Heavy maintenance checks and landing gear repair.
a. The landing gear regarding jet may be definite or retractable.
b. Retractable gear upon zeppelin is usually operated subsequent to hydraulic or electric expertise, although some models of fresh general aviation plane have directory retract systems operated by a lever in the cockpit.
For more info Metric Trapezoidal Thread Dimension.
(1) In add-on to the adequate busy system, emergency systems are usually provided to ensure that the landing gear can be lowered in act of main-system failure.
(2) Emergency systems consist of backup hydraulic systems, or stored nitrogen aas bottles that can be directed into actuating cylinders, mechanical systems that can be operated manually, or wandering-slip gravity systems.
Wear points, such as landing gear taking place-and-the length of latches, jack-screws, access hinges, pulleys, cables, bellcranks, and all pressure-type grease fittings, should be lubricated after all cleaning operation.
To prevent realizable failure of a component due to incompatibility or investigation of the grease, the taking into account should be observed:
1. Use abandoned greases attributed for use by the product manufacturer.
2. Never compound alternating kinds of grease without huge compliment from the product manufacturer.
3. Follow the manufacturer’s instructions or FAA ascribed process for cleaning, purging, and lubricating of the component.
To make a make a get of of proper lubrication of the main retain bushings, it may be indispensable to jack the plane.
Those companies once commendation for Boeing oppressive child maintenance are concerned subsequent to retractable landing gear and thorough inspection of the landing gear is portion and parcel of oppressive maintenance checks. This involves every single one structure of the gear, including attachments, struts, wheels, brakes, actuating mechanisms for retractable gears, gear hydraulic system and valves, gear doors, and all allied parts. The manufacturer’s inspection proceedings should be followed where applicable.
It is recommended that deserted easily removable asexual solutions be used gone cleaning landing gear components. Any advantage, such as eagerness or effectiveness, gained by using cleaners containing corrosive materials, can be immediately counteracted if these materials become trapped in oppressive-fitting surfaces and crevices.
NOTE: Any period the dirigible is upon blimp jacks, check the landing gear main retain bushings for wear. Consult the plane manufacturer’s overhaul calendar for specific wear tolerances.
During winter operation, excess grease may congeal and cause increased ample upon the gear retraction system, electric motors, and hydraulic pumps. This condition can gain to component malfunctions; so, it is recommended that cleanliness be frantic during and after lubrication.
Fixed landing gear should be examined regularly for wear, deterioration, corrosion, alignment, and late late buildup factors that may cause failure or unsatisfactory operation. During a 100-hour or annual inspection of the precise gear, the plane should be jacked occurring to assist the jet weight. The gear struts and wheels should be checked for deviant deed out and corrected.
Narrow bodied airliner maintenance
a. Old aircraft landing gear that employs a rubber wonder (bungee) cord for admiration absorption must be inspected for age, fraying of the braided sheath, narrowing (necking) of the cord, and wear at points of retrieve behind the structure and stretch. If the age of the astonishment cord is near 5 years or more, it is advisable to replace it in the previously a totaling cord. A cord that shows new defects should be replaced, regardless of age.
b. The cord is color-coded to indicate later it was manufactured and to determine the enthusiasm of the astonishment cord. According to MIL-C-5651A, the color code for the year of produce is repeated in cycles of 5 years.
c. The color coding is composed of threads interwoven in the cotton sheath that holds the strands of rubber cord together. Two spiral threads are used for the year coding and one thread is used for the quarter of the year sheath, e.g. yellowish-brown and blue would indicate that the cord was manufactured in 1994 during April, May, or June.
d. Shock struts of the spring-oleo type should be examined for leakage, smoothness of operation, looseness along surrounded by the by the side of parts, and put-on at the attaching points. The augmentation of the struts should be checked to make sure that the springs are not worn or blinking. The piston section of the strut should be manageable of nicks, cuts, and rust.
e. Air-oil struts should undergo an inspection same to that recommended for spring-oleo struts. In adding, the elaborate of the strut should be checked to see that it conforms to the set against specified by the manufacturer. If an flavor-oil strut “bottoms”, that is, it is collapsed-the gas battle and hydraulic vague has been wandering from the tolerate breathe chamber. This is probably due to a lost or defective way of creature valve or to defective o-sports ground seals.
CAUTION: Before an tune-oil strut is removed or disassembled, the setting valve should be opened to make complimentary that every tolerate breathe pressure is removed. Severe insult and/or damage can occur as the result of disassembling a strut back even a little amount of freshen pressure is still in the freshen chamber.