The Davis-Monthan Boneyard: Where America’s Warbirds Are Rested, Retired, and Sometimes Resurrected
by Eric Edwards
Flying over southeast Arizona—where the rugged Rincon Mountains meet the Sonoran Desert sands of Tucson—one might first think he’s looking down on a large military graveyard. And in a sense, he’d be right. The Davis-Monthan Air Force Base (AFB) is home to the Air Force’s 309th Aerospace Maintenance and Regeneration Group (AMARG), which operates the world’s largest storage, preservation, reclamation, and dismantling facility for excess U.S. military and Government aircraft. Furthermore, seeing an aerial view of all these old warbirds lined up in precise geometric patterns across the sprawling 2,600-acre installation, many observers are reminded of the similarly precise patterns of white marble headstones that line the grounds of Arlington, Normandy, and other national cemeteries [1–3].
And perhaps that’s altogether fitting. Though metal and machinery can’t compare to the flesh and blood of America’s Warfighters, parked among the thousands of fixed- and rotary-wing aircraft in this desert flatland are some undeniable war heroes in their own right. During their long service lives, many of these aircraft logged thousands of hours ferrying U.S. combat personnel into and out of harm’s way; executing difficult, dangerous, and critical missions most people will never know of; and surviving a long list of formidable threats thrown at them all over the globe. It’s thus no wonder many former pilots and aircrews still talk about their beloved “rides” as fellow veterans, lifesavers, and even old friends.
And for some of these friends, the mission isn’t yet over. In addition to AMARG’s ongoing responsibilities for demilling, dismantling, and parting out a portion of their aircraft inventory to support the current flying fleet, the group also helps ensure that another portion is carefully preserved, maintained, and kept ready to return to the flightline at a moment’s notice . Furthermore, for the aircraft survivability community, the Davis-Monthan AMARG facility—more commonly known as “the Boneyard”—has long served not only as a sort of survivability “hall of fame” but also as an ongoing goldmine of resources to support a wide range of lethality and survivability/vulnerability studies and live fire test and evaluation (LFT&E) efforts.
A PERFECT PARKING PLACE
The Boneyard is like no other aircraft preservation and storage installation in the world. With a history of housing and maintaining more than 4,000 aircraft at a time (as well as 6,000 aircraft engines and 340,000 pieces of production tooling), the site has become home not only for all the excess aircraft of the U.S. Air Force but also for that of all the other military branches, NASA, and the rest of the federal government as well (see Figure 1) [1–4].
It’s also no accident the facility’s located in the middle of the desert. One might think the blazing sun, high heat, and blowing sands of southern Arizona would be too harsh of an environment to store and preserve planes. However, the location turns out to be an ideal place for AMARG’s specialized work. The combination of the area’s low humidity (between 10 and 20%), small amount of rainfall (about 11 inches/year), high elevation (about 2,550 ft), smog-free climate, and alkaline soil provides an extremely dry, nonacidic environment that naturally helps prevent rust and corrosion [2–5].
In addition, the hard desert surface there—which is more akin to hard-packed dirt than sand—allows the aircraft to be easily moved around and stored without the need for large, expensive paved areas . And 4,000 aircraft could require a lot of pavement! To put the immense size of the Boneyard in perspective, nearly 2,000 football fields could fit within the facility’s 4-square-mile footprint.
As for dealing with the harsh desert sun and high heat, AMARG uses a unique sealing process (detailed later) to protect its aircraft from the sun and outside elements; keep out water, sand, and critters; and reflect sunlight so that interior compartment temperatures never get too hot. Thus, aircraft can be effectively and efficiently preserved there for many years [2, 5].
WARBIRDS WITHOUT A WAR
AMARG officially celebrated its 75th year of operation in 2021; however, planes have been taking off and landing at Davis-Monthan for almost a century . The facility opened in 1927 as a municipal airport (reportedly the largest in the country at the time). It was named in honor of Tucson natives and World War I pilots Samuel Davis and Oscar Monthan, both of whom died in military aircraft accidents. Then, in December 1941, 4 days before the surprise Japanese attack on Pearl Harbor, the facility was renamed the Davis-Monthan Army Air Field .
By the end of World War II, the facility also started serving as temporary housing for German POWs, but its true value and mission were soon to be realized. When the smoke finally cleared from the long conflict overseas and U.S. service personnel began returning home, the military found itself inundated with an inventory of approximately 65,000 warbirds that had no war left to fight . In particular, there were large numbers of Boeing B-29 Superfortresses and Douglas C-47 Skytrains with no good place to go. Some of these aircraft—such as the historic “That’s All, Brother” C-47 that led the D-Day invasion —were converted into civilian cargo planes, while most were scrapped, parted out, or preserved and stored for later action (which many would see in Korea) .
And it didn’t take long for military leaders to realize that Davis-Monthan was an ideal location to perform all of these tasks. By 1946, more than 600 B-29’s and 200 C-47’s had found their way to the Boneyard. Even the two planes credited with ending the war—the B-29 atomic bombers “Enola Gay” and “Bockscar” (shown in Figure 2) —rested there for a time before being relocated to their respective retirement homes at the National Air and Space Museum in Washington, DC, and the National Museum of the U.S. Air Force in Dayton, OH .
DIFFERENT NAMES, SAME MISSION
When the Air Force was officially broken off as a separate military branch in 1948, the storage and preservation unit at Davis-Monthan was renamed the Air Force’s 3040th Aircraft Storage Depot. And the planes just kept rolling in. Between 1953 and 1956, a seemingly endless string of retiring aircraft—including QF-17G Flying Fortress drones, T-6 Texans, F-84 Thunderjets, YC-122 Avitrucs, B-26 Invaders, F-80 Shooting Stars, C-74 Globemasters, F-86 Sabres, HU-16 Albartrosses, B-50 Superfortresses, and (even more) B-29 Superfortresses—continued to arrive for storage, destruction, reclamation, foreign sale/transfer, and/or eventual reactivation to service (see Figure 3). The first Convair B-36 Peacemakers also arrived during this time, with the entire fleet (380 minus 4 saved for museums) eventually being dismantled by 1961 (see Figure 4). Each of the giant B-36’s would yield more than 40,000 lbs of salvaged aluminum [2, 7, 8].
In 1965, the Navy likewise moved all of its surplus aircraft to the Boneyard, and the operating unit’s name was changed again—to the Military Aircraft Storage and Disposition Center—to reflect the facility’s new all-Service coverage. In 1969, the last B-47 Stratojet bomber was retired, and all but 30 of them were flown to the facility and subsequently taken apart as well .
As the Vietnam War neared its conclusion in the 1970s, the site’s inventory reached an all-time high of 6,018 aircraft . The inventory included everything from some of the first U.S. aircraft to see action in Southeast Asia—B-26 bombers, T-28 fighters, and SC-47 transports—to the CH-46 Sea Knight helicopter call-signed Swift 2-2, the very last aircraft out of Vietnam, rescuing the final U.S. Marine security detachment from the U.S. Embassy in Saigon on the morning of 30 April 1975.
Then in 1985, the unit was renamed yet again—to the Aerospace Maintenance and Regeneration Center—to convey the facility’s added expansion to processing intercontinental ballistic missiles and space vehicles (such as that shown in Figure 5) as well as aircraft .
In the 1990s, the Boneyard undertook one of the most monumental tasks it has ever been given. As part of the U.S.-Soviet Strategic Arms Reduction Treaty (START), the facility was charged with destroying 365 B-52 Stratofortress bombers (shown in Figure 6). To do this, a crane-and-cable system were used (at least initially) to repeatedly drop a 13,000-lb steel guillotine blade onto the giant warplanes, cutting through them like butter and creating five large pieces: the tail, two wings, and a bisected fuselage. By agreement, these pieces (shown in Figure 7) were then left out on the Davis-Monthan compound for at least 90 days so Soviet inspectors could verify by satellite surveillance that each asset had truly been dismantled [2, 5].
THE ‘PICKLING’ PROCESS
Today, each aircraft sent to Davis-Monthan for storage/processing typically arrives with its entire documentation history, including all of its maintenance records. The vehicle is then stripped of any guns, ejection seat charges, and classified components. Data plates and clocks (which are popular items to be scavenged by souvenir-seekers) are also removed. Each aircraft also undergoes a through exterior washing, especially if it previously served on an aircraft carrier and/or operated in warm, salty, or tropical (i.e., corrosive) environments [2, 3].
A type of embalming—or “pickling”— process is then used, whereby the aircraft is taken to the facility’s “flush farm,” the fuel system is drained and refilled with a special lightweight oil, the engines are briefly run, and the fuel system is drained again, leaving a protective film of oil on all the fuel system plumbing and engine components [2, 9, 10]. To ensure the engines are not damaged during the pickling process and the fuel-to-oil transfer is complete, workers carefully monitor the running engines and—in a scene reminiscent of the Vatican selecting a new Pope—shut them down as soon as puffs of white smoke are seen .
For fighter jets, such as F-15’s and F-18’s, the powerful afterburners are pickled as well, which requires the planes to be securely tied down to the ground when fired up. And when that happens, the rumbling can reportedly be heard clear across Tucson . The aircraft are then placed into one of the following four storage/processing categories [2, 3]:
- Long Term (Type 1000) – These aircraft are kept intact in “inviolate” storage for potential future flying No parts can be removed without specific permission from the applicable program office. These aircraft are then “represerved” every 4 years.
- Part Reclamation (Type 2000) – These aircraft are kept intact but serve as storage bins—or “cann (cannibalization) ” Spare parts (such as that shown in Figure 8) from these aircraft are harvested as needed to support the flying fleet.
- Flying Hold (Type 3000) – These aircraft are kept in flight-ready Every 30 days, their engines are run, their fluids are serviced, and they are towed around to keep their bearings lubed. These planes require the most active care at the facility and are considered only temporary residents, as they await transfer to another unit, sale to a foreign country (such as shown in Figure 9), or reclassification to another category.
- Excess of DoD Needs (Type 4000) – These aircraft are typically the oldest in AMARG’s inventory, receive the least active care, and are the least likely to be recalled to service. As such, their engines are sometimes removed and stored elsewhere (as shown in Figure 10), and they are sold off whole or in parts. And when all of their usable parts have been harvested, they are scrapped, smelted into ingots, and/or recycled.
As mentioned, aircraft can also be transferred from one category to another while at the Boneyard, depending on the changing requirements of the flying fleet, the emergence of new aircraft, the availability of replacement parts, and the condition of individual assets. For example, after spending more than 2 decades parked in Type 2000 (Part Reclamation) status, one F-4 was reconditioned and flown again as a target drone .
For Type 1000 and 2000 aircraft (as well as engines and canopies of Type 4000 aircraft), a two-coat sealing process is used to protect the vehicles against dust, sunlight, and high temperatures. The process involves applying a sprayable latex material (which is permanently flexible and strippable) to the aircraft’s windows, canopies, engine intakes, other openings, and some exterior surfaces. The under coat (shown in Figure 11) is a black (or blue) coat that seals the asset. The outer coat is a white coat that reflects the sun to keep the interior compartment temperatures within 15° of outside temperatures. The “mummified” aircraft is then towed to its designated resting place, where it begins a new and different kind of survivability battle, this time fighting time and the elements instead of missiles and bullets [3, 5].
Most fighter aircraft require approximately 50 hrs of preparation for storage. Helicopters (such as those in Figure 12) often require a little more time (approximately 80 hrs), as boxes also must often be built to protect their rotor heads. Much larger aircraft, such as B-52’s, can take as much as 300 hrs .
When an aircraft is finally scrapped for good, the AMARG team works with the same speed and efficiency as it uses for everything else. In fact, a humongous C-5 Galaxy—at almost 300 ft long and with a 222-ft wingspan—can be reduced to a pile of truckable pieces in just a few days . If the aircraft is known to have some special significance or name recognition, a portion of it (such as its nose art) will sometimes be saved for a museum or other use. The outer shell of an aircraft may also be saved for use as a “pole model,” for permanent static display outside a military or government building or installation .
TREASURES IN THE DESERT
Today, in addition to AMARG’s aforementioned preservation, dismantling, and storage activities, the group also conducts overflow depot maintenance for the A-10 Warthog and C-130 Hercules programs; serves as an auxiliary facility for the U.S. Air Force Museum; and, as mentioned previously, converts old jets, such as the F-4 Phantom and the F-16 Viper, into aerial target drones [1, 2, 7]. Granted, serving as a target drone isn’t the most glamorous sendoff for these heroic old warriors, but even in this role, they are continuing their mission of supporting U.S. combat personnel by helping them learn to stay safe and effective in hostile battlespaces.
In addition, many survivability practitioners have come to appreciate the invaluable support (and tremendous cost savings!) the Boneyard can provide for their specialized work. For example, the Navy’s Weapons Systems Laboratory (WSL) and other organizations at China Lake have a long history of leveraging AMARG resources—both complete aircraft and parts—for various lethality and survivability LFT&E efforts. Recently, an AMARG F-16 was secured for missile warhead development/lethality testing, as were the tail driveshafts from numerous helicopters (e.g., H-60’s and H-1’s) to help develop a new analyses methodology to better assess and predict driveshaft vulnerability against kinetic threats.
Likewise, the Aerospace Vehicle Survivability Facility (AVSF) at Wright-Patterson AFB used TF-33 engines from retired B-52’s at AMARG to build its state-of-the-art airflow test stands (shown in Figure 13). This use provided not only a significant cost savings over purchasing new engines but also an ongoing ability to quickly secure replacement components when needed. AMARG B-52’s were also used as test beds for internal explosives research and instrumentation in support of the extensive international investigation of the Pan Am Flight 103 bombing over Lockerbie, Scotland, in 1988.
Also, in support of Joint Live Fire (JLF) testing, many full-up, fully functional F-15, F-16, C-130, helicopters, and other front-line aircraft and their components (including fuselages, cockpits, wings, and empennages) have been supplied by AMARG to help simulate “flight and combat” conditions in support of survivability studies involving a wide range of ballistic threats. And many of the lessons learned from these studies (in areas such as testing techniques, vulnerability reduction measures, etc.) were transitioned to newer aircraft, which would eventually be subjected to the Title 10 LFT&E efforts.
Admittedly, the sight of Davis-Monthan’s large collection of once-cherished warbirds now sitting in the Tucson desert awaiting their respective fates may seem to some observers to be a waste of valuable resources. But AMARG officials are quick to point out that the Boneyard’s inventory represents literally billions of dollars of actual and potential savings to U.S. taxpayers. After all, each existing aircraft that can be used to fly (or even potentially fly) a U.S. or allied mission is one less new aircraft that may have to be manufactured, paid for, and/or appropriated. Likewise, each existing part or tooling piece that can be preserved and reclaimed is one less new part or piece that may have to be built or bought.
Even the ultimate grounding and destruction of some of these old planes—as opposed to trying to keep them operational, up to date, and flying—can save millions of dollars in would-be maintenance and modernization costs. And these are dollars that can be redirected toward helping the next generation of U.S. warbirds take to the skies, continue the nation’s long-held legacy in air superiority and survivability, and secure their own venerable places in military aviation history.
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The author would like to thank Mr. Alex Kurtz and Mr. Marty Krammer for contributing the survivability-support examples included in this article.