It's pretty common for interviewers to ask about specific experiences in your past work history. In this case, the interviewer is interested in hearing about your problem-solving skills and ability to adapt to unique challenges. Working on a power line in a unique location as a lineman can present a variety of obstacles, so sharing a successful experience in this area demonstrates your expertise and proves your value to your potential employer. Think of a time when you faced a difficult situation on the job and how you overcame it, emphasizing your resourcefulness and ability to work under pressure.