I copied a little Q&A off Cheryl Cage's website. I thought this would give you more perspective on the situation.
BTW, don't let Preben get under your skin. He's speaking from a Danish perspective...European laws are much more stringent than the USA when it comes to DUIs. When you consider that some countries have a death penalty for DUI, the USA is quite lenient.
At any rate:
I have a DUI in my background. Are my chances of working for a major airline ruined?
We would need a lot more information about your personal background in order to answer that question. Obviously, this is a serious situation and one that a pilot interviewer would review in-depth.
Although age should never be used as an excuse, interviewers are aware that very young people sometimes have lapses of judgment.
Let’s say you received the DUI when you were 19, and you are now 26. This gives the interviewer seven years of behavior to review. In reviewing these seven years the interviewer discovers your driving record has been clean since the DUI, you have been consistently employed within aviation and have made good career progression, and you have excellent recommendations from your past employers. In addition, during your interview you were straightforward, took responsibility, and was willing to discuss the situation in depth. With this type of approach and concrete information the chances of overcoming this black mark on your record are greatly increased. This is because you have proven that the DUI was not a normal pattern of behavior.
However, what if your record shows more traffic violations since the DUI, or a poor recommendation from a past employer, or perhaps several problems with your training? The DUI will then be much more difficult to overcome simply because it is now compounded by other problem areas.
Someone who is commits a DUI when they are an adult is going to have a lot more difficulty overcoming this situation. That doesn’t mean it can’t be done, however it is much more difficult because the only thing that can help to overcome this problem is time. As previously stated an interviewer will need several years between the DUI conviction and the interview to become comfortable with the applicant’s true pattern of behavior. And, quite frankly, as an adult you should know better.
So, to answer your question: Are my chances of working for a major airline ruined? The answer: It depends. It depends on your personal and professional behavior since the DUI, your career progression, and your presentation in the interview.
Obviously, the best case scenario is to never put yourself into this type of situation. Remember, every decision you make and the consequences that come from your decisions will follow you throughout your career.
Hope that helps!