Should a father make an attempt to contact his adult child?

A friend of mine recently came to me with this question. It seems he fathered a child as a result of a casual “pick-up” in the mid-to-late eighties. At the time, he was in his 30’s, a bachelor, working casual jobs, one paycheck away from homelessness, with no real prospects for the future. She had a steady income and a house, but she also had a cocaine problem. As they talked about the pregnancy, they came to several conclusions. The mom said the pregnancy was the best thing that could happen to her, because it incentivized her to clean up her act, and she had resources to raise the child without his involvement. He took her feelings at face value, the intent being to stay around town, keep in contact, and be available if needed.

Shortly after the baby was born, he found work in another state, and went, with the intention of returning and maintaining some type of relationship with the mother and his child.

While he was at his new job, he met a woman who was truly the love of his life. They entered into a long-term committed relationship. However, he was afraid to tell her about the child, thinking it might be a deal breaker in terms of his new love.

He and the new woman eventually got married. They have now been married almost 30 years, and his child (a daughter, by the way) is the only thing he has not been completely honest about.

When he talked to me about the situation, he said not one day has gone by that he did not think about the child he left behind. He does not regret leaving, because it seemed the best for all at the time. He does regret not sticking around to see the child grow.

His current dilemma is this: How should he try to contact the child (now in her 30’s)? Should he contact her directly and try to explain who he is and why he left? Should he contact the mother, to find out if there was another man who acted in lieu as father? Which would be more likely to have a positive result?

I suggested he contact the mother, talk to her, and see if there is another man who acted as father. That way, he would know 1) if daughter knows anything about birth father; 2) if injecting birth father into daughter’s life would or would not be beneficial for all, and 3) if daughter would be better off in not knowing anything more about birth father.

How would you suggest he handle the situation?