The cost savings that carbon brakes offer because of their lighter weight and longer life-cycle have lured several airlines that operate Boeing 737 NGs into retrofit programs in addition to the new-production aircraft they equip. Carbon brakes entered service on the 737 NG fleet relatively recently, with Delta Air Lines launching the Messier-Bugatti version on its new 737-700s in 2008. Because of the rate at which the 737 NG fleet is expected to grow, and the carbon brakes’ increasing popularity on new and retrofitted aircraft, installation and maintenance of carbon brakes may be a third-party business opportunity to watch closely.

An alternative to steel brakes, carbon brakes weigh less and offer up to twice as many landings between overhauls. Carbon brakes weigh 550 lb. less than standard capacity steel brakes for 737-600/-700 NG and 700 lb. less than high-capacity steel brakes for 737-700/-800/-900ER NG. They first were used on high-performance military aircraft and were cost-prohibitive for commercial operations, but today, Boeing says carbon brakes’ life-cycle cost falls about on par with that of steel brakes.

Carbon brakes became basic equipment on many Boeing aircraft, including the 747-400 and -400ER, 757-300, 767, 777, MD-11 and MD-90 in the mid-1980s; they also will be basic equipment on the 787 Dreamliner and 747-8. Via master change service bulletins, 757-200s, 767-200s and -300s and MD-10s can be retrofitted with carbon brakes. And, more recently, Boeing added carbon brakes as an optional feature for 737 NGs and made them available for retrofit.

The 737 NG fleet has two carbon-brake OEM options: Messier-Bugatti and Goodrich. The Messier-Bugatti variety entered service first, following a one-month certification program that ended March 11, 2008. FAA certified the 737 NG carbon brakes on July 24, 2008, and Delta Air Lines received the first of 10 737-700 NGs fitted with the Messier-Bugatti carbon brakes in August 2008. Delta coupled the weight savings the carbon brakes provide with blended winglets to maximize its 737-700 NG fleet’s fuel efficiency.

Goodrich’s Duracarb carbon brakes entered service on March 15, 2010, with flydubai’s seventh new 737-800 NG. Flydubai, Dubai’s first low-cost carrier, contracted Goodrich to supply it with wheels and carbon brakes for more than 50 aircraft it has on order. It also plans to retrofit the six aircraft it received earlier with carbon brakes.

While FAA certified carbon brakes on the 737 NG in 2008, Europe has yet to follow. Boeing expects EASA validation in the third quarter of this year, says 737 program spokeswoman Vicki Ray. “We have a number of European customers,” she points out, “and the timing needs to coincide.”

Earlier this year, Boeing, FAA and EASA compromised on cooling times for 737 NG carbon brakes [Aviation DAILY, Feb. 12, 2010]. EASA requires a longer turnaround period between landing and takeoff to allow the brakes to cool before granting clearance. Boeing accepted the added time of “about five minutes” and plans to begin supplying both the Messier-Bugatti and Goodrich carbon brake option to early European customers such as Norwegian Airlines and TUI Group in the fall.

Early Retrofits

The retrofit program is in the early stages, Ray says. Boeing’s Commercial Aviation Services, or CAS, handles retrofits. A customer interested in retrofitting its 737 NGs submits a request for proposal to CAS. CAS then prepares a unique retrofit package for each customer. Responsibility for all parts and labor fall to the customer; it can either install the brakes in-house or contract the work to a third party.

Ray says it is too early to say whether most customers will opt to perform the upgrade themselves or sent the work out.