On April 2, 1994, about 1439 eastern standard time, a Boeing 727-243, N59412, registered to Wilmington Trust Company Trustee, leased to and operating as Continental Airlines Flight 1447, on a 14 CFR Part 121 scheduled domestic passenger diverted from the planned destination airport, and landed at Orlando International Airport with the left main landing gear in the up position. The airplane sustained minor damage. The airline transport pilot-in-command, first officer, flight engineer, 6 cabin attendants, and 141 passengers exited the airplane down the emergency slide from the left forward door without injury. Visual meteorological conditions prevailed and an IFR flight plan was filed. The flight originated from Newark, New Jersey, about 3 hours 54 minutes before the incident. The airplane came to rest on runway 18R on the left wing leading edge slats, trailing edge flaps, left wing tip, nose tires, and the right main landing gear. Initial examination of the left landing gear system, revealed the left main landing gear door rib attachment fitting had failed preventing the landing gear from extending. Examination of the fitting by the NTSB Materials Laboratory Division, revealed the failure was due to fatigue cracking in the fitting. Review of aircraft records revealed pertinent service bulletins and airworthiness directives pertaining to the fitting had been recorded as having been completed. (For additional information see NTSB Systems Group Chairman's Factual Report, and NTSB Metallurgist's Factual Report). The digital flight data recorder (DFDR) was forwarded to the NTSB Office of Engineering for analysis. Readout of the recorder revealed the unit was working properly, but not receiving valid data from the flight data acquisition unit (FDAU), due to either a failed FDAU or a failed connection between the FDAU and DFDR. (For additional information see NTSB Digital Flight Data Recorder Factual Report). The airplane was released to Continental Airlines on April 5, 1994.