Interesting, but impractical, the focus of the system is too specific, and led to its logical conclusion supports the case for pilotless aircraft which I am, understandably, inherently opposed to.
Our single greatest resource in the cockpit at any given time is a human crew dealing with contingencies as they arise on a case by case basis. I am cognoscent of the rhetoric regarding how much better than people machines and computers can fly airplanes, and not doubt, Dirk, you will aprise me of the facts again citing that computers in fact can be programmed to perform at levels the human brain cannot ever hope to achieve. But as I said above its focus is too specific: it only addresses the case when an aircraft is being used as a projectile by a suicide terrorist.
Crew incapacitation is not, statistically, a factor. Nor is this level of paranoia needed to prevent the crew falling asleep (how about just using good CRM by the FA's continually checking in with the flight deck, as per normal). Additionally, ss mentioned in the article, this system depends SOLELY on the crew having the intestinal fortitude to not divulge the PIN.
What about a stolen PIN? What about a mole on the inside at Boeing? What about the terrorist killing the entire crew and hacking at the panel with the fire axe? I mean, how paranoid can we get here?
We need action, not OVERREACTION. Locked doors, increased vigilance, death to Osama Bin Laden. NOT an alarm every 20 mins, PIN numbers, and geeks on the ground playing RC with transport aircraft. Sorry this solution is last on my list....