Citation 550 crew suffers double engine failure

At the start of my multi-engine flight training on the Cessna 310, the instructor and I practiced the required maneuvers, including the loss of an engine on take-off, as well as engine failure while cruising. To this day, I remember Dave telling me to take cruise engine failure just as seriously as take off from a simple perspective: what killed the first engine might soon claim the second.

In May 2019, the crew of a chartered Cessna Citation 550, operated as an air ambulance flight, suffered a total power loss which began, according to the NTSB, just over an hour after the start. of the flight when the captain attempted to adjust L1. at 103% (normal in this aircraft). The engine power stubbornly refused to stay put. While cruising at 35,000 feet en route between Naples, Fla. (KAPF) and Niagara Falls, New York (KIAG), the left engine began to slow slowly on its own.

“After an unsuccessful attempt to recover engine power,” the NTSB said, “the crew requested a lower altitude from air traffic control and began a descent with the left engine at idle. The captain then noticed that the left engine was not showing any oil pressure and then shut it off. A few minutes later, as the aircraft descended 8,000 feet with the right engine at 65% fan speed and as the crew were preparing for a single-engine approach to Savannah Hilton-Head International Airport (KSAV), the right engine began to slow. The captain declared an emergency and the crew was successful a straight-in approach without an engine across a broken cloudy bridge to runway 19 and landed safely Neither the two airline pilots, nor the two medical teams, nor the three passengers on board were injured.

The NTSB learned during its investigation of the incident that the flight took place earlier in the day from the charter company’s base in Punta Gorda, Fla. (KPGD), where the plane was refueled with 480 gallons. of jet-A that included a fuel system icing inhibitor (FSII) got mixed up. The flight crew then performed the 47 nm flight from KPGD to KAPF without a problem.

During an interview, the CIS noted that during the en route portion of the flight, the left fuel filter bypass light did not come on at any time, but that the right fuel filter did come on. A line service worker at KPGD, where the aircraft was initially refueled, said he noticed the night before the flight that the tanker’s FSII level was low. He went to a hangar where the ISF is normally kept and found two partially full containers. Assuming both bottles contained the same additive, he poured into each other and then filled the tank truck’s FSII tank.

Several days after the incident, the lineman realized that he had inadvertently combined a 5 gallon bucket of FSII and a 2.5 gallon container of Diesel Exhaust Fluid (DEF) instead of two partially empty ISF containers. Fuel samples, fuel system filters and aircraft fuel screens were obtained and sent for laboratory testing. Analysis of fuel contaminants indicated the presence of urea, the main chemical found in diesel exhaust, a chemical added to the emission systems of land vehicles to reduce nitrous oxide emissions.

DEF is not approved for use in airplanes because it reacts with certain chemical components to form crystalline deposits in the fuel system. These crystalline deposits then build up on the filters, engine fuel injectors, and fuel metering components and cause the engine to lose power, as the Citation team found. In an NTSB follow-up alert on the dangers of DEF, the Council reported that in November 2017, at Eppley Airfield (KOMA) Omaha, Nebraska, seven aircraft had DEF directly injected and six aircraft were refueled. with equipment that was on display at DEF, while in August 2018, at the Miami-Opa Locka Executive Airport (KOPF) in Opa-Locka, Fla., five planes had DEF directly injected and nine planes had been refueled with equipment exposed to DEF.

Kevin A. Perras