For the record is it is already a federal crime to operate a common carrier (such as a commercial aircraft) under the influence of alcohol. The offense carries prison time of up to 15 years and a maximum fine of $250,000 dollars. Typically under 100 pilots a year are charged under federal law, because in most cases the aircraft is never allowed to move and they are charged under state law instead.
It should be a federal offense for a person to pilot a commercial airplane to be under the influence. This person not only has the lives of those on board at risk but whomever could be injured or killed in the event of a crash. To be a pilot takes so much skill and constant awareness and ability to make judgment calls that it can be difficult even in the clearest of minds.
A person piloting a plane has great responsibility. Not only do they have to worry about all of the passengers and crew on that plane, they also have to worry about others in the sky and on the runway. When a person decides it is ok to pilot under the influence of drugs or alcohol, they are endangering many unsuspecting people's lives, and need to be dealt with seriously. I think the punishment needs to be fair but firm in cases like this, including no longer being allowed to fly EVER.
When a person gets on an airplane, they haven't had the chance to interview the pilot ahead of time. They don't get to check the star rating of the officer that is going to be operating the plane. They have to rely on the airline and on the officer to be sober enough to operate safely.