It looks like a nightmare situation for airplane passengers: You have a look out the window in between mini-pretzel bites to see an engine cloaked in flames, shedding items of steel mid-flight from 10,000 ft within the air. That’s precisely the sight that greeted passengers of United Flight 328 on Saturday not lengthy after departing Denver for Honolulu.
A roughly 500,000-pound jet with one engine appears as doubtless a candidate to fly as a condor with one wing. And but for all of the hazard posed by the flambé Boeing 777 this weekend—and there was lots, notably to the Denver suburbs subjected to large-scale particles shed by the airplane’s Pratt & Whitney PW4077 engine—staying within the air was extraordinarily low on the checklist. In actual fact, its remaining engine is theoretically sturdy sufficient to have made the rest of the flight by itself.
That wasn’t at all times the case for big plane. For many years, the Federal Aviation Administration didn’t permit twin-engine planes to make journeys over an hour, a lot much less from the Midwest to a Pacific paradise. “It will be a chilly day in hell earlier than I let twins fly long-haul over-water routes,” then-FAA administrator Lynn Helms insisted when Boeing requested the FAA to alter the rule in 1980, in response to Robert J. Sterling’s 1991 historical past of the aerospace big. If an engine didi fail, you’d have not less than two others to depend on.
Finally, the FAA relented, increasing the 60-minute rule to 120 after which 180 minutes because the ’80s wore on. Credit score improved engines for the change of coronary heart, quite than an elevated urge for food for danger.
“One engine has to have sufficient thrust to maintain the airplane going, and even climbing if it must,” says Ella Atkins, an aerospace engineer on the College of Michigan. That applies even to a worst-case situation, she says, comparable to shedding an engine whilst you’re within the technique of taking off. The remaining engine must be sturdy sufficient, if required, to get you airborne by itself.
Which isn’t to say that engine failure is with out consequence, particularly when a fireplace is concerned. It introduces a bunch of problems it doesn’t matter what the dimensions of the plane or the complexity of its automated techniques. “Many pilots undergo their total profession and not using a single engine failure, regardless that we prepare for it,” says Bob Meder, chairman of the Nationwide Affiliation of Flight Instructors. “On the whole, you do your reminiscence objects first for the airplane you’re flying. You’ve received an engine fireplace, you safe the engine and cease the circulation gasoline to the engine.”