Why didn't I think of it before? Every time I fly I'll take my pet rattlesnake with me. (Yes folks..it's well known where I work..I actually AM crazy and keep snakes) If any hijackers board, I'll just let old Fido lose and bite 'em (specially trained to bite groins) In the event of Fido biting the wrong person accidentally, I'll carry a measure of anti-venom. This cannot fail !!
Nobody in their right mind will even try to enter the cockpit.
Trouble is though, I'd have to be single crew, (cos no co-pilot would fly with me)and poor Fido would soon catch cancer going through the xray machines every day.
Spitting cobras are good too 'cos they can blind the attacker before he gets near the door.
Hisssssssssssssssssssssssssssssssss-spit !!