Carbon Brakes For 737

The world’s most popular and best selling airplane of all time is Boeing’s 737 family. Since inception, the 737 family has had two major updates and a plethora of performance enhancing components integrated to make this highly successful airplane even better still.

In a media briefing today, Boeing discussed the 737 and yet another new milestone achievement incorporating the usage of carbon brakes.

The 737 Chief Project Engineer, John Hamilton, laid out a few of the key points about the 737 and the new carbon brakes that will now be a customer option for purchase on new or existing 737NG airplanes (including 737 Boeing Business Jets) using a retrofit kit.

Images courtesy of Boeing

Carbon brakes will not be retrofitted to the 737 Classic family (covering -100 through -500 models).

• Boeing’s desire to innovate & improve, increas value for customers
• Enhance airplane performance, passenger comfort and improve navigation
• Greater ability to fly more precise routes, cutting flight miles, greater use of VSD (Vertical Situation Display)
• All 737NG/BBJ family will have option of steel or carbon brakes
• Messier-Bugatti and Goodrich are the two key suppliers for the wheels/brake systems on the 737NG
• Certification of the Messier-Bugatti brakes due in about a month, EIS in third quarter of 2008 with Delta Airlines
• Redesign of Goodrich wheel underway, flight tests & certification to follow
• New wheels designed especially for carbon brakes
• Hydraulic flow restrictor provides better feel of brakes for pilots coupled with brake monitor system
• Carbon brakes stay on airplane longer
• Weight saving benefits ~ 700lbs on 737NG resulting in 0.5% fuel burn improvement and lower emissions

Also speaking at the briefing was Captain Christine Walsh who is Validation Chief Engineer at Renton Airplane Programs and Commercial Aviation Services (CAS).

Testing of the carbon brakes was covered over 61 days at 6 airports, predominantly in Roswell, New Mexico. For certification compliance with EASA and FAA requirements, Boeing demonstrated equivalent benefits of carbon brakes as opposed to the current set up using steel brakes. Some of the tests conducted are outlined below:

• Take off & landings
• Refused & rejected take offs at a variety of weights and speeds
• Maximum Brake Energy (MBE) tests - 100% load RTO
• Landings using varied flap settings
• Performance landing to validate airplane handling using new carbon brakes
• 30 days spent at Roswell testing new brakes/wheels

In order to meet FAA requirements, no less that 25 brake units and 58 wheel changes were done towards gaining certification.

The new carbon brakes are also available on the 737BBJ, as well as 777 and 787 Dreamliner airplanes. Hamilton pointed out that maintenance costs of approximately 10% are attributable to braking systems alone on airliners today.

I asked Hamilton whether these new brakes would be used on any new 737 replacement, Hamilton said that the company would be exploring all avenues to get the best technology for customers.

3 comments May 2nd, 2008