AIRCRAFT WHEELS, TIRES, AND TUBES
Chapter Objective:Upon completion of this chapter, you will have a working knowledge of maintenance procedures and the precautions necessary to properly maintain aircraft wheels, tires, and tubes.
Modern aircraft wheels are among the mosthighly stressed parts of an aircraft. High tire pressures, cyclic loadings, corrosion, and physical damage contribute to failure of aircraft wheels. Complete failure of an aircraft wheel can be catastrophic. When wheel failure occurs, the fragments are often propelled several hundred feet. You must have the ability to identify potential safety hazards that you will encounter while working on aircraft tires and wheel assemblies. You must practice all the safety precautions related to wheel and tire maintenance procedures. At the organizational maintenance level, aircraft wheels are removed frequently for tire changes, inspections, and lubrication. Familiarity with various types of wheels and tires, and related safety precautions, will increase your ability to perform your duties.
Learning Objective:Recognize the com-ponents of the different types of wheels and the maintenance responsibilities of both the O-level and I-level maintenance activities.
Aircraft wheels are made from either aluminum or magnesium alloys. These materials provide a strong, lightweight wheel that requires very little maintenance. The wheels used on naval aircraft are of two general typesódivided and remountable flange. Both of these designs make wheel buildup a fairly simple operation.
The wheels used with tires and tubes have knurled flanges to prevent the tire from slipping on the wheel. Wheels used with tubeless tires have the wheel sections sealed by an O-ring, and they use special valves that are a part of the wheel.
DIVIDED (SPLIT) WHEEL
Figure 11-1 shows a typical divided (split) wheel.This type of wheel is divided into two halves. The two halves are sealed by an O-ring and held together with nuts and bolts. Each wheel half is statically balanced. This procedure allows any two opposite halves of the same size and type to be joined together to form one wheel assembly. If the outboard half of a wheel is beyond repair, a new outboard half may be drawn from supply. The new outboard half is then matched to the old inboard half. This type of wheel is used on nose, main, and tail landing gears.
REMOUNTABLE FLANGE WHEEL
The remountable flange wheel is made so oneflange of the wheel can be removed to change the tire. The flange is held in place by a lockring. The wheel is balanced with the flange mounted on the wheel. Then, both the wheel and flange are marked. To ensure proper balance of the wheel during assembly, the two marks should be lined up. Figure 11-2 shows a typical remountable flange wheel. This type of wheel is commonly used on the main landing gear.
The similarity of one wheel to another in size andshape is not proof that the wheels can be inter-changed. One wheel may be designed for heavy duty while the other may be designed to carry a lighter load. Also, the wheels may be designed for use with different types of brake assemblies.