Drones Inside: The Hidden Hazards

If you've spent any time flying or hiring drones, you know that the pilot has to read wind, plan a flight path, and give themselves plenty of room to breathe. Take that same pilot and drone inside, and it’s a much different story. GPS may be sketchy, there’s no open sky to bail you out, and the margin for error shrinks from feet to inches. Indoor flight is a discipline unto itself, and the special gear can come with special hazards. Here's what you need to know before your indoor drone project takes off.

A Different Breed?

While many of the indoor drone shots we see these days are captured using “FPV” technology, you can also fly inside with larger “outdoor” drones. (See my FPV article here). The type of drone used should always be dictated by the final product and what you’re trying to achieve. But, whether FPV or traditional, these drones used for indoor work share a few necessary traits that rule out larger, bulky drones. Let’s take a look at what those are.

1.     Smaller Size. They tend to be smaller; easier to thread through windows and doorways, around furniture, and between support beams. Of course, “easier” is a relative term. The pilot must have experience flying in confined spaces without the help of obstacle avoidance systems and stabilization systems. Indoor spaces tend to have plenty of objects to run into, and you probably want to fly close without having the drone take a wide swath around them or simply stop and hover. The small size also means that the air displacement is considerably less, meaning less disruption to the surrounding scene. In other words, it won’t blow the papers off the desk or the actors’ hair into their faces.

2.     Pilot Skill Required. These drones are usually built to fly without reliable GPS which standard drones depend on for stabilization during flight and while hovering. Indoors, satellite signal reception can be patchy and often nonexistent, so the aircraft has to rely on other tools such as optical sensors and visual positioning systems to hold position and avoid undesirable drift. Low indoor light can limit these sensors’ capabilities leading to unstable flight for an untrained indoor pilot.

3.     Propellers. Drones suitable for indoor flight tend to have ducted or guarded propellers. This lets the pilot fly the drone closer to things in the room without crashing into them. Ducted propulsion and blade guards also make the drone safer when flying over and near people in and around the flight area. A rig optimized for wide-open outdoor cinematic shots might be unsafe or unusable in a hallway due to its larger wingspan and a lack of tight maneuverability. In tight indoor spaces, a drone’s prop wash can recirculate off nearby walls and surfaces, creating turbulent airflow that feeds back into the rotors and destabilizes the aircraft.

This doesn’t mean that only small drones should be flown indoors. As with any drone job, you’ve still got to match the aircraft type and size to the environment and the job at hand when thinking about indoor flight.

Consider the Space

We can generally split indoor flight into two different categories: Small rooms and large spaces. It's worth looking at them separately rather than lumping "indoor" into one big category.

1.     Smaller, cluttered rooms. Think hallways, offices, or tight retail floors. These areas are obstacle-dense. Furniture, doorframes, light fixtures, and possibly people are all within a few feet of your flight path at any given moment. The upside is that these spaces are visually rich: there's foreground everywhere, which makes for dynamic, layered shots almost by default. The downside is that your margin for error is razor-thin, and line of sight is often reduced or gone entirely. You’ll probably lose sight of the aircraft when it rounds a corner or drops behind a couch. Precision flying and constant awareness of your surroundings matter more here than raw piloting speed.

2.     Larger, more open spaces. Gyms, warehouses, atriums, event halls all flip the script. Obstacles are few and far between, and you can usually keep a clear line of sight on the aircraft the whole flight. In many cases, these areas can almost be treated as you do the “outdoor” spaces, but more than likely without the GPS lock to keep the aircraft stable. Cinematically, open rooms can feel flat and empty on camera. Without walls, pillars, or objects close to the lens, shots lose the depth and motion parallax that make indoor footage feel dynamic. In these environments, the pilot's job shifts from avoiding everything to finding something: actively seeking out foreground elements to give the shot some life.

Knowing which space you're flying should change your flight plan, camera settings, and honestly, your entire mindset before you even power on.

Liability and Safety

In the U.S., indoor flying is not FAA regulated. That doesn’t mean it’s risk-free or uncontrolled. In fact, your liability exposure can be greater indoors, not less. Outdoors, you can have distance as a buffer and bailout option. Indoors, you might be flying close to people, expensive property, and hard surfaces that don't forgive mistakes.

Flying directly over people can always be dangerous, but especially indoors with props at close range and no easy escape route if something goes wrong. If your flight path takes you over crowds of any size, have safety and contingency plans in place for when things go wrong. And know your insurance limitations. Your liability policies may not extend to indoor drone use, and a "not covered" surprise after an incident is the worst possible time to find that out.

Finally, keep in mind that even where the FAA has no say, the venue does. Building owners and management, event organizers, and insurers often have their own restrictions on indoor drone use, sometimes stricter than any federal regulation. Common sense should prevail here because liability certainly applies.

Healthy Habits

A few unglamorous habits go a long way to keeping indoor flights safe and productive:

1.     Know your fight area. A slow, deliberate walkthrough can reveal glass panels, low-hanging wires & fixtures, and obstacles you might not see until flying. Also focus on any loose objects that could be blown around by the prop wash. Follow the walkthrough with a few rehearsals before flying the routes for real, especially if there's an audience or a client watching.

2.     Talk to Each Other. For synchronized shoots with moving pieces like vehicles and actors, communication and coordination are key. Rehearse the shots with specific blocking for both the drone and the subject being tracked before bringing in extras or non-essential crew.

3.     Consider prop guards. Many pilots look at these as training wheels for “green” pilots, and though they add weight and can reduce maneuverability, they’re worth the consideration, especially in tight or crowded spaces.

4.     Use a spotter. This is particularly important when you're flying near or over any kind of crowd. A second set of eyes watching the people and the environment while you focus on the aircraft catches problems you won’t be able to see alone. For complicated shots, you’ll need more than one.

5.     Make Some Room. Have a designated launch/recover zone that is cordoned off from non-crew members. Having a locked-off flight path is even better to keep bystanders from under a flying aircraft when possible.

Indoor flying rewards preparation over bravado. Match your aircraft to the space, understand whether you're fighting clutter or flying emptiness, and never let the absence of FAA rules lull you into a false sense of complacency. Do the walkthrough, bring a spotter, make a judgment call on prop guards, and rehearse before you perform. Indoor flight has its place in drone video capture and it's a different game than flying outside.

About the Author

Mike Sobola is a Private Pilot and Commercial Drone Pilot with Mid-Atlantic Drones and author of “How to Make Money with a Drone” available on Amazon.  He has logged more than 3000 hours as Pilot-in-Command of a drone-many of those coming from flying indoor missions. Mid-Atlantic Drones specializes in Drone flights throughout the Washington, D.C. Airspace and DC Flight-Restricted Zone.