Key takeaways
- The flight is the short part. On an operating site the schedule is set by the approval chain, and the aviation authorisation is rarely the item that sets it.
- Contractor prequalification is the long lead item and it is often discovered late. It happens once, it can take weeks, and it blocks everything downstream.
- Permit to work is issued against a described task in a described area, so a vague scope cannot be permitted. Writing the scope tightly is what makes the permit routine.
- Simultaneous operations are the usual same-day obstacle. A crane lift, a scaffold build or a hot work permit in the same area outranks a drone flight and will move it.
- Escort and orientation requirements are policy, not negotiation, and they consume site hours you have to plan for rather than resist.
- A collision-tolerant drone removes the entry but never the isolation, purge or atmospheric testing. Confined space stays a confined space.
- Bystanders inside a fence line cannot be cleared the way a public area can, because the people present are staff doing their jobs.
- Approvals that can run in parallel should. The ones that cannot are the ones to start first, and the single most useful question to a new client is who signs the permit.
A drone inspection of a flare tip, a stack, a cooling tower, a tank roof or a structure inside a running facility takes a fraction of a day in the air. Clients are routinely surprised that it takes weeks to arrange. The reason is not aviation. It is that an operating site is a controlled environment, and a contractor entering it to do non-routine work at height passes through a chain of approvals that exists whether the work is done by a drone, a rope crew or a scaffold.
Understanding the chain is worth something, because most of the delay is avoidable. The items that take time are known in advance, several of them run in parallel, and the one that usually sets the date is the one nobody asks about at the start.
What is actually in the chain
The specifics vary by operator, but the shape is consistent across Alberta plants, mines, terminals and utilities:
- Contractor prequalification, meaning the operator's own vendor approval. Insurance certificates, safety statistics, programme documentation, WCB clearance and often a third party prequalification service.
- A signed service agreement or purchase order, which cannot usually be issued before prequalification completes.
- Site orientation for every person entering, which is a scheduled session and sometimes an online module with a validity period.
- A job hazard assessment or safe work plan specific to the task, reviewed by the operator.
- Permit to work for the task, in the area, on the day, issued by the area authority.
- Any additional permits the task triggers, which for aerial work can include elevated work, exclusion zone or isolation permits depending on the site's system.
- Simultaneous operations review, meaning whether other work in the same area conflicts.
- Aviation authorisation, which for most industrial sites is a routine matter and occasionally a controlled airspace coordination.
Only the last item is specific to flying. Everything above it applies to any contractor doing any non-routine work, which is why experienced clients find this familiar and first-time clients find it surprising.
Prequalification is the long lead item
If a drone contractor has never worked for the operator before, prequalification is almost always the item that sets the date. It is a one-time cost for the relationship and it does not depend on the scope of work, which means it can be started before the scope is finalised and frequently is not.
The reason it takes time is that it involves a third party, a document review and sometimes a queue. The documents themselves are straightforward for an established contractor, meaning certificates of insurance with the right limits and endorsements, WCB clearance, safety programme documentation and incident history. The time goes into review cycles rather than preparation.
The practical implication for a buyer is that the first question in a scoping conversation should be whether the vendor is already approved at the site. A vendor who is already in the system can often be on site in a fraction of the time, and that is a legitimate reason to prefer one over another on a time-sensitive scope.
Permit to work needs a described task
A permit is issued against a specific task in a specific area for a specific period. The area authority signing it has to be able to picture what will happen and what could go wrong. That makes vagueness the enemy of a quick permit.
A scope that permits easily says what will be flown, where the aircraft will take off and land, what altitude band it will occupy, where the crew will stand, what the exclusion area is, how long it will take, and what the crew will do if something goes wrong. A scope that says a drone inspection of the unit does not give the signer anything to assess, and the result is a conversation rather than a signature.
This is also where an experienced contractor earns their keep. The hazards an area authority will ask about are predictable, and they include loss of control near equipment, loss of link, battery fire, dropped objects, distraction of operating staff, and interaction with radio or control systems. Having written answers already in the safe work plan turns a review into a formality.
Simultaneous operations decide the day
Approvals get you onto the site. Simultaneous operations decide which day and which hour. Inside an operating facility, a drone flight is a low priority activity competing for the same airspace and ground as work that cannot be moved:
- Crane lifts, which own the overhead space and will not be interrupted.
- Scaffold builds and dismantles in the same area.
- Hot work with its own exclusion zone.
- Vacuum trucks, line breaks, pigging and other operations with their own restricted areas.
- Planned venting, flaring or purging, which changes both the hazard and the thermal picture.
- Turnaround or outage activity, where the area is at its busiest.
The right posture is flexibility rather than insistence. A crew that can shift to a different part of the scope, or come back the following morning, gets the work done. A crew holding out for a specific window on a busy unit gets stood down.
Escorts, orientation and the hours they consume
Most operators require an escort for contractors in process areas, and the escort is one of their own people with other responsibilities. That has two consequences worth planning for. The escort's availability is part of the schedule, and the escort's time is a real cost to the client even when it does not appear on an invoice.
Orientation is similar. It is required for every person entering, it is usually scheduled rather than on demand, and it has a validity period that can expire between visits on a repeat programme. On a multi-visit scope it is worth checking whether the orientation will still be valid for the second visit.
These are not obstacles to argue with. They are site policy and they consume hours. The useful response is to plan the day around them, which usually means fewer productive flight hours per site day than a client expects, and to raise that in scoping rather than discovering it on site.
Confined space keeps all of its requirements
A collision-tolerant drone flying inside a vessel, a tank, a stack, a silo or a duct removes the need for a person to enter. It removes nothing else.
The space still has to be isolated, drained, purged and atmospherically tested. The entry permit system still applies, because the crew is working at the opening. The attendant, the rescue plan and the communication requirements stay in place. What changes is that the time inside the space is spent by an aircraft rather than a person, which is a substantial safety gain and a substantial cost saving where it replaces scaffold or rope access.
Two scheduling consequences follow. First, internal capture is tied to the space being open and isolated, which on most assets means an outage. Second, a radiometric thermal camera needs a temperature differential to detect anything, and a vessel that has been cold and depressurised for days does not provide one. Thermal work belongs on equipment under load, which is a different window from internal visual capture.
The people you cannot clear
Flying over a public area is partly a problem of keeping people out. Inside a fence line that approach does not transfer. The people present are staff doing their jobs in their own workplace, they cannot be removed from an operating unit, and the work they are doing is often the reason the site is running.
So the mitigation shifts from exclusion to coordination. That means a notified flight with the area supervisor, routing that keeps the aircraft away from occupied work areas and walkways, a defined landing area that is not a traffic route, a spotter watching the ground rather than the aircraft, and a crew that can hold or land on a radio call. It is slower than flying an empty site and it is the trade for being inside a facility at all.
Running the approvals in parallel
The reason a well-run job takes weeks and a badly run one takes months is sequencing. Several items do not depend on each other and can be started at the same time:
- Prequalification, which depends on nothing about the scope and should start the moment the work looks likely.
- The aviation side, including any airspace coordination, which depends on the location rather than the site's internal approvals.
- A draft safe work plan, which can be written against the expected scope and refined later.
- Orientation scheduling, which can often be booked against a tentative date.
What cannot be parallelised is the permit itself, which is issued close to the day, and the simultaneous operations check, which is only meaningful against a real schedule. Those two are the last steps and they are short. If they are the only things left when the scope is agreed, the job moves quickly.
The questions that compress the timeline
Four questions asked at the first conversation remove most of the uncertainty about when the work can happen:
- Is the vendor already prequalified at this site, and if not, how long does the operator's process take.
- Who signs the permit to work for the area, and what do they need to see.
- What else is happening in that area in the target window.
- Does the scope include anything internal, which ties part of it to an outage regardless of how fast the approvals move.
None of those are aviation questions, which is the point. On an operating site the flight is the easy part and the approvals are the project.