We’ve all been there: At an en route fuel stop—or after a precautionary landing—we find something wrong with the airplane. Could be a bad magneto, a cold cylinder, a starter that won’t engage or a dead battery. If we’re lucky, the airport at which we find ourselves has a shop that can handle the challenge. If we’re really lucky, they have the parts in stock and a mechanic available to install them. We’re on our way in a couple of hours, albeit with a slimmer wallet. But we’ll still make it to Grandma’s house that night.
If we’re not so lucky—which often is the norm—the airport has no such services; just self-serve fuel and some cheese crackers in a vending machine that takes one-dollar bills. You only have twenties. There’s not even a rental car, and the teenager behind the counter is closing up soon to make their soccer practice. No one is answering at the cab company and your ride-sharing app just says, “searching…searching.” The temptation to push on is strong. It flew in, right? It’ll fly out. Maybe. Maybe not.
The nature of the problem figures prominently in your decision-making, of course. Is it a clogged injector that can be cleaned out with compressed air? A tip tank that won’t transfer fuel? (Hint: Balance the load.) Depending on the circumstances and your own resourcefulness, this could wind up being an epic, four-part-harmony saga you share one evening over an adult beverage. There could even be a movie deal in it. It also could be the straw that broke the camel’s back if you ignore the warning signals the airplane is throwing off.
Background
On November 24, 2021, at 1746 Eastern time, a 1985 Cessna T210R Turbocharged Centurion was destroyed during an attempted emergency landing following engine failure near Grove City, Pennsylvania. The private pilot (65, male) and flight instructor-passenger (55, male) were fatally injured.
The flight originated in White Plains, New York, destined for Akron, Ohio, some 350 nm away. About two hours into the flight, the pilot diverted to Clarion, Pennsylvania, for a reported oil-pressure issue. After landing, witnesses stated the pilot requested six quarts of oil; he also stated that he thought the oil pressure issue was due to the oil filler cap not being properly secured. One witness stated that the airplane was “covered in oil,” with it 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 the six quarts of oil and elected to resume their flight. During the subsequent engine start, a 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 obtained flight following services from ATC and climbed to cruise at 4500 feet msl. About 15 minutes after takeoff, at 1739, the pilot reported a loss of engine power to ATC and requested assistance. The controller provided information on an airport eight miles away, plus a nearby outlet mall.
Shortly, the pilot reported the airport in sight but stated that he did not think the airplane would be able to reach the airport. Communications and radar contact were 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.
According to the NTSB, “Some pilots do not pay adequate attention to indications of aircraft mechanical problems, which can lead to in-flight emergencies and accidents. Powerplant system or component failure is the third-most common defining event for fatal accidents in the personal flying sector of general aviation (GA).” What can you do about it?
Resist the temptation to let external pressures influence you to fly an aircraft that shows signs of a potential problem.
Listen to what your aircraft is telling you, and remember it is better to address a problem on the ground rather than in the air.
Remember: The purpose of a maintenance diagnostic flight and stick to the plan. Be prepared for problems, and do not bring passengers.
Understand that maintenance troubleshooting sometimes takes time. Ensure the aircraft performs correctly after maintenance. If indications of a potential problem persist, get additional maintenance or a second opinion.
Investigation
The airplane impacted trees and steep terrain at an elevation of about 1200 feet msl, about 1.5 miles from the divert airport runway’s approach end. 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. There was no indication of any airframe anomaly or condition that would have precluded normal operation.
There was oil residue observed on the underside of the empennage, left stabilizer and elevator. The factory-remanufactured engine was installed on the airplane on May 16, 2012, and had accumulated about 350 hours total time since installation. 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; little chordwise scraping was observed on all three blades. The propeller spinner exhibited no evidence of rotational damage.
The engine showed evidence of significant heat exposure but was relatively intact. Turbocharger damage was consistent with contact from the compressor; 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.
Two holes were observed on the top of the engine crankcase. One was located forward of the #5 cylinder and was about two inches in diameter. The second hole was adjacent to the #4 cylinder and was about three inches in diameter. The #4 cylinder connecting rod was separated from the crankshaft and the #5 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 #4 and #5 were missing nuts on the right side of the engine and the bolt threads exhibited thermal damage. The two through-bolts connecting cylinders #2 and #3 were missing nuts on the left side of the engine. Those bolts also showed signs of thermal damage. Disassembly and examination of the crankshaft revealed the main journal bearings showed evidence of polishing and metal-to-metal contact.
Probable Cause
The NTSB determined the probable cause(s) of this accident to include: “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.”
The NTSB dismissed any significance of the through-bolts coming loose: “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 Board added.
It’s fairly straightforward: One of the two pilots didn’t secure the oil filler cap while the other one presumed he did. Off they went. The only mechanical surprise is how the engine lasted two hours before the precautionary landing.
But here’s the big question: What would you have done in a similar situation?