When a pilot flies a general aviation aircraft to the airfield where an avionics shop is located for service, he or she may have passed within a few miles of a drone flown by a hobbyist near the airport and not even know it.
Recent research studies by Embry-Riddle Aeronautical University, including one funded by the Federal Aviation Administration, show that it is clearly possible. The studies find that some operators of small, off-the-shelf drones are not steering clear of airports. The FAA has registered more than a million small drones for recreational use so far while there were 277,000 commercial drones in the United States in 2018. Commercial drones may be used in real estate or filmmaking or for inspecting bridges and transmission lines, and these are often professionally flown.
Model aircraft enthusiasts have flown their small craft safely in designated areas for decades and are part of the aviation community. The hazard is being created more by the person who knows nothing about aviation and can go to a big box store, buy a drone, and then kick the tires and light the fires. Clueless pilots may launch their drones near their houses or apartment buildings or over a parking lot regardless of whether the location is relative to airports or airspace. What could go wrong? Plenty, but so far there have only been two collisions recorded by the FAA.
On Sept. 21, 2017, a person who owned several drones but had at best a cursory understanding of the rules and regulations pertaining to them was flying his 3-pound quadcopter two minutes before twilight off the shoreline of Staten Island, New York. The drone operator knew that helicopters frequented the area. The pilots of a U.S. Army UH-60M Black Hawk helicopter operating at 300 feet under visual flight rules in Class G airspace saw the Phantom 4 quadcopter and tried to avoid it, but a collision occurred. The Black Hawk crew then made an immediate landing. A large dent was found in the leading edge of one of the Black Hawk’s main rotors.
“Fortunately, the UH-60 is a battle-hardened aircraft design,” said Chris Martino, vice president of operations for the Helicopter Association International. “If it had been another type of aircraft, we’d be having a different discussion,” he added. Civil helicopters are not designed to sustain battle damage. The Army also found debris in the Black Hawk’s engine oil cooler fan. The serial number found on a drone engine was used to track down the drone operator.
The remote pilot, Vyacheslav Tantashov, 58, was unaware he was flying his drone near temporary flight restriction zones established due to a United Nations General Assembly meeting and travel by the United States president. The TFRs were announced in a notice to airmen, but the drone operator did not receive this data on his Samsung control tablet.
He was operating his drone over the water near the Hoffman Island in lower New York Bay 2.5 miles away from where he was standing, so he could not see the drone. He didn’t realize the drone had been destroyed in a collision, and when he pressed the “return to home” button on his Samsung control tablet, he expected the drone to arrive back at his location.
The National Transportation Safety Board found the probable cause of this accident was the failure of the small drone pilot to see and avoid the helicopter due to his intentional flight beyond visual line of sight. A contributing factor was the remote pilot’s “incomplete knowledge of regulations and safe operating practices.” You can review the NTSB report online at go.usa.gov/xnnkh. This is the first time the NTSB has investigated a mid-air collision between a drone and a manned aircraft, but it will probably not be the last.
Martino said HAI sees another side of the rise of the rotary and fixed-wing drones in that they can do many of the missions a manned civil helicopter does such as power line inspection. Legacy helicopter operators are probably going to operate mixed fleets of drones and helicopters in the future, according to Martino, and HAI already has unmanned aircraft companies as members. The good news is that helicopter operators know all about aviation safety and risk reduction.
The FAA also reports there was a collision between a drone and a hot air balloon in April 2018. This occurred over the Teton Country Fairgrounds in the Teton Valley of Idaho. An inexperienced drone operator was flying a drone and overrode a warning on the controls he was using that he was too close to a local airport. He flew his drone within 5 miles of Driggs-Reed Memorial Airport without contacting air traffic control as he should have.
Nearby, Margaret Breffeilh, owner of Elevated Ballooning, had just taken off in her Lindstrand hot air balloon with two friends aboard. When her balloon got between the drone operator and his small quadcopter, he couldn’t see it to maneuver and it flew into the side of the envelope, hitting it six times.
Breffeilh was concerned for the safety of her passengers fearing the drone might fall or fly down and hit the basket. She worried that the drone could either punch a hole in the polyester envelope or fly down toward the basket then up into the envelope and melt. Melting pieces of drone could then fall and hit her passengers or people on the ground. Her first thought was “where do I go to get away,” and thought it unwise to climb above the drone so she decided to descend.
When the drone lost its rotors and fell to the ground, she landed and collected what was left of it so she could send it to the NTSB for investigation. No NTSB report can be found online, however. The drone’s secure digital memory card captured a video of the encounter from the drone’s camera. No damage was done to the balloon. Breffeilh has since instituted a waiver to prevent drone activity during the Teton Valley Balloon Rally, which she runs once a year during the July 4 weekend. And she sees a huge need for drone operators to be filled in on the rules of the road and how to avoid dangerous conflicts with balloons and other manned aircraft.
Breffeilh stresses that she is not anti-drone. She knows drone operators who are meticulous in learning the rules and flying by them. She also met the man whose drone hit her balloon and found him to be a gentleman who was very chagrined over what had happened.
So what are the chances of mid-air collisions between drones and aircraft of any type occurring again near airports? Embry-Riddle Aeronautical University has done some studies that are a cause for concern. The university has used a DJI AeroScope off-the-shelf drone detection system that weighs less than 20 pounds. It monitors and analyzes radiofrequency signals from small DJI drones. About 70% of the small drones in use in the United States are made by DJI, a Chinese company.
The AeroScope was deployed in an educational building adjacent to Daytona Beach International Airport where ERAU conducts flight operations with a fleet of training aircraft. During just 12 days in May 2018, the system spotted 192 small drone flights by 73 different drones. Almost all were flying within 5 miles of an airport, heliport or seaplane base. Two flights that could not be geolocated were dropped from the data set, so ERAU analyzed 190 flights.
The study focused on the location of the drones relative to three public airports, including Daytona International, two private airfields, four heliports, and one seaplane base. In all, 96.8 percent of the 190 flights were within 5 miles of an aerodrome and as close as a half-nautical mile to public airports and .35 miles to a heliport. Of the flights, 70 involved the DJI MavicPro, a 1.6-pound quadcopter equipped with a camera that can fly up to 40 miles per hour. It has an 8-mile range from its remote pilot on the ground and can reach 16,000 feet. About seven other models of drones were detected. In most cases, these drones stayed below 400 feet of altitude as they are supposed to; however, just a few recorded altitudes as high as 500 or 950 or 1,250 or 1,300 feet.
The data suggests recreational pilots getting home from work Monday through Friday would then take out the drone for a spin. On average, the operators flew during the late afternoon from 4 p.m. to 5 p.m. with peak operations logged between 6 p.m. and 8 p.m. Operations peaked midweek with Saturday operations not as high and Sunday even lower. Nearly half the flights occurred over residential areas near houses and apartments, while another 20% were over commercial/industrial or public spaces (often being flown from parking lots). The researchers expected more operations to be over unimproved land and parks as relatively open areas would allow them to keep drones safely away from obstructions and buildings, but that was only the case for 12% of the flights.
The DJI drone controls warn operators when they are operating in a variety of warning zones such as too near aerodromes or critical infrastructure. But the operators can override the warnings, and all of these flights did operate at some point within warning zones.
The leader of this 2018 study, Ryan J. Wallace, ERAU assistant professor of aerospace, said the university has done similar work in Miami, and “the numbers are staggering.” During a 30-day period, 1,000 drones were spotted near airports in the Miami area. “This is concerning,” he said.
ERAU also studied drones at Tampa, Florida, using AeroScope during a 19-day period and found 258 flights involving 77 different drones for analysis. The authors, led by Wallace, found 93 potential violations of FAA regulations, including intrusion into controlled airspace, exceeding maximum flight altitude and flights after civil twilight. The activity posed potential conflicts in one case with a runway visual approach and created a collision hazard at three heliports.
Many small drone control systems have a feature called geofencing, which uses autopilot software and GPS to put a virtual fence around restricted areas such as aerodromes. This study showed that geofencing systems didn’t work when simply notifying the operator of a hazard without imposing any flight restrictions an operator would have to override.
So what are the chances that the pilots flying into airports and heliports at Daytona and Tampa and Miami saw any of these small drones operating nearby? Not good, as it turns out.
According to Wallace, it is extremely difficult for pilots to spot a small drone. The FAA has funded a project to use drone detection technology to validate sighting reports. There are other small things flying around including birds, so it is difficult to validate sighting reports from pilots. The FAA is now receiving more than 100 such reports per month. Recounting these incidents, it stresses that operating drones near aircraft, helicopters, and airports is dangerous and illegal. To see these reports, visit tinyurl.com/y4a2k5q2.
One example of such a report is one from Mobile, Alabama, on June 30, 2019. The pilots of a CRJ flying at 9,000 feet 11 nautical miles northeast of the Mobile Downtown Airport reported a black and green drone flying 200 feet above the aircraft. The pilots did not take any evasive action.
And the list goes on; this is just the first one recorded by the FAA for the third quarter of fiscal year 2019 from April through June.
The FAA notes that the accuracy and completeness of this data cannot always be validated as the general public is able to submit reports. In addition, small drones are often difficult to definitively identify, and they are often not tracked by radar.
In fact, the FAA recently issued a proposed rulemaking for remote identification of unmanned aircraft systems (also known as drones) and is seeking comment through March 2. This is a top priority for the agency. This will make it possible for the FAA and other agencies to identify small drones in flight and determine who is operating them.
“With remote identification, law enforcement and national security partners will be in a better position to quickly locate the operator and determine if a drone is being operated in a clueless, careless or criminal manner,” the FAA wrote in response to questions. One thing the FAA rules out in the proposal is to have drones use ADS-B, as the reports on ADS-B Out would be a fire hose of data that could overwhelm the system.
Small drones must be registered with the FAA if they weigh more than 250 grams, but DJI has just introduced a 249-gram model with a high-definition camera that fits in the palm of your hand. And the pace of change in the drone space is unrelenting.
“Encounters are becoming more common, and the separation between manned and unmanned aircraft is getting slimmer,” Wallace said. “People (small drone operators) are not following the rules, and they may not even be aware of the rules.” He added that airport managers are realizing that drones aren’t going away, and they are going to have to find a better way to deal with them.
Urban areas are no stranger to these hazards. A news helicopter hit what the pilot thought might have been a drone during a flight over Los Angeles on Dec. 4, 2019. The FAA is looking into this report that resulted in a hole in the helicopter’s tail.
The FAA is working diligently to try to rein in clueless, careless, and criminal activity, but the challenge is a huge one. The agency has a major education initiative with a social media presence and a website to fill small drone operators in on the rules of the road. This educational information can be found at knowbeforeyoufly.org.
The FAA is also funding applied research using high-fidelity computer models to examine the impact of UAS strikes on windshields, fuselages, and engines. The agency completed a study of the impact of a drone on a single-aisle airline jet and a business jet in 2017. The airline/business jet study concluded that the worst damage to these types of aircraft traveling at 250 knots and hitting a 4-pound drone would be to the horizontal and vertical stabilizers. This includes damage to the primary structure of the stabilizer with the front spar being damaged or even perforated. This study is posted on the FAA Alliance for System Safety of UAS through the Research Excellence website at assureuas.org. The FAA-funded study of the damage that could be done to a general aviation aircraft is due to be completed and posted this year.
According to Wallace, when it comes to educating drone operators on the rules and regulations, another challenge is that they are evolving as the situation changes. “Rules change, and trying to keep everyone on the same page is a bit of a challenge,” he said. “Several months ago, it was acceptable when planning to operate within 5 miles of an airport for a drone operator to call a control tower. Now that is no longer acceptable. These nuanced changes are a challenge.”
There are plenty of commercial drone operators trying to do the right thing such as real estate, insurance, utility and agricultural companies among others who are well informed. The problem comes from what Martino of HAI calls the “unreachables” who don’t know what they are supposed to be doing as drone operators.
“The (drone) group that doesn’t know if there are rules and doesn’t follow them is the Wild West portion of the community,” Wallace said. Getting to them is a big challenge for the aviation industry and the FAA that is yet to be solved.
By Avionics News magazine, a monthly publication of the Aircraft Electronics Association.
