It’s like feeling A nightmare scenario for the passengers of the plane: You look out the window between the bites of mini-pretzels to see an engine shrouded in flames, scattering pieces of metal mid-flight 10,000 feet into the air. This is exactly the spectacle that greeted passengers on United Flight 328 on Saturday shortly after departing Denver for Honolulu.
A jet plane of around 500,000 pounds with a single engine seems as likely to fly as a condor with a wing. And yet, for all the danger posed by the Boeing 777 soaring over the weekend – and there was plenty of it, especially in the Denver suburbs subject to the large-scale debris being washed out by the plane’s Pratt & Whitney PW4077 engine. – staying aloft was extremely low on the list. In fact, his remaining engine is theoretically powerful enough to have completed the remainder of the flight on his own.
This was not always the case with large aircraft. For decades, the Federal Aviation Administration did not allow twin-engine planes to make trips longer than an hour, let alone from the Midwest to a Pacific paradise. “It will be a cold day in hell before I let the twins fly long-haul routes over water,” said Lynn Helms, then FAA administrator. insisted when Boeing asked the FAA to change the rule in 1980, according to Robert J. Sterling 1991 history from the aerospace giant. If one engine failed, you would have at least two more to rely on.
Eventually the FAA relented, extending the 60-minute rule to 120 and then 180 minutes as the 1980s wore on. Credit improved the drivers of change of mind, rather than an increased appetite for risk.
“An engine has to have enough thrust to keep the plane running and even climb if it has to,” says Ella Atkins, an aerospace engineer at the University of Michigan. This applies even to the worst-case scenario, she says, like losing an engine while you’re taking off. The remaining engine should be powerful enough, if necessary, to allow you to fly on your own.
This does not mean that an engine failure is harmless, especially in the event of a fire. It introduces a host of complications regardless of the size of the aircraft or the complexity of its automated systems. “Many pilots go their entire careers without a single engine failure, even though we train for it,” says Bob Meder, president of the National Association of Flight Instructors. “Usually you do your memory first for the plane you fly. You have an engine fire, you secure the engine and stop the flow of fuel to the engine.