Innovation, collaboration, and interoperability are increasingly important aspects of public aviation operations using a mix of new and repurposed aircraft designs.
By Don Van Dyke
ATP/Helo/CFII, F28, Bell 222.
Pro Pilot Canadian Technical Editor
A formal definition is provided in Code of Federal Regulations 14 CFR § 1.1. It is recognized that statutory provisions may be difficult to apply to operations conducted by civil contractors for government entities.
PAO limitations are provided in 14 CFR 91.313, Restricted Category Civil Aircraft: Operating Limitations. Oversight of PAO is complex. In 2018, FAA revised Advisory Circular (AC) No. 00-1.1B to assist in determining whether government-owned or government-contracted manned and unmanned aircraft operations conducted within the territory of the United States are public or civil aircraft operations under the statutory definition of “public aircraft” in Title 49 of the United States Code (49 U.S.C.) §§ 40102(a)(41) and 40125 (the statute).
The term “governmental function” in § 40125 means an activity undertaken by a government such as national defense, intelligence missions, firefighting, search and rescue (SAR), law enforcement (LE), aeronautical research, or biological or geological resource management.
The global helicopter services market size was valued at $35 billion in 2019, and is projected to reach $39.9 billion by 2027, at a compound annual growth rate of 3.83%, according to Fortune Business Insights.
Public aircraft may be either purpose-built or repurposed civil or military surplus designs. A restricted category special airworthiness certificate is issued to operate aircraft that have been type certified in the restricted category.
Restricted category certification makes the aircraft ineligible for Part 135 transport category operations. Generally, only crewmembers and qualified non-crewmembers (ie, those required to perform, or are associated with the performance of, a governmental function) are permitted aboard the aircraft.
Qualifying for restricted category certification may be further complicated in cases of repurposed military surplus aircraft. The military is not required to obtain FAA type certificates, and aircraft acceptance is based on conformance to military contract requirements only.
Military aircraft are also not subject to the restrictions of Parts 27 and 29. FAA has issued documents such as Order 8110.56B, Restricted Category Type Certification, to provide guidance on restricted category certification of military surplus platforms.
See faa.gov/documentlibrary/media/order/FAA_Order_8110_56B.pdf for more information. Operation of restricted category aircraft is limited to the special purposes identified in the applicable type design.
Generally, rotorcraft PAO address public need with regard to firefighting, SAR, LE, aeronautical research, biological/geological resource management, or transportation (for other than commercial purposes) of persons by other official agencies of the United States.
Although these operations must continue to comply with certain general operating rules, including those applicable to all aircraft in the National Airspace System (NAS), other civil certification and safety oversight regulations do not apply to these operations.
Accordingly, most aspects of PAO are not subject to FAA oversight. Herein lies a source of possible confusion. Aircraft fitting the previous description shall, notwithstanding any limitation relating to use of the aircraft for commercial purposes, be considered to be a public aircraft without regard to whether the aircraft is operated by a unit of government on behalf of another unit of government, pursuant to a cost reimbursement agreement between such units of government, if the unit of government on whose behalf the operation is conducted certifies to the Administrator of the Federal Aviation Administration that the operation was necessary to respond to a significant and imminent threat to life or property (including natural resources), and that no service by a private operator was reasonably available to meet the threat.
Public aviation operations
While by no means comprehensive, the following presents a descriptive framework for classifying PAO. It must be emphasized that this framework is not internationally harmonized, nor is the permitted use of new or repurposed aircraft for these purposes. Aeronautical research.
Research among the majority of helicopter OEMs pursues wide-ranging solutions in flight testing, noise mitigation, atmospheric research and cloud seeding, ISR sensor development, powerplant development, cybersecurity defense, artificial intelligence, optional manning, and crew training/simulation.
Technology advances have stimulated conversion of several current public aircraft to unmanned aerial vehicle/remotely piloted aircraft system (UAS/RPAS) equivalents as substitutes, decoys, loyal wingmen, or force multipliers. As their use is increasingly pervasive, Table 1 includes OEMs of unmanned platforms which may be suitable for operational pairing with manned public aircraft.
Table 2 presents a range of selected PAO roles in which public aircraft are often employed. Realizing optional piloting expands the concept of mixed-fleet teaming significantly. In the case of helicopters, the prospect of remotely-controlled or autonomous aircraft had to await validation of VTOL controls, as well as control laws.
In the meantime, testing continues to refine technology for optionally-piloted flights in helicopters not originally intended to be unmanned. Environmental management. Climate change is acknowledged as having been a primary catalyst causing drought, intense heat waves, devastating fires, loss of sea ice, accelerated sea level rise, floods, avalanches, and other catastrophic events.
The recent UN Climate Change Conference (COP 26) sought to accelerate achievement of the goals of the Paris Agreement and the UN Framework Convention on Climate Change. Involving helicopters in dispensing and non-dispensing aerial work, animal and insect control, and geophysical survey, are essential elements of environmental monitoring, conservation, and resource management.
Aviation itself is challenged to foster environmental stewardship by meeting aspirational goals for reduction of CO2 emissions and for carbon-neutral growth. Firefighting. Aerial firefighting – the use of aircraft and other aerial resources to combat wildfires – is one of the public services listed explicitly in 14 CFR § 1.1, General Definitions.
The effect of aviation resources on a fire is directly proportional to the speed at which a resource can engage the fire initially, the effective capacity of the aircraft, and the deployment of ground resources.
In the wake of a 2008 accident involving a Sikorsky S-61 near Weaverville CA, the US Forest Service (USFS) and FAA both took steps to strengthen their oversight of contracted firefighting operators, as well as to clarify their respective responsibilities for that oversight.
Today’s interagency standards for fire and fire aviation operations are provided by the National Interagency Fire Center, in Boise ID. For more info, visit nifc.gov/standards/guides/red-book.
The Federal Emergency Management Agency (FEMA) publishes minimum criteria of associated component and capability for helicopters engaged in fire management and suppression.
The National Wildfire Coordinating Group (NWCG) is a subset of the National Interagency Aviation Committee, providing nationally harmonized standards for helicopter operations in the accomplishment of interagency fire suppression and natural resource aviation management. More info can be found at nwcg.gov/publications/510.
Popular firefighting helicopters include variants of the Bell 204, Bell 205, Bell 212, Boeing Vertol 107, Boeing Vertol 234, and the Sikorsky S-64 Aircrane helitanker, which features a snorkel for filling from a natural or man-made water source while hovering.
Currently, the world’s largest helicopter, the Mil MI-26, uses a Bambi Bucket. Helicopter EMS. Contractions planned by OEMs resulted in reduced production and deliveries in 2020, although demand for medevac-configured helicopters increased during the same period.
Helicopters are particularly well suited for rescue, inter-hospital transfers, and repatriation to mainland healthcare services. Law enforcement. Primary core helicopter capability required is for on-scene security, protection, and LE.
Secondary capabilities include their employment for interdiction and disruption. FEMA requirements are for VFR capabilities only.
The need for actionable intelligence is ever more critical and increasingly available through improvements in sensor technology, high-resolution cameras, electro-optics (EO), and infrared (IR) systems which enable the capture of clear images of areas of interest.
Optical sensors used for LE applications include both visible and infrared sensors. EO/IR systems enhance situational awareness in day, night, and in low-light conditions. Maritime. COP 26 also highlighted the effects of climate change on coastlines and on migration patterns, all of which may lead to territorial disputes and even the potential loss of entire nation-states, as well as their corresponding economic zone and fishing rights.
In the future, maritime law enforcement will require greater surveillance to combat high-seas piracy and to expand drug-interdiction operations. These requirements will stand with the traditional role of offshore SAR. Public safety and security.
Heightened geopolitical tensions, irregular warfare, and terrorism have changed the landscape of public safety and the need for advanced, informed security. Command, control, communications, and computers (C4) comprise a central pillar on which defenses against threats of terrorism, insurgencies, and conflicts are founded.
The role of PAO in sustaining needed countermeasures is inestimable. Special transport. Use of public aircraft for special transport is limited to single instances of VVIP personnel and/or cargo, where safety, security, or other qualifying requirements are significantly higher than usual.
Key PAO market drivers include identifiable needs and objectives, technical innovation, performance (aircraft endurance, payload, speed, range), short turnaround fielding, and costs (procurement, modification, operating).
Operational goals will seek to improve utility, redundancy, and reliability, creating greater value in the process while containing costs. Upgraded avionics (digital technologies, sensors, communications, multiple integrated platforms) and shrinking form-factors will encourage ever smaller aircraft to engage in PAO.
Innovation and development of electric vertical takeoff and landing (eVTOL) will lead to significant growth in the PAO market segment. Another aspect will be the yields of collaborative operations involving manned and unmanned rotorcraft.
Prominent challenges facing the rapidly changing PAO market include the evolution of appropriate responses to climate change and the needed for environmental management; a lack of expertise, trained pilots, and operators; increased dependence on avionics and related software; introduction of artificial intelligence; market and budget constraints; and regulations and ethical considerations.
The same creativity and ingenuity that led to the first adoption of helicopters and other rotorcraft for PAO will undoubtedly yield currently unimaginable societal benefits
Don Van Dyke is professor of advanced aerospace topics at Chicoutimi College of Aviation – CQFA Montréal. He is an 18,000-hour TT pilot and instructor with extensive airline, business and charter experience on both airplanes and helicopters. A former IATA ops director, he has served on several ICAO panels. He is a Fellow of the Royal Aeronautical Society and is a flight operations expert on technical projects under UN administration.