(4)Floor beams and pressure webs. Traces of spillage under flooring should
be investigated to determine if corrosion has occurred on floor beams or
pressure webs. Areas around galleys, door entries, lavatories and bat-tery compartments require special attention.
(5)Fairings and surfaces under fairings. Whenever fairings are removed for
routine maintenance, the hidden structure under the fairings should be
examined for indications of corrosion. The fairing, especially fiber-glass fairings, should be examined for coating damage. Fiberglass panels
are either aluminum flame sprayed or conductive coated for static bleed
off and should be inspected for damaged coatings.
(6)Seat tracks. The slots in the seat track collect dirt and moisture and
as a result are particularly susceptible to corrosion.
Volume 1
20-20-00
Page 1
OCT 01/01
CORROSION PREVENTION MANUAL
GENERAL INFORMATION
INSPECTION AND DETECTION
(7)Bilge area under cargo floor. The stringers and frames under the cargo
floor should be inspected for corrosion resulting from accumulation of
dirt, moisture and spillage from the cargo.
(8)Plumbing hardware. Exposed tubing B nuts and hydraulic components, tub-ing identification tapes and braided hoses are to be carefully inspected
for signs of corrosion. Interior surfaces of ram air ducts, especially
where one wall of the duct is a structural member, should be examined
for corrosion damage.
(9)Moisture absorbing materials. In areas where there is little air circu-lation moisture absorbing materials such as leather, paper, foam rubber,
soundproofing and insulation attached to or contacting metal structure
can present troublesome corrosion suspect areas. These items should be
removed for satisfactory inspection.
(10)Piano and other type hinges. Piano hinge failure generally occurs when
the joint corrodes and a lug breaks when the joint is actuated. Inspec-tion should include ease of actuation and evidence of corrosion products
at the hinge mating surfaces. other hinges should be inspected for cor-rosion of bearings, inserts and fasteners.
(11)Integral fuel tanks. Periodic inspections of the integral fuel tanks for
corrosions, pitting and blistering of the coating on the interior sur-faces of the integral fuel tanks should be made. The interior walls
should also be inspected for corrosion. Black areas should be checked
for surface corrosion.
(12)Control cables. Examine the cables at scheduled inspections. Cable cor-rosion can start when the grease used as a corrosion preventive coating
is gone.
C. Special Inspections. In instances where loading of nonstandard cargo (i.e.
livestock) or cargo spillage of harmful products (i.e., mercury) occur, spe-cific inspection requirements are initiated.
(1)Mercury. After a reported mercury spill in the cargo hold area, mainte-nance personnel are instructed to remove the spillage as rapidly as pos-sible due to the damaging effect mercury has with aluminum structures. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：757 防腐手册 CORROSION PREVENTION MANUAL 第二册 一般信息(11)
