It’s like a scene out of the CSI: Miami: After a bank robbery downtown, two thieves in a getaway car race north along Florida’s Intracoastal Waterway. As the minutes tick by and no squad cars appear on their tail, the perpetrators congratulate each other — they’ve escaped!
What the bandits don’t know is that they are being watched by a Miami-Dade Police Department unmanned aerial vehicle flying above, equipped with a video camera and radio transmitter. Success quickly turns into failure as a line of patrol cars block their path. The MDPD apprehends the bad guys without resorting to a high speed chase that puts the public and officers at risk.
This is the future that the MDPD and the Houston Police Department would like to come to pass. And this is why both departments have applied to the Federal Aviation Administration for permission to fly police UAVs. The HPD has even staged a demo flight with FAA approval, and the MDPD hopes to do the same in the Florida Everglades.
When it comes to aerial surveillance, UAVs have some distinct advantages compared to manned aircraft. Because they don’t have to lift human pilots, UAVs can be far smaller than conventional helicopters and fixed-wing aircraft. This weight reduction translates into far lower operational costs — particularly for fuel — and longer endurance in the air.
“Using our manned MD500 helicopter, we can fly for about two hours before having to land and refuel,” said Capt. Tom Runyan of the HPD’s Traffic Division, which manages the department’s helicopter fleet. “In contrast, a UAV can fly for up to 20 hours before landing and refueling.”
Besides flying longer and lighter than manned aircraft, UAVs are far less obvious to ground-based observers, and hence less likely to be noticed during surveillance operations. If a UAV crashes, there’s no flight crew on board to be injured or killed. Plus, many of the small UAVs available to U.S. law enforcement are far less expensive than manned aircraft, an important consideration for budget-conscious government agencies.
All these reasons explain why Houston pushed ahead with its own UAV demo flight, with FAA approval, last November. The demo flight, a four-mile circle 45 miles west of Houston, was conducted with a 44-pound Insitu Insight UAV. Currently used in Iraq by the U.S. Navy and Marines, the swept-wing Insight is launched by catapult and powered by a rear-mounted pusher propeller. It can carry a standard video camera plus an infrared camera mounted in an inertially stabilized turret.
Meanwhile, the MDPD is hoping to use a 17-pound Honeywell Micro Air Vehicle for its demo flight later this year. Unlike the Insight, the MAV is a hovering aircraft.
“The flight would be staged to test the use of an unmanned MAV in tactical situations,” said MDPD spokesperson Det. Juan Villalba. “We’re waiting for the FAA to approve our proposal and we intend to have a Media Day to showcase what we intend to use it for.”
Clearly, UAVs could be a major boon to U.S. police departments. The real-time video could aid law enforcement in conducting air surveillance missions that would last longer and cost less. So why is the FAA so opposed to the idea?
“The answer is that any unmanned aircraft, be it large or small, is still an aircraft and thus has to comply with the same rules that apply to manned aircraft,” explained FAA spokesperson Les Dorr.
Under FAA rules, all aircraft have to be able to see and avoid other air traffic. Large manned aircraft do this by virtue of the pilots’ eyes and onboard collision avoidance equipment, which is expensive and heavy. Small manned aircraft do this using pilot eyes alone.
In sparsely populated areas, there is so little air traffic that the risk of mid-air collisions are virtually nonexistent. This is why the FAA allows the U.S. Forest Service to use UAVs to detect forest fires. But in congested urban areas, especially near airports, the amount of air traffic combined with the UAV’s inability to see 360 degrees around themselves at all times makes them too risky to fly, according to the FAA.
“Both police departments have talked about using UAVs in SWAT situations,” said Dorr. “It’s not uncommon for there to be media helicopters in the area of situations requiring a SWAT team. There’s no technology available today that could prevent police UAVs from colliding with these helicopters. What would happen if the hostage situation happened to be in the approach path to Miami International Airport. Would we risk civilian airliners colliding into police UAVs which were operating independent of air traffic control?
“This is why we have given police departments the right to conduct demo flights, but not to deploy UAVs,” Dorr continued. “These flights will compile useful data about UAVs for police missions and help the departments gain expertise in flying these vehicles. But we are not at a point yet where we can authorize them for use over urban areas.”
The FAA’s fears about UAVs and urban areas are taken seriously by those in the UAV industry. “Such a mid-air collision occurring just once would be devastating to public confidence in domestic UAVs,” noted Dan Fouts, Honeywell’s MAV business development manager.
“There’s a legitimate concern about how we make sure collisions don’t occur and that UAVs don’t fail and fall out of the sky on schools,” agreed Dr. David Vos, senior director of Rockwell Collins Control Technology. “But there is a way to solve this problem at least in the long term.”
The “solution” is Automatic Dependent Surveillance-Broadcast technology. In an ADSB system, aircraft transmit their GPS-determined locations back to ground control on a regular basis. In turn, the ground-based ADSB system compiles and organizes this data in real-time presenting ground control with an ongoing accurate picture of where aircraft are at all times.
The difference between ADSB and conventional air traffic control systems is that human intervention is not required. The ADSB-equipped aircraft interact with the ground-based ADSB system to automatically coordinate their locations with respect to each other and their subsequent flight paths.
“ADSB is currently being used successfully by UPS to coordinate traffic at its St. Louis hub, with tremendous fuel savings due to the system’s superiority to human-directed ATC systems,” said Vos. “Europe is actively deploying ADSB at their airports. Meanwhile, we expect to see U.S. airports fitted with ground-based ADSB technology by 2014.”
In the shorter term, it is possible to integrate UAVs into urban airspace, according to Bob Papp, president of Accurate Automation, which builds unmanned aircraft and patrol boats. “All you would have to do is designate a slice of low altitude airspace for police UAVs, with designated entry and exit points, and with no-fly zones set out around airport runways,” he explained.
“If there was a strong political advocate for it in Congress, the FAA could make it happen. After all, this approach is already used to designate urban airspace for manned helicopters.” Unfortunately, Papp noted, there is no such force promoting UAVs for urban airspace in Washington, DC, today.
The obvious usefulness of UAVs for cost-effective surveillance makes them ideal for police work. As a result, deployment in sparsely-populated areas is likely to be supported by the FAA, under certain limitations.
As for the urban surveillance aircraft that the MDPD and HPD want to deploy? Until solutions improve for collision avoidance, don’t expect the FAA to approve this application anytime soon — police video surveillance takes a back seat to concerns for public safety.
UAV surveillance aircraft cost less to buy and fly than manned aircraft. Plus, they can remain in the air for dozens of hours, compared to a manned helicopter’s two-three hour capability.
UAVs In America
UAVs do fly in the continental United States, but not in urban areas. “In the U.S., the military usually tests and trains with its UAVs in restricted airspace,” explained Matt Twiggs, vice president of engineering and technology for UAV Communications. “Outside of restricted airspace, UAVs are being used on a limited basis by other government organizations for purposes such as border patrol and wildfire monitoring. Some state and local public safety organizations have also begun testing smaller UAVs to provide aerial surveillance for emergency and post-disaster situations.”
According to Twiggs, the FAA’s requirements for collision avoidance in U.S. airspace are quite strict. “Some UAVs are implementing sense-and-avoid technologies to help avoid collisions, but the FAA specifies that one or more visual observers on the ground who can see the UAV and communicate with the UAV pilot are the primary means of avoiding collisions with aircraft or other obstructions,” he said. “An observer must maintain visual contact with the UAV at all times, following it as necessary to stay within a mile of the UAV.”
Law enforcement agencies that want to fly UAVs domestically will need to get a Certificate of Authorization from the FAA first, and advanced coordination and notification of any UAV flights are essential, according to Twiggs. Having trained pilot/observer personnel and sufficient communications between them are needed to ensure safe flight operations. In addition, selecting a UAV that can operate safely in the proposed flight area is vital during the COA stage. “If the UAV needs a lot of room to maneuver,” he added, “it may not be well suited for operation in a dense urban area.”