Via Giavann iAgusta ,520

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**~-- ----**  **---- -------**  **-AN** AGUSTAWESTLAND C O M PANY 

# =tJj------- TRANSLATION OF 

## BOLLETTINO TECNICO N" 

# 109-110
The technical content ofthis document is approved under the authority of DOA nr. EASA
.21J
.005 DATE July 28, 1999

Compl iance with this bulletin is: 

# MANDATORY REv
.A December 12, 2005

THIS BOLLETTINO CANCELS AND SUPERSEDES THE BOLLETTINO TECNICO TELEGRAFICO 

### W 109-5, DATED JANUARY 27, 1987. SUBJECT: INSPECTION FOR CRACKS OF TAIL ROTOR BLADES P/N 

# lA 109-0132-02-11/-15/-121
. REASON: To emphasize the importance of performing a detailed inspection of the subject tail rotor blades for cracks , already prescribed in Bollettino tecnico telegrafico no 109-5, dated January 27, 1987
. HELICOPTERS AFFECTED: All Agusta helicopters A109A and A109AII equipped with tail rotor blades P/N 109-0132-02-11/-15/-121 with 400 (four-hundred) or more flight 

# lA hours
.

COMPLIANCE: PART 

### 1": NOTE Tail rotor blades P/N 109-0132-02-125 do not require compliance with this Bollettino. Upon receipt of this Bollettino for blades having accumulated 400 (four hundred) flight hours, if the Bollettino tecnico telegrafico no 109-5, dated January 27, 1987 has not been accomplished. PART II": Prior to the first flight ofthe day
. PART Ill": Each 100 (hundred) flight hours
.
An appropriate entry should be mode in 'the aircraft lag book upon accomplishment If ownership of aircraft hos changed, please, forward to new owner. Page 1 of 6 

# lAB
.T. 109-110
DESCRIPTION : A second case has been reported of failure of one tail rotor blade P/N 109-0132-02, followed by the loss oftail rotor and 90° gearbox assembly. The crack originated in the central area of the blade , in proximity of the tip of the root doubler in the chordwise sense. The scope of this Bollettino is to prescribe a visual inspection (PART II/\) and a liquid penetrant inspection (PART 

### 1/\ and PART IW) for presence of eventual cracks
. Subsequently new tail rotor blade P/N 109-0132-02-125 were designed and certified which have improved structural characteristics with respect to the blades P/N 109-0132-02-11/-15/-121 , and do not require compliance with this Bollettino. REQUIRED MANPOWER: The following estimated manpower hours are necessary, for each blade , for compliance with this Bollettino : PART 

### 1/\: 1
.5 manpower PART 11/\: negligible PART 

### 111/\: 1 manpower WARRANTY: N
.A. REQUIRED MATERIALS: The following consumable materials are Bollettino: necessary to accomplish this PART 

### 1/\: SPECIFICATION MIL-R-25134 MIL-L-81352 or MIL-PRF-81352 NOMENCLATURE Ardrox 204S , solvent (code 531 056779) Transparent acrylic lacquer Q
.TY A.R. A.R.

. In addition the materials indicated in the PART IW of this Bollettino are

necessary.

A 

## I Page 2 of 6 PART 11/\: SPECIFICATION TT-N-95 PARTE 

### 111/\:. SPECIFICATION TT-N-95 NOMENCLATURE Aliphatic naphtha (code 531 055030) NOMENCLATURE Aliphatic naphtha (code 531 055030) Materials to perform the liquid penetrant inspection: • visible dye penetrant P6R available from BRENT International , • dry developer 901 B available from BRENT International , Q
.TY A.R.
Q
.TY A.R.

• a white light source able to give an illuminance of at least 1000 lux on the area of inspection
.B

### .T. 1 09-11 0
Instead of the indicated penetrant and developer, other products can be used providing that: • they comply with the requirements · of AMS 2644 (type 2 and method "C" for the penetrant and form "e" for the developer) , • they are listed in the pertinent QPL-AMS-2644-1 , • they are (penetrant and dry developer) produced by the same company. SPECIAL TOOLS: N.A. WEIGHT AND BALANCE CHANGES: N.A. REFERENCES: Maintenance Manual. PUBLICATIONS AFFECTED: Maintenance Manual. Flight Manual. COMPLIANCE INSTRUCTIONS: NOTE The procedure reported below is applicable to each one of the two tail rotor blades, if affected by this Bollettino
. PART 

### 1": 1
. Identify and outline with adhesive tape the inspection area in accordance with figure 1 (blade upper and lower sides)
. 2. Using solvent Ardrox 204S or equivalent (MIL-R-25134) , remove the finish paint in the above area without removing the primer underneath
. To remove the transparent paint, use solvent abundantly, in order to completely remove all paint residue
. CAUTION 1 Paint removal procedure is of the utmost importance. Failure to thoroughly remove all paint may lead to the occlusion of cracks
. CAUTION 2 Use of methylethylketone is not recommended as damage to the bonding agent may occur. Do not use abrasive materials to remove the paint to avoid damaging the areas of the blade
. In case of presence of damage refer to the Maintenance Manual. Page 3 of 6 

# lAB.T. 109-110

A 

# I Page 4 of 6 3
. Perform the liquid penetrant inspection as follows: CAUTION Personnel conducting the liquid penetrant inspection for this specification must be qualified in accordance with the ASNT practice SNT-TC-1A or other equivalent practice or standard. The inspection shall comply with the requirements of ASTM E 1417. The blade, penetrant and ambient temperatures shall be in the range from 4 to 45 °C. 3.1
. On the area of paint removal apply the penetrant for 30 to 40 minutes of dwell time
. NOTE Remove the excess of penetrant with a cheesecloth soaked with aliphatic naphtha or equivalent. The solvent shall not be poured directly on the inspection area . 3
.2
. Apply a uniform and thin layer of developer by means of a powder bellows; after 10 to 15 minutes of developer time , illuminate the area at 1000 lux minimum and carefully inspect it. If presence cracks is detected , the blade must be removed from service
. In this case , please inform Agusta immediately. NOTE The potential crack would be shown running in a straight line, exactly parallel to the blade chord; it does not therefore follow the contour of the doubler and it is clearly different from evidence of bonding agent porosity that may appear along the edge ofthe doubler. 3
.3
. Upon completion of the inspection , if no cracks are found , clean the stripped areas with aliphatic naphtha , and protect with transparent acrylic lacquer in accordance with the Maintenance Manual. Return the hel icopter in ready to fl ight condition
. PART 

### 11/\: 1
. Use a cheesecloth soaked with aliphatic naphtha or equivalent to clean the protected area with transparent lacquer of the tail rotor blade (ref. figure 1 )
.B.T. 109-110
2
. Perform a visual inspection on blade upper and lower sides for cracks , if necessary use a 3 to 5 power magnifying glass. If presence of cracks is suspected perform the PART Ill" of this Bollettino
.

PART Ill": CAUTION In case of presence of other damage (nicks, dents, corrosion , etc.) on the metal refer to Maintenance Manual. 1. Using solvent Ardrox 204S or equivalent (MIL-R-25134) , remove the transparent lacquer in the identified area shown in figure 1 (blade upper and lower sides), without removing the primer underneath. To remove the transparent lacquer use solvent abundantly, in order to completely remove all paint residue. CAUTION 1 Paint removal procedure is of the utmost importance. Failure to thoroughly remove all paint may lead to the occlusion of cracks
. CAUTION 2 Use of methylethylketone is not recommended as damage to the bonding agent may occur. Do not use abrasive materials to remove the paint to avoid damaging the areas of the blade
. In case of presence of damage refer to the Maintenance Manual. 2
. Perform the liquid penetrant inspection in accordance with paragraph 3
. of PART I" ofthis Bollettino. If presence of cracks is detected , the blade must be removed from service
. In this case , please inform Agusta immediately
.

Page 5 of 6 

# lA"'U Q) co CD 0) 0 - 0) Center of the blade retention bolt hole **fifi~:** 100mm

**~oc::** '-...., 220 mm al

h\J] Inspection area (upper and lower sides) FIGURE 1 OJ :--1 -->. 0 <.0
I -->. -->. 0