The FAA should change its approach to assessing safety risk when it considers unmanned aircraft systems (UAS) operations, the Washington DC-based National Academies of Sciences, Engineering and Medicine recommended in a study released June 11.

The study—which was required by the FAA Extension, Safety and Security Act of 2016—found that current safety risk management (SRM) processes developed for manned aviation, when applied to UAS, “too often [have] resulted in overly conservative risk assessments” that have prevented beneficial drone operations from being approved.

“Traditionally in manned aviation, assessments of risk have focused on [the] probability of passenger fatality. This measure clearly does not correspond well to UAS operations,” the study said. “Further, given the substantial variety of types of UAS operations, no single measure of risk can likely be found that can adequately characterize the benefit and risk of all UAS operations.”

The authors called on the FAA “expand its perspective” on a quantitative approach to assessing the risk of drone operations that considers safety benefits more holistically, such as the benefit of conducting cell tower inspections without a human climbing a cell tower.

“UAS operations should be allowed if they decrease safety risks in society—even if they introduce new aviation safety risks—as long as they result in a net reduction in total safety risk,” the study said.

Within six months, it said, FAA should make “top-to-bottom” changes in its management process “aimed at moving smartly to a risk-based, decision-making organization” with clear lines of authority to apply probabilistic safety risk assessments to UAS operations.

Also within six months, the FAA should develop a plan to voluntarily collect safety data from drone operators in a central repository, similar to the models established by the Commercial Aviation Safety Team and the General Aviation Joint Steering Committee, with the goal of activating the repository within a year.

Within a year, FAA should publish guidelines for a “predictable, repeatable, quantitative risk-based process” for certifying UAS and granting operational approvals, the study recommended.

SRM processes described in the Safety Risk Management Policy (FAA Order 8040.4B) that became effective in May 2017 should be improved to conform to a probabilistic risk analysis process based on acceptable safety risk, one in which the FAA relies on the operator to demonstrate the level of safety, the study stated.

Reacting to the National Academies study, FAA said it is working to accelerate the introduction of drones into the airspace system “on multiple fronts,” including through the UAS Integration Pilot Program, the expansion of the Low Altitude Authorization and Notification Capability and two proposed rulemakings on expanded drone operations and security issues.

“The report confirmed that the FAA executive team has a consistent approach to risk management,” the agency added. “The specific recommendations are aligned with FAA’s ongoing efforts and we see them as an endorsement of our efforts and encouragement to accelerate our efforts particularly in the area of change management.”

Bill Carey, bill.carey@aviationweek.com