Via G iovann iAgusta ,520

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# IC.T... 21017 Cascina Costa di Sarnarate (VA) Italy

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# 109-123 BOLLETTINO TECNICO The technical content of this document is approved under the authority of DOA nr EASA.21 J .005 . DATE November 16, 2006

Compliance with this Bollettino is : 

# MANDATORY REV.

SUBJECT: INSPECTION TO GROOVED CLAMPS P/N 4606AC THAT ATTACH THE ENGINE EXHAUST DUCTS. REASON: Perform an inspection to the subject grooved clamps for cracks and/or corrosion. HELICOPTERS AFFECTED: All Agusta A 1 09A, A109AII and A 1 09C helicopters. COMPLIANCE: Within the next 50 (fifty) operating hours and however within and not later than March 31 , 2007 . Successively every 300 (three hundred) hours/annually. DESCRIPTION: A case of the grooved clamp P/N 4606AC fixing the external left side engine exhaust duct fracture and the consequent loss of the exhaust has been reported on an A 109A helicopter. The failure caused an emergency landing without any consequences for the occupants . The investigation performed on the grooved clamp has revealed that the static fracture , due to an excessive load , has occurred in correspondence with the rivets in presence of evident corrosion. This Bollettino is issued in order to perform a visual inspection of the grooved clamps P/N 4606AC for cracks by means of a magnifying glass, and fo r presence of corrosion. REQUIRED MANPOWER: For the accomplishment of this Bollettino an estimated 4 (four) manpower hours are required .

An appropriate entry should be mode 1n the oorcroft log book upon accomplishment. If ownership of aircraft has changed, please, forward to new owner. Page 1 of 4B.T. 109-123 WARRANTY: N.A. REQUIRED MATERIALS: The following consumable material is required for compliance with this Bollettino : SPECIFICATION TT-N-95 Type 2 DENOMINATION Aliphatic naphtha (cod . 531 055030) Q.TY A.R. SPECIAL TOOLS: N.A. WEIGHT AND BALANCE CHANGES: N.A. REFERENCES: Pertinent Maintenance Manual. PUBLICATIONS AFFECTED: Pertinent Maintenance Manual. COMPLIANCE INSTRUCTIONS:

Page 2 of4 (See figure 1) 1. Prepare the helicopter on ground for a safe maintenance , disconnect any power supply. 2 . In accordance with the instructions provided in the pertinent Maintenance Manual remove the engine cowlings . NOTE Thi s inspection must be accomplished on all four grooved clamps P/N 4606AC fixing the engine exhaust duct. 3. In accordance with the instructions provided in the pertinent Maintenance Manual remove the grooved clamp from the engine exhaust duct. Clean the grooved clamp with aliphatic naphtha or equivalent. NOTE Before the grooved clamp removal , perform a reference mark between clamp, exhaust tube and engine , in order to reinstall it in the same position.B.T. 109-123 4 . Perform the grooved clamp visual inspection as follows (see figu re 1 ) : 4. 1 . Inspect the inboard and outboard joint areas of the two half clamps in correspondence of the rivets , for presence of cracks by means of a 10 X magnifying glass . 4.2. Inspect the clamp for presence of corrosion, especially in the inboard and outboard joint areas of the two half clamps in correspondence of the rivets. CAUTION In case presence of cracks and/or, corrosion are found, discard and replace the affected grooved clamp . 5. In accordance with the instructions provided in the pertinent Maintenance Manual reinstall the grooved clamp. 6. In accordance with the instructions provided in the pertinent Maintenance Manual reinstall the engine cowlings . 7. Return the helicopter in ready to flight condition. 8. Record compliance with this Bollettino in the helicopter log book.

Page 3 of4B.T. 109-123

Inboard joint area in which the inspection is performed. Typ . 4 places .

Page 4 of4 Outboard joint area in which the inspection is performed . Typ . 4 places .



# FIGURE 1