Keith,

Most important to me is that Disc's dissipate heat much better. Drums are outstanding for stopping if you don't stop or use them often, but as you know prolonged stopping is very detrimental to drum brake system. I know the first contacting shoe in a drum brake applies force to the second shoe multiplying the pressure applied to the drum, but this only works until the heat boundary layer builds up and is trapped in between the shoe and drum. Disc brakes have reduced mountain brake issues/failures dramatically. Fewer little ovens with brake parts inside running around.

I have lost stopping power on cement mixers and dump trucks on several occasions just due to heat. The truck was stopping fine and then it felt like we hit a sheet of ice. When they cooled down all was fine. We haven't seen drum brakes on an aircraft since the 40's. Vented rotors simply dissipate heat much better, but in turn we lose surface area and application force. Electric supplemental boosters may help solve the force issue.

I am waiting for them to be used on larger vehicles and the supplemental electric hydraulic booster that is sold by Summit Racing only adds hydraulic pressure to the system without changing the original configuration much. It appears it is being used in race cars to apply more force to the rotors. It reads that it plumbs into an existing system. If it fails you still have your original brakes.

All new stuff, we will see where it goes.

Take care,
Tom K.