Essay Flashcards
Corrosion preventive maintenance includes the following specific functions:
- Adequate cleaning.
- Thorough periodic lubrication.
- Detailed inspection for corrosion and failure of protective systems.
- Prompt treatment of corrosion and touchup of damaged paint areas.
- Keeping drain holes free of obstructions.
- Daily draining of fuel cell sumps.
- Daily wipe down of exposed critical areas.
- Sealing of aircraft against water during foul weather and proper ventilation on warm sunny days.
- Maximum use of protective covers on parked aircraft.
CORROSION REMOVAL
In general, any complete corrosion treatment involves the following
(1) cleaning and stripping of the corroded area,
(2) removing as much of the corrosion products as practicable,
(3) neutralizing any residual materials remaining in pits and crevices,
(4) restoring protective surface films, and
(5) applying temporary or permanent coatings or paint finishes
The following is a general stripping procedure:
- Brush the entire area to be stripped with a cover of stripper to a depth of 1/32 to 1/16 inch. Any paintbrush makes a satisfactory applicator, except that the bristles will be loosened by the effect of paint remover on the binder, and the brush should not be used for other purposes after being exposed to paint remover.
- Allow the stripper to remain on the surface for a sufficient length of time to wrinkle and lift the paint. This may be from 10 minutes to several hours, depending on both the temperature and humidity, and the condition of the paint coat being removed. Scrub the surface with a bristle brush saturated with paint remover to further loosen finish that may still be adhering to the metal.
- Reapply the stripper as necessary in areas where the paint remains tightly adhered or where the stripper has dried, and repeat the above process.
Only nonmetallic scrapers should be used to assist in removing persistent paint finishes. Non-woven abrasive pads intended for paint stripping may also prove to be useful in removing the loosened paint. - Remove the loosened paint and residual stripper by washing and scrubbing the surface with water and a broom, brush or fresh non-woven abrasive pad.
If water spray is available, use a low to medium pressure stream of water directly on the area being scrubbed.
SEVERE TURBULENCE INSPECTION/OVER “G” INSPECTION
Through the inspection doors and other accessible openings, inspect all spar webs from the fuselage to the tip. Check for buckling, wrinkles, and sheared attachments. Inspect for buckling in the area around the nacelles and in the nacelle skin, particularly at the wing leading edge
Check for fuel leaks. Any sizable fuel leak is an indication that an area may have received overloads which have broken the sealant and opened the seams.
If the landing gear was lowered during a period of severe turbulence, inspect the surrounding surfaces carefully for loose rivets, cracks, or buckling. The interior of the wheel well may give further indications of excessive gust condition
Modification can be evaluated on the component level and also on the system level when installed on the aircraft. Tasks typically performed during evaluation of a modification are as follows:
- A review of the installation plan and wiring.
- Verification of the presence of labels.
- Evaluation of the structural installation.
- A safety analysis.
- Evaluation of the conditions equipment/aircraft environment.
- Structural justifications.
- A written evaluation of electrical aspects of repair.
- A statement/analysis of the effect of the modification on weight and balance
The purpose of an AD is to notify aircraft owners:
- That the aircraft may have an unsafe condition, or
- That the aircraft may not be in conformity with its basis of certification or of other conditions that affect the aircraft’s airworthiness, or
- That there are mandatory actions that must be carried out to ensure continued safe operation, or
- That, in some urgent cases, the aircraft must not be flown until a corrective action plan is designed and carried out
Typical inspection and check unscheduled maintenance items are:
- Corrosion treatment.
- Adjustment or replacement of components that are not performing to standards.
- Repair of structural cracks and deformations out of tolerances in pressurized areas
SEVERE TURBULENCE INSPECTION/OVER “G”
- Through the inspection doors and other accessible openings, inspect all spar webs from the fuselage to the tip.
- Check for buckling, wrinkles, and sheared attachments.
- Inspect for buckling in the area around the nacelles and in the nacelle skin, particularly at the wing leading edge
- Check for fuel leaks. Any sizable fuel leak is an indication that an area may have received overloads which have broken the sealant and opened the seams.
- If the landing gear was lowered during a period of severe turbulence, inspect the surrounding surfaces carefully for loose rivets, cracks, or buckling. The interior of the wheel well may give further indications of excessive gust condition
The purpose of an AD is to notify aircraft owners:
Fire extinguishers should be checked periodically utilizing a checklist. If a checklist is unavailable, check the following as a minimum:
·Proper location of appropriate extinguisher
·Safety seals unbroken
·All external dirt and rust removed
·Gauge or indicator in operable range
·Proper weight
·No nozzle obstruction
·No obvious damage