It’s not a great time for either airlines or air plane manufacturers in the shadow of Covid, but this week, things got demonstrably worse for embattled U.S. aircraft manufacturer Boeing when one of its 777 planes was forced to make an emergency landing in Denver Airport, Colorado after flight 328 from Denver to Honolulu was aborted after take-off. Fortunately no-one was physically injured after one of the plane’s engines started to break up in flight, but their confidence in 777s would have been badly shaken. Perhaps luckily for Boeing, the focus will be on the type of engine involved and the airline’s inspection routine, not Boeing itself.

There were 231passengers and 10 crew members on board the plane at the time of the incident.

The 777 is a wide body jet much in use on the routes in and out of Hawaii and Europe.

The right side engine burst into flames and parts of the engine detached from the aircraft, some of them falling on to the ground below the plane’s trajectory out of Denver. The engines on the 777s are manufactured by Pratt & Whitney. The only U.S. based airline with 777s that are equipped with Pratt & Whitney engines belong to United Airlines. All United’s 777s with this type of engine have now been grounded under a directive from the U.S. Federal Aviation administration (FAA). There are other airlines based outside of the U.S. that also have Pratt & Whitney engines. These are Japan and Korean Airlines. Japan’s civil aviation watchdog has already grounded its 777s.

If you are booked on a United Airlines flight and are now worried that you could be at risk, you may be comforted by the fact that United also has 777s that run on GE engines. Because of the grounding directive, you will not be flying on one of the affected planes. The only other airline that uses 777s is American Airlines. It uses its 777 fleet exclusively for flight within the U.S. due to the pandemic, but its planes are equipped with GE and Rolls Royce engines, not Pratt & Whitney’s.

What went wrong?

Until investigators from the National Transportation Safety Board (NTSB) conclude their inspection of the affected Pratt & Whitney engine, there is no hard and fast answer, but one strong possibility is that it was a failure in one of the fan blades. Undetected cracks in a fan blade can cause a part or parts of the fan blade to be flung off at high speeds. The uncertainty and unpredictability with these sorts of incidents is what the broken blade parts hit as they are ejected. Aircraft crash investigators and engineers say that there is a difference between a “contained” engine failure and an “uncontained” engine failure. A containment means that pieces of broken engine parts are contained within the engine cowling and do not pose an impact problem to other parts of the aircraft. An uncontained engine failure means that parts of the engine manage to escape from the engine compartment and potentially damage other parts of the plane’s superstructure.

The engine failure experienced by United Flight 328 fits the “uncontained” description with parts of the engine cover falling on the city of Brookfield, Colorado. The NTSB is at this point in time not yet prepared to classify it as an uncontained engine failure despite the evidence of ejected material from the plane.

The NTSB considers engine failures as extremely rare, but potentially very dangerous. Past engine failures in the U.S. have seen a female passenger killed as she was struck by an engine part flung out from a Southwest Airlines airline that led to series of events ending in the window shattering next to the woman and striking her fatally.

Another engine failure took place on a similar 777 with a Pratt & Whitney engine on route to Honolulu. A crack in one of the fan blades caused it to break and the broken off part shattered the engine cover. The incident happened on the descent to Honolulu with no injuries reported on board.

Air safety experts say that these sorts of engine failures should never happen because plane components should be regularly inspected and any potential problems like cracks in fan blades detected and remedied before the plane is certified fit to fly again.

At this stage, it seems that the FAA will issue a new directive updating the inspection routine of all 777-200 planes with Pratt & Whitney engines. United will have to wait for the directive to be announced before resuming flights with the grounded planes.

Aviation accidents don’t just happen

Engine failures of the sort that happened to the United 777 over Colorado are fortunately rare, but extremely disconcerting when they do occur. Most aviation accidents are due to poor maintenance and pilot error in small privately owned planes, but design failure and failures in inspection routine can also lead to potentially devastating incidents in commercial airplanes. If you, or a loved one, have been a victim of any kind of aviation accident, you should contact a dedicated and experienced aviation accident attorney at Keith Williams Law Group in Nashville. You can contact Keith Williams at (866) 820-4457.