RWY EXCURSION; OFF INTO THE DITCH.

Narrative

I VEERED OFF THE RWY DURING LNDG. NORMAL TOUCHDOWN; PLANE VEERED SHARPLY L. WIND STRAIGHT DOWN THE RWY; 10 DEGS GUSTING 18 KTS; DAMP RWY IN LIGHT RAIN. AFTER LNDG; PLANE WENT L. I APPLIED FULL R RUDDER; BUT PLANE CONTINUED TO GO L. I DID NOT APPLY THE BRAKES TILL OFF THE RWY SINCE I HAVE BEEN TAUGHT TO STAY OFF DIFFERENTIAL BRAKES DURING FAST ROLLOUT DUE TO THE POSSIBILITY OF OVERCTLING AND GND LOOP. THE PLANE CONTINUED ON INTO A DITCH AND SUSTAINED MODERATE DAMAGE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR WAS FLYING A MOONEY MK 20C. HE HAD BEEN PICKING UP PITOT ICE; SO HAD TURNED ON THE PITOT HEAT. BELIEVES THAT HE WAS RECEIVING GOOD AIRSPD INFO. THERE IS AN ESTIMATE OF $28000 DAMAGE. THE NOSE GEAR WAS BROKEN OFF; PROP WAS BENT; SOME WING SKINS WERE DENTED AND THERE WILL HAVE TO BE AN ENG TEARDOWN FOR SUDDEN STOPPAGE. THE RPTR HAS RECEIVED A '609 RIDE' FROM THE FAA IN ANOTHER MOONEY. THE RPTR BELIEVES THAT EITHER THE NOSE GEAR WAS COCKED TO THE L OR THE L BRAKE WAS PARTIALLY LOCKED ON. THE FAA SAYS THAT HE MUST HAVE BEEN FAST AND GOT UP ON THE NOSE GEAR. HE HIT THE DITCH GOING ONLY ABOUT 20 KTS. HE IS SURE THAT HIS AIRSPD WAS UNDER CTL. THERE WAS NO FORMAL INVESTIGATION OF THE INCIDENT. THE NTSB DECLARED THIS TO BE AN 'INCIDENT.'