I hadn't thought about pipeline surveys. What speed would a helicopter fly at if conducting this work?
I don'y fly rotary, but would hazard a guess at 90-150kts!
The one that comes and does the overhead cables close by every few months does about 20 kts, but since it's next to the overhead line, it's not likely to be a hazard for anyone. I can't imagine a pipeline being surveyed at 150 kts.