Repair of the Debonded Top Layer at the Inner Area of the Cargo-Compartment Sandwich Panel(s)

TASK 25-50-00-340-812-A
Repair of the Debonded Top Layer at the Inner Area of the Cargo-Compartment Sandwich Panel(s)

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

WARNING: DO NOT GET THE FLUID ON YOUR SKIN OR IN YOUR EYES. IF YOU DO:

FLUSH IT AWAY WITH CLEAN WATER
GET MEDICAL AID.

WARNING: MAKE SURE THAT THE TRAVEL RANGE OF THE CARGO DOOR IS CLEAR BEFORE YOU UNLOCK IT. STAY AFT OF (LEFT OF) THE DOOR WHEN YOU UNLOCK IT BECAUSE IT CAN OPEN SUDDENLY AND CAUSE INJURY.

CAUTION: USE ONLY THE SPECIFIED MATERIALS AND OBEY THE INSTRUCTIONS FROM THE MATERIAL MANUFACTURERS. OTHER MATERIALS CAN CAUSE DAMAGE TO THE SURFACE PROTECTION OF THE COMPONENTS AND THE RELATED AREA.

ZONE: 130
ZONE: 150
ZONE: 160

1. Reason for the Job
Refer to the AMM TASK 25-50-00-200-024.
This procedure gives the instructions necessary to repair the sandwich panel(s) that has (have) a honeycomb core in the lower-deck cargo compartment.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT)
No specific	1	CLOTH - ABRASIVE (GRADE 120-180)
No specific	1	CLOTH-EMERY (GRADE 320 - 400)
No specific	1	CLOTH-EMERY (GRADE 80 - 120)
No specific	1	ROUTING TOOL
No specific	2	WARNING NOTICE(S)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.05EGC2)	Epoxy Adhesive-Furnishing Flame Retardant -
(Material No.08BBD1)	Non Aqueous Cleaner-- Isopropyl Alcohol -
(Material No.13XBD5)	Laminate Repair Patch-Cured - Fire compliant Intumescent Cargo 2
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
130	FWD CARGO COMPT AFT BULKHEAD OF AVNCS COMPT TO FWD PRESSURE BULKHEAD OF WING CENTER BOX
150	AFT CARGO COMPARTMENT FWD PRESS BULKHEAD TO AFT BULKHEAD OF AFT CARGO COMPARTMENT
160	BULK CARGO COMPARTMENT AFT BULKHEAD OF AFT CARGO COMPARTMENT TO AFT BULKHEAD OF BULK CARGO COMPARTMENT

D. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 24-42-00-862-001-A	De-energize the Ground Service Network Supplied from the External Power
TASK 25-54-11-000-001-A	Removal of the Forward Cargo-Compartment Partition FR24A
TASK 25-54-11-400-001-A	Installation of the Forward Cargo-Compartment Partition FR24A
TASK 25-54-12-000-001-A	Removal of the Forward Cargo-Compartment Partition
TASK 25-54-12-000-002-A	Removal of the Ceiling Panels in the Forward Cargo Compartment
TASK 25-54-12-000-003-A	Removal of the Sidewall Panels in the Forward Cargo Compartment
TASK 25-54-12-400-001-A	Installation of the Forward Cargo-Compartment Partition
TASK 25-54-12-400-002-A	Installation of the Ceiling Panels in the Forward Cargo Compartment
TASK 25-54-12-400-003-A	Installation of the Sidewall Panels in the Forward Cargo Compartment
TASK 25-55-11-000-001-A	Removal of the Aft Cargo-Compartment Partition at FR47
TASK 25-55-11-000-002-A	Removal of the Ceiling Panels in the Aft Cargo-Compartment - FR47/FR59
TASK 25-55-11-000-003-A	Removal of the Sidewall Panels in the Aft Cargo Compartment - FR47/FR59
TASK 25-55-11-400-001-A	Installation of the Aft Cargo-Compartment Partition at FR47
TASK 25-55-11-400-002-A	Installation of the Ceiling Panels in the Aft Cargo-Compartment - FR47/FR59
TASK 25-55-11-400-003-A	Installation of the Sidewall Panels in the Aft Cargo Compartment - FR47/FR59
TASK 25-55-12-000-001-A	Removal of the Aft Cargo-Compartment Partition at FR65
TASK 25-55-12-000-002-A	Removal of the Ceiling Panels in the Aft Cargo Compartment at FR59/FR65
TASK 25-55-12-000-003-A	Removal of the Sidewall Panels in the Aft Cargo Compartment - FR59/FR65
TASK 25-55-12-400-001-A	Installation of the Aft Cargo-Compartment Partition at FR65
TASK 25-55-12-400-002-A	Installation of the Ceiling Panels in the Aft Cargo Compartment at FR59/FR65
TASK 25-55-12-400-003-A	Installation of the Sidewall Panels in the Aft Cargo Compartment - FR59/FR65
TASK 52-30-00-860-001-A	Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
TASK 52-30-00-860-002-A	Close the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
Cargo-Compartment Sandwich Panels - Identification of the Damaged Area for the Repair of the Debonded Top Layer
Repair of the Debonded Top Layer of the Cargo-Compartment Sandwich Panel

3. Job Set-up
Subtask 25-50-00-861-061-A

A. Aircraft Maintenance Configuration
(1) Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).

Subtask 25-50-00-010-128-A

B. Get Access
(1) For the forward cargo compartment:
(a) Open the forward cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(b) Put the ACCESS PLATFORM 2M (6 FT) in position below the forward cargo-compartment door.
(c) Set light switch 6LU to ON.
(d) Put the WARNING NOTICE(S) in position on the control panel of the forward Cargo Loading System (CLS) to tell persons not to operate the forward CLS.
(2) For the aft cargo compartment:
(a) Open the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(b) Put the ACCESS PLATFORM 2M (6 FT) in position below the aft cargo-compartment door.
(c) Set light switch 8LU to ON.
(d) Put the WARNING NOTICE(S) in position on the control panel of the aft CLS to tell persons not to operate the aft CLS.

Subtask 25-50-00-220-071-A

C. Identification of the Damaged Area of the Cargo-Compartment Sandwich Panel(s)

NOTE: Debonding is referred to as damage in this procedure.

Cargo-Compartment Sandwich Panels - Identification of the Damaged Area for the Repair of the Debonded Top Layer

(1) Measure the dimensions of the damaged area of the cargo-compartment sandwich panel(s):

L is the widest diameter of the damaged area at the inner area of the cargo-compartment sandwich panel.
W is the maximum width of the damaged area measured in a direction that is perpendicular to L.
dD is the minimum distance between two damaged areas or the minimum distance between the damaged area and the other repaired area(s).

(2) Make sure that the total damaged area of each cargo-compartment sandwich panel is not more than 25% of its total surface area.
(3) On each cargo-compartment sandwich panel, make sure that distance dD is a minimum of 76 mm (2.99 in.) between the damaged area at the inner area of the cargo-compartment sandwich panel and:

The other damaged area(s) and/or
The other repaired area(s).

NOTE: If distance dD between two damaged areas is less than 76 mm (2.99 in.), the two damaged areas are one damaged area.

(4) If the total damaged area on the cargo-compartment sandwich panel is more than the permitted limits, replace the cargo-compartment sandwich panel.

Subtask 25-50-00-020-069-A

4. Procedure
Subtask 25-50-00-340-081-A

A. Repair of the Debonded Top Layer of the Cargo-Compartment Sandwich Panel

Repair of the Debonded Top Layer of the Cargo-Compartment Sandwich Panel

(1) Prepare the damaged area of the cargo-compartment sandwich panel for the repair as follows:

CAUTION: BE CAREFUL WHEN YOU CUT THE TOP LAYER OF THE CARGO-COMPARTMENT SANDWICH PANEL. IF YOU ARE NOT CAREFUL, YOU CAN CAUSE DAMAGE TO THE HONEYCOMB CORE.

(a) Cut the debonded top layer of the cargo-compartment sandwich panel.
(b) Carefully lift the debonded top layer of the cargo-compartment sandwich panel from the honeycomb core.
(c) If necessary, use the ROUTING TOOL and carefully remove the damaged material(s) from:

The honeycomb core
The debonded top layer of the cargo-compartment sandwich panel.

(d) Use the CLOTH-EMERY (GRADE 80 - 120) and make the rough area of the cargo-compartment sandwich panel smooth.
(e) Use a Textile-Lint free Cotton - (Material No.14SBA1) made moist with Non Aqueous Cleaner-- Isopropyl Alcohol - (Material No.08BBD1) and clean the damaged area.
(f) Make sure that the damaged area is dry.
(2) Repair the damaged area of the cargo-compartment sandwich panel as follows:
(a) Prepare the Epoxy Adhesive-Furnishing Flame Retardant - (Material No.05EGC2) . Refer to the manufacturer's instructions.
(b) Apply a layer of Epoxy Adhesive-Furnishing Flame Retardant - (Material No.05EGC2) on the rear side of the debonded top layer.
(c) Attach the debonded top layer to the honeycomb core of the cargo-compartment sandwich panel.
(d) Apply weight (for example, sandbags) on the surface of the repair area at room temperature. This is to make sure that the debonded top layer correctly attaches to the honeycomb core of the cargo-compartment sandwich panel.
(e) Remove the unwanted adhesive from the cargo-compartment sandwich panel.
(f) Obey the manufacturer’s instructions for the correct curing time of the adhesive.
(g) After the adhesive is cured, remove the weight from the surface of the repair area.
(h) Use the CLOTH - ABRASIVE (GRADE 120-180) and make the repair area smooth.
(i) Use a Textile-Lint free Cotton - (Material No.14SBA1) made moist with Non Aqueous Cleaner-- Isopropyl Alcohol - (Material No.08BBD1) and clean the repair area.
(j) Make sure that the repair area is dry.
(k) Cut a Laminate Repair Patch-Cured - Fire compliant Intumescent Cargo 2 (Material No.13XBD5) as follows:
1 Make sure that the repair patch is 38 mm (1.50 in.) larger than the repair area in all the directions of the repair area:

NOTE: The repair patch can be less than 38 mm (1.50 in.) larger than the repair area if the damaged area is at a distance of less than 38 mm (1.50 in.) from the edge of the cargo-compartment sandwich panel.

a If the repair area has one or more attachment holes, make sure that there is a minimum overlap of the repair patch on the attachment hole(s) of 15 mm (0.59 in.) in all the directions of the attachment hole(s).
b Make sure that the repair patch does not make an overlap on the other repair patch(es).
(l) Use the CLOTH-EMERY (GRADE 320 - 400) and make the edges of the repair patch smooth.
(m) Put the repair patch on the damaged area of the cargo-compartment sandwich panel as follows:
1 Remove the protective foil from the repair patch.
2 Put the repair patch on the damaged area. Refer to the manufacturer's instructions.
(n) If the repair patch is on one or more attachment holes:
1 Drill one or more new holes into the cargo-compartment sandwich panel at the same position(s) and with the same dimension(s) as the initial hole(s).
2 Do a check of the grip range of the related fastener(s).
3 Install the fastener(s) that has (have) the correct grip range.

5. Close-up
Subtask 25-50-00-420-070-A

Subtask 25-50-00-410-120-A

B. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) For the forward cargo compartment:
(a) Remove the WARNING NOTICE(S) from the control panel of the forward CLS.
(b) Set light switch 6LU to OFF.
(c) Close the forward cargo-compartment door (Ref. AMM TASK 52-30-00-860-002).
(3) For the aft cargo compartment:
(a) Remove the WARNING NOTICE(S) from the control panel of the aft CLS.
(b) Set light switch 8LU to OFF.
(c) Close the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-002).
(4) Remove all the fixtures, tools, test and support equipment used during this procedure.

Subtask 25-50-00-862-061-A

C. Aircraft Maintenance Configuration
(1) De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).
(2) Put the aircraft back to its initial configuration.

[Rev.10 from 2021] 2026.04.01 06:24:31 UTC