The CIA’s Bird-Shaped Aquiline Drones Could Still Be Caged Up At Area 51

According to the CIA's paper trail, Aquiline was intended for “multi-sensor collection and advanced emplacement capability for collection of intelligence” and to “enable an almost completely surreptitious penetration” into unfriendly skies. Aquiline's designers attempted to mimic the characteristics of a bird in order to allow it to remain as undetectable as possible, a feature that can clearly be seen in some of the drone's prototypes. While the project was terminated before it ever reached operational status, the Aquiline documentation released by the CIA shows that after it ended, all Project Aquiline assets were stored at Area 51 "semi-permanently." It's unknown what became of them after that. 

The CIA hosts the full collection of declassified documents related to Aquiline on its online reading room site.

In the midst of the Cold War, the CIA found itself in need of an unmanned aerial reconnaissance vehicle that could be sent deep into adversarial airspace. The U-2 spy plane was proving itself too vulnerable to missile defense systems, particularly after the Soviet Union shot one down flown by pilot Gary Powers, marking the end of manned overflights of America's Cold War adversary. While the A-12 Oxcart and SR-71 programs were underway at the time the Aquiline project began, Aquiline was designed to offer a very different capability: the ability to conduct overhead penetrating surveillance completely undetected.

Reconnaissance satellites were becoming more prevalent at the time, but early designs had limited capabilities, not to mention the fact that satellite launches require a much larger share of resources and time to prepare than the deployment of a small unmanned aircraft system. Most of all, the enemy knew when spy satellites were overhead and they could only capture a moment in time. Thus, throughout the 1960s, the Department of Defense (DOD) continued to be interested in more flexible options that could be deployed rapidly, in an unpredictable fashion, and could provide persistent reconnaissance right over the enemy's heads without them even knowing. 

It is worth noting that by the early 1980s, Northrop's Tacit Blue demonstrator would finally prove that a penetrating, persisting, and survivable airborne reconnaissance capability was possible via leveraging stealth technology, as well as low probability of intercept datalinks and radar. Even so, the concept of using stealth technology to do this dates back to two decades earlier, via the far ahead of its time Quiet Bird concept. Regardless, Tacit Blue would go on to secretly change the reality of what airborne reconnaissance in denied environments could be. Today, the RQ-170 Sentinel fills this role in an operational sense, among potentially even more clandestine, strategically oriented assets.

Back to 1965—in order meet the need for a penetrating, low-observable (of sorts) vehicle for intelligence gathering in denied airspace, the CIA's Office of Special Activities (OSA) began working together with the Office of Research and Development's Applied Physics Division to develop an unmanned aircraft referred to by the codename Aquiline. The Aquiline project, from the Latin word meaning "eagle," specifically sought to develop a small stealthy drone that resembled a bird and had low radar, acoustic, infrared, and visual signatures. While the Aquiline program ended prematurely, as so many other ambitious aerospace projects of the era did, it nonetheless had a long-lasting influence on future surveillance drone designs.

In 1969, the CIA signed a contract with the McDonnell Douglas Astronautics Corporation (MDAC) to begin developing technologies for the Aquiline program. Personnel were deployed to Area 51 the next year to begin flight testing, which was set to end in early 1971 when the contract reached completion. It was thought that a working Aquiline drone would have been developed by that date, at which point the program would have entered operational status.

The Aquiline drones were intended to have first entered into service on a "limited capability" capacity in early 1971, meaning that some of the planned capabilities would have not been ready by this point. Full capability was planned to be ready by July 1, 1972, including a full-range airborne communications relay. It was thought that the drones would be able to fly one mission per month during this phase.

Exact specifications and design details are scarce, but what is known is that Aquiline drones were made to resemble birds and featured a single tail propeller. Initially, the prototypes were powered by chainsaw motors. In one memo in the CIA's reading room, the Aquiline drone is referred to as a "high characteristic operating model plane with a lot of expensive gadgetry."

Sensor systems were embedded in the aircraft's nose, and included optical cameras and infrared sensors, and even electronic intelligence packages. The drones were intended to have also been able to drop “black box” sensor systems into hostile territory, as well, so some form of payload carrying capability must have been included in at least some of the Aquiline designs. Specifically, one of the CIA’s documents states that one of the test drones was designed to carry payloads weighing up to five pounds. 

In a research and development study published in 1967, it’s stated that Aquiline’s low-altitude and low-speed capabilities would give it long loiter times, allowing for unprecedented levels of intelligence gathering for the time. “Further,” the authors wrote, “its small size and innocuous nature would make it more politically palatable in tense situations than conventional aircraft.” The CIA even planned for Aquiline to help support on-the-ground operations by providing clandestine overhead surveillance for agents conducting missions in the field.

A flight test range was established for Aquiline at Randsburg Wash at the Naval Ordnance Test Station at China Lake, California in 1967. "The facilities and facilities support are being supplied by the Navy under a task order from the Agency," one document states about the range.

The Aquiline drones were so difficult to observe visually during testing that engineers once had to paint one of the drones bright orange so that it could be more easily seen by a chase plane during a test flight. Despite the paint, the crew of the chase plane still found it difficult to see the drone in the air.

The exact range of the Aquiline drones remains unknown, and is redacted in all of the CIA’s declassified documents. 

However, one account states that Aquiline was able to fly for 130 miles while obtaining "very high resolution photography," while another document states one of the proposed mobile control units would have a range of 1,200 miles. A dedicated satellite was planned to offer a long distance communications link for Aquiline drones, but was never launched. 

There were even plans to use radioisotope propulsion systems later in the program's development, which were claimed to be able to give the drones 50-day endurance. These types of propulsion systems are powered by the heat given off by radioactive isotopes as they decay, and have been used for decades by NASA and the DOD for space missions. The Apollo missions to the moon and the Viking and Curiosity missions to Mars all used radioisotope systems to power various systems, which have no moving parts, can last decades, and can be miniaturized to fit in a variety of vehicles and systems.

Another document declassified by the CIA states that by 1971, Aquiline drones would have an unlimited range and be able to reach "any target."

That same document lists several potential targets for Aquiline, including the coasts of Cuba, the Barents Sea in the Arctic near the border of the then-Soviet Union and Norway, the Lop Nor nuclear facility in northwestern China, and Sary Shagan, a Soviet anti-missile weapons testing facility. The Aquiline program intended to have secure communications and sensor emplacement capabilities by 1969, and unlimited loiter times by 1970. While initial intelligence-gathering capabilities in 1968 would have been limited to "low altitude imagery" in addition to signals intelligence (SIGINT) and electronic intelligence (ELINT), the Aquiline program intended its drones to be capable of collecting missile telemetry reconnaissance, nuclear staging and yield intelligence, and even real-time "intelligence processing." It's unknown exactly what form these more advanced capabilities would have taken.

Despite these impressive planned capabilities, Aquiline drones had a major drawback: they possessed no landing gear of their own, and so they had to land by careening into nets. This caused frequent damage to the wings and propellers of the drones, creating major testing delays due to constant repairs being made. Three Aquiline prototypes were destroyed entirely from these net landings.

In a personal account hosted on RoadrunnersInternationale.com, a site which preserves “the history of the aviation pioneers and programs that developed the U-2, A-12 and YF-12 during the Cold War,” John H. Meierdierck, retired Air Force Lieutenant Colonel, offers a brief recollection of the Aquiline program as he remembered it, writing:

Accompanying Meierdierck’s account is a series of images depicting a small, bird-like model, and the note “The fotos [sic] shown are of the only model ever made of the 'BIRD'. I have the model at home, on my bar.”

Fast forward to today, and some smaller reconnaissance drones commonly use nets for recovery. While it may have not worked out for the material and mechanical capabilities of its time, the concept was, without a doubt, ahead of its time.

Like a number of highly classified programs centered around intelligence-gathering aircraft, the Aquiline project was housed at Area 51, the existence of which was still largely unknown to the American public at the time. That level of security was exactly what a program as sensitive as Aquiline needed. A 1969 CIA document outlining the objectives of the project states that “An important element in the security of the vehicle's operation is that its existence, configurations and unique operating characteristics not be known, thus, every effort is being made to avoid any publicity or knowledge of the vehicle." To that end, all of the program's activities were classified at the Secret level. The CIA's Aquiline Concept of Operations document even states that the final drones, when built, would live at Area 51 in between being flown to and from mission areas along with their control units.

In the end, Aquiline was doomed like so many other ambitious military or intelligence programs due to rising costs and the difficulty in making new technologies practical for deployment. In 1971, after being estimated to take two to three more years and require $35 million more in funding, Aquiline was cancelled.

Project Aquiline phaseout documents reveal that after the program's termination, all assets were transferred to Area 51 to “protect the Agency role in the Program and prevent unauthorized individuals from becoming aware of the existence of the AQUILINE vehicle, the covert testing site and the Agency's overt/covert procurement and contracting methods.” Another memo laying out the disposition of the program's assets states that all Aquiline hardware would be stored at Area 51 "semi-permanently" in one of the base's buildings.

Individuals from the U.S. Army, Air Force, Navy, and Marine Corps were briefed on the Aquiline program upon its cancellation and offered all remaining Aquiline assets. None of the branches was interested in the Aquiline program as a whole, but "low key inquiries" were made into various subsystems and components developed for or used aboard the Aquiline drones. "Therefore, predicated on the absence of any demonstrated interest in acquiring the program intact," one Disposition of Project Aquiline Assets memo reads, "it is believed that the AQUILINE Program assets should be made available for redistribution on a subsystem, subcomponent level, effective on or about 1 July 1972."

The Aquiline program apparently had a little-known successor program, Axillary, another CIA effort to build a "Miniature Multi-Purpose Airborne Vehicle." In the now-declassified document titled "The Central Intelligence Agency and Overhead Reconnaissance:  The U-2 and OXCART Programs, 1954-1974," the authors write that while the Axillary drone's radar cross section and acoustic signatures rendered it useless as a covert recon vehicle, it could have been armed with a small warhead and repurposed as a remotely-piloted munition for targeting surface-to-air missile radar systems in North Vietnam. However, like Aquiline, it seems Axillary was cancelled before it ever saw deployment. Nevertheless, Axillary can in some ways be seen as the grandfather of modern suicide drones and loitering munitions as we know them today.

The fact that the Aquiline assets came to be stored at Area 51 would seem to confirm at least some of the longstanding rumors that the base serves as an exotic boneyard and museum of sorts, at least in a secondary role, alongside its primary mission as a development and flight test facility. One popular, but still unconfirmed, rumor states there is a facility known as "Dyson's Dock," named after test pilot Norman "Ken" Dyson, at Area 51, in an extension of Hangar 18. Supposedly, it houses some of the still classified prototypes and other experimental vehicles from the installation's long legacy of clandestine American aerospace innovation. Bird of Prey and Tacit Blue, which were declassified years after their last flights, were rumored to have been stored there before being migrated to the National Museum of the U.S. Air Force following declassification. The facility may serve as something of a treat for distinguished visitors and those who find themselves working at the base in certain capacities. There's arguably no better way to make the base's massive value clear for high-ranking visitors.

It is largely understood that the desert surrounding the base is pockmarked with the unmarked "graves" of buried aircraft whose existences were too secret to leave out in the open and for which there was no room inside the facility's hangars for long-term storage. Properly declassifying them or destroying using traditional channels was likely deemed too costly and/or too risky. As such, base personnel just buried them around the very high security facility, especially those aircraft that were involved with mishaps. It's certainly possible that some of the Aquiline drone prototypes are among those buried within Area 51's perimeter, or, just maybe, put on display in what would be the ultimate of all aviation museums—if it does indeed exist.

Regardless, the documents about Aquiline's storage at Area 51 lend credence to the real possibility that the clandestine test base serves as a long-term depository of sorts for its one-time active residents. 

Aside from being stored at Area 51, it could be that at least one of the Aquiline prototypes made it to the CIA's internal museum, known as the "best museum you'll never see," in which artifacts from throughout the Agency's history are preserved for distinguished visitors. While this would make sense, we could not determine that conclusively at this time. Aside from that possibility, as far as we can tell from the CIA's documentation, the majority of the Aquiline drone prototypes likely lived out their lives cooped up at Area 51 surrounded by miles and miles of Nevada desert sand. 

While the Aquiline drone never made it past the development and testing phase, it was nonetheless an important milestone in the history of unmanned aerial vehicle and reconnaissance aircraft development. In fact, the CIA describes Project Aquiline as a distant ancestor to modern unmanned aerial vehicles on their reading room landing page: 

Acquiline's command and control and communications architecture, at its most basic organizational level, resembles that of the MQ-1 Predator. It entered operational service in 1995 and was a game-changer for the CIA, revolutionizing the Agency's operations, especially in the post 9/11 era of the Global War on Terror. As such, its roots can be traced tangetially to Aquiline just as the CIA mentions.

Aquiline's legacy can also be seen in many recent innovative animal-inspired UAV designs that could potentially hide in plain sight. The Defense Advanced Research Projects Agency (DARPA) has developed small, hummingbird-like winged drones small enough to fit in a human hand, for example.

Meanwhile, the Air Force Research Laboratory has experimented with a wide variety of animal- or insect-inspired micro air vehicles, including some small enough to fit on a human fingertip.

Private aerospace firms have developed similar concepts for tiny, sensor-packed UAVs that resemble birds and are incredibly difficult to spot. In 2013, a Florida-based firm was awarded a $4.5 million contract from the U.S. Army's now-defunct Rapid Equipping Force to produce 36 bird-like drones with flexible wings for "an urgent, but undisclosed, need." Global defense contractor Expal Systems sells its realistic-looking SHEPHERD-MIL autonomous bird drone to customers worldwide.

Start-ups have also popped up exclusively devoted to developing bird drones, such as the aptly-named Bird Drone Company in the Netherlands. The Bird Drone Company designed their falcon-like UAVs with animal control in mind, although the firm notes that its other models are ideal for "covert surveillance, reconnaissance, and other types of monitoring." 

America's adversaries have pursued similar biomimicry designs for micro UAVs intended for surveillance. China has developed tiny UAVs that look just like doves in flight, even as far as having robotic flapping wings. Meanwhile, Russia has shown off prototype surveillance drones that mimic the appearance of owls. It's unknown if any of these drone designs ever made it to operational status. After all, if you at least think your adversaries have stealthy, bird-shaped drones in deployment, then it could make you wonder about every bird you see overhead in the field.

In 2011, a bird-shaped drone crashed in southwest Pakistan, and was later reported to be similar to a separate bird drone which turned up in Iraq in 2009. The operators of those bird drones were never identified.

Bird drones have also been deployed in Somalia, as shown in 2016 when a crashed dual-propeller bird drone was found in Mogadishu. Like in Iraq and Pakistan, it remains unknown who was operating it. 

The U.S. Navy is currently pursuing a wide range of "bio-inspired" autonomous vehicles, including some that are planned to transition between air and water and others that resemble marine life to conduct essentially similar types of surveillance Aquiline was planned for using innocuous designs that could go unnoticed - except underwater in this case. Given the wide range of animal-inspired designs the DOD has openly researched, there's no telling what could be deployed in the classified realm.

While ambitious bird-inspired drone designs like Aquiline have long been pursued by militaries and intelligence agencies worldwide, we've yet to see evidence that any of them have been deployed operationally in a major capacity. However, given the capabilities of modern UAV technologies, the basic concept behind Aquiline is certainly within reach, especially for tactical applications. But there are other ways of conducting penetrating intelligence, surveillance, and reconnaissance (ISR) duties on a higher end level using larger, more traditional and capable UAV designs. Still, in a new era of menacing loitering munitions and the constant threat of low-end drone surveillance on the battlefield, masquerading as a bird may have more importance than ever.  

Nevertheless, the influence that the Aquiline program has had on small, low-observable surveillance drones is clear to see. Given that all four branches of the Armed Forces were interested in at least some of the subsystems involved with Aquiline, it's possible that some of the drone's components or concepts made their way into UAV designs that could still be classified to this day. In addition, distributed surveillance and swarming capabilities could also make such a concept more relevant than it had been in decades past and more technologically achievable. 

In an age when visual stealth is becoming somewhat more important than it has been for some time, surveillance systems like penetrating UAVs don't have to disappear completely to reduce their visual signatures, but instead can simply mimic something common and innocuous like a bird in flight or even something far stranger to mask their true nature. This is especially relevant for countries that cannot acquire or develop advanced stealth technologies. 

In the end, it seems that Aquiline failed simply because it was too ahead of its technological time. The program also serves as another reminder that Area 51 is built not just for keeping hardware secret, but also for radical designs like the bird-shaped drones to have a safe place to fail in testing outside of the scrutiny of extreme oversight found in the unclassified realm. 

If the rumors are to be believed, there's a chance an example or two of Aquiline still exists among the other strange birds caged up in the darkness at Area 51.

Author's note: Tyler Rogoway contributed to this report.

Contact the author: Brett@TheDrive.com