New Details Emerge On The “Highly Modified Drone” That Outran Police Helicopters Over Tucson

Last month, The War Zone reported on a bizarre drone encounter that occurred in the skies above Tucson, Arizona. According to reports, on the evening of February 9, 2021 around 10:30 PM local time, a helicopter belonging to U.S. Customs and Border Protection, or CBP, encountered what has been described by KOLD’s Dan Marries, who interviewed an FBI agent assigned to the case, as a “highly modified drone” in controlled airspace. Another helicopter operated by the Tucson Police Department’s Air Support Unit was called in to help track and potentially identify the drone alongside the one from CBP, but the drone was able to evade them both and remain unidentified. Shortly after the incident was disclosed, the FBI released a statement asking for help from the public regarding any information related to the encounter. 

In the days since we first reported on the Tucson drone encounter, individuals have reached out with new information that adds further context to this still-developing story. A source with direct knowledge of the incident’s details told The War Zone they believed the drone was highly unlikely to be battery-powered based on the altitude, distance, and speed at which it flew. The source also stated it seems as though the drone was equipped with an infrared camera based how it was able to dynamically maneuver, including in relation to the helicopters chasing it, despite the low level of ambient light at the time of the incident. They also added that it is “only logical that it was looking towards DM’s [Davis Monthan AFB] flight line” based on its location. 

We can now also confirm that the CBP helicopter involved was indeed an Airbus AS350, commonly used by CBP’s Air and Marine Operations (AMO) branch for aerial patrol and surveillance missions.

An Airbus AS350 operated by U.S. Customs and Border Protection, CBP

The same source also tells us that the unusual drone was first spotted near a complex of fuel tanks just west of Runway 12 at the U.S. Air Force’s Davis-Monthan Air Force Base. This is well within the Class C airspace that surrounds Davis-Monthan, as well as the Tucson International Airport, and is very close to the fence line surrounding the base. Class C airspace is defined by the FAA as “airspace from the surface to 4,000 feet above the airport elevation (charted in MSL) surrounding those airports that have an operational control tower, are serviced by a radar approach control, and have a certain number of IFR [instrument flight rules] operations or passenger enplanements.” The FAA states that “for flight near airports in controlled airspace, drone operators must receive an airspace authorization prior to operation” and that these authorizations “come with altitude limitations and may include other operational provisions.”

In a statement, the FBI wrote that the drone violated 18 USC 39B, “Unsafe operation of unmanned aircraft,” which includes “knowing or reckless interference or disruption of a manned aircraft, and the operation of unmanned aircraft in close proximity to airports.” The FBI called the drone’s actions “illegal and extremely dangerous,” yet added that it’s “possible the drone operator(s) are not aware they are violating the law.”

The description of the drone’s initial observed location would appear to match the location of a terminal owned by Kinder Morgan, an energy company that operates fuel pipelines and other energy infrastructure. Some 40% of the natural gas consumed in America flows through Kinder Morgan’s pipelines. On their website, Kinder Morgan states that their terminals are used to store and handle various fuels, petroleum products, and chemicals – clearly not the place anyone would want an unauthorized or unidentified drone to be loitering. While drones are used in pipeline and tank inspections, and by Kinder Morgan specifically for those tasks, the unique nature of what has been reported in this incident does not appear to suggest this drone’s operators were executing that type of professional work.

Runway 12 at Davis-Monthan AFB, right, and the Kinder Morgan terminal, left. , Google Maps

The drone’s initial observed location was also largely confirmed by a post from another individual on, which describes itself as “an online community of airline, corporate and professional pilots including air traffic controllers, dispatchers and mechanics.” In a forum post dated February 10, 2021, a moderator of that forum with the username MikeD wrote the following account of the incident:

Last night, there was one just east of KTUS at about 1200’ AGL cruising eastbound. It passed about 30’ away co-altitude with a police helicopter flying the opposite direction. Helo made a 180 turn to give chase. The quad copter was described as approximately 5 feet long by about 3 feet wide, with a single green flashing LED light. It continued east into KDMAs airspace and began orbiting the base over the parallel taxiway near the fighter jet ramp. TUS and DMA towers were unaware of it, as was U90 [an FAA approach tower] controllers. The operator apparently realized by this time that the drone was being followed, because it then proceeded northwest at high speed and climbing, with the helo and another LE helo in trail. The copter began to climb and flew out of the TUS area about 50 miles to the northwest of town into the middle of nowhere desert out by the mine west of KAVQ. It was last seen climbing through 14,000’ and into the undercast, where it disappeared. The helos remained in VMC [Visual Meteorological Conditions] obviously, and one hung around for about an hour, to see if it would reappear descending, or if there was any vehicles driving through the middle of nowhere as either the operator or someone to potentially recover it. Neither appeared. U90 informed their FAA chain of command about it, but that’s as far as I’ve heard so far.

Interesting in both the range and the altitude, both control-wise in terms of line of sight, as well as battery life as it comes to the endurance of the thing. The concerns with it being around air traffic and a near mid-air, as well as it being over an Air Force base with security sensitive aircraft, are all all concerning. Definitely not something commercial off-the-shelf that one would buy at the local store.

The radar track of the Tucson Police Department helicopter that pursued the drone, a Bell 206B JetRanger II with the U.S. civil registration code N305PD, shows that it took off from Tucson International Airport and flew towards the edge of the airspace above Davis-Monthan. It then followed the drone to the northwest away from the city before circling back. Sources have confirmed this was indeed the police helicopter that was sent to aid the CBP AS350.


These new accounts add a fairly significant detail to the story: that the mystery drone spotted over Tucson was first seen in the airspace adjacent to, or even over, Davis-Monthan Air Force Base and later flew through the base’s confines. As such, this incident would add to the growing number of recent drone incursions which have worryingly occurred in military-controlled airspace or near sensitive installations. In fact, there is a precedent for unknown drones flying at night being interested in critical energy infrastructure in Arizona. In September 2019, the Palo Verde Nuclear Generation Station near Phoenix was the site of what the Nuclear Regulatory Commission (NRC) described as a “drone-a-palooza,” an incident which remains unexplained to this day.
The Class C airspaces surrounding Tucson International Airport (KTUS) and Davis-Monthan AFB (KDMA),

So far, the controller of the drone remains unidentified, as does the drone itself, which seems to have had advanced capabilities based on multiple accounts. Curiously, a portion of a police report which aired on a local news report about the incident notes that the observer in the Tucson Police Department’s helicopter was unable to observe the drone when looking through night vision goggles. 


There is a precedent of drug cartels using drones to transport both drugs and munitions across the southern border, and it has been speculated that this may have been the case in this instance, but Tucson is over 50 miles from the border. In addition, it makes little sense why smugglers would have an interest in an energy storage depot or an Air Force Base. There is also plenty of experimental aircraft activity in the area, with multiple airstrips of varying sizes in close proximity. Raytheon Missiles and Defense also operates a facility just south of Tucson, but this type of unscheduled flight close to a major metropolitan area and even over an Air Force Base and up into flight levels, above where a normal helicopter can fly, is far from typical when it comes to experimental aircraft testing. In fact, it is outright illegal behavior by the FAA’s own rules. 

Whatever the case may be, the drone’s reported proximity to both an international airport and an Air Force base is worrying. The drone’s reported altitude and the fact that it outran two law enforcement helicopters is also concerning, given the increasing threat drones pose to critical infrastructure and defense installations. 

We will continue to investigate this strange incident and will report back when we find out more.

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