Brake Disc PMA FAR 23 - Testing

[ngaad]

I am trying to put together a data package for a PMA for a client, who wishes to manufacture brake discs for a light commuter aircraft.
The Original Equipment Manufacturer stopped making the discs quite a few years ago, and consequently they are not interested in providing any support.

I am wondering if anyone has any experience with brake compliance?

I am looking into achieving compliance with the brake energy absorption requirements of FAR 23.735 through a dynamometer test, rather than risking an aircraft and its crew.
The initial thought was to set up a dynamometer test, 'simulating' the aircraft's kinetic energy by attaching the brake disc to a flywheel. However the size of the flywheel required would make this expensive, and the speeds involved would be dangerous.
It seems that the only other option is to simulate the aircraft's kinetic energy by using a motor to apply a continuously decaying torque to the disc, while the brake is applied to the disc.
Does anyone know of any facilities for conducting such tests?
Does anyone have any other suggestions as to how compliance may be acheived?

Any help would be very much appreciated!

 

[der8110]

Dynamometer tests are the typical certification method.

RAPCO has such a test facility:

http://www.rapcoinc.com/

http://www.rfsbrakes.com/

Since they already make PMA discs and pads, they might be naturally hesitant to help a startup competitor.

Expensive and dangerous are relative terms.

 

[kontiki99]

Maybe you could retrofit an existing prony brake setup with one of the Units Under Test.

http://en.wikipedia.org/wiki/De_Prony_brake

 

[aeroz]

Does the original wheel/brake assembly meet a TSO such as 'TSO-C26c Aircraft Wheels & Wheel Brake Assemblies'? If it does then this TSO may give you the guidelines you need to certify your replacement part.

Good luck!

 

[aeroz]

Just another thought 'ngaad', maybe have a look at FAA AC23-17B (particularly page 70 & 74 - 75), I suspect this is what the FAA (or your NAA) will require for your substantiation submission.

 

[ngaad]

Thanks for your assistance der8110, I am investigating that.

The AC and TSO are also very useful (although I am not sure if the existing disc meets the TSO) - thanks aeroz.