On July 2, 1996, at 1045 central daylight time, a Cessna 421B, N450SU, collided with a Cessna 152, N94532, while landing near Stillwater, Oklahoma. Both airplanes were substantially damaged. The commercial pilot and the passenger on the Cessna 421B were not injured. Likewise, the solo student pilot in the Cessna 152 was uninjured. Both airplanes were being operated by the Oklahoma State University of Stillwater, Oklahoma, under Title 14 CFR Part 91. Visual meteorological conditions prevailed and a flight plan had not been filed for the flights by either aircraft. According to personnel at the Stillwater Municipal Airport, the Cessna 421B executed an straight-in visual approach to runway 17 upon return from a local maintenance test flight to check the pressurization system. The Cessna 152, being flown by a student pilot on his second supervised solo flight, was on closed traffic for runway 22. The two airplanes collided at the intersection of runways 17 and 22. According to engineering drawings for the Stillwater Airport, the distance from the landing threshold of runway 17 to the collision point is 3,650 feet. Likewise, the distance from the landing threshold of runway 22 to the collision point is 3,400 feet. A witness at the airport observed the collision. He stated that the Cessna 152 maintained a high rate of speed during the landing roll on runway 22. The airplane "stayed on the runway centerline during most of the rollout, beginning to veer to the right as it approached the intersection." He reported that he also observed the Cessna 421 applying heavy breaking and veering to his right to avoid the Cessna 152. The Cessna 152 pilot stated in the enclosed NTSB Form 6120.1/2 that he was in the pattern for runway 17 and he changed over to runway 22 because the winds were "down the runway for 22." The student pilot further stated that he announced his intentions on the Unicom frequency and he never heard any other traffic announcing their intentions to land at the Stillwater Airport. The added that he never saw the Cessna 421 until just before the collision. The Cessna 421 pilot stated in the enclosed NTSB Form 6120.1/2 that the winds were from 170 degrees at 3 knots and he executed his approach to runway 17. He added that while on final approach he made two calls on the Unicom, one at 3 miles, and another at 2 miles. He added that the Cessna 152 landed long, approximately 1,800 feet from the landing threshold, about 5 to 10 seconds after he landed on runway 17. The Stillwater Municipal Airport is an uncontrolled airport with Unicom service, which was reported to be operational at the time of the accident. Both airplanes were equipped with operational 2-way radios. A flight instructor operating near the Stillwater Airport at the time of the collision heard the radio calls and confirmed that both pilots made the radio calls as they stated. Examination of the airplanes revealed that the left wing tip tank on the Cessna 421 was punctured when it impacted the fully deployed right flap on the Cessna 152. Additionally, right engine propeller damaged the right wing and aileron for the Cessna 152. The blades on the left propeller displayed rotational gouging and scratching consistent with impact with the wing; however, the right propeller on the Cessna 421 was found in the feathered position.