They only have to let the drone (or drones) sit there. It may be a 1 in a 1000 chance, but that would be about a typical day at a busy airport. The odds of bringing down the aircraft are almost zero because they can land just fine on the other engine. But the fear factor would be great. And the overreaction would be even greater.
Think Boston. "Shelter (cringe) in Place" for the whole airport.
Hitting the moving target at hundreds of miles per hour of the jet engine intake a couple feet across in the 3 dimensions space needs a lot more zero's behind than 1000.
“The odds of bringing down the aircraft are almost zero because they can land just fine on the other engine. But the fear factor would be great.”
True. But two terrorists operating two drones could knock out both engines. This JKF drone event on March 5, 2013 could have been a proof of concept.
The cost of drones is now so low and drone swarming software is now available so that a swarm of drones could be maneuvered into the GPS coordinates for ZULAB in the Jeppesen. This would reverse-engineer a bird-strike crash such as Captain Sully experienced.
Here is a video of coordinated drone swarming recently achieved which terrorists could soon be bringing to the Runway Kill Zone (RKZ) or the Landing Approach Kill Zone (LAKZ) near you!:
Video: Swarm of Tiny Quadcopters Do a Delicate Dance
“Towards a Swarm of Nano Quadrotors”
Alex Kushleyev, Daniel Mellinger, Vijay Kumar, GRASP Lab, University of Pennsylvania
“Perhaps it’s somewhat hyperbolic, but seeing the ease and grace with which these things move in and out of formation, negotiating obstacles and ducking seamlessly between each other as they execute a figure eight really tickles the fanciful, sci-fi-friendly part of the brain. GRASP Lab creations have already shown us how quadcopters can work together to manipulate objects and even build structures together. The idea of looping more than a dozen of these things together—as we see in the video below—and putting them to work on complex projects makes this kind of precision performance feel very much like the future.”