It almost sounds counterintuitive, but United Technologies' (NYSE: UTX) airplane-brakes business just keeps gaining speed.

On Tuesday, the aerospace giant announced yet another deal to sell yet another airline its special high-tech carbon braking systems, and wheels, with which to equip its fleet of Boeing (NYSE: BA) airplanes. This time, it's China's Spring Airlines Japan signing on the dotted lines, choosing wheels and carbon brakes to install on its new fleet of a20 Boeing 737-800 Next Generation airplanes.

Spring's first new 737 is due to arrive later this month, and when it does, UTC Aerospace Systems will be installed on it.

According to UTC, the main attraction helping it to win these contracts is the proprietary "DURACARB" carbon heat sink material built into its brakes, which helps improve braking performance and extend the lifespan of the brakes by 35% over competing products. In addition, UTC says its brakes are 700 pounds lighter than the average steel braking system, adding fuel-cost savings to the list of advantages.

UTC notes that Spring Airlines has also signed an agreement to have UTC perform brake services on its planes at UTC's Hong Kong service center.