Boneyard – 309th Aerospace Maintenance and Regeneration Group

The 309th Aerospace Maintenance and Regeneration Group (AMARG), often called The Boneyard, is a United States Air Force aircraft and missile storage and maintenance facility in Tucson, Arizona, located on Davis-Monthan Air Force Base. AMARG was previously Aerospace Maintenance and Regeneration Center, AMARC, the Military Aircraft Storage and Disposition Center, MASDC, and was established after World War II as the 3040th Aircraft Storage Group.

AMARG takes care of nearly 4,000 aircraft, which makes it the largest aircraft storage and preservation facility in the world. An Air Force Materiel Command unit, the group is under the command of the Ogden Air Logistics Complex at Hill Air Force Base, Utah. AMARG was originally meant to store excess Department of Defense and Coast Guard aircraft, but has in recent years been designated the sole repository of out-of-service aircraft from all branches of the US government.

There are four categories of storage for aircraft at AMARG:

Long Term – Aircraft are kept intact for future use
Parts Reclamation – Aircraft are kept, picked apart and used for spare parts
Flying Hold – Aircraft are kept intact for shorter stays than Long Term
Excess of DoD needs – Aircraft are sold off whole or in parts

An aircraft going into storage undergoes the following treatments:

Ejection seat charges, and classified hardware are removed.
All aircraft are carefully washed with fresh water, to remove environment residue, and then allowed to dry.
The fuel system is protected by draining it, refilling it with lightweight oil, running engines to coat fuel system plumbing and engines, and then draining it again. This leaves a protective oil film.
The aircraft is sealed from dust, sunlight, and high temperatures. This is done using a variety of materials, including a high tech vinyl plastic compound that is sprayed on the aircraft. This compound is called spraylat after its producer the Spraylat Corporation, and is applied in two coats, a black coat that seals the aircraft and a white coat that reflects the sun and helps to keep internal temperatures low. The plane is then towed by a tug to its designated “storage” position.

References: Wikipedia