Most PBH contract have "Act of God" limitations within them. Thus bird lightning strikes et al are excluded as they can not be reasonably insured against. Insured is of course the key work here...that's all that PBH is. The airline oprates the aircraft and the engine an pay an amount per hour to the owner/lessor. The hourly rate could include on wing maintenace/off wing maintenace and LLPs. The rate is negotiable!! What is key to PBH is that it flat rates the cost of operation of an aircraft engine per hour and or per cycle. For a start up operator it means that he is unlikely to take on a second hand aircraft and then suddenly get hit for a bill for $700KUS because his engine has cooked......the PBH reseves will/should cover the cost.