(c)
Use the solvent and a wiping cloth to clean the damaged area.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
21-23-02
ALL ú ú 01A Page 804 ú Jun 18/00
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL
S 348-007
(6) Cut a piece of the Fiberglass or Kevlar cloth that is 3-inches wide and long enough to go around the duct a minimum of two times.
E. Repair the Taped Joint
S 348-008
(1)
Apply a thin, smooth layer of primer to the duct joint area and let it dry at room temperature for a minimum of 1 hour.
S 348-009
(2)
Apply the sealant to one side of the Fiberglass or Kevlar cloth.
S 348-010
(3)
Wind the Fiberglass or Kevlar cloth around the duct joint a minimum of two times.
NOTE: Make sure the sealant on the Fiberglass or Kevlar cloth is in
____
contact with the duct.
S 348-011
(4) Put a piece of plastic sheet on the Fiberglass or Kevlar cloth and press lightly with a squeegee or with your hand.
NOTE: Make the Fiberglass or Kevlar cloth smooth from the center to
____ the edges of the cloth to remove any bubbles or any wrinkles and to remove unwanted resin.
S 348-012
(5)
Remove the plastic sheet from the Fiberglass or Kevlar cloth and remove unwanted resin with a wiping cloth.
S 348-013
(6)
Wrap pressure sensitive glass cloth tape around the two edges of the cloth repair.
NOTE: Make sure the tape lies flat with no wrinkles or gaps.
____
F. Put the Airplane Back to Its Usual Condition
S 428-068
(1) If insulation was removed from the duct joint, install new
insulation.
EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
21-23-02
ALL ú ú 01A Page 805 ú Jun 18/00
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A
747-400
MAINTENANCE MANUAL
S 418-015
(2) Install the panels or other airplane structure removed to gain access to the duct joint.
TASK 21-23-02-308-016
3. Fiberglass or Kevlar Duct - External Patch Repair (Fig. 801)
_________________________________________________
A. General
(1)
This procedure gives instructions for the repair of a crack or cut in a fiberglass or Kevlar air conditioning duct with an external patch.
(2)
An external patch is applicable when the cut or crack is less than 1/4 inch wide and 3 inches long.
B. Consumable Materials
(1)
Fiberglass cloth - minimum 0.007 inch thick (MIL-C-9084 Type VIII) -commercially available
(2)
Kevlar cloth - minimum 0,007 inch thick (alternative to the Fiberglass cloth)
(3)
Plastic sheet - polyethylene or vinyl (commerically available)
(4)
Resin for repair of Fiberglass duct - R109A Hetron 92 Polyester
(5)
Resin for repair of Kevlar duct - BMS 8-201 Type II (Epocast 50-A)
(6)
Sandpaper - 320 grit (commerically available)
(7)
Solvent - Butyl carbitol (alternative to B01011, Series 91) -commerically available (AMM 20-30-91/201)
(8)
Solvent - B01011, Series 91 - commercially available (AMM 20-30-91/201)
(9)
Squeegee - commercially available
(10)
Wiping cloth, lint-free (commerically available)
C. References
(1) AMM 36-00-00/201, Pneumatics - General
D. Prepare for the Repair
S 868-043
(1)
Remove the pneumatic power (AMM 36-00-00/201)
S 868-044
(2)
On the bleed air control module on the pilots' overhead panel, put the pack control switches in the OFF position.
S 018-046
(3)
Remove the applicable ceiling, sidewall, or floor panels to gain access to the damaged air conditioning duct.
(4)
If insulation is installed on the duct, remove the insulation.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：747-400 AMM 飞机维护手册 空调 AIR CONDITIONING 1(32)
