UAS Liabilities and the Responsibility of Professional Land Surveyors

Is your survey team ready to add aerial capabilities?


Aerial surveys can be a great asset to a surveying team, but any firm interested in launching these services must also consider the many liabilities associated with unmanned flight. Anytime you put an unmanned aircraft system (UAS), or drone, in the sky you can experience unforeseen issues and need to troubleshoot on the fly.


A strong UAS survey program can increase efficiency, collect real-time data, and safely survey hazardous areas with ease. As great as these benefits are, adding aerial services to check off a box without an experienced program coordinator will not be successful. To develop a safe and beneficial program, you’ll need a dedicated professional that has the flexibility and time to train your surveyors as Part 107 remote pilots on both the physics and hazards of flying a UAS. Part 107 is the section of rules from the Federal Aviation Administration (FAA) that covers small UAS operations.


When it comes to flying drones in the field, it’s not a question of if but when you’re going to need a plan B. Having a few contingency plans in place is vital because circumstances can change abruptly. Even on a day with ideal conditions, a small distraction or gust of wind could cause the type of failure that can ground an entire program.


Some risk factors to consider when flying are:

  • Battery Failure
    • One of the most common failures in drones are lithium batteries which are infamously unstable. Carelessness with batteries (i.e. lack of monitoring battery performance, leaving them in the truck overnight, leaving them on charge for a month, using damaged batteries, etc.) could have devastating consequences. In a hypothetical situation, you may be flying over an active landfill and battery failure could produce an intense blue flame to fall from the sky causing a catastrophic event too egregious for any insurance policy.

  • Impact risks
    • A DJI Phantom 4 pro falling from 400’ AGL has 1,225 ft/lb of kinetic energy at impact. There are numerous published studies on live flight and falling impact tests which detail range of injury risk to humans. Safety standards exist to regulate the potential for catastrophic injury and death.
  • Inflight collisions
  • The UAS being targeted by landowners (shooting at a UAS is considered a felony in the same way as shooting at a plane or helicopter)
  • Controller and UAS link loss
  • Poor evaluation of payload capabilities
  • Flying near high voltage equipment

Good pilots are acutely aware of the capabilities of their equipment, their abilities as a pilot, and the environment in which they are flying. Beyond altitude limitations, airspace complexity, and safety concerns, they consider if there are visible areas for target placement and appropriate visual-line-of-sight. Most importantly, a good pilot flying for survey knows when a drone isn’t the right tool for the job. Airspace restrictions, vegetation, and the size and type of survey are all factors a survey remote pilot considers when picking the tools for the job.


Professional Land Surveyors (LS) have a background in solving technical issues and dealing with challenges pertaining to checking data from the field. They are skilled in interpreting data and understanding how to replicate accurate results. Smoothed Best Estimate of Trajectory (SBET), LiDAR return data, and attributes relating to sensor data are beneficial to know to avoid ambiguity and errors which cause a divergence of position.


When you have the combined expertise of an LS and a Part 107 remote pilot, your aerial services division can truly take off.


An LS who holds a remote pilot’s license can expertly judge and execute a variety of jobs. They also hold the responsibility of educating the end user and mitigating expectations. Some of the questions an LS will consider before the start of a project are:

  • What are the limitations of the job? The flight?
  • What features can be adequately defined?
  • What methods are chosen to create a deliverable which is aesthetically pleasing and accurate?
  • How much data is necessary?
  • Should you use LiDAR, photogrammetry, or conventional and why?
  • Contours out of the box versus a de-densified and spatially sampled grid surface look and act differently. Which is right for this job?

Other expectations:

  • Knowing FAA Policy, proposed rules, and familiarization with lobbying efforts
  • Understanding how and when to obtain FAA airspace authorizations and waivers
  • Educating the public on drone safety and integration into the airspace
  • Maintaining checklists and flight logs
  • Assuring quality control of photogrammetric and LiDAR data
  • Defining aircraft and associated components maintenance policies and procedures in accordance with manufacturer and FAA guidance

Professional surveyors with Part 107 certificates experienced in the civil environment help mitigate risks associated with UAS usage. They are also key in processing data, setting client expectations, and knowing when a drone isn’t the right tool for the job. With the help of these skilled professionals, a UAS program can operate safely and effectively.


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