THE PILOT REPORTED HE WAS LANDING ON A 1700' AIRSTRIP THAT HE HAD ROUTINELY USED. HE SAID HE LANDED SLIGHTLY SHORT & BELOW THE RUNWAY GRADE, STRIKING THE RIGHT MAIN LANDING GEAR ON THE LIP OF THE RUNWAY. THE RIGHT MAIN GEAR FAILED & SEPARATED FROM THE WING, DAMAGING THE WING SPAR. THE PILOT SAID HE HAD SOME DIFFICULTY WITH THE APPROACH TO LANDING DUE TO SUNGLARE. ON A SUBSEQUENT APPLICATION FOR MED CERT, DATED 3/28/90, THE PLT RPRTD 8000 HRS OF FLT TIME.