Aviation Accident Summaries

Aviation Accident Summary ERA22FA076

Grove City, PA, USA

Aircraft #1

N6209U

CESSNA T210R

Analysis

During the visual flight rules cross-country flight, the pilot and pilot-rated passenger, who was also an aircraft mechanic, diverted due to an oil pressure issue. Witnesses at the diversion airport stated that, after landing, the pilot requested 6 quarts of oil and rags to clean his airplane. The airplane was “covered” with oil on the fuselage, wings, and engine cowling. The pilot stated that the oil loss was the result of an unsecured oil filler cap. After servicing the airplane with all 6 quarts of oil and cleaning the residual oil off the airplane, the pilots departed. A witness reported that the airplane’s engine made “abnormal cracking and popping” noises during engine start and taxi, and that the pilots departed without performing an engine run-up. About 15 minutes after departure, while cruising at 4,500 ft mean sea level (msl), the pilot reported a loss of engine power to air traffic control and was given vectors to a nearby airport; however, he was unable to glide to the airport and the airplane impacted trees and steep terrain. A significant post-impact fire ensued. Postaccident examination of the wreckage revealed that the engine exhibited features consistent with a loss of oil lubrication. Although several of the crankcase through-bolts were missing their respective nuts, this was likely the result of postimpact thermal damage rather than improperly secured nuts. Based on the available information, it is likely that the internal components of the engine sustained damage due to oil starvation after the pilot failed to secure the oil filler cap. This damage was sufficient to result in catastrophic engine failure when the engine continued to be operated, even after adding oil. The pilots’ decision to depart on the accident flight without further examining the engine for signs of damage or conducting an engine run-up contributed to the accident.

Factual Information

On November 24, 2021, at 1746 eastern standard time, a Cessna T210R, N6209U, was destroyed when it was involved in an accident near Grove City, Pennsylvania. The private pilot and pilot-rated passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The flight originated from Westchester County Airport (HPN), White Plains, New York, and was enroute to Akron Fulton Airport (AKR), Akron, Ohio; a distance of about 350 nautical miles. About two hours into the flight, the pilot, who was also the owner of the airplane, diverted to Clarion County Airport (AXQ), Clarion, Pennsylvania, for a reported oil pressure issue. Witnesses at AXQ stated that, after landing, the pilot requested 6 quarts of oil; he also stated that he thought the oil pressure issue was due to the oil filler cap not being properly secured, which resulted in a loss of oil through the dipstick tube. One witness stated that the airplane was “covered in oil,” with oil present on the empennage, lower fuselage, and engine cowl. The pilot and passenger, who was also an aircraft mechanic, cleaned the airplane with rags, serviced the engine with 6 quarts of the new oil, and elected to resume their flight. During the subsequent engine start, one of the witnesses, who was a helicopter mechanic, heard the airplane’s engine making “abnormal cracking and popping” noises. The pilot taxied to the end of the runway and departed without performing an engine run-up. After departure, the pilot contacted air traffic control, climbed to 4,500 ft mean sea level (msl) and requested visual flight rules flight following to AKR, which was about 95 nautical miles west. About 15 minutes after takeoff, at 1739, the pilot reported a loss of engine power, and he requested assistance. The controller provided instructions to land at Grove City Airport (29D), Grove City, Pennsylvania, at the airplane’s 12 o’clock position and 8 miles away, then several minutes later offered an alternative landing site at a nearby outlet mall if he could not make the airport. Shortly after the pilot reported the airport in sight, at 1744, he stated that he did not think the would be able to reach the airport. Communications and radar contact were subsequently lost at 1746. A security video at the airport showed the landing light of the airplane during the approach. The landing light descended rapidly and disappeared behind terrain followed by an explosion. The airplane impacted trees and steep terrain at an elevation of about 1,200 ft msl, about 1.5 miles from the approach end of runway 28 at 29D. The initial tree impact was about 250 ft from the main wreckage, which came to rest on a 35° incline against several trees. A 24-inch section of the left wingtip was located near the initial tree impact and several broken branches were observed on top of an approximately 75-ft-tall pine tree. A post-impact fire consumed the fuselage and cockpit area. The instrument panel and all associated instrumentation, gauges, and electronic devices were destroyed by fire. The empennage separated during impact; the vertical and horizonal stabilizers, rudder, and elevators remained attached. There was oil residue observed on the underside of the empennage, left stabilizer, and elevator. The flight control cables exhibited breaks consistent with overload. Several portions of the left wing were located along the wreckage path and near the main wreckage. The right wing was damaged by impact forces and fire. The aileron control cables were traced to the cockpit through breaks in the cables that were consistent with overload. There was no indication of any airframe anomaly or condition that would have precluded normal operation. The factory-remanufactured engine was installed on the airplane on May 16, 2012, and had accumulated about 350 hours total time since installation. The engine was partially separated from the main wreckage but remained attached to the engine mounts and firewall. The three-blade propeller and spinner remained attached to the crankshaft flange. Two of the three propeller blades were bent aft in a relatively uniform manner. The third blade was bent aft and exhibited severe gouges and scrapes on the upper surface and leading edge of the blade tip, but little chordwise scraping was observed on all three blades. The propeller spinner was crushed uniformly from the front to aft and exhibited no evidence of rotational damage. The engine showed evidence of significant heat exposure but was relatively intact. The turbocharger was examined and static impact impressions consistent with contact from the compressor wheel were observed. There was no rotational damage to the blades or housing. The top spark plugs were removed; the No. 5 spark plug electrode was damaged and covered with oil. The Nos. 3 and 2 spark plugs were covered with oil. The remaining spark plugs remained intact and exhibited minimal wear when compared to the Champion Check-A-Plug chart. Two holes were observed on the top of the engine crankcase. One hole was located forward of the No. 5 cylinder and was about 2 inches in diameter. The second hole was located adjacent to the No. 4 cylinder and was about 3 inches in diameter. The No. 4 cylinder connecting rod was separated from the crankshaft. The No. 5 cylinder piston was fragmented into small pieces with the piston pin still installed in the connecting rod. The oil filler cap was securely installed. The two through-bolts that connected cylinders Nos. 4 and 5 were missing nuts on the right side of the engine and the bolt threads exhibited thermal damage. The two through-bolts that connected cylinders Nos. 2 and 3 were missing nuts on the left side of the engine and the bolts showed signs of thermal damage. Half of a nut was discovered in debris under the No. 3 cylinder and showed signs of thermal damage and was brittle when handled. Disassembly and examination of the crankshaft revealed that the main journal bearings showed evidence of polishing and metal-to-metal contact.

Probable Cause and Findings

A catastrophic engine failure due to oil starvation after the pilot’s failure to secure the oil filler cap before flight. Contributing to the accident was the pilots’ decision to continue the flight following the oil loss event and precautionary landing.

 

Source: NTSB Aviation Accident Database

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