On February 15, 2006, about 1510 eastern standard time, a Beech C90A turboprop airplane, N12LE, sustained substantial damage following a collapse of the right main landing gear after landing on runway 18L at the Tampa International Airport, Tampa, Florida. The airplane was being operated as a visual flight rules (VFR) cross-country positioning flight under Title 14, CFR Part 91, when the accident occurred. The airplane was owned and operated by ULAIR Aviation, LLC., Tampa. The airline transport pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed, and company flight following procedures were in effect at the time of the accident. The flight originated at the Miami International Airport, Miami, Florida, about 1345. The pilot submitted a written statement, dated March 4, 2006, which was included with the National Transportation Safety Board (NTSB) Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1) submitted by the operator. The pilot reported that while on approach to the Tampa International Airport, he moved the landing gear control selector to the down position, and saw a red annunciator warning light indicating that the right main landing gear was not safe for landing. The pilot discontinued the approach, advised the local control tower controller of the situation, and climbed the airplane to 1,600 msl so he could evaluate the source of the unsafe landing gear warning light. During climb out he elected not to retract the landing gear. The pilot said that during his assessment of the situation, he selected the landing gear control selector to the up position, and the landing gear retracted normally. He waited about 30 seconds, selected the landing gear control selector to the down position, and he again saw a red annunciator warning light indicting an unsafe right main landing gear. He referred to the emergency and abnormal procedures section of the pilot's checklist, but noted that he was unable to find any clear direction that pertained to his specific condition. He then contacted the Raytheon service center located at the Tampa International Airport, to request technical assistance, but the technician was unable to offer any additional assistance. The pilot said he retracted and extended the landing gear for a third time, but the right main landing gear red annunciator warning light remained on. The Beech C90A airplane flight manual, abnormal procedures section states, in part: "If landing gear fails to extend... See landing gear manual extension" which provides instructions to manually pump the landing to the down and locked position. The manual further states: "If One or More Green Gear-Down Annunciators Do Not Illuminate, For Any Reason, and a Decision is Made to Land in This Condition" the manual states: "Alternate Extension Handle...Continue Pumping. (a) Continue to pump until maximum resistance is felt. (b) When pumping is complete, leave handle at the top of the stroke. DO NOT LOWER AND STOW." Additionally, the manual states that after landing: "Pump the handle again, when conditions permit, to maintain hydraulic pressure until the gear can be mechanically secured. The pilot retuned to the Tampa International Airport and prepared to land. Before landing he requested to fly by the local control tower so air traffic control tower personnel, along with technicians from the Raytheon service center, could inspect the landing gear prior to landing. At the completion of the fly by, the pilot was advised that the right main landing gear appeared to be down, and the airplane was subsequently cleared to land on Runway 18L. The pilot reported that after landing, as the airplane's ground roll slowed to 20 knots, the right main landing gear collapsed. The right wing struck the surface of the runway and sustained substantial damage. The airplane was recovered from Runway 18L and transported to the Raytheon service center hangar by recovery personnel. Recovery crews reported that during recovery efforts, and once the airplane's right wing was lifted, the right main landing gear would not lock into the down position. A recovery crew technician noted that a temporary bracing system had to be installed before the airplane could be towed to the Raytheon service center hangar. A postaccident inspection of the main landing gear system revealed no preaccident mechanical anomalies. The airplane was placed on jacks and airplane's landing gear retraction system was cycled, numerous times, with no mechanical anomalies noted. Each time the landing gear was lowered, three green landing gear safe lights illuminated. At the request of the NTSB investigator-in-charge (IIC), the accident airplane's right main landing gear actuator, part number 90-388000-1, and the right main landing gear downlock switch, were removed for additional testing and evaluation. On March 8, 2006, a Federal Aviation Administration (FAA) aviation safety inspector assigned to the Manufacturing Inspection District Offices (MIDO), Wichita, Kansas, witnessed the functional test and examination of the right main landing gear actuator. The test was conducted at Airight, Inc, Wichita, Kansas. Airight, Inc. is the manufacturer of the actuator for Beech. According to the FAA inspector the landing gear actuator functioned normally, and no mechanical anomalies were discovered. On October 4, 2006, at the direction of a service difficulty engineer from the FAA's Aircraft Certification Office (ACO), Wichita, the right main landing gear downlock switch was functionally tested. The testing was conducted at the Raytheon Aircraft Company's analytical laboratory in Wichita. According to the FAA engineer, as well as an air safety investigator from Raytheon Aircraft Company, the landing gear downlock switch functioned properly, with no mechanical anomalies noted. The Safety Board released the airplane to the owner's representatives at the Tampa International Airport on February 15, 2006. The cockpit voice recorder (CVR), right main landing gear actuator, and right main landing gear downlock switch were the only components retained by the Safety Board for examination. The right main landing gear actuator was released to Raytheon Aircraft Services, Tampa, on March 26, 2006. The CVR was released to Raytheon Aircraft Services, Tampa, on June 10, 2007. The right main landing gear downlock switch was released to International Loss Management, Miami, on July 3, 2007.