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Post Office Box 2200 Huntsville, Alabama 35804 USA Telephone: (256) 851-7001 Fax: (256) 859-8822 

Component Service Bulletin 

ATR-42 / ATR-72 #2 Forward Side Window 

PART NUMBERS 

NP-158862-1 

NP-158862-2 

NOTICE: EAR-Controlled "Technology"

“These commodities, technology or software are 

controlled by the United States in accordance with the 

Export Administration Regulations (“EAR”). Diversion 

contrary to U.S. law is prohibited.”
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Component Service Bulletin 

REVISION TRANSMITTAL SHEET 

SUBJECT: P/N NP-158862 Service Bulletin for the ATR-42 / ATR-72.

This page transmits Revision 1 of the PPG Service Bulletin P/N NP-158862 for the 

ATR-42 / ATR-72 #2 Forward Side Window. 

REASON 

The Service Bulletin is revised to reflect the changes listed below. 

CHANGES 

Revision 1 Addition of Inspection Aid information to 

clarify inspection process. 

 
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APPROVALS 

 

Prepared By: 10 Jan 2013

 Andrew Troller Date 

 Product Support Engineer 

Approved By: 10 Jan 2013

 Stirling Macfarlane Date 

 Manager, Product Support Engineering 

Approved By: 10 Jan 2013

 David Lair Date 

 Design Engineer 

 

Approved By: 10 Jan 2013

 James Romano Date 

Commercial Market Segment Manager 
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Component Service Bulletin 

SUBJECT: #2 Forward Side Windows (Cockpit Forward Side Windows) –Inspection and 

Conditional Removal 

1. PLANNING INFORMATION 

A. Effectivity 

This inspection and conditional removal applies to the components shown below. 

Part Number Name Used On 

NP-158862-1 Left Hand #2 Side Window ATR-42, ATR-72 

NP-158862-2 Right Hand #2 Side Window ATR-42, ATR-72 

B. Concurrent Requirements 

None. 

C. Reason 

1) Origin 

Events occurred in which the forward side window was separated from the aircraft. 

2) Evidence 

The investigation performed thus far revealed some anomalies that are considered 

as physical pre-cursors to the failure and could be associated with an air/water leak 

at the interface between the z-bar and the external glass and at the interface 

between the glass and the inner retainer on the internal side. 

3) Substantiation 

The presence of an air/water leak coming from between the z-bar and the outer 

glass ply or between the inner retainer and inner glass ply is an indication that 

structural components within the window have begun to deteriorate. 

Note: There are no repair procedures within the Abbreviated Component 

Maintenance Manual (ACMM) for this type of damage. The attempted repair of this 

type of air/water leak in the same area, followed by continued service can allow 

deterioration of the window structure and can ultimately result in failure. 

The purpose of this service bulletin is to inspect the sealant condition at the level of 
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the external z-bar and inner retainer for evidence of these physical pre-cursors. 

4) Benefits 

Accomplishment of this service bulletin will ensure that all #2 forward side windows 

with a discrepant condition are removed from service (See Section 1.C.3). 

D. Description 

This service bulletin instructs operators to inspect the z-bar and inner retainer, and to 

replace any #2 forward side windows that are identified as having a discrepant 

condition (See Section 1.C.3). 

E. Compliance 

This service bulletin is mandatory. Airworthiness Directive No.: 2009-0159-E was 

issued by EASA on 20 July 2009 and Airworthiness Directive FAA AD 2009-18-18 was 

issues by FAA on 24 September 2009. 

F. Approval 

The technical content of this document is approved in accordance with CE 1702/2003 

regulation and is rendered mandatory by an EASA Airworthiness Directive No.: 2009-

0159-E. 

G. Manpower 

This service bulletin will require one (1) person a total of .5 man-hours to accomplish 

the inspection for two (2) windows on a single aircraft (left and right hand #2 forward 

side windows). 

H. Weight and Balance 

Not changed. 

I. Electrical Load Data 

Not changed. 

J. Software Accomplishment Summary 

Not applicable. 
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K. References 

1) PPG Drawing NP-158862, Revision K, dated November 18, 2010 

2) PPG Abbreviated Component Maintenance Manual, ATA No. 56-12-00, Revision 

2, dated May 20, 2011. 

L. Other Publications Affected 

1) PPG Abbreviated Component Maintenance Manual, ATA No. 56-12-00, Revision 2, 

dated May 20, 2011. 

M. Interchangeability or Intermixability of Parts 

Not changed. 

2. MATERIAL INFORMATION 

A. Material – Price and Availability 

Spare forward side windows may be obtained by contacting PPG Customer Service at 

the following address: 

 PPG Aerospace 

 PO Box 040004 

 Huntsville, AL 35804 

 USA 

 

 Phone: (256) 851-7001 

 Facsimile: (256) 851-8822 

B. Industry Support Information 

All windows identified with the discrepant condition (see Section 1.C.3), within PPG 

warranty, will be replaced free of charge. All windows outside of PPG warranty will be 

replaced at charge. Commercial terms have been established and may be discussed 

with the responsible PPG Account Manager. 

C. Material Necessary for Each Component 

None. 

D. Material Necessary for Each Spare 

None. 
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E. Re-identified Parts / Existing Parts Accountability 

None. 

F. Special Tooling – Price and Availability 

None. 

G. Special Tooling Necessary to do this Service Bulletin 

None. 

3. ACCOMPLISHMENT INSTRUCTIONS 

A. Provide access to the #2 forward side window exterior surface through use of a sturdy 

ladder or other elevated platform. See Figure 1 for window location. 

Figure 1: Location of the #2 Forward Side Window 

B. Perform all maintenance tasks necessary to perform interior maintenance on the flight 

deck windows. 

C. Remove watches, rings, bracelets, and other metallic objects that could come in 

contact with the glass surface of the window 

CAUTION: metallic objects can scratch/damage the glass surface of the window and 

possibly result in fracture or optical problems for the flight crew. 

#2 Windows
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D. Equipment needed: 

A flat, thin, non-metallic shim or taper gauge (0.5 mm or 0.020 in. thick). Use only light 

pressure to identify existing gaps (do not create gaps with excess force). 

Figure 2: Equipment - Plastic Shim Stock 

E. Inspect the periphery of the #2 forward side window to identify the following conditions: 

1) Standard Condition - See Figures 3 & 4. 

Figure 3: Cross-sectional View of the #2 Forward Side Window – Standard Condition 

Plastic Shim Stock
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Figure 4: Z-bar & Fillet Seal – Standard Condition 
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2) Discrepant Condition 1 – Inspect the z-bar for existing sealant repair. 

Inspect the z-bar for existing repair of the z-bar sealant fillet (See Figures 5 and 

6). If any evidence of a repair attempt is visible, replace the forward side window. 

NOTE 1: a 2.3 mm (.090 in.) sealant fillet at the edge of the z-bar (See Figures 3 

and 4) is standard on the window at time of manufacture and may or may not be 

present on the window depending upon window age and typical wear in flight 

conditions. 

NOTE 2: Removal of any visible repair to the sealant is not allowed and is cause 

for removal of the window. 

Figure 5: Cross-sectional View of the #2 Forward Side Window – Discrepant 

Condition Showing an Attempted Repair of an Air Leak 

Figure 6: Inspection – Discrepant Condition 1 

Example of Sealant 

over Z-bar and Glass
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3) Discrepant Condition 2 – Inspect for z-bar deformation. 

This inspection is intended to identify displacement or bowing of the z-bar at any 

point around the periphery of the window (See Figure 7). 

Figure 7: Cross Cross-sectional View of the #2 Forward Side Window – Discrepant 

Condition Showing Z-bar Bowing or Displacement 

Use a flat, thin, non-metallic shim or taper gauge to probe at the edge of the z-bar 

around the periphery of the window. A discrepant condition exists if the tip of the shim 

or gauge penetrates between the z-bar and the outer glass ply in excess of 4 mm 

(0.160 in). See Figures 8 & 9 showing the #2 forward side window with displacement 

or bowing of the z-bar and the tip of a non-metallic shim inserted under the z-bar. In 

case of a discrepant condition, replace the window.

Figure 8: Inspection Technique – Discrepant Condition 2 
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Figure 9: Inspection Technique – Discrepant Condition 2 

“On-Wing” Photograph 

4) Discrepant Condition 3 – Inspect the gap between the retainer and inner glass ply. 

This inspection is intended to identify a separation or gap in the sealant bond 

between the inboard retainer and the inner glass ply (See Figure 10). 

Figure 10: Cross Cross-sectional View of the #2 Forward Side Window – Discrepant 

Condition Showing a Gap Between the Retainer and Inner Glass Ply 
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Use a flat, thin, non-metallic shim or taper gauge to probe at the edge of the 

inboard retainer around the periphery of the window. A discrepant condition exists 

if the tip of the shim or gauge penetrates between the retainer and the inner glass 

ply in excess of 7.5 mm (0.300 in) or for smaller separations with cumulated length 

exceeding 300 mm (12 in). See Figures 11 & 12 showing the #2 forward side 

window with a gap between the retainer and the inner glass ply and the tip of a 

non-metallic shim penetrating the gap. In case of a discrepant condition, replace 

the window. 

Figure 11: Inspection Technique - Discrepant Condition 3 

Figure 12: Inspection Technique - Discrepant Condition 3 

“On-Wing” Photograph 
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5) Discrepant Condition 4 – Z-bar deformation and retainer gap at the same location. 

This condition exists when discrepant condition 2 (z-bar deformation) and 

discrepant condition 3 (inner retainer gap) co-exist at the same hole locations (See 

Figure 13). 

Figure 13: Cross Cross-sectional View of the #2 Forward Side Window – Discrepant 

Condition Showing Both a Z-bar deformation and a Gap Between the 

Retainer and Inner Glass Ply 

Any window showing both sealant separation between the z-bar and outer glass 

ply, and separation between the inboard retainer and inner glass ply, common to 

the same hole location and with at least one of these discrepancies exceeding a 

length (span) of 225 mm (8.86 in / approximately 6 holes) identifies a discrepant 

condition and shall be replaced. See Figure 14. 

Figure 14: Inspection Technique – Discrepant Condition 4 
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6) Discrepant Condition 5 – Z-bar deformation and retainer gap in window corner. 

This condition exists when discrepant condition 2 (z-bar deformation) and 

discrepant condition 3 (inner retainer gap) co-exist in same window corner. 

Any window showing both sealant separation between the z-bar and outer glass 

ply, and separation between the inboard retainer and inner glass ply, common to 

the same window corner and with at least one of these discrepancies including the 

entire arc of a window corner identifies a discrepant condition and shall be 

replaced. 
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F. Accomplishment Report: 

Fill in the enclosed Accomplishment Report (Page 12) and send it to both: 

ATR techdesk 

1 ALLEE PIERRE NADOT 

31712 BLAGNAC CEDEX 

FRANCE 

Phone: +33 (0)5 62 21 62 21 

Fax: +33 (0)5 62 21 67 18 

Email: techdesk@atr.fr

PPG Aerospace 

ATTN: Andrew Troller 

P.O. Box 2200 

Huntsville, AL 35811 USA 

Phone: +1 256 859 2500 ext. 2544 

Fax: +1 256 859 8155 

Email: atroller@ppg.com 

G. Should the window need replacement, it should be returned to PPG Aerospace for 

further analysis at the following address: 

PPG Aerospace 

1719 Highway 72 East 

Huntsville, AL 35811 

USA 

ATTN: Andrew Troller 

Phone: +1 256 859 2500 ext. 2544 

Fax: +1 256 859 8155 
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