History of Flight
On September 17, 2016, at approximately 1236 mountain daylight time, a Beech 95-B55 airplane, registration N413D, impacted terrain about 30 miles southeast of Broadus, Montana. The airline transport pilot and two passengers were fatally injured, and the airplane was substantially damaged. The flight was operated under Title 14 Code of Federal Regulations Part 91 as a personal cross-country trip. It departed Billings Logan International Airport (BIL), Billings, Montana, around noon, bound for Rapid City Regional Airport (RAP), Rapid City, South Dakota.
The wreckage was discovered by a ranch caretaker around 1300 while returning from lunch. The caretaker reported hearing an airplane between 1130 and 1200 but did not go outside to look or hear the impact.
Radar track data from Harris OpsVue, based on FAA radar with an altimeter correction (error ±300 ft), showed the airplane departing BIL near noon with transponder code 0456, then turning right southeast. About six minutes later, it climbed to 5,500–5,600 ft and switched to squawk 1200. Data consistent with the accident airplane continued for about 13 minutes. No data was available between 1213:13 and 1225:03; then a track resumed at 5,800 ft heading southeast for 36.5 nautical miles. Another data gap occurred from 1233:04 to 1235:28; a track then began at 5,800 ft, 7.3 nm from where it stopped. At 1235:57, the track started a left turn, with data ending at 1236:04 at 5,800 ft. The last data point was about 43.35 nautical miles southwest of Broadus. The accident site was about 58 miles southeast of the last radar track at an elevation of 3,751 ft, approximately 30 miles southeast of Broadus.
Personnel Information
The 64-year-old pilot held an airline transport pilot certificate with ratings for airplane single- and multi-engine land, and a flight instructor certificate for single-engine airplanes. On his most recent FAA medical application, dated March 3, 2016, he left the total flight time blank. On a previous application dated March 4, 2014, he reported 4,116 total flight hours. He held a third-class medical certificate with a limitation requiring corrective lenses.
Aircraft Information
The 1974 twin-engine Beech 95-B55 (T42A), serial number TC-1726, was powered by two Continental Motors, Inc., IO-470-L21A engines (left serial: 454399; right serial: 454385) with Hartzell Propeller, Inc., model BHC-C2YF-2CHUF propellers. According to logbook entries dated May 25, 2016, annual inspections for the airframe, engines, and propellers had been completed and signed off. Total airframe and left engine time was 4,337.5 hours; the left engine had 653.2 hours since overhaul and 16 hours since the last annual inspection. The right engine had 4,326.3 total hours, 1,410.3 hours since overhaul, and 16 hours since annual. During the annual inspection, an overhauled cylinder was installed at the No. 2 cylinder position on the right engine. The propeller logbook reported 80.5 hours since overhaul.
Meteorological Information
A National Transportation Safety Board meteorologist reviewed the weather. The accident site was in a warm air sector of a front with westerly wind of 15 to 20 knots and clear skies. National Weather System radar showed no echoes over the region. The closest official observation, at Dawson Community Airport (GDV), Glendive, Montana (about 9 miles east of the accident site, elevation 2,458 ft), reported wind from 220° at 13 knots, visibility 10 statute miles, sky clear below 12,000 ft agl, temperature 26°C, dew point 7°C, and altimeter 29.77 inches of mercury. No specific turbulence was reported below 12,000 ft.
Wreckage and Impact Information
An NTSB investigator, an FAA inspector, and a Textron Aviation representative examined the site. The airplane came to rest on flat, open land covered with tall grass on a magnetic heading of 143°. The main wreckage was confined to the impact area, with all major components present. Flight control continuity was established from the cockpit to all primary surfaces. Both left and right wing bladder fuel tanks were breached, and the smell of 100 low-lead fuel was evident. The nose landing gear was retracted and pushed up and aft into the cockpit, impacting the front carry-through spar.
The left wing was canted forward with leading-to-trailing edge crush damage along its entire length. The ground scar matched the left-wing leading edge dimensions. The left engine was canted down and partially separated; the propeller assembly separated and was found 10–15 ft forward of the main wreckage. Propeller blades had light chord-wise scratches; one blade was bent aft mid-blade and remained attached at the hub; the other was loose. The propeller spring was buried vertically in the ground aft of the left wing leading edge scar.
The right wing was canted forward with damage from the wing root to the engine nacelle; the outboard portion remained intact. The right engine remained partially attached, with a cracked case forward of cylinders No. 5 and 6. The propeller assembly separated and was found under the right-side cabin fuselage. One blade was bent aft at the hub and slightly curved, loose in the hub; the other had minimal damage and remained in the hub. Ground scars indicated both propellers impacted in a near-vertical attitude and separated from their engines.
Examinations were conducted on October 25–27, 2016, at Osterman's Auto Service in Belgrade, Montana. Visual examination of the left engine showed the bottom crankcase fractured from impact. Crankshaft and camshaft continuity was verified; thumb compression was obtained at all cylinders. Borescope inspection found no foreign debris. Both magnetos produced spark when rotated manually. The engine-driven fuel pump, throttle body/metering unit, and fuel manifold valve showed no discrepancies. For the right engine, the crankcase, camshaft, and No. 6 connecting rod were fractured, with no signs of lubrication distress consistent with impact forces. The oil pan was crushed. Borescope examination revealed no preimpact anomalies. Both magnetos separated but produced spark. No discrepancies were found in the fuel system. Propeller blades L2 and R1 exhibited chordwise/rotational abrasion, mainly on the camber side. Hydraulic units fractured; pitch change rods bent. Preload plates opposite blades L2 and R1 were marked near the high end of the normal range. Blades L2 and R1 had fractured pitch change knobs; the R1 blade bearings were fractured with ball imprints. Damage was consistent with power development from each engine at impact. The propeller manufacturer stated that damage and blade angle marks suggested a low-power range and sudden stoppage (less than one revolution) during impact. No discrepancies were noted that would have prevented normal operation.
Medical and Pathological Information
The Department of Justice Forensic Science Division, Missoula, Montana, performed an autopsy. The cause of death was multiple blunt force injuries due to a light airplane crash, and the manner was accident. The FAA Bioaeronautical Sciences Research Laboratory conducted toxicology tests; cyanide was not tested, and carbon monoxide, volatiles, and tested-for drugs were not detected.