What does it take to safely stop a 150,000-pound aircraft in its tracks? While this is a complex process, the main answer is the brakes. Traditional steel brakes have played this essential role in bringing speeding aircraft to a halt for more than 75 years, but today, innovative, long-lasting and lightweight carbon brakes are triggering radical improvements in aircraft braking efficiency.
UTC Aerospace Systems engineers have developed carbon brakes with fewer parts and a lifespan that is many times longer than steel brakes, enabling aircraft to fly longer and more often, with long-term cost savings for both commercial airlines and military fleets. And, since most aircraft carbon braking systems were first deployed on civil commercial aircraft, the military has reaped the benefits of using these systems without having to invest in the up-front development costs. Modern examples include the carbon brakes for the F-16, which were derived from those in use on the Boeing 747-400, as well as the new C-130 carbon brakes, which were a derivative of those in use on the Airbus A320 and Boeing 777LR.
Rick Pyatt, director of defense and aerospace policy at United Technologies Corporation (UTC) Global Government Relations, and Jeff Atkinson, director of military programs for UTC Aerospace Systems Landing Systems, explained why these carbon brakes make a big difference, and how the military is benefitting from these commercially-derived innovations. Here are four ways carbon brakes work better for military and commercial aircraft:
Less downtime
Carbon brakes have a much faster cooling rate versus steel brakes, which can require over an hour to cool down. Carbon brakes also “operate better at higher temperatures than steel brakes,” Atkinson said. This innovative technology means aircraft spend less time on the ground cooling their brakes, so planes can turn more quickly for the next flight or mission – a critical requirement for the military. This is especially important for U.S. Central Command military flights operating in high-temperature regions like the Persian Gulf where crews must land, refuel, rearm and fly again.
Lighter weight = less fuel burn = savings, and enhanced operational flexibility
“On big airplanes, if you take steel brakes off the plane and use carbon brakes, you can reduce the aircraft weight by 2,000 pounds, saving thousands of dollars in fuel costs annually,” said Pyatt, who is a former Air Force pilot and commercial airline Captain. This grows to millions of dollars when aggregated across a fleet of aircraft. Equally important, carbon brakes enhance operational flexibility, allowing pilots the option to carry more fuel, more cargo, or more people per mission.
As an example, on long range flights, Pyatt said “the ability to carry more fuel provides an important operational advantage; giving pilots the opportunity to re-route around bad weather, hold while destination weather improves, have enough fuel to make another approach to the runway when the weather is really bad or divert to a suitable alternate airfield.”
This provides additional cost savings, according to Pyatt. “There are costs associated with not completing a flight or mission as planned,” Pyatt said. “Carbon brakes provide fuel saving up front and dollar savings at the end of the flight because my airplane, its people, and cargo are where they’re supposed to be.”
Less maintenance
Carbon braking systems last longer than steel braking systems. “They perform as well on the 2,000th landing as on the first,” Atkinson said. Carbon brakes are widely used in U.S. Air Force planes such as the C-130 and C-5 cargo planes, as well as various fighter aircraft like the F-15 and F-16 and are factory-installed in most new aircraft. “Carbon brakes stay on the aircraft longer, reducing taxpayer costs, reducing work for maintainers and the downtime associated with more frequent brake changes,” Pyatt said.
Shorter braking distance
Pilots have reported shorter stopping distances using carbon brakes versus steel brakes. “The stopping advantage of carbon brakes provides an enhanced safety cushion for pilots, especially when they are landing on shorter runways, landing with higher than normal gross weight and when stopping during an aborted takeoff.”
Benefits of Using Carbon Brakes and Lock Ring Wheels on C-130 Aircraft:
Despite these benefits, carbon brakes are not on every airplane. UTC Aerospace Systems hopes to change that. “Carbon brakes developed for the commercial market have brought major benefits to the commercial airlines, and now to the U.S. Air Force. This innovative technology also offers improved braking performance and fuel savings, operational flexibility, lower maintenance costs, and longer brake life for the Army, Navy and Marine Corps too,” Atkinson said.
