From Drum to Disc: How Airplane Brakes Evolved for Modern Aviation
The braking systems on commercial aircraft have undergone a important transformation, shifting from older drum brake technology to the now-standard disc brake systems. This evolution isn’t merely a matter of engineering preference; it’s a critical safety upgrade driven by the demands of increased aircraft weight, higher landing speeds, and the need for reliable stopping power. Understanding this change reveals the complex engineering that underpins every landing and takeoff.
For decades, airplanes relied on drum brakes, similar in principle to those found in older cars. However, as aircraft grew larger and faster, the limitations of drum brakes-specifically their susceptibility to overheating and reduced stopping efficiency-became increasingly apparent. The transition to disc brakes addressed these concerns, offering superior heat dissipation and more consistent performance, ultimately enhancing flight safety. This shift continues to impact aircraft maintenance, design, and operational costs for airlines worldwide.
Disc brakes represent a major advancement over their drum brake predecessors.They function using metal discs, known as rotors, connected to the wheel hub, and stators fixed to the brake housing. Calipers apply pressure to create friction between these components, slowing the wheel’s rotation. A key advantage of disc brakes is their open design, which allows for efficient air cooling. In contrast, drum brakes’ enclosed structure traps heat, leading to reduced effectiveness, particularly during high-speed landings or repeated braking events. This heat dissipation issue was the primary driver for phasing out drum brakes in aviation.
Today, disc brake configurations vary based on aircraft size and braking requirements. Smaller, lighter aircraft typically utilize single-disc brakes, featuring one rotor and pistons within the caliper to apply pressure on both sides. Medium-sized aircraft frequently enough employ dual-disc brakes, incorporating two rotors and linings within a carrier, clamping both discs simultaneously for increased friction and torque.The largest commercial jets rely on multiple-disc brakes, consisting of stacked rotors and stators compressed by hydraulic pistons, generating substantial friction capable of halting immense weight.
