~PILATUS~ 

TM-06-000004 

Iss ue 01, Page 1 of 4 16.05.2013 

Technical Memo 

METRIC RIVET ISSUE - FERRY FLIGHT CONDITION 

1 INTRODUCTION 

Metric rivets with an ultimate shear allowable of about 50% were installed on several PC·6 

assemblies on new production aircraft and some spare parts. The affected in-service PC-6 are MSN 

735, 863, 909, 923, 948, 956, 958, 977, 978, 979, 980, 981, 982, 985 and 986. 

The affected rivets are Solid Rivet, Universal Head, Aluminium Alloy 2117·T4 with a diameter 

3.0mm and 3.5mm having specific lengths. The affected PI N's are: 

• PI N 939.16.81.275 Solid Rivet, Universal Head, Aluminium Alloy 2117-T4, 3.0*6 

• PI N 939.16.81.277 Solid Rivet, Universal Head, Aluminium Alloy 2117-T4, 3.0 * 7 

• PI N 939.16.81.301 Solid Rivet, Universal Head, Aluminium Alloy 2117-T4, 3.5*8 

• PI N 939.16.81.303 Solid Rivet, Universal Head, Aluminium Alloy 2117·T4, 3.5*10 

• PI N 939.16.81.304 Solid Rivet, Universal Head, Aluminium Alloy 2117-T4, 3 .5* 11 

The affected rivets must be replaced. A ferry flight to a repair station might be necessary. 

The scope of this memo is to define the ferry flight condition and a pre-flight inspection. 

2 MAIN SECTION 

2.1 AFFECTED STRUCTURE 

The affected PC-6 are not affected to the same extent. Figure 6-3 and Table 7-1 provide an overview 

of the affected structural areas and serve as basis for the pre·flight inspection defined in the next 

chapter. 

Not affected are the components flap, horizontal stabilizer, elevator, cockpit doors and cabin doors. 

2.2 INSPECTION BEFORE FERRY FLIGHT 

Before a potentially necessary ferry flight the following pre-flight inspection shall be performed. 

Perform a visual inspection of the aircraft skins as being identified as affected in the previous 

chapter. The inspection focus is on loose or missing rivets. 

If affected by the wing, perform an additional visual inspection as follows. 

TO EASA 

CC 

Department ECE ECE EC ECV E 

Approvals Author Checked Approved Verified Approved 

Name M.,Kell, r JMangold M. Keiser D. Bretscher A. von Rotz B. Cervia'------

Si

Date 

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1

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6.05.20'13 

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f.I t.c'lQ) 

S A3 

(7f- • ~ <I ~ /0 J.d.J 4(,. 0 . 13 ~b_>;f3 

Onglnal @ Group of Author 
TM-06-000004 Issue 01, Page 2 of 4 16.05.2013

 Remove access panels LB10 and RB9 to get access to wing strut fitting installation area as 

per AMM 57-00-02. See Figure 6-1.

 Inspect shear field and vertical stiffener rivet positions 1 to 8 as identified Figure 6-2 with the 

aid of a lamp and inspection mirror for any signs of rivet deterioration. If any sign of 

deterioration is found, contact Pilatus for assistance.

2.3 FERRY FLIGHT CONDITION

The scope of the ferry flight condition is to define a minimum airframe loading for a potentially 

necessary ferry flight to the repair station.

 Flight to be made in calm air conditions

 No abrupt manoeuvres

 Maximum bank angle of 45°

 Maximum speed not to exceed VC = VA = 119 knots IAS

 Minimum Fuel required for ferry flight

 Empty cabin except empty seats

3 PILATUS POSITION

Successful completion of the pre-flight inspection and considering the ferry flight condition defined 

in this memo the PC-6 affected by the rivet issue satisfies the continued airworthiness for a one 

time ferry flight to a repair station.

4 REFERENCES

[1] Document No. 01975, PC-6 B2-H2/B2-H4 Aircraft Maintenance Manual

5 REVISIONS

Issue 01: Initial Issue
TM-06-000004 Issue 01, Page 3 of 4 16.05.2013

6 FIGURES

Figure 6-1 Wing Access Panels LB10 and RB09

Figure 6-2 Shear Field and Vertical Stiffeners above Wing Strut Attachment Fitting

1 2 3 4

6

7

8

5

Side View

Up View
TM-06-000004 Issue 01, Page 4 of 4 16.05.2013

Figure 6-3 Affected Skins

7 TABLES

Table 7-1 Affected Skins per MSN MSN Wing Aileron Engine Cowling Fuselage Floor Rear Fuselage Rudder Tail Cone, short

New Production 977 X

978 X X

979 X X

980 X X X X X X X

981 X X X X X X X

982 X X X X X X X

985 X X X X X X X

986 X X X X X X X

Spares 735 X

863 X

909 X

923 X

948 X

956 X

958 X

Tail Cone , short, 

Frames 12-13