C-DRONE GUIDE · 1 SEPTEMBER 2026

Flying a Drone Indoors on a Professional Site: Legal Framework, Uses, Price

A maintenance manager wants the roof truss and crane runway of a 12-metre-high industrial hall surveyed without erecting a platform, a logistics director wants high-bay pallets counted without tying up a forklift driver, a communications team wants the production line filmed for a recruitment video. All three ask their contractor the same question : « do we need a civil aviation authorisation ? » The answer is surprising : for a flight kept strictly inside a closed building, no — and this is neither a tolerance nor a grey area, it is written in plain terms in the official French DSAC guide. EU regulation governs airspace ; the inside of a building is not part of it. But the exemption is far narrower than people assume, and above all it removes nothing else : not aircraft registration, not the prevention plan, not insurance, not GDPR, not the site operator's authorisation. Here is where the boundary lies, what takes over, what an indoor drone can really do, and what it costs.

Published on 1 September 2026, reviewed on 1 September 2026 — regulations in force as of September 2026.

What « indoors » means in aviation law: the definition of an enclosed, covered space

The starting point is a question of scope, not of exemption. Implementing Regulation (EU) 2019/947 organises drone operations in airspace ; the inside of a building is not part of airspace as defined by the European texts that organise it. The word « indoor » in fact appears nowhere in Regulation 2019/947 : the exclusion is not written into it, it follows from it. This reasoning is no lawyer's construction ; it is the one the French administration adopts.

The DSAC Open-category guide — « Guide to leisure and simplified professional uses of unmanned aircraft », edition 2, version 1.0 of 31 December 2025, published by the French civil aviation authority — devotes its paragraph 3.8 to « exceptions and special cases » and deals with enclosed, covered spaces first. The rationale is explicit : European regulation applies within European airspace, « which does not contain enclosed and covered spaces », the guide pointing to the EU regulation organising the use of airspace in the single European sky. And it immediately states the counterpart : « It is then for the owner of the place and for the remote pilot to take all necessary precautions to ensure the safety of the people present. » In other words : the State steps back from the aviation side and hands safety to the site owner and the pilot.

The definition the guide uses is short and operational : an enclosed, covered space is a « building, tent, mesh or netting cage, or any other structure such that the probability of the aircraft leaving it is negligible ». Three points deserve attention. First, the test is functional : what matters is not the nature of the structure but the practical impossibility of getting out — a netting cage rigged inside a sports hall qualifies, a solid-walled hall with one open gable does not. Second, the wording is old and stable : it appeared word for word in article 1 of the French order of 17 December 2015 on the design of civil unmanned aircraft, which excluded from its scope « aircraft used inside enclosed and covered spaces » — an order repealed on 31 December 2020 when the European framework took over, but whose doctrine outlived the change of regime. Third, it is cautious : « negligible » is not « nil », and it falls to the site operator and the remote pilot to justify their judgement.

One clarification avoids a common misreading : this exclusion concerns the operation, not the product. Delegated Regulation (EU) 2019/945, which imposes CE marking and class identification labels (C0 to C6), is market-placement legislation : it applies to the drone you buy, regardless of where it will later fly. The indoor exemption therefore does not legalise the use of a non-compliant aircraft — it merely removes the need to comply with subcategories A1, A2, A3 and their distances from people, and to seek a specific-category operating authorisation. If you are unsure which regime applies as soon as the mission leaves the building, our guide on choosing between the Open and Specific categories sets out the criteria.

Borderline cases: open-sided hall, inner courtyard, dock door, roof

This is where most mistakes are made, and they almost always go the same way : a volume that is not indoors gets labelled « indoors ». The DSAC test — negligible probability of the aircraft leaving — is applied building by building, not by category of building. Four configurations come up constantly on industrial and logistics sites :

• The hall open on one or two sides (aggregate storage, covered quay, farm shed, sorting canopy) : covered, but not enclosed. The flight takes place in airspace.
• The inner courtyard, including one closed on all four sides by buildings : enclosed laterally, but not covered. A drone climbs out of it through the top ; that is an outdoor flight, with all the consequences that follow in a built-up area.
• The roof, the glass canopy, the plant terrace : plainly outdoors, even when reached from inside the building and even when the inspection concerns the same roof structure.
• The loading dock with the door raised : the most insidious case, because it is temporary. A warehouse perfectly sealed at 6 a.m. no longer is at 8 a.m., when the docks open for goods-in. The classification is assessed during the flight, not on the building's floor plan.

The practical consequence is simple, and it is as much the client's responsibility as the contractor's : closing the openings for the duration of the flight slot must be written into the mission preparation, with a named owner on the site side, exactly like locking out a production line. When closure is impossible — a dock that has to stay open, a hopper open to the outside — there are two options : move the flight to a closed slot (night, weekend, planned shutdown), or treat the mission as an outdoor flight and prepare it as such. The third option, « let's call it indoors », is not one : after an incident, the classification will be revisited by the insurer and, where relevant, by the labour inspectorate.

Two grey areas deserve a mention because they recur in tenders. First, technical volumes reached through an opening — tank, silo, boiler, penstock, sewer. The flight itself is indoors within the meaning of the definition, but the deployment phase (take-off outside, passing through the manway, coming back up) is an outdoor flight, however brief ; this is precisely the point raised by manufacturers of confined-space inspection drones, who estimate that a majority of their missions include an open-air portion. Our guide to tank, boiler and confined-space drone inspection covers that sequence. Second, indoor drone shows. The DSAC guide is unambiguous — « aerial displays, including those held in an enclosed, covered space with unmanned aircraft, are subject to a specific regulation ». A drone choreography in an exhibition hall or a conference centre falls under the aerial-display order, indoor exemption or not.

What the exemption does not remove: registration, site authorisation, GDPR

The DSAC guide does not stop at stating the exclusion : it immediately opens a box headed « rules do still apply to these flights ». The first is registration : any unmanned aircraft over 800 g — mass including equipment and battery — must be registered by its owner on the AlphaTango portal, « even » when used only in an enclosed, covered space. This obligation does not come from EU law but from a national public-security provision : the decree of 11 October 2018 on the registration of civil unmanned aircraft, detailed by the order of 19 October 2018. An inventory drone that will never leave its warehouse is therefore covered as soon as it exceeds 800 g ; our guide to AlphaTango operator and aircraft registration walks through the procedure.

The second obligation has nothing to do with aviation, yet it is the one that most often blocks a mission : the site operator's authorisation. Inside a building the State steps back and the owner or operator becomes the de facto authority — the DSAC guide says as much, entrusting them, together with the remote pilot, with the safety of the people present. In practice that means written agreement from the site manager, an approved time slot, a named contact, and often a third party's sign-off : the landlord if the building is leased, the site's insurer, a neighbouring operator in an industrial co-ownership. On a regulated site, the operator will add its own instructions. This is no formality : it is the only document that actually authorises you to fly.

The third belongs to data protection and labour law, and it is massively underestimated indoors, because a drone there films employees at their workstation almost mechanically. As soon as a person is identifiable, GDPR applies to the capture itself, before any publication : legal basis, informing the individuals, retention period, fate of the rushes — our guide to GDPR applied to professional drone work covers impact assessment and anonymisation. On top of that sits a distinctly French and often forgotten layer : article L. 1222-4 of the labour code forbids collecting information personally concerning an employee through a device that has not been brought to their attention beforehand, and article L. 2312-38 requires the works council (CSE) to be informed and consulted before the decision to implement means or techniques allowing employee activity to be monitored. A drone filming a production line clearly falls into that category if it becomes recurrent ; anticipating the CSE step prevents a shoot being halted on the morning itself.

The regime that takes over: workplace safety, prevention plan, co-activity

Once the aviation exemption is established, a legal framework remains, and it is markedly more demanding than the one just left behind : the labour code. A drone flight in a production hall is an outside company intervening on a user company's site : a textbook case of co-activity. The applicable regime is that of articles R. 4511-1 and following : prior joint inspection of the premises, joint analysis of interference risks, definition of preventive measures.

The prevention plan must be drawn up in writing and before work starts in two cases set out in article R. 4512-7 : where the operation represents at least 400 hours of foreseeable work over twelve months or less, continuous or not ; or, whatever its duration, where it involves dangerous work listed in the order of 19 March 1993 — work exposing people to ionising radiation, to explosive, oxidising, highly flammable or toxic substances, to pathogenic biological agents, among others. The consequence is counter-intuitive and worth remembering : a two-hour inspection in a silo or a boiler house may require a written prevention plan where a three-day campaign in a dry-goods warehouse does not. Outside those two cases the prevention plan may remain oral — never a good idea for a drone flight. Our guide to hosting a drone mission on an industrial site takes this sequence from the client's side, with the matching checklist.

Three measures recur in every risk assessment of an indoor flight. Marking out a ground perimeter, physically delimited and supervised, beneath the flight zone and immediately around it : that is the basic collective protection, and it means negotiating with operations, because it closes an aisle or a bay. Managing co-activity : stopping or diverting handling equipment, locking out the lines concerned, coordinating with overhead cranes — a travelling crane and a drone in the same volume is a collision risk that no avoidance sensor handles cleanly. And kitting out the team : site PPE for the remote pilot and their spotter, briefing on internal rules, safety induction. On the pilot's employer's side, these risks must also appear in the single risk assessment document — the subject of our guide to the workplace safety obligations and risk assessment for a salaried drone pilot.

One methodological point to close, because ignoring it is expensive : indoors, the loss-of-control scenario has no automatic solution. Outdoors, a drone that loses its link performs a satellite-guided return to home. Without GNSS, that behaviour does not exist : the only response is to land or cut power on the spot, and the risk assessment must therefore describe what lies beneath the drone at every point of the flight plan — a running machine, an open tank, an occupied workstation.

Insurance: the question to ask before the job, not after

The insurance obligation on aircraft operators stems from Regulation (EC) No 785/2004, supplemented in French law by article L. 6131-2 of the transport code : an aircraft under 500 kg must be covered by a minimum guarantee of 750,000 SDR for damage caused to third parties. Our guide to professional drone liability insurance covers that baseline and observed prices. The point here is a different one, and no text settles it : does your policy cover a flight in an enclosed space ?

The question deserves to be asked head-on for a substantive reason : indoors, the nature of the loss changes completely. The typical risk of an outdoor flight is a fall onto a bystander or a vehicle, exactly what aircraft liability cover targets. The typical risk of a flight in an industrial hall is contact with production equipment : a propeller touching a limit switch, a drone catching a sprinkler head and triggering suppression over a storage zone, an aircraft dropping into a running conveyor. Direct material damage is often modest ; what costs money is the production stoppage and the clean-up. And those are precisely the items standard policies treat most restrictively.

Four points to have confirmed in writing before scheduling the job, on both the contractor's and the client's side : explicit cover for flights in an enclosed, covered space (some policies are drafted by reference to the Open/Specific category framework, with nothing provided outside that scope) ; cover for damage to entrusted property and to the host company's property, which does not fall under ordinary liability cover ; the existence of an explosive-atmosphere exclusion, almost systematic wherever an ATEX zone is involved ; and the treatment of the site's business interruption should it be immobilised. On sensitive sites, operators increasingly ask to be added as an additional insured or to receive a named certificate stating the building and the date — a requirement to build into the schedule, because it takes a few days.

The B2B uses that genuinely justify an indoor flight

An indoor flight only makes economic sense in one configuration : when the alternative is an aerial platform, scaffolding, a confined-space entry or a production stoppage. That is the only criterion that matters when deciding, and it rules out half the enquiries straight away. A study by O. Maghazei and T. Netland, published in 2020 in the Journal of Manufacturing Technology Management, offers a useful reading : drawing on interviews with 66 experts from 56 companies across 13 countries, supplemented by presentations, catalogues and technical reports, the authors build a typology of industrial drone uses around four capabilities — see, sense, move, transform — and observe that the genuinely mature factory applications belong to the first two, visual inspection and data collection, while intralogistics transport largely remains at pilot stage (see the study on Google Scholar). That hierarchy shows up unchanged in quotation requests.

Five families account for most indoor missions on professional sites :

• Warehouse stock inventory : reading labels and barcodes at high-bay locations without tying up a forklift driver or a platform. This is the most industrialised use, detailed in our guide to warehouse stock inventory by drone.
• Inspection of roof trusses, crane runways and roof soffits : condition of connections, corrosion of purlins, deformation of a crane rail, cladding fixings, traces of water ingress from below. The drone photographs at 12 m what a platform would take two days to reach bay by bay.
• 3D survey of a workshop or machine room : a point cloud of a cluttered volume, ahead of installing a new line or to feed a model — see our guide to the digital twin of a building through photogrammetry and scan-to-BIM.
• Confined-volume inspection : silo, tank, hopper, boiler, chimney from the inside, where the drone replaces a human entry under permit.
• Corporate filming in a production environment : a shot travelling along a line, an overview of a workshop, a recruitment film — the subject of our guide to corporate drone filming in a factory.

On the first of these uses, research has documented the central trade-off. A study by D. Cristiani, F. Bottonelli, A. Trotta and M. Di Felice, presented in 2020 at the IEEE WoWMoM conference, proposes a complete mini-drone inventory architecture — path planning, package identification, data validation, recharging — and analyses its performance : the authors bring out an explicit trade-off between inventory accuracy and the time needed to complete it (see the study on Google Scholar). That is exactly the discussion to have with a contractor : targeting 100% of locations costs disproportionately in flight hours, whereas a fast pass cross-checked against the WMS is enough to pinpoint discrepancies.

Without GPS: SLAM navigation, caged drones, light, dust and ATEX

An outdoor drone does not work indoors, and the gap is not a matter of settings. Under a roof and among steel structures, the GNSS signal is blocked or, worse, intermittently degraded : position hold collapses, return-to-home no longer exists, and the aircraft drifts without the pilot being able to compensate for long. The technical answer is to rebuild localisation from onboard sensors : optical-flow cameras, rangefinders, LiDAR, inertial measurement unit, all fused in a SLAM algorithm (simultaneous localisation and mapping) that builds the map of the volume while finding its way through it.

This approach has long been documented on exactly the kind of structure that concerns us. A study by T. Özaslan, G. Loianno, J. Keller, C. J. Taylor, V. Kumar and co-authors, published in 2017 in IEEE Robotics and Automation Letters, addresses the autonomous inspection of penstocks and tunnels by micro air vehicle : the authors estimate six-degree-of-freedom pose and velocity by fusing data from an inertial measurement unit, a LiDAR and a set of cameras, with all computation carried onboard — no satellite input whatsoever, and in an environment with no usable visual texture (see the study on Google Scholar). That is the building block of today's commercial confined-inspection aircraft ; our guide to tunnel and underground gallery drone inspection covers what GNSS-denied navigation changes in the running of a mission.

The hardware follows the same logic. Indoors, the reference aircraft is not a camera drone but a caged drone : a spherical or cylindrical protective structure surrounding the propellers, tolerating contact with a wall and preventing injury to a person or damage to equipment on first brush. The most widespread model in this segment, Flyability's Elios 3, weighs about 2.35 kg, carries an Ouster OS0-32 LiDAR and a proprietary SLAM engine that builds the 3D map in flight ; endurance runs to around a dozen minutes, with long-life battery and tethered power options for tall volumes. These orders of magnitude explain a methodological point : indoors you do not plan « a flight » but a series of short flights, with battery changes and multiple launch points.

Three environmental constraints remain, and clients regularly underestimate them. Lighting : a confined volume has no light of its own, so the aircraft carries its own, which costs payload and endurance and forces a shorter working distance. Dust : propeller downwash re-suspends settled particles ; in a silo or a hopper this can saturate the image and corrupt the LiDAR within minutes — hence segmented flights and a progression order designed to avoid flying into your own cloud. Finally ATEX : as soon as a workplace is zoned for explosive atmospheres (zones 0, 1, 2 for gases, 20, 21, 22 for dust), an off-the-shelf drone is uncertified electrical equipment within the meaning of Directive 2014/34/EU. In practice, flight is ruled out in zone 0, and is only considered in zone 1 after the volume has been opened to the atmosphere and gas-free readings taken. Our guide to hydrocarbon storage tank drone inspection and the ATEX framework details that sequence, which drives a shutdown schedule far more than drone availability does.

Method and 2026 prices: how an indoor mission is costed

The method that works has five steps, and the first three happen on the ground. Preliminary technical visit : qualify the volume (enclosed and covered or not, openings to close, clear height, clutter, lighting, any ATEX zoning), identify the site contact and record what lies beneath each flight zone. Documentation framing : written authorisation from the operator, prevention plan (in writing as soon as either case in article R. 4512-7 applies), insurance certificate mentioning enclosed spaces, informing employees and consulting the works council if the flight becomes recurrent. Choosing the slot : this is the real economic decision, because a shutdown slot (night, weekend, planned outage) costs more in labour but removes co-activity and makes the building genuinely enclosed. Then come the segmented flight, volume by volume and battery by battery, with the ground perimeter held ; and the deliverable — indexed photo record, point cloud, dated inspection report.

Orders of magnitude observed in France in 2026, excluding VAT :

• Targeted indoor inspection (one hall, one workshop, one volume, half a day on site) : €700 to €1,500, indexed photo record and short report included.
• Full day (several buildings or several volumes on the same site) : €1,500 to €3,000.
• Shutdown campaign (several days, confined volumes, detailed report) : €3,000 to €8,000.
• 3D survey option for the volume (LiDAR or SLAM point cloud delivered) : +€800 to €2,500 depending on area and the level of cleaning expected.
• Corporate filming in a production environment (half a day, indoor drone, editing included) : €1,500 to €3,500.
• Warehouse inventory : €1,500 to €9,000 depending on the number of locations — detailed scale in the dedicated guide.
• Night, weekend or public-holiday slot premium : +20 to 40%.
• ATEX-classified volume : on quotation, once the gas-freeing procedure has been validated with the operator.

A warning about reading these figures, because it often changes the decision : the heaviest line item is almost never the flight. On a mission in a production environment, the dominant cost is stopping or slowing the line during the slot, and on some sites that runs into thousands of euros an hour. This is also why the relevant comparison is not « drone versus drone » but « drone versus the scenario avoided » : erecting and dismantling internal scaffolding, hiring a platform with a certified operator, or a human confined-space entry under permit with a rescue team standing by. On a hall roof structure or a tank, the gap runs into tens of thousands of euros and days of downtime, which makes the trade-off obvious long before the hourly rate is discussed.

For an indoor mission, request a quote stating the type of building, the clear height, what needs to be observed, any ATEX zoning and the possible slot — the four parameters that between them determine both feasibility and price.

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