# ALERT

BOLLETTINO TECNICO N° 

# 139-018

The technical content of this document is approved under the author i t y of D O A nr. EASA.21J.005 D A T E October 18, 2006

REV. B

Compliance with this bulletin is:



# A LERT Page 1 of 9 SUBJECT: middle section frame 5700 inspection

REASON: to verify the structural in tegrity of the frame – STA 5700

HELICOPTERS AFFECTED: all AB139/AW139 helicopters ex cept for the prototypes (S/N 31002, 31003, 31004 and 31007) B

COMPLIANCE: within and not later 10 flight hour s from the issue date of present Bollettino and subsequently every 100 flight hours. For helicopter that have not yet accumulated 100 flight hours this Bollettino must be applied, in the terms above mentioned within 10 f/h and subsequently every 100 f/h, only when 100 f/h are reached. B

DESCRIPTION: the scope of the inspection is the locating of possible damage and / or fatigue failure

REQUIRED MANPOWER: it is estimated that in order to accompli s h this Bollettino 1 man-hour is necessary.
WARRANTY: N.A.

## B.T. 139-018 Rev.B

Page 2 of 9 REQUIRED MATERIALS: N.A.

SPECIAL TOOLS: 9 borescope; 9 drill;

WEIGHT AND BALANCE CHANGES: N.A.

REFERENCES: N.A.

PUBLICATIONS AFFETCTED: 9 AW139 Maintenance Planning Information

COMPLIANCE INSTRUCTIONS: 1. Prepare the helicopter for a safe ground ma intenance. Disconnect the battery and all the electrical power sources and/ or the external power supply. 2. Remove the cabin liners to get access to the left and right side of upper middle section of the fuselage (passenger cabin). 3. On the helicopters equipped with the inspec tion panel (as shown on Fig.3 and 4), do a detailed inspection of frame 5700 as follows:
3.1. Remove the screws that attach the in spection panel on the stru cture, on the left side of passenger cabin, (as shown on Fig. 3), to permit the borescope head
insertion. 3.2. Do a detailed inspecti on with the borescope of the frame 5700 with particular attention to any evidence of cr acks around the area shown on Fig. 5 3.3. If a photo camera is available, take a picture of any damage found and record damage dimensions. Record damage dimensi ons too in case the photo camera is
not available. 3.4. In case you are not sure to have obtai ned best investigation results (from step 3.1 to 3.3), do an hole into skin that cover the structure of frame 5700, on the left side

## B.T. 139-0018 Rev.B

Page 3 of 9 of passenger cabin, (as shown on Fig. 4). The diameter of the hole, must permit the borescope head insertion and shall not exceed 20 mm. (0.7874 Inches).

CAUTION To avoid damaging the helic opter structure, do not
drill through the 5700 frame lip. The frame lip is 50
mm wide (25/25) see detail A of fig.1 for typical
inspection holes location.

3.5. Perform another detailed inspection wi th the borescope of the frame 5700 with particular attention to any evidence of cracks damage around the area shown on Fig. 5 3.6. Take a picture with the photo camera of any damage found and record damage dimensions. Record damage dimensions t oo in case the photo camera is not
available. 3.7. Do again the procedures indicated from step 3.1 to step 3.6 on the right side of upper middle section of the fuselage (passenger cabin). 4. On the helicopters with fuselage not equipped of an inspecti on panel (as shown on Fig.1 and 2), do a detailed inspec tion of frame 5700 as follow:
4.1. Make an hole into skin that cover the structure of frame 5700, on the left side of passenger cabin, (as shown on Fig. 1). T he diameter of the hole, must permit the borescope head insertion and shall not exceed 20 mm. (0.7874 Inches).
CAUTION
To avoid damaging the helic opter structure, do not
drill through the 5700 frame lip. The frame lip is 50
mm wide (25/25) see detail A of fig.1 for typical
inspection holes location.

4.2. Do a detailed inspecti on with the borescope of the frame 5700 with particular attention to any evidence of cracks damage around the area shown on Fig. 5.

## B.T. 139-018 Rev.B

Page 4 of 9 4.3. If a photo camera is available, take a picture of any damage found and record damage dimensions. Record damage dimensi ons too in case the photo camera is
not available. 4.4. In case you are not sure to have obtai ned best investigation results (from step 4.1 to 4.3), make a second hole into skin that cover the structure of frame 5700, on the left side of passenger cabin, (as shown on Fi g. 2). The diameter of the hole, must permit the borescope head insertion and sha ll not exceed 20 mm. (0.7874 Inches).
CAUTION
To avoid damaging the helic opter structure, do not
drill through the 5700 frame lip. The frame lip is 50
mm wide (25/25) see detail A of fig.1 for typical
inspection holes location.

4.5. Perform another detailed inspection with the borescope of the frame 5700 with particular attention to any evidence of cracks damage around the area shown on Fig. 5. 4.6. Take a picture with the photo camera of any damage found and record damage dimensions. Record damage dimensions t oo in case the photo camera is not
available. 4.7. Do again the procedures as indicated from step 4.1 to step 4. 6 on the right side of upper middle section of the fuselage (passenger cabin). 5. If any damage is found, contact the manufac turer for the corrective action definition.
6. Install the cabin liners on the left and right side of upper middle section of the fuselage (passenger cabin). 7. Return helicopter to flight configuration and record for compliance of this Bollettino.

## B.T. 139-0018 R ev.B

Page 5 of 9 Detail A

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