NEW BERLIN, IL, USA
N472TL
Beech BE 58
The twin-engine airplane began its instrument flight loaded about 800 pounds beyond its certificated maximum gross take off weight. Shortly after reaching its assigned altitude of 7,000 feet above mean sea level, the pilot advised the FAA controller, '...we have an engine problem.' The problem was not identified during a subsequent radio transmission. Shortly after the pilot's last radio transmission, witnesses on the ground observed the airplane in a counterclockwise flat spin. The on-scene examination revealed the left engine had suffered a mechanical failure. Continuity of the flight, engine, fuel and propeller controls was established. An oil film was found on the left engine's nacelle, inboard half of the wing, left side of the fuselage and the horizontal stabilizer and elevator. The left engine case had fractured near the number 2 cylinder. Examination of the case fracture surfaces revealed fatigue failure at its initiation point. The fatigue extended about 7 inches from its origin. Additionally, the number 2 cylinder connecting rod had separated from the crankshaft journal. Maintenance records showed the engine had a crankcase crack that was not covered by an FAA Airworthiness Directive or engine manufacturer specifications. The maintenance personnel informed the pilot about the crack. Examination of the airplane's hangar floor revealed a pool of fresh oil beneath the area where the left engine would have been positioned. Oil-based tire imprints made by the left main landing gear tire were found on the hangar floor that lead from the oil pool to the ramp outside the hangar. The pilot's logbook records showed he had received 4 hours of multi-engine flight instruction during one flight session on one day. The next day the logbook showed the pilot had received 10-hours of multi-engine instruction during 2 flight sessions. He obtained his multi-engine rating on the third day. Before these instructional entries were made there were 6 other flight instruction entries showing, 'X Country IFR.'
HISTORY OF FLIGHT On October 30, 1997, at 1648 central daylight time (cst), a Beech BE-58 Baron, N472TL, piloted by a private pilot, was destroyed during a collision with the ground following a witness reported flat spin. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 business flight was operating on an IFR flight plan. The pilot and 5 passengers were fatally injured. The flight departed Macomb, Illinois, about 1610 cdt. The pilot called the Federal Aviation Administration (FAA) Flight Service Station (FSS) at 1554 cdt on the accident date. He obtained a weather briefing for an IFR flight from Macomb, Illinois, to Sikeston, Missouri. At the end of the weather briefing the pilot filed an IFR flight plan with the FSS specialist. At 1610 cdt the pilot of N472TL called the FAA's Air Route Traffic Control Center controller (controller) advising the airplane was airborne and requesting his IFR clearance. The controller issued the IFR clearance and told the pilot to climb the airplane to 5,000-feet above mean sea level (msl). During the climb the pilot called the controller and asked if he could climb the airplane to 7,000-feet msl to get above the clouds. The pilot was given clearance to climb N472TL to and maintain 7,000-feet msl. The pilot reported N472TL was level at 7,000-feet msl at 1622 cdt and was told to contact Springfield, Illinois, Capitol Airport's FAA approach controller. N472TL's pilot acknowledged and contacted the controller shortly after receiving the directive. According to the FAA radar track data, N472TL's ground speed was 152 knots at 1634:08 cdt, the altitude was reported to be 7,000 feet msl. Twelve seconds later the ground speed was reported as 81 knots. The radar track data showed the ground speed had slowed to 70 knots by 1634:32 cdt. There were no altitude reports given for the 81 and 70 knot ground speeds. At 1634:55 cdt the pilot of N472TL said, "Tower, Baron four seven two Tango Lima, we have an engine problem." At that time the reported ground speed was 152 knots and altitude was 5,600 feet msl. The controller called N472TL's pilot 2 times before the pilot responded by saying, "Baron four seven." Subsequent calls to the pilot of N472TL were not answered. The FAA controller handling N472TL said the airplane's transponder's Mode-C readout showed a rapid descent until radar contact was lost. The last radar contact was at 1635:20 cdt. At that time the reported altitude was 2,900 feet msl. Witnesses about 1/4 to 1/2-mile from the accident site said they observed the airplane in a nose level, counterclockwise rotation, spin. One witness said he saw the airplane "Real high up, sorta nose down, spinning. Then it went flat, completely level for the last half of the descent." Some witnesses reported hearing an engine sound. One of them said the engine sound stopped when the airplane was about 150 to 200-feet above ground level. The witnesses reported seeing the airplane collide with the ground and bounce into the air and then collide with the ground a second time. According to witness statements in the Sangamon County Sheriff's Office Narrative Report (report), one witness reported hearing the airplane's engine "...surge and make a loud noise. When the engine quit the plane went into a flat spin... ." The report said one witness said "...the engines were screaming...and the landing gear was up." Another witness statement said, "...the plane was low to the ground and the engine was making a high-pitched whine sound." Other witness statements in the report said the engine was running as the airplane descended in what they called a spinning or spiraling motion. PERSONNEL INFORMATION According to FAA records, the pilot had a private pilot's certificate with a multi-engine rating. The pilot's logbook (logbook) showed he had obtained his multi-engine rating in N472TL on June 17, 1996. The logbook showed his first flight in N472TL was on May 23, 1996. The logbook entry for that flight showed "Local" dual flight instruction that lasted 2.0-hours. Six logbook entries following that flight showed "X Country IFR." On June 15, 1996, the logbook showed the pilot received 4.0-hours of instruction that included 10 instrument approaches. The logbook entry showed, "IFR Appr., Single eng. appr., single eng. Ops, Vmc demo, Avionics familiarization, autopilot ops." This entry showed 10 landings were made. There were two June 16, 1996, logbook entries. One entry showed 5.5-hours of dual and the second entry showed 4.5-hours of dual. The 5.5-hour entry showed, "Vmc, feather procedures, unfeather procedure, single eng. Ops, cross country TS, avoidance (?) Radar ops." The 4.5-hour entry showed, "X country T&L." The pilot's multi-engine flight test was given on June 17, 1996. The pilot was approved for this rating. The checkride involved 3 takeoffs and landings and .5-hour of simulated instrument flight, according to the Designated Pilot Examiner's logbook entry. The remainder of the logbook entries showed all pilot-in-command flight time and showed either "X Country" or "X Country IFR" until the date of the accident. A copy of the pilot's logbook is appended to this report. AIRCRAFT INFORMATION N472TL's airframe maintenance records (records) showed it had its annual inspection completed on April 18, 1997. The records showed it had a total airframe time of 2594.1-hours and a Hobbs time of 529.1-hours. The right engine's maintenance records showed its annual inspection was completed on April 18, 1997. On that date the records showed it had 1,111.9-hours since its last overhaul. The record showed, "Run up and operational check OK. No leaks found." The records for the left engine showed its annual inspection was also completed on April 18, 1997. On that date the records showed it had 1,111.9-hours since overhaul. The record showed, "Run up and operational check OK. No leaks found." A "Service Description" form found among the maintenance records dated July 14, 1997, stated the "Owner requests crack in engine case be checked. Dye penetrated crack in left engine case, crack has continued past previous scribe mark approximately 3/8-inch. Notified owner." The maintenance records for the left engine did not show the location or length of the crack. There was no entry showing that the crack was repaired. According to the form, the tach time was 587.3-hours. This crack was not reported in the engine's July 16, 1997, maintenance logbook entry. An airplane maintenance discrepancy list dated May 30, 1996, showed one item that said "Oil leak toward rear of left engine." An entry into the left engine's logbook, showing the oil leak had been repaired, was not found. A "Service Description" form dated May 18, 1997, showed four oil leak discrepancy line items associated with the left engine. One discrepancy involving the left engine's leaking oil sump had corrective action applied: "retorqued left engine oil sump bolts." The remaining three were deferred: "Number one cylinder left engine leaking around jug base. Number 3 cylinders lower plugs appears to have oil leaking. Number 5 cylinder oil leaks from a plug hole." A review of logbook entries after the date of these maintenance comments revealed no corrective action being taken. The engine maintenance paperwork included AeroTech Publications, Incorporated's "Continental Engine adNote" sheet that said the FAA Airworthiness Directive (AD), 77-13-22, is not applicable to the left or right engine because both serial numbers were not included in the AD. A copy of this publication is appended to this report. A review of the AD showed N472TL's engines were not covered by the FAA's Airworthiness Directive (AD), 77-13-22 that covers cracks in engine crankcases. The AD states that "This A.D. does not apply to engines [IO-520-C series] bearing the following serial numbers: -C 561476 and up... ." The engine that suffered the mechanical failure was an IO-520-CB whose serial number was 571476. A copy of the AD is appended to this report. WRECKAGE AND IMPACT INFORMATION N472TL's wreckage was located in a plowed field about 300-feet east of Sangamon County, Illinois, County Road 10 and about 1,500-feet south of County Road 4.25S. The wreckage was confined to the immediate location of N472TL. Small pieces of side window were scattered on the west and east sides of the airplane. The airplane's heading was on a magnetic heading of about 045-degrees. N472TL's fuselage was crushed upward along its longitudinal axis. The empennage separated from the fuselage and both elevator trailing edges were buried in the dirt. Flight control continuity was established for all 3 axis'. The flaps and landing gear were in the retracted position. Throttle, propeller and mixture control cable and rod continuity were established for both engines. The fuel selector functioned and the lines from it were not blocked. Air was blown through each position without restriction. An oil residue was found on N472TL's left engine's nacelle, rear half of the left wing in the immediate area of the nacelle and fuselage, the left side of its fuselage cabin area and the horizontal stabilizer and elevator. One propeller blade was above ground. Oil residue covered its leading edge. The remaining 2 blades were buried in the soil. The blades appeared to be in a low pitch, high RPM, position. The linkage on the propeller governor showed the propeller to be in the high RPM setting. Examination of the left engine's cowl access door and inside the top cowling revealed they were also oil soaked. The cowl access door to the engine's oil dip stick was open and the dip stick was missing. The dip stick was not found after a search of an approximate 200 yard arc around the airplane. There were no rub or deforming marks on the inside of the access door. The oil filler neck and dip stick cap locking slots were not damaged. The left engine mounts were broken. The engine's case was broken at each of the engine mount attachment locations. A hole was noted in the engine's case under the left magneto next to cylinder number 2. The number 2 cylinder connecting rod was sticking up into the hole. The rod cap had separated from the number 2 cylinder's connecting rod and only one rod bolt appeared to have been broken. The rod bearing halves were not found. However, the rod end cap and the number 2 cylinder connecting rod journal had a shiney appearance and did not have an overheated appearance. A smaller hole was found in the top of the right case half between cylinders 1 and 3. Both case halves had a crack running between the two holes. The number 2 cylinder connecting rod had separated from the crankshaft journal. This cylinder had almost separated from the case. The left magneto was broken from its mount and its bottom side showed considerable metal machining damage. Before disassembly thumb compression was established for all cylinders except the number 1 and 2 cylinders. Cylinder number 1 did not produce compression because its bottom section was partially separated from the case. The right magneto produced spark when hand rotated. The left magneto would not turn because of the previously mentioned damage. The starter had been crushed into the engine support structure and the starter adapter was broken. The fuel manifold valve had fuel in it. Its diaphragm was intact and the screen was clean. Fuel was found in the line to the throttle body. The throttle body butterfly valve was found in the 2/3-open position and the mixture was at the mid point location. The engine driven fuel pump was examined and functioned mechanically. The pump had fuel in its chamber and did not have debris in it. The left engine's oil filter was opened and fine metal particles were present in its element. The engine's oil pump pickup screen was crushed. Various-sized pieces of metal-colored flakes were on the screen. The left engine's oil pump was removed and its gears turned freely when hand rotated. Metallic colored flakes were noted inside the pump. The engine's oil sump was crushed flat. The oil filler tube had been driven through the bottom of the sump. The section of the sump that was punched out was found pressed into the dip stick tube. There was no dip stick end imprint on this piece of metal. Various sized pieces of metal debris were found in the bottom of the sump. Also found in the sump were the number 2 cylinder's connecting rod cap, one of the bearing halves, 2 rod bolt nuts, a piece of one rod bolt and pieces of cotter key(s). A metal washer was also found. The left engine's crankshaft bearing surfaces were intact. The main and connecting rod journals were shiney and not scored. There was no evidence of metal overheating. The main bearing tang slots did not appear to be elongated. The engine's rear counterweights had to be impact damage. All the counterweights moved freely on their pins. The camshaft also had impact damage in the area of lobes number 1 and 2. The lobes were smooth and not pitted. The propeller was attached to the crankshaft flange. One blade appeared undamaged and was almost vertical to the ground. The second blade was bent forward about 5-degrees. It was buried in the ground up to the junction with the spinner. No leading edge or chord wise damage was observed on this blade. The third blade was also buried as the second blade. It was bent aft about 5-degrees. This blade did not have any leading edge or chord wise damage. The left engine's propeller cycled normally with shop air pressure from the start lock position to the low pitch stop position. The feathering spring moved the 3 blades into the feather position when the high speed stop was removed. The pitch-change cylinder was sectioned to expose its interior and associated components. The feathering spring was intact and unremarkable. The hard plastic or nylon spring retainer cup was sectioned. Indent and score or drag markings were observed on its interior wall. The indent markings, located on the forward end of the retainer matched the contour of the high pitch stop weights. These marks measured about 0.567 and 0.847-inches. The marks showed the position of the propeller would be at, or very close to, the feather position. The right engine's propeller had one blade in the near-vertical position while the other two were partially buried in the dirt. This propeller's governor's linkage and blade angle showed it was the high RPM setting. This engine was canted about 5-degrees downward from its firewall mount. The cowl access door to the engine's oil dip stick was open. The dip stick was partially out of its guide tube and had a Z-like bend in it. No distinguishing marks were observed inside the cowl access door. Examination of the right engine revealed thumb compression on all six cylinders. Mechanical continuity was established between the front and rear of the engine. Fuel was found in the engine's fuel manifold valve (manifold) and fuel line to the fuel servo. The manifold's diaphragm was intact and the screen was clean. The spark plug's electrodes were a grey color and no debris was observed on them. The engine mounts were broken. Both magnetos were broken from their mounts. When the magnetos gear drives were rotated, both magnetos produced spark. The starter was broken off its mount. The right engine's propeller was attached to the crankshaft flange. It had one blade that was undamaged. A second blade was bent aft about 25-degrees at the hub. There was no leading edge damage noted on this blade. The third blade was bowed aft around the right side of the engine. N472TL's vacuum pumps were internally intact. Their rotors, vanes and drive couplers were not damaged. The attitude and heading indicator rotors had scuff marks on their surface and case. The aileron trim tab was found in a neutral position by actuator extension measurement. The aileron cockpit trim indicator showed 3 degrees right wing down. Measurement of the right rudder trim tab actuator extension showed it was 3 degrees tab right. The rudder trim
A loss of engine power due to separation of the left engine's number 2 connecting rod as a result of fatigue failure. Also causal was the pilot's failure to maintain adequate airspeed which resulted in a stall/spin. Contributing to the accident was the pilot's operation of the aircraft with known deficiencies and exceeding the maximum gross weight of the airplane.
Source: NTSB Aviation Accident Database
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