Introduction
Statements of Operating Intent and Usage (SOIU) must effectively describe the intended roles, usage and operating environment for a particular Defence aircraft type. This chapter expands on multiple DASR policy areas to present coherent guidance to Capability Managers (CM), Military Air Operators (MAO) and Project Offices (PO) on producing SOIUs.
The SOIU requirements for an aircraft are derived from a series of capability requirements documents. The SOIU provides the broad operating parameters within which the aircraft type can safely operate. The SOIU must have sufficient detail to support identification of system requirements for a Defence aircraft type under acquisition or modification via a Major Change to Type Design. Accordingly, the SOIU is a key document in developing the Type Certification Basis (TCB) for new Defence aircraft or Major Changes to Type Design. In addition, the SOIU defines the intended scope of employment of an aircraft by a Military Air Operator (MAO) during flight operations.
Purpose
This chapter describes the lifecycle of an SOIU for Defence certified aircraft (including certified UAS). Development of an SOIU is not mandatory for a Non-Defence Registered Aircraft (NDRA), but may assist a MAO to establish the operational context of their intended NDRA operations to assist with identification of any additional safety controls required in order to eliminate or minimise risks SFARP. This chapter describes the relationship between the SOIU and other key project documents and DASR authorisations. For non-certified UAS refer to DASPMAN Volume 3 Part 2 Chapter 3.
SOIU Relationship to Capability Strategy, Plans and Policy
The SOIU synthesises the capability requirements into intended functional, enabling and sustainment requirements for a Defence aircraft system. Capability requirements may stem from Defence strategic policy (such as the Defence Strategic Review), Service capability plans/strategies, and aircraft platform Operations Concept Documents (OCDs) and Capability Realisation Plans (CRPs). They may include interoperability, force generation and preparedness outcomes. Thus, the SOIU is subordinate to these capability documents and (together with the Integrated Program Management Plan (IPMP)) establishes the concept of operations and system level requirements to support safe introduction into service (and subsequent sustainment) of an aircraft type. In turn, the SOIU plays a foundational role within the system of DASR authorisations for an aircraft platform. Figure 1 shows the synthesis of platform capability requirements into the SOIU. A depiction of the DASR artefacts that are dependent on the SOIU is contained at DASPMAN Vol 3 ASAMP Chapter N Annex A.
Figure 1: Capability Requirement Inputs to SOIU Development
DASR Requirements
The SOIU enables identification of aviation system requirements that underpin Initial Airworthiness certification activities and Flight Operations authorisations regulated under DASR. The following DASR, associated Guidance Material (GM) and Acceptable Means of Compliance (AMC) applicable to this chapter are:
Uses of the SOIU by various stakeholders
Due to the prevalence of the SOIU in multiple DASR policy areas, different stakeholders use the SOIU for differing purposes. A PO (or Military Type Certificate Holder (MTCH)) uses an initial SOIU to determine an appropriate Certification Basis for a Type. The initial SOIU also documents the intended aircraft usage spectrum, which underpins the aircraft and engine structural certification requirements. MAO use initial SOIU to inform the intended bounds of aircraft operations. This supports a MAO in establishing a Flying Management System (FMS) for an Aircraft Type. In sustainment, the SOIU is used to communicate how the MAO-AM is currently operating, and how they intend to operate the platform in the future. As a result, variation of the SOIU will have an impact across multiple stakeholders and previously issued DASR authorisations.
SOIU Lifecycle
The SOIU is subject to regular variation, due to changes in intended aircraft capability, usage or operating environment. Amendment of the SOIU triggers a cascade of stakeholder actions to implement revised capability and seek a range of DASR authorisations. Figure 2 depicts the SOIU lifecycle.
Figure 2: Depiction of the SOIU Lifecycle within DASR
Step 1 – Capability Definition and/or requirement. The decision of when to develop an initial SOIU for Defence aircraft or capability may vary across the One Defence Capability System (ODCS) (formerly known as the Capability Life Cycle (CLC)) dependent on the scope and complexity of the project. Usually, development of an initial SOIU occurs post Gate 0, to support the risk mitigation and requirements setting phase of the ODCS. At the very latest, an approved SOIU must be in place to support commencement of acquisition activities (Investment Committee Gate 2 decision). SOIU development is one of the first planning milestones within an Aviation Safety Acquisition Management Plan (ASAMP). Following Introduction Into Service (IIS), emerging capability needs may necessitate variation of the SOIU, if they substantially alter the intended aircraft role, usage or operating environment of the subject aircraft.
Step 2 – SOIU Development. The acquisition PO initially develops the SOIU as a joint operational and technical document. At this stage, the SOIU must have sufficient information to inform type certification activities and support identification of anticipated organisational approval and authorisation requirements. The MAO is responsible for in-service management of the SOIU, supported by the Continuing Airworthiness Management Organisation (CAMO) and MTCH (or delegate). The MTCH should ensure that the proposed SOIU is compatible with the Type Certification Basis.
There should be sufficient detail in an SOIU to articulate intended aircraft system roles, tasks, functional requirements, operating environments and anticipated aircraft usage. DASR ARO.50 does not mandate further detailed SOIU content requirements. DASA has developed an SOIU template (on the DASA website) as per DASR ARO.50.a (GM), based upon observed regulated community best practice. Further guidance on suggested SOIU content is in paragraph 16.
Step 3 – DASA Endorsement. DASR ARO.50 requires that DASA endorse SOIU for Defence registered aircraft. DASA endorsement will be scaled based on program maturity and recognising that further maturation of the SOIU will occur during early phases of acquisition. All applications for DASA endorsement of an SOIU need PD/MTCH and operator evidentiary statements to confirm the engagement of relevant stakeholders during the development of the SOIU. DASA endorses the SOIU as an appropriate input to Initial Airworthiness approvals. In providing endorsement of the SOIU, DASA assures the MAO arrangements underpinning the MAOC Operations Compliance Statement (OCS) are consistent with the SOIU scope of intended current operations. This endorsement does not approve any role or usage stated within the SOIU. Where necessary, DASA staff will identify caveats to endorsement, which may include Specific Limitations against the affected aircraft type within the MAOC OpSpec. Particularly, staff from each of the DASA Directorates (Initial Airworthiness, Continuing Airworthiness, Aviation Engineering and Aviation Operations) will assure the SOIU is sufficiently detailed to:
establish and maintain the Type Design of the aircraft
ascertain whether or not any changes to the CRE alter the validity of the MAOC OpSpec
ascertain whether any Human Factors/Human Machine Interface (HF/HMI) requirements, performance and handling qualities impacts have been identified
ascertain whether the SOIU (mainly Flight Profiles, Mission Mix and Rate of Effort) provide sufficient detail to manage aircraft and propulsion system structural life-limits and management.
Step 4 – Command Approval. The Environmental Commander (COMAUSFLT/ COMD AVNCOMD/ ACAUST) approves the SOIU for their respective services, following endorsement by the Defence Aviation Authority’s airworthiness delegate (DG DASA). SOIU approval represents:
confirmation that the SOIU meets capability requirements as laid out in platform Operational Concept Documents and Joint / Service Capability Strategies
approval of the intended scope of aircraft operations and environment
commitment of resourcing to meet intended ROE (and force generation requirements)
part of the direction for the MAO and MTCH to proceed with developing applications for necessary changes to DASA organisational approvals and authorisations.
Step 5 – MAO-AM Development or Update. Upon receipt of an approved SOIU, the MAO (supported by the MTCH, CAMO and PO) should undertake a program of work to develop submissions to DASA for Type Certification, Organisational Approvals and other required DASA Authorisations that will underpin implementation of the SOIU intent. These submissions are ensure actions as shown at DASPMAN Vol 3 Chap 6.2.1 Annex A. For initial SOIU (or major changes in capability), this will likely involve development of planning documentation such as the Aviation Safety Acquisition Management Plan (ASAMP), Certification Program Plan (CPP) and Organisational Approvals and Authorisations Plan (OAAP) (if not already developed at Step 1). SOIU variations involving Major Changes to Type Design will follow the Type Certification process under DASR 21.A.17. Concurrently, the MAO will develop updates to Orders, Instructions and Publications (OIP), establish training, and pursue all other necessary changes in order to support variation of the MAO OCS per DASR ARO.100. This step will culminate in the MAO application to the Authority for issue of (or variation to) a MAOC OpSpec commensurate with the new or modified SOIU (including the SOIU version number and approval date), citing evidence of changes underpinning the revised MAOC OCS.
Step 6 – DASA Approval. DASA directorates provide independent assurance to support the issue of changes to Type Design and DASA Authorisations. DASA bases these activities on objective evidence accompanying submissions. DASA only considers an SOIU authoritative when the MAOC OpSpec reflects the authorised version.
Step 7 – Operations. Per DASR ARO.100, ORO.05, and ORO.10, the intended scope of operations are within the SOIU and authorised by the MAOC OpSpec. For an aircraft system in being there will always be an authorised SOIU annotated on the MAOC OpSpec Type Annex. Other draft SOIU variations may be in development and progressing along the SOIU lifecycle.
SOIU Content Guidance
The MAO/PO routinely updates the SOIU to distinguish between the intended scope of current operations from potential future capabilities. DASA has developed an SOIU template based upon observed best practice in the regulated community. The following SOIU topics are applicable to all new or modified aircraft types:
Description of Aircraft Roles. Describe the aircraft role in terms of the predominant operations the aircraft will undertake. This is usually in terms of the operational effect associated with conduct of the role, such as Offensive Counter Air, Anti-submarine Warfare or Air Logistics Support. An aircraft may undertake several different roles. The level of detail in the description for each role must be commensurate with the need to define those roles for which the aircraft is authorised and inform the definition of associated tasks, flight profiles and operating environment. While the role of the aircraft is a sub-element and intrinsic attribute of capability, the MAO/PO should not include the capability objectives that the aircraft supports.
Description of Aircraft Tasks. Aircraft tasks are subordinate elements (or discrete activities) that are necessary in order to fulfil an aircraft role. These can relate directly to the conduct of operations or considered as force enabling tasks. Examples of role related tasks for an aircraft might include Humanitarian Aid and Disaster Relief, Aerial Delivery, Search and Rescue or Passenger Transport. Enabling tasks may include Aircraft Initial and Conversion Training, Flight Test activities, Flypast and Flying Displays or Air to Air Refuelling. Task descriptions should discuss particular aircraft configuration requirements (such as enabling role or mission equipment) or intended operating environment factors (such as for embarked helicopter operations and sustainment) that are unique to the conduct of the task. The formulation of flight profiles uses this detail.
Flight Profiles. Depending on the number of intended tasks, Flight profiles may be included in the main body of the SOIU or as annexes. Flight profiles should have sufficient detail to establish aircraft usage monitoring programs, enable generation of training packages and development of MAO OIP. Flight profiles should be compiled into logical groups such as ‘Common Profiles’, ‘Ground Attack’, ‘Air-to-Air’, ‘Aeromedical Evacuation’ and similar logical groupings. There may be benefit to include a short discussion of intended aircraft configurations for each flight profile, including intended role equipment and Minimum Equipment List (MEL) impacts (if applicable). A list of suggested parameters, graphics and tabulated manoeuvre depictions to include in flight profiles is contained within the DASA SOIU template.
Physical Operating Environment. Usually, the physical operating environment is broken into the airborne physical environment and ground physical environment. The intended physical operating environment will have bearing on the aircraft limitations documented within the TCDS (and in turn the Aircraft Flight Manual) and will inform the aircraft usage monitoring, engine and structural integrity programs. A list of suggested operating environment parameters is contained within the DASA SOIU template.
Functional Operating Environment. The functional environment should describe the intended flight operation considerations associated with airspace access regulations (e.g. Communication, Navigation, Surveillance / Air Traffic Management (CNS/ATM)), operations in electromagnetic (EM) and threat environments, or where compliance provides desired safety enhancements for certain niche activities (e.g. frequent operations close to the ground or prolonged overwater). The functional environment section should also articulate the intended applicability of Specific Purpose Approvals under DASR SPA. For items that are potentially classified above OFFICIAL: Sensitive, a reference to the applicable document that contains the required information is appropriate.
Intended Rate of Effort and Planned Withdrawal Date. The intended rate of effort and planned withdrawal date should align with ADF capability strategies and the aircraft’s OCD.
Consideration of ADF unique policy and procedural impacts. There may be ADF policies and procedures (eg Aviation Safety Design Requirements Manual), or Australian legislative requirements (eg Work Health and Safety Act 2011) that could affect Defence aircraft design, type certification or intended operations. This section of the SOIU should capture the unique Australian requirements to inform Type Certification requirement setting or the need for MAOC OpSpec Specific Limitations. Therefore, this section should describe any unique ADF policy and procedures that could influence the Defence aircraft operations, as well as identify any Australian legislation that must be complied with that could affect the aircraft design or operations.
Clearly segregated discussion of anticipated future capabilities or changes. The anticipated future capabilities or changes section is to segregate any anticipated change in the aircraft Configuration, Role and Environment (CRE), which deviates from the stated intent of current operations in the main body of the SOIU. This segregation is imperative to understand the approved scope of current aircraft operations implemented via the TCB and MAOC OpSpec and for the MAO to maintain compliance with DASR ORO.05 and ORO.10. This definition of future intended capabilities or changes may be used to support requirement setting activities.
SOIU Terminology. As the SOIU defines an intent, the drafter should utilise words like ‘intends’, ‘plans’, ‘anticipates’ and ‘expects’ in preference to words like ‘approved’, ‘capable’, and ‘certified’. This is to clarify that the document is a statement of intent only and with implementation recommendations. The authoritative documents that limit aircraft operations are comprised of the Type Certificate Data Sheet (TCDS) (for aircraft limitations and environmental limitations) and the MAOC OpSpec (for task related Specific Approvals and Limitations).