Original Message

Patrol is part 91 no matter who is paying the bill. Fuel stops within that patrol are also part 91. The reg is plan language backed with FAA case law.
Now, if the patrol ends with your customer being intentionally delivered to somewhere other than the pick up point 135 rules apply.
If you’re doing work where the lineman is on a platform or skid or if you’re doing HEC work that lineman is a class B or D load and a 133 certificate would be needed.