This document is property of the Vulcanair S.p.A. and is issued with the understanding that neither this document, nor any of the information it contains shall be reproduced, copied, used for the manufacture, repair or overhaul of any apparatus or otherwise disclosed to anyone outside the recipient’s busine ss organisation without written consent of the Vulcanair S.p.A. 

# P68 Variants

NOR10.771-52 1 st 

# ISSUE (01 March 2010)

MAINTENANCE MANUAL SUPPLEMENT

Approved by EASA with No. 10028661 on 02 February 2010



# WING SAFE LIFE LIMITS AND RELEVANT INSPECTIONS ON WING AND STABILATOR STRUCTURES (As per change No. 

## MOD.P68/144) - Applicable to all the P68 Aircraft Variants -

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page i 

### LIST OF EFFECTIVE PAGES

Page

TITLE ......................................................................................................................... 0

LISTOF EFFECTIVE PAGES ................................................................................. i

LOG OF REVISIONS ............................................................................................... ii

RECORD OF TEMPORARY REVISIONS ........................................................... iii

LIST OF APPLICABLE SERVICE BULLETINS ................................................ iv

TABLE OF CONTENTS .......................................................................... 1

GENERAL ................................................................................................................. 2

1. DESCRIPTION............................................................................. 1-1

2. AIRWORTHINESS LIMITATIONS ....................................................... 2-1 through 2-7

3. INSTRUCTIONS FOR SPECIAL INSPECTIONS ................................... 3-1 through 3-7

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page ii 

### LOG OF REVISIONS

REF. APPROVAL REV.

No. REVISED PAGES DATE No. Dated

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page iii 

### RECORD OF TEMPO RARY REVISIONS (Revisions which do not require EASA Approval) (To be compiled by operator)

REV.

No. ISSUE DATE INSERTION DATE BY REV. No ISSUE DATE INSERTION DATE BY

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page iv 

### LIST OF APPLICABLE SERVICE BULLETINS (To be compiled by operator)

SERVICE BULLETIN No. ISSUE DATE SUBJECT REVISION No. INCORP. DATE

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 1 

### TABLE OF CONTENTS

Page
GENERAL ....................................................................................................................... ................. 2

1. DESCRIPTION.......................... .................................................................................... 1-1

2. AIRWORTHINESS LIMITATIONS ...................................................................... 2-1
2.1 SAFE LIFE LIMITS OF WING STRUCTURE ................................................. 2-1

2.2 CERTIFICATION MAINTENAN CE REQUIREMENTS (CMR) ...................... 2-6

3. INSTRUCTIONS FOR INSPECTIONS ............................................................ 3-1 3.1 INSTRUCTIONS FOR SPECIAL INSPECTIONS ON THE WING STRUCTURE...................................................................................................... 3-1
3.2 INSTRUCTIONS FOR INSPEC TIONS ON THE STABILATOR STRUCTURE...................................................................................................... 3-7

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 2 

### GENERAL

This supplement must be attached to the Approved Ai rcraft Maintenance Manual of all the P.68 aircraft variants (P.68, P.68B, P.68R, P.68C , P.68C-TC, P.68 Observer, P.68T C Observer, P.68 Observer 2). It provides the Airworthiness Li mitations for wing structure and the special inspections for wing and stabilator structures.

The instructions herein contained are for use of on ly competent Authority approved Maintenance Repair and Overhaul facilities.

WARNING This document calls for the use of substances and/or procedures that may be injurious to health if adequate precautions are not taken. This document refers only to technical suitability and in no way absolv es the Operator from statutory and other legal obligation relating to health and safety at an y stage of manufacture or

use.

CAUTION This document has been released including the latest engineering information. Vulcanair reserves the right to revise the document. Always contact Vulcanair to obtain the current (valid) re lease of this document.

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 1-1 

### 1. DESCRIPTION

This supplement establishes the Safe Life Limits for wing structure and th e Special Inspections to be carried out on wing and stabilator st ructures as per change No. MOD.P68/144.

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 2-1 

### 2. AIRWORTHINES S LIMITATIONS

2.1 SAFE LIFE LIMITS OF WING STRUCTURE

For aircraft from S/N 357 onward s (see SECTION 2 on Table 2-1)

The Safe Life Limit of the wi ng structure is established in:

a) 23900 Flight Hours for only P.68 aircraft variants not embodying the change No. MOD.P68/97 or No. MOD.P68/124.

b) 21550 Flight Hours for only P.68 aircraft variants embodying the change No. MOD.P68/97 or No. MOD.P68/124.

For aircraft from S/N 01 up to S/N 356 (see SECTION 1 on Table 2-1)

Table 2-1 hereunder shows the Safe Life Limits of the wing structure as a function of wing spar configuration. This table must be read by crossing rows and columns; it is divided into 2 sections and 6 columns as follows:
SECTION 1 shows the conditions applicable from S/N 01 up to and including S/N 356.
SECTION 2 shows the condition applicable from a nd including S/N 357 onwards.
COLUMNS 1 and 2 show the application or not of the modification kit required by Service Bulletin No. 65, first issue or revision 1 or 2 or 3.
COLUMN 3 shows the result of the inspection required by Service Bulletin No. 65, first issue or revision 1 or 2 or 3 (crack found or not on the concerned area of the wing front spars).
COLUMN 4 shows the Safe Life Limits of the wing structure.
COLUMN 5 shows the applicable Continued Airworthiness Requirements that must be complied up to Wing Safe Life Limit is reached.
COLUMN 6 shows the action to be performed to extend the Wing Safe Life Limit where allowable.

The following data are necessary for the Table 2- 1 reading in order to i ndividuate which of the conditions in rows from (a) through (f) is applicable for the concerned aircraft:

For aircraft from S/N 01 up to and including S/N 356: a) Aircraft Serial Number; b) Application of Service Bulletin No. 6 5, first issue or revision 1 or 2 or 3: - Whether or not the modification kit require d by Service Bulletin No. 65, first issue or revision 1 or 2 or 3 was installed (columns 1 and 2);

- Crack found or not in the concerne d wing front spar areas (column 3).

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 2-2 For aircraft from and including S/N 357 onwards:

a) Aircraft Serial Number; b) If the aircraft embodies or not the ch ange No. MOD.P68/97 or No. MOD.P68/124.

Four practical examples for the Table 2-1 reading are below reported:

Example 1 a) Aircraft S/N 335; b) Kit 68-037 installed; c) Front spars without cracks in the critical area indicated by Service Bulletin No. 65 first issue or revision 1.

The data a) locate the Section 1 as applicable for Aircraft Serial Number; The data b) locate the Column 1 as applicable for type of m odification carried out on wing front spars (refer to Service Bulletin No. 65 first issue); The data c) locate the condition in row (b) as applicable for this example; Crossing the row (b) with Column 4 it results that the Safe Life Limit for the wing structure is 21500 flight hours. Crossing the row (b) with Column 5 it results the Continued Airworthiness Requirements that must be complied up to Wing Safe Life Limi t is reached, are as per the paragraph 2.2 hereunder. Crossing the row (b) with Column 6 it results th at no extension of wing Safe Life Limit is allowable.

Example 2 a) Aircraft S/N 287; b) Kit 68-038 installed; c) Front spars with cracks in the critical area i ndicated by Service Bull etin No. 65 revision 2 or 3.

The data a) locate the Section 1 as applicable for Aircraft Serial Number; The data b) locate the Column 2 as applicable for type of m odification carried out on wing front spars (refer to Service Bulletin No. 65 rev. 2 or 3); The data c) locate the condition in row (e) as applicable for this example. Crossing the row (e) with Column 4 it results that the Safe Life Limit for the wing structure is 23900 flight hours.

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 2-3 Crossing the row (e) with Column 5 it results to be complied with a Mandatory Action that requires to repair the wing front spars as per Service Instruction No. 88, within the time of compliance stated in the Service Bulletin No. 162. Crossing the row (e) with Column 6 it results th at no extension of wing Safe Life Limit is allowable.

Example 3 a) Aircraft S/N 303; b) Kit 68-038 installed; c) Front spars without crac ks in the critical ar ea indicated by Service Bulletin No. 65 revision 2 or 3.

The data a) locate the Section 1 as applicable for Aircraft Serial Number; The data b) locate the Column 2 as applicable for type of m odification carried out on wing front spars (refer to Service Bulletin No. 65 rev. 2 or 3); The data c) locate condition in row (d) as applicable for this example. Crossing the row (d) with Column 4 it results th at the Safe Life Limit for the wing structure (23900 flight hours max) must be calculated as per the instructions hereunder. Crossing the row (d) with Column 5 it results the Continued Airworthiness Requirements that must be complied up to Wing Safe Life Limi t is reached, are as per the paragraph 2.2 hereunder. Crossing the row (d) with Column 6 it results th at no extension of wing Safe Life Limit is allowable.

Example 4 a) Aircraft S/N 442.

The data a) locate the Section 2 (row f) as applicable for Aircraft Serial Number. Crossing the row (f) with Column 4 it results that the Safe Life Limit for the wing structure is: - 23900 flight hours if the aircraft does not embody the change No. MOD.P68/97 or No. MOD.P68/124; - 21550 flight hours if the aircraft embodi es the change No. MOD.P68/97 or No. MOD.P68/124. Crossing the row (f) with Column 5 it results the Continued Airworthiness Requirements that must be complied up to Wing Safe life Limit is reached, are as per the paragraph 2.2 hereunder. Crossing the row (d) with Column 6 it results th at no extension of wing Safe Life Limit is allowable.

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 2-4

COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6

Kit 68-037 or kit 68-037/B (Ref. SB 65 rev. 0 or rev. 1) Kit 68-038 (Ref. SB 65

rev. 2 or rev. 3) Spar Crack Safe Life (flight hours) Continued Airworthiness Requirements

up to SLL Safe Life extension

(a) NO NO NO 16200 As per paragraph 2.2

hereunder It is possible to extend safe life up to 23900 by replacing the four main spar lower cap angles (Kit SB162) and installing reinforcements P/N 1.4145-001/-002 (Kit SB 162/A) as per S.I. No. 89

(b) YES ---------- NO 21500 As per paragraph 2.2

hereunder --------------

(c) YES ---------- YES 13400 As per paragraph 2.2

hereunder It is possible to extend safe life up to 21500 by replacing the four main spar lower cap angles (Kit SB162) as per S.I. No. 89

(d) ---------- YES NO To be calculated as explained

hereunder (23900 max) As per paragraph 2.2

hereunder -------------- S E C
T I O N

1From S/N 01 up to and including S/N 356

(e) ---------- YES YES 23900 (See Column 5) Mandatory Action Replace the four main spar lower cap angles (Kit SB162) as per S.I. No. 88 within within the time of compliance stated in SB 162. After repair proceed as per paragraph 2.2 hereunder --------------

23900
If the aircraft does not embody Mod. P68/97 or Mod. P68/124 (*) S E C
T I O N

2From S/N 357

(f) ---------- ---------- ----------
21550
If the aircraft

embodies Mod. P68/97 or Mod. P68/124 (*) As per paragraph 2.2

hereunder --------------

Table 2-1 - Safe Life Limits of the wing stru cture as function of wing spar configuration
Note (*): Mod. P68/97 increases MZFW up to 1967kg on P.68C and P.68C-TC aircraft from s/n 443 onwards; Mod. P68/124 increases MZFW up to 1967kg on P.68C aircraft from s/n 402 to s/n 440 included.

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 2-5 For aircraft from S/N 01 up to S/N 356 affected by condition reported in row (d) of Table 2-1

Safe Life Limit to be calculated For aircraft from S/N 01 up to and includi ng S/N 356 on which no cr acks were found on the concerned areas of the front and rear wing sp ars during inspections in accordance with the Mandatory Service Bulletin No. 65 and on which the modifica tion Kit 68-038 was installed in accordance with Revision 2 or Revision 3 of the sa me Service Bulletin, the new Safe Life Limit (SLL) in flight hours must be determined thr ough a calculation taking into account the flight hours accumulated before the installation of the Kit 68-038 as detailed hereunder:

) 4753

. 0 ( 23900 Y SLL

⋅ − =
Where “Y” represents the accumulated flight hours before installation of the Kit 68-038.

Practical example: Consider an aircraft which ha d installed Kit 68-038 with 3456 flight hours accumulated on the wing structure:

s flighthour SLL 22319 ) 3456 4753

. 0 ( 23900 = ⋅ − =

For all the aircraft

Safe Life Limit for the new wing stru cture which is installed as spare part

In case the wing structure is replaced with ne w one incorporating the reinforcements P/N 1.4153- 1 and P/N 1.4141-1 or P/N 1.415- 001 and P/N 1.4145-002, as applicab le, on the front and rear wing spars, together with the re levant wing to fuselage attachme nts, the Safe Life Limit on the wing structure will be:

• 23900 Flight Hours for all the P.68 aircraft variants up to S/N 356;

• 23900 Flight Hours only for P.68 aircraft vari ants from S/N 357 onwards not embodying the change No. MOD.P68/ 97 or No. MOD.P68/124;

• 21550 Flight Hours only for P.68 aircraft variants from S/N 357 onwards embodying the change No. MOD.P68/97 or No. MOD.P68/124.

For the replacement of the wing, contact Vulcanair to obtain al l the information necessary and for a proper technical support pr ovide it with the following:

1. Aircraft Type and Serial Number; 2. Registration Marks;

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 2-6 3. Fuel Tanks capacity; 4. If the aircraft is equipped with th e Integral Wing Auxiliary Fuel Tanks; 5. All the required parts needed for the wing replacement; 6. List of all the equipment installed on the wing; 7. Aircraft owner inclusive of postal and e-mail address; 8. Any other information you think it is important.



### 2.2 CERTIFICATION MA INTENANCE REQUIREMENTS (CMR)

Mandatory inspections have been established for th e wing and stabilator structures to be added to the current approved maintenan ce program of the aircraft.



### SPECIAL INSPECTIONS ON THE WING STRUCTURE

The inspections on the wing structure are classified as “Special” only because they are dictated by the necessity to keep under surveillance the wing structure in the critical locations. The following Special Inspection Chart (Table 2-2) shows the mandatory intervals at which the wing structure is to be inspected:

NATURE OF SPECIAL INSPECTION INSPECTION INTERVALS



### WING STRUCTURE Check for absence of fatigue crack and corrosion the front and rear spars on wing areas indicated with numbers 1, 2 and 3 in Figure 3-1, in accordance with the procedure explained in paragraph 3.1 hereunder. First Special Inspection at 6000 flight hours, and subsequent Special Inspections at 12000 and 18000 flight hours.

Note:

Only for aircraft affected by the condition reported in row (e) of Table 2-1 in paragraph 2.1, the first Special Inspection on the wing structure must be performed conjointly with the mandatory modification to be carried out, then proceed with subsequent Special Inspections every 6000 flight hours thereafter up to the wing Safe Life Limit is reached. For these aircraft the Maintenance Program must be updated as per Table 2-4 hereunder.

Table 2-2 Special Inspection Chart on the wing structure

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 2-7 

### INSPECTIONS ON THE ST ABILATOR STRUCTURE

The following Inspection Chart (Table 2-3) shows th e mandatory intervals at which the stabilator structure is to be inspected:

NATURE OF INSPECTION INSPECTION INTERVALS



### STABILATOR STRUCTURE
Check for absence of corrosion and cracks of all the inside parts of the stabilator structure in accordance with the procedure explained in paragraph 3.2 hereunder. First inspection at 8500 flight hours and subsequent repetitive inspections every 500 flight hours.

Table 2-3 Inspection Chart on the stabilator structure

Only for aircraft affected by the condition repo rted in row (e) of Table 2-1 in paragraph 2.1 and for aircraft affected by conditions reported in rows (a) and (c) in the same Table 2-1, if these last have embodied the optional instal lation of the Kit SB162 or Kit SB162 plus Kit SB162/A, as applicable, in order to extend the Wing Safe Life Limit.

For these aircraft the Maintenance Program must be updated adding the following inspections to the current approved maintenan ce program of the aircraft:

NATURE OF INSPECTION INSPECTION INTERVALS

LEFT AND RIGHT WING FRONT SPAR REPAIRED AS PER DRAWING R.0441 Check the area of the front spar of the wing concerned by the repair scheme R.0441 for condition. Referring to drawing R.0441, check installation of the doublers item 2 for security. At every 1500 flight hours or every 5 years, whichever occurs first, conjointly with the Scheduled Maintenance Program in the latest applicable revision of the basic aircraft Maintenance Manual.

Table 2-4

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 3-1



### 3. INSTRUCTIONS FOR INSPECTIONS

3.1 INSTRUCTIONS FOR SPECIA L INSPECTIONS ON THE WING STRUCTURE

INSPECTIONS IN AREAS 1 and 3 (R efer to Figures 3-1 through 3-4)

NOTE: The following instructions are for both wing structures.

1. Switch OFF all electrical loads, remove th e baggage bulkhead and disconnect the battery wires (negative wire first); 2. Referring to removal procedures laid out in the applicable aircraft Maintenance Manual,

remove:

a. The cabin ceiling panel in the wing area and soundproof materi al if present; b. The wing to fuselage fillets and the upper centre fairing;

c. The engine cowlings; d. The inboard and outboard wing leading edges;

e. The inspection access covers under th e wing skin, near the wing root; 3. Position a trestle with height adjustable cradles under each left and right wing in correspondence with ribs. No.17; 4. Referring to Figure 3-2 DETAIL A, one at time remove the two nearest wing centre line fastening bolts from the front spar upper and lo wer caps joining plates and, with the aid of 10x magnifying glass, carry out a visual insp ection of the removed bolts for corrosion and cracks. In any case discard the removed bolts to be replaced with new ones;
5. Using a rigid boroscope of an appropriate diamet er, positioned at a right angle with a visual angle of 60 degrees, perform a visual inspec tion of the holes for corrosion and cracks;
6. If during above inspections, seve re corrosion and/or cracks are f ound, one at time remove all the remaining bolts and inspect the bolts an d holes as per the previous steps 4 and 5 respectively. In any case discard the removed bolts to be replaced with new ones. Repair the damaged wing structure in accordance with the Re pair Procedures laid out in the FAA AC 43.13-1B;
7. In absence of damage, referring to Figure 3-2, install new bolts in replacement of the previously removed ones, interposing a film of corrosion inhibitive compound (Specification MIL-PRF-8116C). Torque to 247-273 lb.in.;
8. Referring to Figure 3-2 DETAIL B, one at time remove the two nearest wing centre line fastening bolts, from the rear spar upper and lo wer caps joining plates and, with the aid of 10x magnifying glass, carry out a visual insp ection of the removed bolts for corrosion and cracks. In any case discard the removed bolts to be replaced with new ones;
9. Using a rigid boroscope of an appropriate diamet er, positioned at a right angle with a visual angle of 60 degrees, perform a visual inspec tion of the holes for corrosion and cracks;
10. If during above inspections, seve re corrosion and/or cracks are f ound, one at time remove all the remaining bolts and inspect the bolts an d holes as per the previous step 8 and 9 respectively. In any case discard the removed bolts to be replaced with new ones. Repair the damaged wing structure in accordance with the Re pair Procedures laid out in the FAA AC 43.13-1B;

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 3-2 11. In absence of damage, referring to Figure 3-2, install new bolts in replacement of the previously removed ones, interposing a film of corrosion inhibitive compound (Specification MIL-PRF-8116C). Torque to 247-273 lb.in.;
12. Carry out a detailed visual inspection of the fr ont and rear spar caps and spar webs in the Area 1 and 3 in Figure 3-1; in particular, after to have cleaned the area from eventual dirty, visually inspect the front and rear spar lowe r caps in the attachment to fuselage zone for corrosion and absence of fatigue crack with the aid of a powerful light source (see Figure 3- 3), positioning the light beam with an angle from 5° to 45° (see Figure 3-4). Only for aircraft affected by the conditions reported in rows (a), (b), (c) and (d) on Table 2-1 in paragraph 2.1, in presence of cracks, perform a more detail ed inspection using a ma gnifying glass 5x and, within the next 100 flight hours, replace the f our lower spar cap angles according to the to Service Instruction No. 89 to be downloade d from Vulcanair web site www.vulcanair.com;
13. For aircraft affected by the conditions reported in rows (e) and (f) on Table 2-1 in paragraph 2.1, if a cracks is detected, please contact Vu lcanair for the correctiv e action to be taken;
14. In absence of damage, where necessary, clean the wing areas with Methyl-ethyl-Ketone or equivalent cleaning solvent and touch up themwith epoxy primer (Specification MIL-PRF23377); 15. In any case communicate to Vulcanair the results of the insp ection performed.

INSPECTIONS IN AREA 2 (Refer to Figure 3-1)

16. Using a suitable boroscope, through the latera l gaps between the engine firewall and the wing front spar, inspect the wing spar web and spar caps for cracks and corrosion in the areas behind the firewall; 17. Open the two inspection access covers located at the rear and under the engine nacelles. Refer to Service Bulletin No. 93 for P.68 Series aircraft up to and including S/N 400; 18. Using a suitable boroscope, through the in spection holes under the engine nacelles, previously opened, accurately inspect the areas of the front and rear spars on the inside of the wing box for corrosion and cracks, as well as the relative wing rib attachments; 19. With the aid of a powerful light source and 10x magnifying glass, visually inspect all the accessible areas of the wing sp ars for cracks and corrosion; 20. Should any damage be detected, as a result of the above inspections, repair in accordance with the Repair Procedure laid out in the FAA AC 43.13-1B; 21. Referring to installation procedur es laid out in the applicable aircraft Maintenance Manual, reinstall the left and right i nboard and outboard wing leading edges, the engine cowlings and all the previously removed items. Clos e all the opened inspection access holes.

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 3-3 1. Spar area between the wing to fuselage attachments. 2. Spar area near the nacelle fi rewall and its adjacent areas. 3. Spar area between the wing root and engine mount.



### Figure 3-1 Spar Areas for - Non Dest ructive Inspections (NDI)

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 3-4 

### Figure 3-2 Spar Joining Plates

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 3-5 

### Figure 3-3

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 3-6 

### Figure 3-4

### P68 variants MAIN TENANCE MANUAL
SUPPLEMENT NOR10.771-52

ISSUED: March 2010 Page 3-7



### 3.2 INSTRUCTIONS FOR INSPECTION S ON THE STABIL ATOR STRUCTURE

1. Referring to removal procedure laid out in th e basic Aircraft Maintenance Manual, remove the two half stabilator structures; 2. On bench, with the aid of a suitable boroscope, inspect the inside struct ural parts of the both half stabilator structures for co rrosion and cracks. Should any dama ge be detected as a result of the above inspections, repair in accordance with the Repair Procedure laid out in the FAA AC 43.13-1B; 3. In absence of damage, with re ference to the installation procedure laid out in the basic Aircraft Maintenance Manual, reinstall the two half stabilator structures; 4. No stabilator backlash is permissible. Refe rring to figure 3-5, check the stabilator for horizontal and vertical backlash as follows: a) Acting on the tip of the left or right half stabilator, lightly shake the half stabilator longitudinally, up and down and along its hinge bearing axis and check for absence of backlash. Repeat above check for th e other remaining half stabilator.



### Figure 3-5