Conroe

While conducting a post maintenance test flight in visual flight rules conditions, the private pilot of the multi-engine airplane reported an oil leak to air traffic control. The controller provided vectors for the pilot to enter a right base leg for a landing to the south at the nearest airport, about 7 miles away. The pilot turned toward the airport but indicated that he did not have the airport in sight. Further, while maneuvering toward the airport, the pilot reported that the engine was "dead," and he still did not see the airport. The final radar data point recorded the airplane's position about 3.5 miles west-northwest of the approach end of the runway; the wreckage site was located about 4 miles northeast of the runway, indicating that the pilot flew past the airport rather than turning onto a final approach for landing. The reason that the pilot did not see the runway during the approach to the alternate airport, given that the airplane was operating in visual conditions and the controller was issuing guidance information, could not be determined. Regardless, the pilot did not execute a precautionary landing in a timely manner and lost control of the airplane. Examination of the airplane's left engine revealed that the No. 2 connecting rod was broken. The connecting rod bearings exhibited signs of heat distress and discoloration consistent with a lack of lubrication. The engine's oil pump was intact, and the gears were wet with oil. Based on the available evidence, the engine failure was the result of oil starvation; however, examination could not identify the reason for the starvation.

Visual meteorological conditions prevailed for the planned cross-country flight for which the pilot obtained a weather briefing, filed an IFR flight plan, and received an ATC clearance. Approximately 8 minutes after takeoff, radar indicated the airplane was at 11,200 feet msl, heading 241 degrees, with a ground speed of 180 knots. No distress calls or additional communications with the pilot were recorded, and radar contact was lost. The airplane impacted the ground in an uncontrolled descent. The right wing tip tank separated from the airplane and was found 0.18 nautical miles from the main wreckage. The teardown and examination of both engines disclosed that the type and degree of damage was indicative of engine power section rotation and operation at the time of impact. There were no complete systems intact at the accident site due to the impact sequence and post-impact fire which consumed the aircraft. The landing gear and flaps were found in the retracted position. The portion of the right propeller shaft coupling found at the site was fractured through 360 degrees. Metallurgical examination revealed that the propeller shaft coupling failed in fatigue. The presence of the fatigue cracks indicated the coupler fractured in fatigue in service, and the fatigue cracks were not the result of ground impact. The circumferential fracture intersected the ends of several internal spline teeth. The origin of the fatigue crack could not be determined because of severe corrosion damage on the fracture surface. Fatigue propagation was in the aft direction and from the inside to the outside of the coupling. The engine core rotating components would have bee free to rotate when uncoupled from the propeller shaft. The maintenance records indicated that the failed coupling had accumulated approximately 4,000 hours since new, and 1,250 hours since engine overhaul in 1989. Since 1990, as a result of fatigue fractures, the manufacturer introduced several design changes for the propeller shaft coupling via optional Service Bulletins to be accomplished at the next access or hot section inspection (HSI). Impact and thermal damage of the right propeller precluded a determination of the in-flight blade angles. The calculations by the airplane manufacturer indicated that "the [intact] airplane was capable of continued flight" with the right propeller feathered, and that the "airplane can keep attitude, but cannot climb and cannot maintain altitude" with the right propeller in the flat pitch or wind milling positions, respectively. Metallurgical examination of the component brackets and associated bolts from the right tip tank revealed the separation of the tip tank resulted from a single-event overstress fracture of both the forward and aft tank attachment fittings. Calculations showed that a 3.763 radians per second (35.9 RPM) spin rate would cause the failure of the forward wing fuel tank attachment fitting. There had not been a previous in-flight separation of a wing tip fuel tank on this model airplane.

During initial takeoff climb the copilot who was manipulating the controls called for METO (maximum except takeoff) power. After the pilot-in-command set METO power, the left engine lost power. The PIC took the controls from the copilot and called for him to feather the left propeller. The copilot did not hear the call to feather the left propeller. Maintaining an indicated airspeed of 90 knots and wings level attitude, the airplane descended into trees and impacted a rural residential paved street. The cockpit area and main fuselage were consumed by a post crash fire. Examination of the throttle quadrant revealed the propeller control levers were forward, the mixture control levers were autorich, the throttle for the right engine was forward, and the throttle for the left engine was at idle. According to a FAA operations inspector maintaining 90 knots with the propeller not feathered would result in the aircraft descending. The pilot and copilot had not completed a proficiency check or flight check for the DC3 type aircraft within the previous 24 months. Examination of the left engine did not disclose any preexisting anomalies.

During taxi to takeoff the crew sensed an odor similar to an electrical fire, and smoke became apparent in the cockpit. Both generators and the battery master were secured. The right generator would not accept a load and smoke was coming from the right wing accessory jbox in the right wheel well. Three occupants deplaned and initially extinguished the fire, which reignited due to hot metal and compromised fuel/oil lines. All systems were secured and the pilot then evacuated the airplane, which was consumed by the fire. The pilot estimated that fire fighting equipment did not arrive for 20-25 minutes after the fire began. Faa inspectors were unable to determine the fire source from the burned wreckage. However, the operator's report stated that the right starter solenoid did not open after engine start causing the starter to remain linked to the electrical system. This resulted in a system overload and subsequent electrical fire. Both fuel and oil lines were routed through the right wheel well for cockpit indications.

The aircraft collided with power lines and trees while on final approach. The reported weather immediately following the accident was an indefinite ceiling zero, sky obscured, and visibility 1/16 of a mile in fog. No preimpact failures or malfunctions of the aircraft were found. The pilot had diverted from his intended destination due to fog. The pilot, sole on board, was killed.

The aircraft crashed while on an ILS approach to the Gainsville Airport. Investigation revealed that the pilot had advised approach control that he was 'low on fuel.' After two missed approaches the pilot radioed that he was 'out of fuel.' The pilot did not have charts or approach plates aboard the aircraft, however ATC was not aware of this factor. Attempts to acquire additional information from the pilot have been unsuccessful. All three occupants escaped with minor injuries.