Nº 5 2015 > Aviation
Safety and efficiency of global aviation
Dr Fang Liu
Secretary-General, International Civil Aviation Organization (ICAO)
The International Civil Aviation Organization (ICAO), like ITU, is, a specialized agency of the United Nations. ICAO develops standards and recommended practices (SARPs) enabling today’s global air transport network to operate safely, efficiently and securely throughout the world. At any given moment, there are around a million aircraft passengers being carried by our global network across the world’s skies, and over 100 000 flights are managed each and every day. Last year alone, aviation moved some 3.3 billion passengers in total, fostering greater peace and economic prosperity wherever aircraft fly.
States have recognized that the future development of international civil aviation could greatly help to create and preserve friendship and understanding among the nations and peoples of the world. The States who established the Convention on International Civil Aviation agreed on certain principles and arrangements in order that international civil aviation could be developed in a safe and orderly manner, and such that international air transport services would be established on the basis of equality of opportunity and operated soundly and economically.
In the ITU World Radiocommunication Conference context, ICAO’s role is to convey the coordinated position of the entire international civil aviation community, including States, airlines, airport and air navigation services operators, and other stakeholders. And given the extensive use of the radio-frequency spectrum for functions critical to the safety and efficiency of aircraft operations, it should come as no surprise that the aviation community has strong views on a number of WRC‑15 agenda items.
On behalf of ICAO, I am pleased to have the opportunity to address three items of particular importance to the safety and efficiency of international civil aviation, in advance of WRC‑15, namely: global flight tracking (GFT); unmanned aircraft systems (UAS); and the protection of aeronautical use of very-small aperture terminals (VSATs) in the African and Indian Ocean region.
Global flight tracking for civil aviation
One of the reasons why aviation has consistently improved upon its renowned levels of safety and efficiency over the decades has been its willingness to invest significant effort and resources to learn important lessons — even from rare events. While 2014 represented one of aviation’s safest years in terms of the number of accidents, the tragedy of missing Malaysia Airlines flight 370 in March 2014 highlighted vulnerabilities in the global air navigation system, requiring urgent mitigation.
In order to address those vulnerabilities, the aviation community has embarked on a global effort under the joint auspices of ICAO and the International Air Transport Association (IATA) to develop and implement a Global Aeronautical Distress and Safety System (GADSS), encompassing all phases of flight under all circumstances, including distress.
A fundamental component of the GADSS objectives is global flight tracking (GFT), which enables aircraft operators and air navigation service providers to obtain a real-time record of aircraft positions worldwide. ICAO is currently developing international SARPs for GFT using a “performance-based” approach, whereby ICAO SARPs set minimum performance requirements but do not prescribe the specific technological systems or solutions needed to meet those requirements. Several viable candidate technologies are already available to address this new requirement, and developments are also underway to enhance the capability of some of them to track commercial aircraft.
One such development builds on currently available automatic dependent surveillance — broadcast (ADS‑B) technology, whereby aircraft can broadcast position reports at 1090 MHz. ADS‑B, in principle, provides all the information required for GFT. A significant limitation, however, is that its broadcasts can only be received by ground stations within line of sight of an aircraft, and not over the remote and high seas territories where flight tracking needs are most acute.
To remove this limitation, a new satellite constellation is currently being deployed which can capture ADS‑B reports from aircraft located in polar, oceanic and other remote areas and then re-broadcasts them to GFT ground systems. An important advantage of this solution is that it leverages and complements existing ADS‑B aircraft capabilities without requiring aircraft retrofits.
Early indications of system performance are promising, but one regulatory hurdle persists. While current ADS‑B transmissions use an existing ARNS allocation, reception of ADS‑B by satellite would require an Earth-to-space aeronautical mobile satellite (route) service (AMS(R)S) allocation, consistent with the physical location of the receivers (on a satellite) and with the purpose of the reception (safety-of-life). But no such allocation exists today.
Fortunately, thanks to ITU’s prompt response to the MH 370 tragedy and to the foresight of the recent ITU Plenipotentiary Conference (PP‑14), an opportunity to introduce the necessary spectrum allocation is now available. We should recall that Resolution 185, adopted at PP‑14, resolved to instruct WRC‑15 to include in its agenda, as a matter of urgency, the consideration of global flight tracking.
ICAO certainly shares the sense of urgency voiced by PP‑14, and believes that this unique opportunity should be seized without delay to introduce the necessary Earth-to-space AMS(R)S allocation at 1090 MHz. This band should be used for the satellite reception of existing aircraft ADS‑B signals that operate in accordance with recognized international standards, under the condition that existing aeronautical safety systems are not constrained.
In light of the progress in the ITU Radiocommunication Sector (ITU–R) studies, and the great benefits offered by this spectrum allocation, ICAO is confident that the radio regulatory community will again step forward proactively to help global civil aviation States and operators maintain and improve their ability to protect the lives of aircraft passengers and crew.
Unmanned aircraft systems
The level of impact of the ongoing introduction of unmanned aircraft systems (UAS) in civil aviation has been compared to what was seen in air transport after the arrival of jet engines in the 1950s. UAS have been breaking many paradigms underpinning the existing global aviation system, and are opening new and exciting frontiers of operational innovation for many citizens and businesses in every world region. Their safe and efficient incorporation into the aviation system is a challenge that will involve far-reaching changes and the determined cooperation of all aviation stakeholders, and as part of this process ICAO is committed to developing a comprehensive, safe and harmonized international UAS aviation regulatory framework.
Along with its aeronautical regulatory aspects, the introduction of UAS also poses challenges to the existing radio-frequency regulatory framework. In particular, it now seems likely that the available AMS(R)S allocations for beyond-line-of-sight (BLOS) control and non-payload communications (CNPC) will be insufficient to meet UAS requirements.
Existing satellite networks operating in the fixed-satellite service (FSS) at 14/12 GHz and 30/20 GHz have potential capacity available which could be used for UAS CNPC under certain conditions. The FSS is not recognized in the ITU as a safety service, however, and therefore its use for CNCP raises potential concerns.
To address these issues, studies ongoing within the ITU–R are focusing on performance and compatibility matters. For its part, ICAO has identified seven conditions that should be satisfied in order to enable the use of FSS for UAS, partitioned into two sets: three to be addressed in the ITU Radio Regulations (RR), and four which must be dealt with through ICAO. The set of conditions relevant to ITU jurisdiction focus on providing a radio regulatory framework for the safe operation of UAS CNPC links in FSS bands, thus obtaining international recognition along with the basis for avoiding harmful interference. It includes the following conditions:
- That the technical and regulatory actions be limited to the case of UAS using satellites, as studied, and not set a precedent that puts other aeronautical safety services at risk.
- That all frequency bands which carry aeronautical safety communications be clearly identified in the ITU Radio Regulations.
- That the assignments and use of the relevant frequency bands be consistent with provision No. 4.10 of the ITU Radio Regulations, which recognizes that safety services require special measures to ensure their freedom from harmful interference.
The availability of a robust radio regulatory framework meeting these conditions would enable the development of ICAO SARPs for UAS CNPC, addressing technical and operational requirements for specific airspace types and frequency bands.
Protection of aeronautical VSATs
The provision of air navigation services requires a ground communication infrastructure with high availability, reliability and integrity. In parts of the African and Indian Ocean Region, the difficulty of fulfilling these requirements through the terrestrial infrastructure has led to the widespread use of very small aperture terminal (VSAT) technology operating in the 3.4–4.2 GHz range.
Today, VSATs constitute a critical infrastructure network spanning the African continent, such that availability of the entire band is crucial in that region to support the continued growth of air traffic, while maintaining required safety parameters.
However, following the allocation by WRC‑07 of the 3.4–3.6 GHz band to the mobile service (MS) in some countries (RR No. 5.430A), the deployment of mobile service (MS) systems in the vicinity of airports has led to an increased number of cases of interference into aeronautical VSAT receivers. In order to prevent such occurrences in the future, additional measures need to be adopted to improve the protection of the FSS links supporting aeronautical communications. This is recognized by Resolution 154 (WRC‑12), which calls for the ITU–R:
“to study possible technical and regulatory measures in some countries in Region 1 to support the existing and future FSS earth stations in the 3400–4200 MHz band used for satellite communications related to safe operation of aircraft and reliable distribution of meteorological information”.
ICAO has participated in the ITU–R studies and supports the modification of Resolution 154 as exemplified in the CPM report (Section 5/9.1.5/4), including the introduction of a reference to the Resolution in RR No. 5.430A.
Looking to the future
The onset of our 21st Century digital communications environment, inclusive of all its benefits in terms of technical progress and cultural and information exchange, could not have been realized without the solid foundation that ITU has established over the past 150 years, as well as its vision and forward-looking decisions in more recent global forums.
Air transport serves as an important enabler of socio-economic development in States and regions all over the world, and is an essential contributor to achieving the UN Sustainable Development Goals. The significance of obtaining the required frequency spectrum allocations needed urgently by the aviation sector to ensure the safe and efficient future operations of civilian aircraft is more critical today than at any point in the history of international civil aviation.