This month UTC Aerospace Systems will complete deliveries of new brakes and wheels for the U.S. Air Force’s entire Lockheed Martin C-130 Hercules fleet. The brakes replace the original equipment, offering significant performance improvements, enhanced maintainability and reduced life-cycle costs. Compared to the original steel brakes, the new brakes cool much quicker, resulting in reduced time on the ground in “hot” landing zones.
UTC’s Duracarb carbon disk technology is at the heart of the new brake. Compared to the standard steel brake, the Duracarb disk is good for 2,000 landings as opposed to 250, translating to a 10-year life with typical usage instead of 1.3 years. The wheels offer a 25,000-hour roll life instead of 4,200 hours.
Impressive though these figures are, it is the reduction in cooling time after a heavyweight landing with anti-skid employed from 65 minutes to 15 minutes or fewer that provides the Hercules with enhanced survivability when operating into airfields that are under the threat of hostile fire. MERTO (maximum-energy rejected takeoff) tests of the standard steel brakes, conducted with a 155,000-pound load at 127 knots, resulted in potentially serious fires in the undercarriage area. However, a test conducted with the Duracarb brake resulted in nothing more than a glowing disk. Furthermore that test was conducted at a higher weight (175,000 pounds) and with a disk previously worn down so that just 10 percent of its life remained.
Duracarb brakes are part of new wheels designed for the C-130 that include other advances. The brake pistons are fully sealed so that they do not leak potentially dangerous hydraulic fluid, as well as being protected against stone and dust damage. The wheel also features a simple boltless attachment that allows tires to be changed rapidly. A two-piece locking ring is quickly released to allow the tire to be removed and replaced. For a standard C-130 wheel the process takes around four hours and 15 minutes, whereas with the new system it takes just 52 minutes.
Having re-equipped the U.S. Air Force fleet, UTC Aerospace Systems (Stand 1854) is in discussions with the U.S. Navy, Coast Guard and Marine Corps to retrofit their Hercules fleets, and is actively promoting the wheel in the export market. While UTC admits that the wheel is more expensive than the standard unit, it provides savings in terms of life-cycle costs in the longer term. The company has calculated that the cost differential typically evens out after five to seven years of service, after which the Duracarb brake is saving money.