspection of area around the inboard side of WS 6-7 access panel 

doubler fingers and between STGR’s 5 and 11.

(4) Do a High Frequency Eddy Current (HFEC) inspection of the lower skin area at STRG’S 

6, 8, and 10 and the WS 6-7 access panel doubler fingers. Refer to Kelowna Flightcraft 

NDT Technique 5-0201.

(5) Record findings (crack or no crack) in Table 1 - Inspection Results. 

NOTE: Report all findings (negative or positive) to Kelowna Flightcraft Convair 

Division (matt_palmberg@flghtcraft.ca).

B. Test

Not applicable

C. Material Sample Removals

Not applicable.

Table 1: Inspection Results

Serial Number Hours Cycles Crack Detected

No Yes Comments
Feb 12/2013 

KELOWNA Flightcraft Ltd. CONVAIR® DIVISION

SERVICE BULLETIN

Figure 1. Inspection of Wing Lower Surface WS 5-6