You must have received that new issue of United Services. JFKMM is a group assigned to change engines of aircraft that are AOG. They all have alot of experience/training changing engines, which is important because when an aircraft is out of service, revenue is lost...so the quicker the job is accomplished the better. Otehr airlines have field trips available for technicians when one of their own aircraft is out of service. The filed can can be anywhere they fly or even where an aircraft may have to divert. Well, UAl does these kind of things for themselves and otehr airlines under contract with them.
Ohh....no I am not part of the engine change kit. Just familiar with it.