Amateur/Home Built/Experimental
Flight Crew Private
Flight Crew Last 90 Days 2; Flight Crew Total 1385; Flight Crew Type 356
Aircraft Equipment Problem Critical; Ground Event / Encounter Other / Unknown; Ground Excursion Taxiway
Aircraft Aircraft Damaged
Aircraft
The plane had just been released from its annual condition inspection; which included replacing the brake pads and brake disks. I had just finished 'conditioning' the brake pads by doing several high speed taxis (30-40 mph) on the runway followed by hard application of the brakes. No flight was planned. When I got close to the end of the runway the right brake pedal went to the floor. At that point I thought the only thing wrong was either a failure of the plastic brake line or a brake line fitting came loose. So; I thought I would try to 'nurse' it back to the hangar. When I got onto Taxiway Alpha on the far north end of the runway; smoke started coming up into the cockpit and the plane ran off the taxiway into the grass. I got out of the plane and saw that the right wheel pant was on fire and a small grass fire had started. The fire department was called by the lineman on duty and the fire trucks were there within approximately 5 minutes and extinguished the fire. Unfortunately; the fiberglass resin burns quickly and the plane was a total loss. I am thankful that I was able to get out of the plane in plenty of time.I believe that the hard application of the brakes caused a rupture of the plastic brake line that goes to the brake caliper resulting in brake fluid spilling onto the very hot brake pads and igniting the brake fluid. I have done this conditioning process at least two times before without incident. I believe to minimize this from happening in the future; the plastic brake line leading to the brake caliper should be replaced with a metal line.
Experimental aircraft pilot reported a brake failure during brake conditioning taxi operations resulted in a taxiway excursion; smoke and fire from the brake assembly.