By Rick Durden Aircraft Brakes: Brakes Stopping general aviation airplanes has come a long way from the days when a pilot simply closed the throttle, pulled back hard on the stick to drive the tail skid into the turf and hoped.
Contact Aircraft Brakes Very early aircraft have no brake system to slow and stop Modern aircraft brakes aircraft while it is on the ground.
Instead, they rely on slow speeds, soft airfield surfaces, and the friction developed by the tail skid to reduce speed during ground operation. Brake systems designed for aircraft became common after World War I as the speed and complexity of aircraft increased and the use of smooth, paved runway surfaces proliferated.
All modern aircraft are equipped with brakes. Their proper functioning is relied upon for safe operation of the aircraft on the ground. The brakes slow the aircraft and stop it in a reasonable amount of time.
On most aircraft, each of the main wheels is equipped with a brake unit. The nose wheel or tail wheel does not have a brake. Pushing on the top of the right rudder pedal activates the brake on the right main wheel s and pushing on the top of the left rudder pedal operates the brake on the left main wheel s.
The basic operation of brakes involves converting the kinetic energy of motion into heat energy through the creation of friction. A great amount of heat is developed and forces on the brake system components are demanding. Proper adjustment, inspection, and maintenance of the brakes is essential for effective operation.
Types and Construction of Aircraft Brakes Modern aircraft typically use disc brakes. The disc rotates with the turning wheel assembly while a stationary caliper resists the rotation by causing friction against the disc when the brakes are applied. The size, weight, and landing speed of the aircraft influence the design and complexity of the disc brake system.
Single, dual, and multiple disc brakes are common types of brakes. Segmented rotor brakes are used on large aircraft. Expander tube brakes are found on older large aircraft. The use of carbon discs is increasing in the modern aviation fleet.
Single Disc Brakes Small, light aircraft typically achieve effective braking using a single disc keyed or bolted to each wheel. As the wheel turns, so does the disc. Braking is accomplished by applying friction to both sides of the disc from a non-rotating caliper bolted to the landing gear axle flange.
Pistons in the caliper housing under hydraulic pressure force wearable brake pads or linings against the disc when the brakes are applied.
Hydraulic master cylinders connected to the rudder pedals supply the pressure when the upper halves of the rudder pedals are pressed. Floating Disc Brakes A floating disk brake is illustrated in Figure 1. A more detailed, exploded view of this type of brake is shown in Figure 2.
The caliper straddles the disc. It has three cylinders bored through the housing, but on other brakes this number may vary.
Each cylinder accepts an actuating piston assembly comprised mainly of a piston, a return spring, and an automatic adjusting pin. Each brake assembly has six brake linings or pucks. Three are located on the ends of the pistons, which are in the outboard side of the caliper.
They are designed to move in and out with the pistons and apply pressure to the outboard side of the disc.REPORT ON MATERIALS AND PROCESSES USED IN THE MANUFACTURING OF MODERN AIRCRAFT BRAKES FUTURE TRENDS The aircraft brake is dependent on the situation of the aircraft industry and influenced by the development of aerospace technology.
In fact, unlike the thrust reversers on most airliners, including the Boeing jumbo, they do not stop the aircraft in a shorter distance than brakes and spoilers alone. They do, however, take some of the strain off the brakes and are useful if water or snow makes the runway slippery. Aircraft Disc Brake Aircraft Brake Design.
Wheel brakes are normally used to slow the aircraft down during landing roll on the runway and to aid in directional control during ground handling operations as taxiing, steering and parking. Modern aircraft brakes are reliable, effective and inexpensive to keep up, if common sense preventive maintenance is performed.
We stand on them, we ride them, we ignore them—and yet, fortunately, they rarely let us down. In fact, unlike the thrust reversers on most airliners, including the Boeing jumbo, they do not stop the aircraft in a shorter distance than brakes and spoilers alone.
They do, however, take some of the strain off the brakes and are . Generally in older aircraft as well as some light modern aircraft the brakes where more or less the same as modern day disk brakes on cars.
Most were manufactured from gray iron or high carbon steel, with a copper core.