Sun Country Airlines Boeing 737-800 Diverts to Spokane After Engine Shutdown

On June 14th, 2024, a Sun Country Airlines flight from Seattle, Washington, to Minneapolis, Minnesota, experienced an inadvertent engine failure. The twin-engine Boeing 737-800 had a left engine failure during the cruise phase of the flight shortly after departing Seattle. The aircraft landed safely, and no injuries were reported.

What Happened?

Sun Country Airlines Flight 286 operates a nonstop flight from Seattle-Tacoma International Airport (SEA) to Minneapolis-Saint Paul International Airport (MSP). However, an engine failure en route on Friday evening prevented the flight from being completed. According to the Aviation Herald, the aircraft reached its filed cruising altitude of 37,000 ft and was roughly 120 NM (222 km) east of Spokane International Airport (GEG) when the left engine, a CFM International CFM56 turbofan, failed.

The crew reported the engine failure, and after being unable to restart it, they shut it down and decided to divert. The engine failed approximately 45 minutes into the flight, according to the Flight Aware flight profile. The crew then turned around and landed safely on GEG’s runway 21, 30 minutes after the engine failure.

In a statement to Simple Flying, Sun Country Airlines said:

"Sun Country flight 286 from Seattle to Minneapolis St. Paul experienced an engine shutdown and diverted to Spokane Friday evening. Our pilots followed procedures, and the flight landed safely at Spokane. The safety of our passengers and crew are our priority, and we appreciate the work of our pilots and flight attendants to ensure the safety of our customers. We worked to provide accommodations for our passengers overnight, and the flight departed at 10:30 am local this morning on another aircraft. The flight is due to land in MSP in a few minutes."

The Boeing 737-800 (registered N856SY) is 10.3 years old and was delivered to the airline in March 2024. The cause of the engine failure has not been identified yet.

Engine Failure in Flight

Engines have come a long way since the early days of aviation when reliability was a significant issue. Today, engine failures are rare due to regular inspections and maintenance, but they do occur. According to the Federal Aviation Administration, turbine engines have a failure rate of one per 375,000 flight hours.

The most common causes of jet engine failures are similar to those of piston engines: fuel starvation or mechanical failure. Turbine engines are subjected to high pressures, temperatures, and stress.

The leading causes of mechanical failures are:

• Blade Fatigue: Over time, the blades of the high-pressure and low-pressure turbines can wear out, resulting in micro-fissures that cause the blades to crack and break.
• Bearing Failure: Bearings reduce the friction within an engine's spinning components and can fail due to normal wear and tear or poor lubrication.
• Seal Deterioration: The engine seal helps maintain pressure in the different sections of the turbine engine. If a seal fails, the engine will cease producing thrust effectively.

The leading causes of fuel failures leading to engine failures are:

• Fuel Contamination: Water or contaminants in the fuel can cause the engine to break down.
• Fuel Distribution Issues: Fuel leaks and blockages could prevent the engine from receiving adequate fuel.
• Pump Failures: Fuel pump failures prevent the engine from receiving fuel and can result in fuel starvation.

In Conclusion

The quick response of the Sun Country Airlines crew ensured the safety of all passengers during the engine failure incident. While engine failures are rare, this event highlights the importance of rigorous maintenance and the skills of aviation professionals in handling emergencies. The aircraft involved remains grounded pending inspection and maintenance.