Although it is no longer the prime contractor for KC-135 programmed depot maintenance (PDM), Birmingham, Ala.-based Pemco Aeroplex continues to play a major role in the program under a subcontract to Boeing. As Boeing's huge San Antonio facility books more government work, particularly on the C-17 transport and the KC-10 tanker/transport, more KC-135 PDM is likely to be sent to Pemco.

Despite the advancing age of most of its variants, the C-130 Hercules continues to soldier on, and even now is playing a prominent role in the U.S. war on terrorism.

Maintenance of older business aircraft often becomes even more complicated when gaps appear in the recording of repairs and modifications performed over what could be decades of service. Lack of a complete set of documents is one of the most significant emerging issues facing repair stations, owners and reputable aircraft management firms, according to Bill Zink, director of maintenance business for San Francisco-based TAG Aviation USA, which operates aircraft under both FAR Part 91 and Part 135.