Reply to post: Stating the obvious, much?

Stating the obvious, much?

Ok, the British study was an incompetent politically motivated exercise (imagine our surprise) but it makes sense to conduct some realistic experiments, just as has been done in the past with the "chicken cannon"—which ISTR once caused a lot of damage with an un-defrosted fowl?

But I don't think we're going to learn much that common sense couldn't have told us. Yes, most impacts by small drones will be unlikely to bring an airliner down. Given we've seen 737s, 747s and others make successful landings with some big bloody holes in them, even with half the undercarriage torn away, on a couple of occasions with major damage to the control surfaces, we know that modern western airliners can take a fair bit of punishment. A drone is unlikely to hit a plane at 37,000 feet where sheer speed might magnify damage.

The real question is, what's the realistic likelihood of a worst case scenario? That would seem to be a drone being inhaled by the turbofan of a twinjet at MTOW just as or before it leaves the ground. Given that either Terrorist Bastard or a foolish amateur photographer might be responsible for such a calamity, it is worth considering. In the scenario I've described the plane should be able to continue its climbout, albeit at a reduced rate, and safely return later for landing after using up some fuel—IF the engine suffers only a contained failure, without explosion or fire or other collateral damage (e.g. to control surfaces, fuel lines, hydraulic pipes etc).

Given turbofan engines are tested literally to destruction (usually by blowing a fan blade clean off at full power in a static ground test), we can *hope* that five or six pounds of Li-Ion battery and a mess of wires and cameras will not cause an uncontained failure ... but this is surely the likeliest and riskiest scenario, so this is the one I would have expected to see tested. It would be an expensive test, so it should be done once and correctly. (IMHO I'd like to see AAIB plan and supervise it, not those clowns at Qinetiq.)

And of course it still doesn't insulate us against malice: An ordinary drone bearing three and half pounds of the hardback set of "Fifty Shades of Utter Crap" might not cause an uncontained failure ... what about our evil friend, Terrorist Bastard, if he puts a couple of kilos of tungsten shrapnel in, instead?