Reminded me of something my son was telling me about the airlines...

Seems that almost none of the airlines actually OWN the engines on their planes. They are LEASED from the manufacturer, I suppose for liability reasons so they have access to inspect and final say in operation (my guess).

What I found odd was that the airline is charged a premium for any time the engines are run at full throttle. Most pilots shove the throttles on take off but back off as soon as the wings are trimmed. The manufacturer expects this but wants it minimized for engine stress and life of the engine. Most pilots are pressed for optomizing engine performance, but are faced with the reality that when hitting the ground they arrive first! LOL So when power is needed it is USED.