From time to time, we see news reports about some jet going down after a flock of geese is sucked into its engine. This may be a dumb question, but couldn't jet builders put some sort of heavy-duty, convex grill over whatever openings the geese keep getting sucked into to prevent this? Jeez, even cars have grills to keep unwanted stuff from entering the engine.
-- Just Wondering, San Carlos
For safety's sake, we took a train to get the answer to this one. Rolls-Royce in Reston, Virginia, was glad to help; and, they point out, the information applies worldwide, to every jet-engine manufacturer. Imagine the following delivered in a precise British accent. It adds that final note of credibility the elves and I can rarely muster.
Your scenario: A jet leaves New York and cruises at 35,000 feet or so to, say, Los Angeles, with big screens over the jet's air intakes (the gaping hole at the front of the engines). To kill time while we wait for our luggage, we check your goose-catcher. Stuck to the outside are a wad of old newspapers, busted balloons, seagulls, leaves, huge gobs of mashed moths -- enough crud to severely block airflow to the turbines. This is not good. Something like having squirrels nesting in your car's air filter. Your car would cough to a stop; the plane would fall out of the sky. Large volumes of air are necessary to keep jet engines purring at several thousand RPM, and that flow must be unrestricted.
So, what's a jet builder to do? The answer seems to be, test the heck out of every engine that comes off the line. The FAA and the Canadian and joint European aviation agencies specify the test conditions an engine must pass. The engine makers rev each one up and aim a massive hose at the intake to make sure the engine can maintain power in a big rain storm. They haul out a special gun that fires a barrage of 1/4-, 1/2-, and 1-inch ice pellets into the scoop to simulate a hail storm. An explosive charge is affixed to one turbine fan blade then detonated with the engine at cruising speed. Does it keep cruising? Did the flying blade damage the engine compartment? And then comes the goose test. Advice to vegans and animal-rights folks: Add jet travel to the list of things you can't do/eat/use.
Somewhere in England there's a farmer who has a contract to raise turkeys for Rolls-Royce. Same in the U.S. The birds are reared to a certain weight (ten pounds or so), "humanely sacrificed," then trucked to the jet maker's test facility, where the carcasses are shot at high velocity out of another large gun into the engine. It must keep putting along after a certain weight of dead turkeys is fired at it. As we like to say here at the Matthew Alice We-Don't-Make-This-Stuff-Up Laboratories -- hey, we don't make this stuff up. And no, the mashed birds that eject from the back of the engine are not used to make the next day's in-flight entrée. Too hard to pick out the feathers, apparently.