I'm looking into the use of electromagnetic pulse (EMP) devices in crashing planes and more "coincidental" similarities between the "accidents" involving Wellstone in 2002, Carnahan in 2000, and JFK Jr. in 1999.
All those "accidents" involved planes already descending towards their landing that suddenly wandered off their approach paths and crashed.
In all three cases, radio contact appears to have been cut off while the planes were still in the air, possibly indicating electrical failures on board.
One way to sabotage a landing airplane would be to use a focused electromagnetic pulse (EMP) device.
These machines are already being manufactured and marketed to law enforcement agencies to stop fleeing vehicles. In fact, here is a link to a US Dept. of Justice document describing these devices:
http://www.ncjrs.org/txtfiles/sl298.txt
Theoretically, a person a few miles from the runway could bombard the aircraft with an intense electromagnetic pulse, which could cause an electrical failure, instantly knock out radio communication, disrupt normal engine ignition, and cause loss of steering control.