Article Summary: The 309th Aerospace Maintenance and Regeneration Group (AMARG), also known as the Boneyard, stores and preserves over 4,400 military aircraft at Davis-Monthan AFB in Arizona. With low humidity and stable ground, the facility protects aircraft for future reactivation, parts reclamation, and foreign military sales.
Key Point #1 – Some, like the B-52 and F-16, have even returned to service. AMARG plays a crucial role in U.S. military readiness, keeping aircraft in various states of preservation while supporting global allies.
Key Point #2 – Learn how this unique facility extends the lifespan of America’s aerial fleet and ensures critical warplanes remain ready when needed.
The 309th AMARG: Where Retired Aircraft Get a Second Life
The 309th Aerospace Maintenance and Regeneration Group — also known as AMARG, or alternatively as the Boneyard — is a specialized facility located at Davis-Monthan Air Force Base in Tucson, Arizona.
Covering around 2,600 acres, AMARG is the primary storage and maintenance site for retired military aircraft from the U.S. Department of Defense and other government agencies.
The facility manages over 4,400 aircraft and 13 aerospace vehicles, including those from the U.S. Air Force, U.S. Army, U.S. Navy, U.S. Marine Corps, U.S. Coast Guard, as well as NASA.
AMARG: The Perfect Environment
The environment of Tucson offers the perfect conditions for long-term aircraft storage thanks to its low humidity and the relatively infrequent and insignificant amount of rain it receives, which helps counter the rise of corrosion and extend airframe life.
In addition, the area’s soil — hard, relatively alkaline — offers a hard, stable foundation for aircraft weighing quite a bit, preventing them from sinking into the soil without the need for paving an enormous area with concrete.
Aircraft Storage Categories and Procedures
Once they arrive at AMARG, aircraft are cataloged, and components that could degrade are protected, removed, or stored elsewhere.
The aircraft are given a designation that correlates to how useful they may be in the future:
Long-Term Storage or Type 1000: Aircraft are preserved for potential future use. Preservation includes draining fuel and hydraulic lines, sealing openings, and applying white protective coatings to help reflect sunlight, reduce heating, and prevent damage from the environment damage.
Parts Reclamation or Type 2000: Aircraft are stored and used as parts depots for active fleets. When needed, components are removed, and the airframe is maintained to prevent as required.
Flying Hold Type 3000: Aircraft are maintained in an almost-ready state for potential return to service in the United States or abroad. These aircraft go through regular maintenance and system checks to preserve rapid reactivation capability.
Excess of Department of Defense Needs Type 4000: These airframes are stored with basic preservation, as they are not meant for future use.
The specific procedures for each storage level may vary by airframe, but usually involve assessments, necessary maintenance actions, as well as periodic inspections to make sure the aircraft remain in the condition they are supposed to.
Reactivation of Stored Aircraft
The Boneyard plays a pivotal role in the reactivation of stored aircraft to meet future needs. For example, in May 2019, AMARG brought a B-52 bomber back to active duty — after more than a decade in storage. In addition, the facility has brought back retired F-16 fighter jets into a state to fly again as full-sized, remotely piloted aerial targets for piloted aircraft as target practice.
Annual Aircraft Processing and Current Inventory
Each year, AMARG receives and processes a varying number of aircraft, depending on the needs and budget considerations, particularly of the U.S. Air Force. While specific intake numbers change each year, the facility is in charge of a pretty substantial inventory. As per recent reports, AMARG looks over more than 4,400 aircraft as well as 13 aerospace vehicles from various branches of the U.S. military — and other government agencies.
A B-52 Stratofortress aircraft flies overhead near the Air Force Flight Test Center. The Stratofortress is carrying AGM-86 air-launched cruise missiles.
In addition to storage for domestic reactivation purposes, the Boneyard also aids foreign military sales by storing and maintaining aircraft destined for further service with allies of the United States. This includes preserving aircraft in ready condition until they are transferred to other countries.
The 309th Aerospace Maintenance and Regeneration Group is a significant asset to the United States Department of Defense. Thanks in part to Arizona’s dry, stable environment, and especially thanks to the careful preservation and periodic maintenance tables, the Boneyard ensures that a variety of aircraft are on hand to service aircraft in active service or potentially to fly again themselves with the United States or for friends and allies.
Airmen from the 96th Bomb Sqaudron load gear onto a B-52H Stratofortress at Barksdale Air Force Base, La., Oct. 13, 2020. The crew took part in a NATO crossover exercise designed to increase interoperability with NATO mission partners. (U.S. Air Force photo by Airman 1st Class Jacob B. Wrightsman)
About the Author: Caleb Larson
Caleb Larson is an American multiformat journalist based in Berlin, Germany. His work covers the intersection of conflict and society, focusing on American foreign policy and European security. He has reported from Germany, Russia, and the United States. Most recently, he covered the war in Ukraine, reporting extensively on the war’s shifting battle lines from Donbas and writing on the war’s civilian and humanitarian toll. Previously, he worked as a Defense Reporter for POLITICO Europe. You can follow his latest work on X.
