Pratt & Whitney’s PW4000: A Faulty Design

Hiathan Nguyen

This month, another PW4000 engine on a Boeing 777-200 caught fire during an interstate flight. According to NBC, this is the third time one of Pratt & Whitney’s PW400 engines has malfunctioned in the past three years. 

The disaster, photographed by a passenger (figure 1), looked like something out of a Michael Bay movie. Metal shrapnel plummeted down covering lawns and houses as the pilots made an emergency landing in Denver. Everyone on board was safe. 

The cause of the fire was a broken blade that had shot back into the engine. “This isn’t the first time this happened,” said Greg Feith, a former Air Safety Investigator. The PW4000’s hollow fan blades have caused a lot of problems in the past. Three years ago, a blade broke over the Pacific Ocean; last December, two blades broke during a flight over Japan. More recently, a smaller version of the PW4000 caught fire in Holland. Luckily, each plane had only been in the air for a short time and they were able to land safely. If, however, they “had been over the ocean for one or two hours, the bigger concern is that there is a fire suppression system on the engine and the fire continued to burn” (Feith). 

These incidents caused the grounding and federal investigation of all model 777-200 planes with PW4000 engines. A report from the investigation stated: a “lack of training resulted in the inspector making an incorrect evaluation of an indication that resulted in a blade with a crack being returned to service where it eventually fractured.” Lethal mistakes like these are intolerable, especially in the aviation industry. Jim Hall, a retired National Transportation Safety Board chairman, believes “the reason the planes are all being taken out is because they (the FAA and Pratt&Whitney) don’t have any inspection process in place and they’re embarrassed.” Furthermore, “for the last decade, the FAA has been responding to the economic interests of the aviation industry, which has taken precedence over safety.”

The FAA announced inspections would be “stepped up for the hollow fan blades that are unique to this model of engine, used solely on Boeing 777 airplanes.” Furthermore, Pratt & Whitney will be revising the PW 4000’s inspection interval (how frequently it gets inspected). 

Hopefully this accident serves as a wake-up call for the aviation industry to prioritize safety above all else. A careful inspection is tedious but can save hundreds of lives. 

Image Credit: NBC 

https://www.nbcnews.com/news/us-news/plane-engine-caught-fire-united-airlines-flight-over-denver-has-n1258557