Making it safe for drones to fly over people

February 20, 2019  - By

Changes to the Federal Aviation Administration (FAA) operational drone restriction were recently proposed in order to allow some flights over people. This proposed rulemaking appears to be a major step forward. Mail-order delivery flights, newsgathering, real-estate sales movies and building inspection, to name a few markets, all begin to make more sense, maybe even become viable.

Some night operations could also be possible.

Risk assessment methodology appears to be logical; a number of UAV categories are proposed, and there is a way to assess if operators are in compliance.

The Alliance for System Safety of UAS through Research Excellence (ASSURE) undertook a ground impact study to determine the possible risk of injury to people from drones falling out of the sky. Assessments were made using existing automotive standards and a military standard for debris impact, plus there was testing using automotive crash dummies.

It was a lot of work, but the bottom line appears to be that possible injuries to people are more likely to be minor than major. Bear in mind that UAS fly at relatively low altitude, are made with materials that make them somewhat elastic in nature, and that it may be possible for people in a crowd to see a flailing, falling UAV and move to avoid an impact.

Nevertheless, I do have a picture in my mind of a wayward drone crashing to the pavement after hitting a skyscraper in San Francisco, and I’m really glad I wasn’t down on the sidewalk below.

Building inspection using drones. (Photo:

Urban building inspection using drones. (Photo:AeroSIM RC)

Then I read an article by James Poss, a retired military major, who seems to suggest that although the conclusion of the ASSURE assessment was that 2,000 grams was an OK weight for an sUAV to avoid serious injury to anyone, the FAA appears to have proposed limitations for sUAS which are only 1/10th of this weight. This is more in line with the weights in the mil-spec standard that are based on small, fast, solid-metal blast fragments.

It might help us to also consider how often or badly people are injured by golf balls, baseballs, tennis balls or squash/racket balls — for instance, I’ve survived several golf ball impacts and even an impact with a squash racket during play without major damage. These are things we all take in our stride as part of (almost) normal human activity. I wonder how often recreational enthusiasts have actually been injured during model-aircraft flying gatherings?

FAA restricts flights over government facilities

In cooperation with the Department of Justice (DOJ) and the Department of Defense (DOD), the FAA has just established temporary restrictions on drone flights within 400 feet of the lateral boundaries of a number of sensitive federal facilities. This is in addition to previous restrictions over prisons, NGA facilities, DoD ships and other facilities.

The most recent proposed Notice to Airmen (NOTAM) lists federal correctional facilities in almost half of the states in the U.S., several medical centers, U.S. Army facilities, ammunition plants and Pearl Harbor in Hawaii. It’s hard to understand why there aren’t already permanent UAV prohibitions over all such sensitive facilities across the whole U.S. I tried to check status, but the FAA UAS Data Display System didn’t list this proposed NOTAM which apparently goes into force on Feb. 26.

Think it’s probably a question of preventing bad guys from planning or doing harm rather than being shy to be caught on video — but, for sure, these places should be as secure as possible.

The FAA UAS data map shows all drone-restricted areas, once updated. (Screenshot: FAA)

The FAA UAS data map shows all drone-restricted areas, once updated. (Screenshot: FAA)

Security at the Super Bowl

Well the game wasn’t the most exciting, with New England doing all that was needed to win in the fourth quarter, but the security for the event in Atlanta was humongous.

The area around the stadium was cleared of threats even before the game, attendees were screened for prohibited items and the airspace within 30 miles was restricted for general aviation and drone access. There were even Defense Department F-16 airspace patrols, and the Customs and Border Patrol had a Black Hawk helicopter available to intercept any aircraft penetrating the exclusion zone.

Nevertheless, the FAA still approved the operation of two tethered drones. One was flown close to the stadium by security personnel to provide live images of crowd movements in and around the stadium. The second system was operated at 45 meters above the rooftop of the CNN building facing the Mercedes Benz Stadium. CNN used it to provide aerial imagery of the scene before and after the game.

Elistair base station and DJI M200 at Super Bowl. (Photo: Elistair)

Elistair base station and DJI M200 at Super Bowl. (Photo: Elistair)

The tethered drone setup included two DJI M200 drones and two Elistair Ligh-T base stations, with monitoring, control and power provided to each drone by lightweight tethers. The security system was continuously operationed for 10 hours of captive flight during the Super Bowl, and for 14 hours total over two days — all while tethered to the Ligh-T control station. Security officials expressed their interest in using this solution more often because of the ability to follow a subject continuously without having to switch from one fixed camera to another, which risks losing the subject.

To sum up, new pending FAA regulations that support operations over people may have a few flaws. Other new FAA rules are aimed at protecting DOD and DOJ facilities from drone overflights, and tethered drones were used at the Super Bowl for crowd security and by CNN for color coverage.

New applications, new opportunities and preventive controls to maintain security at sensitive facilities — all moving in the right direction.

Tony Murfin
GNSS Aerospace

About the Author: Tony Murfin

Tony Murfin is managing consultant for GNSS Aerospace LLC, Florida. Murfin provides business development consulting services to companies involved in GNSS products and markets, and writes for GPS World as the OEM Professional contributing editor. Previously, Murfin worked for NovAtel Inc. in Calgary, Canada, as vice president of Business Development; for CMC Electronics in Montreal, Canada, as business development manager, product manager, software manger and software engineer; for CAE in Montreal as simulation software engineer; and for BAe in Warton, UK, as senior avionics engineer. Murfin has a B.Sc. from the University of Manchester Institute of Science and Technology in the UK, and is a UK Chartered Engineer (CEng MIET).