Mike Jenvey
I had read your previous post, perhaps I put it badly. The CAA asked for the legislation, no idea why, and from what you have posted there seems to be no logical reason for it.
The CAA would not have had input into the BAC levels set, any more than than DVLA would have into the drink drive limits. That would have been done by advice from the Dept of Heath (or whatever its called this week). Like the limits for driving they are set given the level of impairment on somones ability to preform a task compared to when they have no alcohol in thier body.
You mention fatigue, and the effrect that has on a pilots ability, adding alcohol to that would only make it worse.
I accept again what you say about this being a about public transport, but the this legislation makes no distinction between the 2, if you are acting as crew of an aircraft you are covered by it.
The alternative is to say that if you hold a PPL, you can't drink but if you hold an public transport one you can....an unacceptable diffenrence by any standard.
It may be that the CAA have been influenced by the actions of others in the GA in other countries, but the end result is the same, the legislation exists, and isn't going to go away.
Having established that, then either people have to learn to live with it, or do something positive to prevent themselves being caught out, one way to get your own test kit. The other is for employers to make everyones life easier by providing the facility for staff to test themselves before they are in a position where they could be committing an offence.
One thing I think is obvious and hasn't really been mentioned is that any pilot or ATCO and probably engineer caught committing this offence is stands a very high chance of going to prison, because of the position of high responsibilty and public desire for thier transport needs to be in safe hands. In that you arn't alone, the same would happen to a train driver, or ship's captain.
Estimates of how many pilots have a drink problem are probably wrong yes, but are based on the population as a whole. In any group of people there will be some that can't control thier desire for a drink. Pilots are no exception.