How safe are cockpits? Aviation experts weigh in after security scare on board Horizon Air flight

abcnews.go.com:

Aviation experts say the incident in which an off-duty pilot tried to disable a jetliner in midflight renews questions about the threat posed by insiders — airline workers who have special access to places where passengers can't go

The attempt by an off-duty pilot to shut down the engines of a U.S. airliner in midflight highlights the threat that insiders pose to aviation safety with their ability to go where passengers are prohibited.

Events like the one Sunday on a Horizon Air jetliner are very rare, but they are potentially devastating.

The captain and co-pilot prevented disaster by subduing the off-duty Alaska Airlines pilot who — from his perfect vantage point in the cockpit jump seat — tried to cut fuel to the engines.

“We’re just lucky he wasn’t flying the plane when he decided to do this. What’s going to stop that?” said Jon Loffi, a longtime law enforcement officer who teaches aviation security at Oklahoma State University and wrote a paper on identifying insider threats.

There is something of a see-something, say-something mindset in aviation, where employees are encouraged to voluntarily report anything that raises a safety concern, including suspicious behavior of colleagues. It's not clear how often that happens, however — if ever.

The pilot who was arrested after Sunday's flight didn't appear to raise alarms. Neighbors and fellow members of a flying club where he was an instructor described him as a great guy who was obsessed with safety.

Pilots are required to undergo psychological screening as part of their regularly scheduled medical exams. The pilot involved in Sunday's incident got his most recent exam in September, according to Federal Aviation Administration records.

However, the pilot, Joseph David