Aviation Accident Final Report

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Page 1 of 6 National Transportation Safety Board Aviation Accident Final Report Location: NORTH PLATTE, NE Accident Number: CHI98LA178 Date & Time: 05/28/1998, 1300 CDT Registration: N888AA Aircraft: Cessna 414 Aircraft Damage: Destroyed Defining Event: Injuries: 3 Minor Flight Conducted Under: Part 135: Air Taxi & Commuter - Non-scheduled Analysis The airplane had just taken off and was at approximately 300 agl when the right engine 'had a sudden and catastrophic failure.' The right propeller stopped spinning with the blades in the low-pitch position. The pilot initiated a right turn back toward the airport, but the airplane would not maintain altitude. The pilot rolled out of the turn, but the descent continued until the airplane struck the trees. Examination of the airplane's right engine revealed that the crankshaft was broken at the number 3 short cheek, just forward of the number two cylinder piston rod. The number two crankshaft bearing was broken and melted. The oil feed line to the number two bearing was blocked by a piece of the broken bearing. The Single Engine Climb Data table in the Cessna 414 Pilot's Operating Handbook indicates that an airplane weighing 5,680 pounds, with gear and flaps retracted and the inoperative propeller in feather, operating at a density altitude of 5,055 feet, will have a best climb indicated airspeed of 115 knots. The rate of climb will be 308 feet per minute. Probable Cause and Findings The National Transportation Safety Board determines the probable cause(s) of this accident to be: the slipped number two bearing in the airplane's right engine, which blocked the bearing's oil feed line, causing the bearing and the crankshaft to overheat and fracture. A factor contributing to this accident was the trees. Page 2 of 6 CHI98LA178 Findings Occurrence #1: LOSS OF ENGINE POWER(TOTAL) - MECH FAILURE/MALF Phase of Operation: TAKEOFF - INITIAL CLIMB Findings 1. (C) ENGINE ASSEMBLY,BEARING - SLIPPED 2. (C) FLUID,OIL - STARVATION 3. (C) ENGINE ASSEMBLY,BEARING - FRACTURED 4. (C) ENGINE ASSEMBLY,CRANKSHAFT - FRACTURED 5. ENGINE ASSEMBLY,CRANKCASE - FRACTURED ---------- Occurrence #2: IN FLIGHT COLLISION WITH OBJECT Phase of Operation: EMERGENCY DESCENT/LANDING Findings 6. (F) OBJECT - TREE(S) ---------- Occurrence #3: IN FLIGHT COLLISION WITH TERRAIN/WATER Phase of Operation: DESCENT - UNCONTROLLED Page 3 of 6 CHI98LA178 Factual Information On May 28, 1998, at 1300 central daylight time (cdt), a Cessna 414, N888AA, operated by an airline transport pilot, was destroyed when on initial climb, the airplane's right engine lost power. The airplane subsequently struck some trees and impacted the terrain in an inverted attitude. Visual meteorological conditions prevailed at the time of the accident. The flight was being conducted under 14 CFR Part 135. An IFR flight plan was on file. The pilot and two passengers on board the airplane sustained minor injuries. The cross-country flight originated at North Platte, Nebraska. In his written statement, the pilot said that he had just taken off and was at approximately 300 feet above ground level (agl) when the right engine "had a sudden and catastrophic failure." Before he could complete his emergency checklist, the right propeller stopped spinning with the blades in the low-pitch position. The pilot said that he initiated a right turn back toward the airport, but noted that the airplane would not maintain altitude. The pilot rolled out of the turn, but the descent continued. The airplane struck the trees. The pilot said that on impact he was knocked unconscious and could not remember anything after realizing that the airplane was going to hit the trees. A Federal Aviation Administration (FAA) inspector examined the wreckage at the accident site. The accident site was located in a wooded area on the north bank of the North Platte River, approximately 3/4 of a mile south of the North Platte Regional Airport, North Platte, Nebraska. The airplane rested inverted on the ground and was oriented on a 200-degree heading. Several nearby trees, aft of the wreckage, were broken and damaged. The nose of the airplane was crushed inward and aft to the forward pressure bulkhead. The airplane's cabin and aft fuselage remained intact. The left wing was broken aft beginning outboard of the engine nacelle. The outboard portion of the left wing was located just right of the fuselage. It showed numerous areas of aft crushing and denting along the entire length of the leading edge. Both wing sections remained attached by the engine and aileron flight control cables. The left engine had separated from the nacelle and was located 33 feet south of the fuselage. The airplane's left propeller was broken off at the flange and rested just 48 feet forward of the fuselage. It showed torsional bending and chordwise scratches. The airplane's right wing was broken off at the wing root. It was found resting 58 feet aft of the fuselage. The right engine was broken out of the nacelle, but remained attached by the engine control cables. The right propeller was broken at the flange. One of the three blades was broken out of the hub. All three blades showed little damage. The airplane's empennage was bent downward. The vertical stabilizer and rudder were bent aft and broken. Flight control continuity was confirmed. Examination of the airplane's left engine revealed no anomalies. Examination of the airplane's right engine revealed that the crankshaft was broken at the number 3 short cheek, just forward of the number two cylinder piston rod. The number two crankshaft bearing was broken and melted. The oil feed line to the number two bearing was blocked by a piece of the broken bearing. The Single Engine Climb Data table in the Cessna 414 Pilot's Operating Handbook indicates that an airplane weighing 5,680 pounds, with gear and flaps retracted and the inoperative propeller in feather, operating at a density altitude of 5,055 feet, will have a best climb