Aircraft Accidents and UAS Data, Part IX

Beginning in November 2016, with Aircraft Accidents and UAS Data, Parts One and Two; then in October 2018 with Parts Three and Four; March 2019 was Parts Five and Six. In May 2019, Part Seven was written; Part Eight in October. The unmanned aerial system (UAS) and the national airspace system (NAS) continues to need dedicated professionals who both understand the UAS industry and comprehend the need for rules. The fifth Article (study) has been written by principal authors: Ryan Wallace of Embry-Riddle University (ERAU); Jon Loffi, Samuel Vance, Jamey Jacob and Jared Dunlap of Oklahoma State University (OSU). Their study titled: Cleared to Land: Pilot Visual Detection of Small Unmanned Aircraft During Final Approach is a qualified sequel to the four previous studies. This article was printed in the ERAU Scholarly Commons, Volume 6, Issue 5, Article 12.

As with the previous studies, the author team makes use of real-time situations and equipment to simulate as closely as possible the concerns. In the accomplishment of the previous studies, the teams have employed manufacturer-specific equipment to track certain sUASs; they have observed airspace violations around major airports, e.g. Daytona Beach IA, and commercial air routes, e.g. banner-towing. They have made use of the services of volunteer project pilots, with qualifying FAA-certifications.

More importantly, the teams have contributed to the future of unmanned flight safety. All the studies conducted had a unique theme; when taken together, the themes demonstrate a step-by-step story about how the UAS industry should prepare their operators for inclusion in the NAS. The writer for this website has written about these studies, to point out the futility many persons have of trusting to government to solve all the problems with UAS safety.

The article’s Problem statement is: “The threat of a midair collision between a sUAS [small UAS] and manned aircraft is heightened during the final approach phase of flight, as aircraft transition from higher-altitude airspace into the low altitude arena now populated by small unmanned aircraft. Absent benchmarks for electronic detection and sense and avoid systems, pilots rely primarily on visual senses and proper visual scanning techniques to ensure a positive separation and collision avoidance from sUAS platforms during this segment of flight.”

This problem statement demonstrated the correct concern for sUAS that threaten aviation safety; the concern has grown exponentially over the years: “The number of pilot-reported encounters with unmanned aircraft has been on the rise, since 2014 …” The article further stated, “… more concerning is the number of unreported UAS encounters during the final approach phase of flight.”

A Notice of Proposed Rule Making (NPRM) called Safe and Secure Operations of Small Unmanned Aircraft Systems, was introduced in 2019, to combat the intrusion of sUAS vehicles. It gave aviation professionals an opportunity to vent their concerns. However, an NPRM is a feeble argument; it holds no consequences and cannot be acted upon in a timely manner; it is a band-aid.

The article raised three questions:

  • What is the visual detection rate for a small unmanned aircraft system by an aware pilot when transitioning from an instrument approach to visual landing?
  • What is the mean distance at which a small unmanned aircraft system can be detected by an aware pilot when transitioning from an instrument approach to visual landing?
  • What factors affect visual detection of small unmanned aircraft systems by pilots?

The study was conducted under controlled conditions, a safe distance from regular commercial traffic. The place: a modest landing strip in rural Oklahoma. The approach was at 60 to 70 knots. The weather conditions: visual flight rules. Pilots: two per single-engine aircraft. The sUAS: a DJI Phantom (white quadrotor) against a green and brown terrain. Even with the pilots knowing the sUAS was either to port or starboard, the visual detection rate was “… 12 out of 40 possible events, resulting in an overall detection rate of 30.0%”. Moving sUAS were detected during 9 out of 18 possible events, resulting in a detection rate of 50.0%. Static sUAS were detected during only 3 out of possible 22 possible events, yielding a detection rate of 13.6%.”

Question: Given the study pilots’ awareness of an sUAS in his approach vicinity, how much harder would it be to see an sUAS against a background of dense visual ‘noise’? The study employed pilots watching for known targets against contrasting farmland, which easily betrayed the white sUAS in flight. But what about an approach into La Guardia airport at 140 to 150 knots? Would a B737 pilot easily distinguish an sUAS on approach over the mosaic that is Jackson Heights to runway 4 in midday?

The authors were very familiar with the effects of sUAS interference on populated airports. ERAU is near Daytona Beach International Airport (IA) and close to Orlando IA. OSU is near Tinker Air Force Base and Will Rogers World Airport. They understood that reaction times for pilots, whether a Cessna 150 or a B737, were extremely limited. From the study, they learned the fact that visually detecting an sUAS was almost impossible when the pilot did not know the sUAS was there and not camouflaged against a multicolor background or below line-of-sight over the nose of the aircraft.

What is required is perspective. This writer is not a pilot; never, outside of a simulator, landed an aircraft. What would happen to a car’s windshield or frame if someone hit a solid object (not a bird) at the approach speed of a Cessna single-engine aircraft: 60 to 70 knots (70 to 80 miles per hour)? The solid object would penetrate the windshield, kill the driver; the object would make the car undriveable and unsafe. The car, driving on a two-dimensional plane (X and Y-axis), could result in the death of the vehicle’s occupants and, perhaps, wiping out anyone else within crashing distance.

What about a car driving at the speed of a B737 on approach, at 140 to 150 knots (161 to 172 miles per hour); what would the effect be on that car if it operated in a three-dimensional plane (X, Y and Z-axis)? All passengers would be at risk; everyone below the approach would be at risk (think American 587); the engine could be destroyed at a critical point of approach (think US Airways 1549); if the driver survived a windscreen impact, he would be trying to safely land the vehicle … somewhere; an impossibility over a major city.

There remains through all these studies one simple question no one has asked: Why would anyone need to violate NAS airspace and endanger lives? This website addressed this concern in last week’s archived article:

An analogy for this activity is: the equivalent of randomly dropping a brick off a highway overpass or shining a laser at an approaching airliner. Are these thoughts speculation? Perhaps, but speculation based on fact is theory and theories are proven by using facts. Unless we continue to shut our eyes to the danger, a midair sUAS impact will prove these theories to catastrophic effect.

For instance, in April 2018, Southwest Airlines flight 1380, validated the dangers of an engine when its blades separate at operating speeds; this would be the scenario should an engine fan, turning at over 1800 rotations per minute, hit a solid object, e.g. sUAS. A windscreen, designed to absorb the impact of semi-solid objects, such as a bird, will not be able to sustain the damage made by an sUAS and will result in the pilot(s) being killed. That is a fact; the windscreen will not survive an impact with a solid object. It was never designed to. This is the fifth installment in the authors’ attempts to educate the aviation community, as a whole, about real dangers. Their intention is to make known possible threats to all aviation-minded people and to provide the facts for the industries to base productive conversations on, work proactively towards safety as opposed to reactively, to challenge the industries to prevent accidents before they happen.

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