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ParaZero Comments on FAA NPRM for Operations Over People

Aaron Gliner

ParaZero Technologies comments on the Notice of Proposed Rulemaking regarding the Operation of Small Unmanned Aircraft Systems over People

Dear Secretary Chao and Administrator Elwell:

ParaZero appreciates the opportunity to provide these public comments on the FAA NPRM for sUAS Operations Over People. ParaZero develops smart parachute safety systems for sUAS. The company’s goal is to enable the commercial UAS industry to reach its full potential by increasing the safety of UAS operations. UAS technology has the potential to transform many industries and markets. First responders will be able to respond faster and more effectively while reducing the risks that they take on a daily basis. Construction sites use UAS for virtual design and construction, 3D modelling and more. Building and infrastructure inspections can be performed at a lower cost and lower risk to workers while allowing companies to better maintain the assets we all depend on. News and media companies can generate content that previously required helicopters or was simply unattainable. These are just a few examples of how the technology can make our lives better.

There is no doubt that allowing operations over people and at night is an important step in enabling the industry to grow as well as the value society gains from it. Therefore, ParaZero would like to thank the FAA for publishing this NPRM and allowing us, the industry and the public to voice our opinions and comments on the draft.

ParaZero is a partner in two UASIPP teams (North Dakota and Kansas). ParaZero’s parachute system for the Phantom 4 was used by North Dakota operator, Botlink, to secure a waiver for flight over a tailgating event outside a Fargo, ND football game. The company’s products have since been used for other approved waivers (such as Airobotics’ and a second Botlink waiver). ParaZero is a member of ASTM F38 Committee on Unmanned Aircraft Systems and specifically the working group that developed the ASTM F3322-18 Standard Specification for sUAS Parachutes. ParaZero is currently part of the working group developing a new standard that will define how to perform UAS drop tests to determine their human injury potential.


Performance based standard:

The FAA designed the requirements for Category 2 and Category 3 as performance-based standard. This makes a lot of sense and is a clever way to achieve safety goals while still allowing for innovation and creativity.

Operations over moving vehicles should be included:

The exclusion of operations over moving vehicles is a major detriment to the industry and a lost opportunity for significant progress and growth. Restricting flight over moving vehicles essentially means that many of the operations that this NPRM is intending to unlock, will not actually be unlocked. This will have a negative effect on the growth of the industry as well as on the FAA. The restriction will force operators to continue using the existing waiver system instead of streamlining the process and alleviating some of the workload on the FAA waiver team.

The RCC standard used by the FAA to define the category thresholds were originally used for missile and rocket range tests. They define the allowable impact energy for debris that may fall from such tests. As far as we know, the RCC standard does not differentiate between unprotected people and people in moving vehicles. The RCC standard is already considered to be the most conservative of the human injury standards. There is no reason to add additional restrictions on top of it.

To the extent the FAA’s concern is that an overflying UA could distract a driver and lead to a potential accident, drivers are taught about handling distractions and indeed face distractions every day from other vehicles, horns/sirens, billboards, and wildlife, among other things. There is nothing unique about the distraction that a UA might cause that should warrant a complete prohibition on flights over moving vehicles. Moreover, motor vehicles provide the vehicle occupants with reasonable protection from a UA, just as people are protected under a covered structure or inside a stationary vehicle (both of which a UA can currently fly over under Part 107). To date, ParaZero is not aware of any confirmed motor vehicle accidents in the United States as a result of being hit by a UA.

There is no doubt that operations over moving vehicles on restricted access roads should be permitted as the risk of distraction-related crashes is mitigated by the driver’s awareness of the UAS operation. For example, filming of movies or car commercials and operations over construction sites that may have moving vehicles.


Threshold levels are too low:

ParaZero finds it odd that the FAA did not adopt the results of the ASSURE research that the FAA itself funded. The implications of the overly conservative thresholds for the commercial UAS industry are significant. If the FAA finalizes the proposed rule as written, even when equipped with a parachute, very few UA models will be capable of meeting the Category 2 KE thresholds and Category 3 compliance will be limited to parachute equipped UA weighing only a few pounds. Such a result will limit the growth of the UAS industry and the value that society can gain from it.

The 11 ft-lbs and 25 ft-lbs thresholds were derived from two existing KE impact thresholds “that analyze public safety risk from commercial space launches, government space launches, and aircraft operations at national test ranges,” and that “presume all kinetic energy from a rigid object would transfer to a person upon impact.” Those types of operations and space vehicles, however, are very different from UA. They involve heavy, metallic fragments, whereas most commercial UA do not. They are rigid, whereas most UA are flexible and thereby absorb energy.

ASSURE conducted FAA-funded research as part of Task 14 to evaluate human injury related to UA impacts with the non‐participating public. ASSURE explained that the two proposed thresholds are roughly the “same energy of the fastest pitch thrown in 10U or 12-14 year old boys Little League Baseball, respectively,” and then pointed out that a baseball is rigid and not flexible (like a tennis ball or a UA). Based on that and other research, ASSURE raised serious concerns in its comments about the NPRM’s proposed 11 ft‐lbs and 25 ft‐lbs KE impact thresholds being too low and off by a factor of at least ten.

It would also make sense for the NPRM to consider flights over people using Personal Protective Equipment (PPE) such as hard-hats etc. These are common on construction sites and some first response operations. KE thresholds in these scenarios should be higher than unprotected scenarios to allow for heavier UA and more sophisticated payloads.

Transferred KE is not the only factor that effects risk:

The NPRM requires and incentivizes risk mitigations that effect the transferred KE. These include reducing mass and velocity and increasing UA material flexibility and frangibility. The draft rule assumes that the probability of a UA failure is 100% and the probability that the failed UA will hit a person is 100%. Clearly these assumptions are inherently wrong. The NPRM does not credit or incentivize mitigations that reduce the probability of impact with a human or the probability of failure of the UAS. For example, a parachute equipped UA that includes and audio-warning buzzer is capable of alerting bystanders of the incoming danger, sometime 15 seconds before the UA hits the ground, thus providing enough time to move out of the way. This simple device significantly reduces the probability of the UA hitting a person, yet no credit is given to manufacturers and operators who use them.

We thank you for your consideration of ParaZero’s comments.


Eden Attias, CEO


Avi Lozowick
Director of Policy and Strategy