This was always going to be the most emotive issue in the nations response to 911.And I say nation because it is primarily an American predicament.The Europeans negative response is understandable if you consider that it wasnt their pilots who were summarily ejected from the cockpit,had their hands tied and forced to watch the demise of their ship,crew and pax.If they had,perhaps their response would be somewhat different.
The possible dangers in arming pilots(and there are some I agree) are simply outweighed by the need to ensure that the fate of the pilots dependents are never again relinquished from his/her control in such an atrocious fashion.
The concerns seem to be threefold:
i)That the firearms will be commandeered by would-be hijackers
ii)That the pilot will misuse the firearm
iii)That the use of firearms in flight will cause other scenarios of equal gravity to that of a hijack.
I think that (i) can be addressed by good training and the acceptance of sky marshalls as the first line of defence and buffer to the flight deck.
The dangers of (ii) are equally valid but less transparent in that you can train a pilot to shoot straight in 2 weeks but you cant teach good judgement in that time.However,this too can be addressed successfully if we accept that pilots already possess good judgement and that the use of the firearm is a last ditch option and its use subject to the ship being in
dire peril.
(iii)is very subjective and depends on your POV.I cannot imagine any scenario worse than 9/11.