I am a police officer of 15 years service and at present I am a member of a team that provides armed protection to senior members of the UK government including the PM and believe I am qualified to give my opinion on this subject
Spookily enough i compiled a report on this subject for a 'low cost carrier' in the UK about 3 months ago.
Tactically having armed personnel on an aircraft is an option though a minimum of three persons would be required.Arming the flight crew or cabin crew is not an option,they have their own jobs to do in an emergency of any kind.
Contrary to popular belief firearms could be discharged in an aircraft without a rapid decompression taking place,handguns that we in the Metropolitan police use(Glock 17) with low grain rounds would not penetrate an aircrafts structure,but I agree the confines of a cabin would make an unattractive battleground.
IF the UK were to go down this road the armed personnel would have to be police officers, our laws do not provide for any other government or private agency to carry firearms(except the military but this takes us into a different ball park).
The Guvnor states that 'skymarshalls' would stand out like a sore thumb.If I were in charge that is exactly what I would want.When we protect the PM you can see us a mile off-prevention is better than cure.Also we are not gun totting thugs looking to shoot the next innocent person...On an aircraft you would have highly trained officers who can see 'if someone is not right' hopefully before anything takes place.Having armed police officers on an aircraft makes it a thousand times more unattractive as a terrorist target.
Having said all that this government would not even consider this as an option.
So this leads us onto unarmed private airline security personnel an option that I favour.
I am talking about highly trained people here not your uniformed security men from Tescos. Again at least three men(or women).Here you still have a deterent from your would be terrorist,people who can spot when things are not right,who have superior physical skills and hostage negotiation skills.Personnel who can be used on a daily basis also to deal with and prevent air rage and yobbish behaviour. But this is not attractive to the airlines because 1) you are usng three revenue seats on each flight
2) he airlines would have to recruit people with these skills from the police and military so you would be lookind at salaries of 40-50K pa to attract the right people( police officers in London protecting the PM earn in excess of this amount).
To summarise
Airliners at present are soft targets not only for terrorists but also for your drunken thug
Highly trained law enforcment or private personnel would prevent rather than cure
Safety in the air should be paramount and not based on financial considerations but i understand that airlines are in the business of making money.
These are my personal views and not those of the Metropolitan police .
Or you could always employ someone like me who finishes ATPL at the end of the year!!!