On July 11, 2007, about 1215 eastern daylight time, a Piper PA-31-350, N105GC, was undamaged following a forced landing to a field near Orlando, Florida. The certificated airline transport pilot was not injured. Visual meteorological conditions prevailed, and the airplane was operating on an instrument flight rules flight plan, destined for Orlando International Airport (MCO), Orlando, Florida. The positioning flight, which departed Melbourne International Airport (MLB), Melbourne, Florida, at 1143, was conducted under 14 Code of Federal Regulations (CFR) Part 91. According to the operator, the airplane had undergone routine maintenance, and was returned to service on the day prior to the incident flight. The purpose of the incident flight was to reposition the airplane to MCO and pick up passengers for a 14 CFR Part 135 revenue flight. The incident flight was the first since the airplane was returned to service. While in cruise flight at 4,000 feet msl, the pilot heard a "loud bang," and saw that the right forward windscreen and right side window had broken. He then saw that the right engine's top cowling was missing, and felt the aircraft "shudder" as it began to descend. The "strong vibration" of the airframe continued, and the pilot elected to secure the right engine, and continued to the airplane toward MCO, the nearest suitable airport. Although full power was applied to the left engine, the airplane would not maintain altitude, so the pilot attempted to land the airplane on a paved site he had identified. The pilot subsequently realized, while attempting to land, that the airplane did not have a sufficient glidepath to clear a tree line and buildings, and landed the airplane in a clearing about 1,500 yards short of the intended landing area. The airplane came to rest in a field of scrub brush, and about 5 minutes after the pilot deplaned, the grass under the left engine ignited. The subsequent brush fire consumed the airplane. The pilot held an airline transport pilot certificate with ratings for airplane single and multiengine land, and instrument airplane. He reported 13,000 total hours of flight experience, 200 hours of which were in the incident airplane make and model. Examination of the remaining portion of the right engine cowling, by Federal Aviation Administration inspectors, revealed that the outboard latching fasteners were set to the "open" position. During an interview with company personnel, the mechanics who had performed the most recent maintenance on the airplane stated that they were comfortable with the cowling installation procedure, and did not reference the aircraft maintenance manual. A subsequent review of the maintenance manual revealed that the procedure the mechanics used was not the one described in the manual. The mechanic who had been working on the outboard side of the engine stated that he was not certain that he fastened the three primary outboard cowl fasteners before he left the airplane during the installation to retrieve a step ladder. Additionally, when asked about the security of the cowling during the preflight inspection, the pilot stated that he "just missed it."