It feels like A nightmare scenario for airplane passengers: you look out the window between mini pretzel snacks to see a flame-shrouded engine throwing 10,000-foot pieces of metal into the air mid-flight. That is exactly the sight that greeted the passengers of United Flight 328 on Saturday not long after departure from Denver for Honolulu.
A jet of about 500,000 pounds with one engine seems just as likely a candidate to fly as a condor with one wing. And yet, despite all the danger the flambéed Boeing 777 poses this weekend – and there was plenty, especially in the Denver suburbs exposed to large-scale debris thrown off the plane by the Pratt & Whitney PW4077 engine – remained extremely low on the list in the air. In fact, the remaining engine is in theory strong enough to have made the rest of the flight on its own.
That was not always the case for large aircraft. For decades, the Federal Aviation Administration did not allow twin-engine planes to make trips of more than an hour, let alone from the Midwest to a paradise in the Pacific. “It’s going to be a cold day in hell before I fly twins over long distances over water,” urged then FAA administrator Lynn Helms when Boeing asked the FAA to change the rule in 1980, according to Robert J. Sterling’s 1991 history of the space giant. If one engine failed, you should rely on at least two others.
Eventually, the FAA gave in and expanded the 60-minute rule to 120 and then 180 minutes as the ’80s progressed. Credit improved engines for the change of heart, rather than increased risk appetite.
Passengers on United Flight 328 were alarmed to discover that the left engine had caught fire a few minutes after takeoff.
Photo: Chad Schnell / Getty Images“One engine must have enough thrust to keep the plane running, and even climb if necessary,” said Ella Atkins, an aerospace engineer at the University of Michigan. That’s true even for a worst-case scenario, she says, like losing an engine while taking off. The remaining engine, if necessary, should be strong enough to get you into the air independently.
That is not to say that engine failures have no consequences, especially if there is a fire. It introduces a multitude of complications regardless of the size of the aircraft or the complexity of the automated systems. “Many pilots go through their entire careers without a single engine failure, even though we train for it,” said Bob Meder, president of the National Association of Flight Instructors. “In general, you do your memory items first for the plane you are flying with. You have an engine fire, you lock the engine and stop the flow of fuel to the engine. “