Aerospace and Electronic Systems Magazine July 2017 - 9

Lim et al.
ceptable level during normal/emergency operations, and that pilot
incapacitation does not compromise flight safety. The operational
requirements for commercial air transport are described in FAR
121; in FAR 121.385(c), a minimum of two pilots is required for
commercial operations. For air operators, guidance for operations
and certification is provided in two documents from ICAO.
For SPO, the main guidelines for crew responsibility and authority are described in FAR 23.1523, EASA Annex VIII Part-SPO
(Special Operations), Subpart A (SPO.GEN.105/106/107). Unlike
FAR 25.1523, FAR 23.1523 does not have a similar requirement
mandating a minimum of two pilots for operation. EASA's AMC/
GM to Annex III provides additional guidelines for SPO personnel
(SPO.100), high-risk commercial operations (SPO.110), and CRM
training (FC.115). ICAO Annex 1, Section 2.1.3 provides recommendations for class and type ratings for single-pilot aircraft. Section 9-11 to 9-17 of FAA-H-8083-9A gives an overview of single-pilot resource management (SRM); FAA AC 91-73B provides
guidelines for taxi procedures for Part 91 and 135 SPO; CASA
EX43/11 provides an exemption for SPO in Cessna 550/560 aircraft along with accompanying requirements and conditions; CAA
AC 91-11 is an advisory circular for SPO under instrument flight
rules (IFR) containing the relevant checklists, CRM guidelines,
and outline of a typical SPO flight; CAA Standards Document
14 provides guidance for the required skill tests and proficiency
checks in the certification and licensing of SPO aircraft.
For RPAS, ICAO's manual on RPAS provides a broad overview of various operational aspects including the integration of
RPAS into civil airspace; EASA A-NPA-2015 provides some classification and specification frameworks; the Joint Authorities for
Rulemaking of Unmanned Systems (JARUS) gives some recommendations regarding flight crew licensing; Chapter 2 of RTCA
DO-304 and Volume 1 DO-344 discuss operational and functional
requirements; while Australian and British Civil Aviation Authorities provide some material on operational procedures (CASA AC
101-1), airworthiness framework (CASA DP-1529US), and general operational procedures (CAP 722 Section 5).

Technical Aspects
Technical considerations capture the requirements and recommendations for the design and development of CNS systems. Requirements from two-pilot operations provide the required framework, with RPAS references covering aspects of the command
and control (C2) link and sense-and-avoid functionalities. There
are no specific technical requirements unique to SPO at this point,
although some are embedded into two-pilot requirements (e.g.,
EASA Annex VIII, SPO.IDE.A.126, FAA AC 91-100(0) Sect. 6).
For two-pilot aircraft, the requirements for system design and
installation are given under FAR 25, along with the communication (RTCA DO-238, ICAO 9869 AN/62), navigation (ICAO 9613
AN/937) and surveillance (RTCA DO-289, ICAO 9224) system requirements. For RPAS technical requirements, references are made
to both civil and military domains. For civil aviation, Chapters 10 to
13 of ICAO's Manual of RPAS make technical recommendations for
communications, surveillance, and C2 systems. JARUS D.04 covers
the required C2 link performance, Appendix C.3 of FAA's roadmap
covers the future technical requirements for integrating UAS into the
JULY 2017

civil airspace [19], including ground-based/airborne sense and avoid,
as well as C2 and interoperability requirements; these are expected
to be (or have already been) captured in FAA Technical Standard Orders (TSO) and RTCA Minimum Operational Performance Standards
(MOPS) referenced in its Appendix. CAP 722 provides some guidance
on system autonomy, as well as sense-and-avoid. Military regulations
for unmanned systems are specified in NATO's STANAG 4586 and
DOD's Unmanned Systems Integrated Roadmap - the former defines
the interoperability and HMI requirements for RPAS in NATO's Joint
Service Environment while the latter recommends research areas to
achieve greater interoperability (Chapter 4), system autonomy (Chapter 5), and airspace integration (Chapter 6) as well as required communications (Chapter 7) and HMT (Chapter 10) capabilities.

Safety Aspects
The safety requirements for system design are extracted from FAR
25.1309 and the corresponding Advisory Circular FAR AC 25.13091A on showing compliance with fail-safe design. SAE provides
Aerospace Recommended Practices for the development and design
(ARP-4754A) and safety assessment (ARP-4761) of avionics systems. JARUS AMC RPAS.1309 provides a means of compliance for
the safety and risk assessment of RPAS systems, also making reference to ARP-4754A, ARP-4761, and CAP-722. EUROCAE ER-010
accompanies RPAS.1309 and presents the safety objectives, risk assessment approach, and guiding principles for safety/risk assessment.
CAP 722 Section 4, Chapter 4 offers additional guidance for general safety assessment, and ICAO 10019 AN/507 Chapter 7 provides
guidelines for safety management in the operational context.

Human Factors Aspects
The HF considerations provide a framework for interface and
interaction design, system behaviour, CRM, and HMT. FAA TC13/44 is a recent report by the FAA, comprehensively addressing
the HF considerations on the flight deck. These include the design
and evaluation of display formats; the organization and content of
information elements; visual and auditory alerting, control/input
devices; design philosophy and function; error management, prevention, detection, and recovery; workload and automation. Additional information can be found in FAR AC 25.1302-1, which
provides the AMC for reducing design-related human error on the
flight deck. ARINC 837 goes into detail regarding design guidelines for cabin HMI. Part two of ICAO's Human Factors Training
Manual (9683 AN/950) is a resource for CRM (Chapter 2) and
automation training (Chapter 3). The SPO publications in this area
are related to SRM in GA aircraft (CAAP 5.59-1(0)). For RPAS,
CAP 722 provides an overview of the HF issue in design, production, operations, and maintenance. STANAG 4586, Appendix B3
provides the HMI requirements for interoperability within NATO
operations, and Chapter 10 of the DOD Unmanned Systems Roadmap (11-S-3613) provides a discussion of past, present, and future
requirements of HMT with autonomous systems.

Test and Evaluation Aspects
Finally, the T&E considerations for two-pilot operations cover the
different phases of T&E of the relevant CNS systems, from soft-

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Table of Contents for the Digital Edition of Aerospace and Electronic Systems Magazine July 2017