There are thousands of people worldwide who want to get on an explosive on a plane, but have failed. Even the shoe bomber got nowhere.
He WAS on the plane, but his explosives failed to detonate. Same thing happened to the underwear bomber - failed to detonate, just burned the hell out of his private areas.
Both were subdued by passengers, which I'll argue is much more likely to happen now that we know the attackers' intent is to take over the plane and fly them into buildings. It used to be that the hijackers just wanted something so they'd hold everyone hostage. That made passengers compliant to demands - their lives weren't in imminent danger.
I'd argue we should go the other way - arm the pilots, arm the stewards, let the passengers be armed. It's widely known and statistics prove that attackers favor "soft" targets. It's also less-widely known but statistics prove that in a life-or-death situation, with seconds to decide, the police are often minutes away. We need to take personal security seriously and stop being sheep. Nobody can protect you from a person willing to do you and others harm ... except yourself.