3.1 Aircraft flight recorder equipment provides data that may be used for the purposes of accident/incident investigation, and therefore contribute to the safety of future aircraft operations. Locating equipment provides the means by which an aircraft and personnel can be located following an accident. DASR ORO.85 Flight Recorder and Locating Equipment requires a Military Air Operator (MAO) to ensure that Defence aircraft are fitted with flight recorder and locating equipment appropriate to its military configuration, role and operating environment (CRE) to:
locate aircraft and personnel in the event of an aircraft crash
provide data that can be downloaded, interpreted and analysed by approved personnel to assist in the prevention of further aviation safety occurrences.
3.2 While the Authority recognised civil Airworthiness Codes defined in Section 1 of this manual prescribe suitable requirements for flight recorder and locating equipment, clear and comprehensive design requirements are not prescribed in all Authority recognised military Airworthiness Codes. Consequently, the Authority prescribes airworthiness design requirements for flight recorder and locating equipment to supplement the Airworthiness Codes.
3.3 This Chapter presents Authority prescribed airworthiness design requirements for Defence aircraft flight recorder and locating equipment.
3.4 Flight recorder equipment is any type of receiver installed in the aircraft for the primary purpose of complementing accident/incident investigation. Flight recorder equipment in Defence aircraft normally consists of a Flight Data Recorder (FDR), a Cockpit Voice Recorder (CVR) and an Underwater Locating Device (ULD). For the purpose of defining design requirements for flight recorder equipment, Defence aircraft have been grouped into the following three broad categories:
large fixed wing, multi-engine aircraft
small fixed wing, fighter/attack/trainer aircraft
rotary wing aircraft.
3.5 The following paragraphs define the Authority prescribed flight recorder equipment airworthiness design requirements. Where reference to a specific standard is made within these requirements, the latest version of the standard applies.
3.6 Design Requirement (Essential). Flight recorder equipment fitted to Defence aircraft must satisfy the requirements defined in Section 2 of EUROCAE ED-112 Minimum Operational Performance Specification for Crash Protected Airborne Recorder Systems, as follows:
Large fixed wing aircraft. ED-112 Part I for Class 1 CVRs, and ED-112 Part II for Class A FDRs, including data recording requirements.
Small fixed wing aircraft. ED-112 Part I for Class 1 CVRs, and ED-112 Part II for Class B FDRs, including data recording requirements.
Rotary wing aircraft. ED-112 Part I for Class 1 CVRs, and ED-112 Part II for Class B or D FDRs, including data recording requirements.
3.7 Defence aircraft flight recorder equipment should provide sufficient data both in terms of number and type of parameters and recording timeframe to support comprehensive accident and incident investigations. EUROCAE ED-112 defines the contemporary requirements against which civil flight recorder installations are certified, and provides an acceptable basis for Defence aircraft flight recorder equipment certification. For certain aircraft types (eg Navy helicopters) deployable FDRs that comply with ED-112 Part II Class D requirements may be more appropriate, and this should be established in consultation with the capability manager prior to specifying the required design standard.
3.8 While ED-112 has been adopted by the Authority as the benchmark airworthiness design requirement for flight recorder equipment, military aircraft are often not designed to satisfy the ED-112 standard. However, some parameters used for accident investigation purposes may be available from other aircraft sources or their absence may not preclude a successful accident/incident investigation. Therefore, before embarking on often expensive modifications to comply with the full scope of ED-112 requirements, the Authority should be approached for advice on the acceptability of the current flight recorder installation.
3.9 Design Requirement (Essential). In addition to data recording requirements defined in ED-112, unique design or operational characteristics of Defence aircraft that may impact safe flight must be evaluated to establish if recording of additional parameters for these features is warranted.
3.10 Defence aircraft configurations may include military unique safety related design features that are not included within the ‘standard’ suite of recorded parameters required by ED-112. In particular, mission system modifications may introduce failure modes or operational characteristics that adversely impact safe flight. A flight recorder system that complies only with the requirements of ED-112 may not capture data parameters associated with these systems and, therefore, may not furnish accident investigators with sufficient data to identify the cause of an accident. Consequently, Defence aircraft modifications, particularly those fitted to civil-derivative Defence aircraft, must be evaluated to determine whether recording of additional data parameters is warranted.
3.11 Design Requirement (Essential). Flight recorder equipment must remain powered throughout all phases of aircraft operation, and following total loss of aircraft primary power sources.
3.12 Electrical power to flight recorder equipment must be maintained throughout all aircraft operating modes to ensure the continued recording of aircraft parameters post power failure. To establish the adequacy of power supply arrangements for ensuring data integrity for future incident/accident investigation purposes, the potential for complete aircraft power supply failure to the flight recorder equipment should be evaluated. Where flight recorder equipment is not powered from an aircraft supply that ensures continued recorder operation following primary aircraft power supply failure (eg connection via the essential/battery bus), a supplementary flight recorder power supply will be required. In these circumstances a Recorder Independent Power Supply (RIPS), which ensures that the equipment will continue to record aircraft data parameters, may be appropriate. RIPS fitted to Defence aircraft flight recorder equipment should comply with the requirements of ED-112 Section 5.
3.13 Design Requirement (Essential). Underwater location devices (ULD) must comply with the following:
37.5 kHz ULD fitted to non-deployable flight recorder equipment:
SAE AS8045A,
EUROCAE ED112, and
TSO C-121b.
8.8 kHz airframe ULD fitted to Defence aircraft:
ARINC Specification 677, or
SAE AS6254A, and
ETSO C-200a.
3.14 ULDs assist in the location of flight recorder equipment (in particular the data storage module(s)) and the aircraft itself following an aircraft accident over water. Consequently, all Defence aircraft flight recording equipment must be fitted with a ULD that transmits a signal compatible with extant search and rescue monitoring requirements and has appropriate battery life. Where ULD are fitted to Defence aircraft airframes, to aid in location of aircraft wreckage that may have become separated from the flight recorder equipment, these ULDs also must transmit signals compatible with extant search and rescue monitoring requirements.
3.15 This section presents design requirements for Defence aircraft locating equipment (Emergency Locator Transmitter (ELT) systems). An ELT provides the means by which an aircraft and personnel can be located following an aircraft accident. ELTs broadcast distinctive signals on designated frequencies and, depending on application, may be automatically or manually activated.
3.16 Design Requirement (Essential). Emergency Locator Transmitter (ELT) fitted to Defence aircraft must provide dual 121.5/406 MHz capability and comply with FAA TSO-C126 or EASA ETSO-2C126, 406 MHz Emergency Locator Transmitter.
3.17 The fitment of 406 MHz ELTs enables the emergency satellite monitoring system to detect a crashed aircraft, while the 121.5 MHz capability will assist with radio location of the crash site by search and rescue aircraft when in close proximity. Note that portable signalling equipment, such as personal locator beacons, may also be fitted to Defence aircraft (or carried on board with crew/passengers) and should also be confirmed as being compatible with current emergency response search and rescue frequencies. Any proposal to utilise such portable signalling equipment as a substitute for the fixed aircraft ELT must be communicated to the capability manager who will determine if such use is appropriate in consultation with the Authority.
3.18 Continuing airworthiness requirement. A flight recorder equipment maintenance program should be established so that Defence aircraft flight recording equipment and associated sensors remain operable during the aircraft’s service life.
3.19 Flight recorder equipment, and associated sensors, maintenance requirements should be established and promulgated, and include as a minimum:
an annual check of the serviceability of data sensors
annual download and analysis of flight recorder data to confirm fidelity of the recording.
3.20 Detailed considerations for the conduct of annual checks of flight recorder equipment are contained in the Defence Aviation Safety Manual.
3.21 Continuing airworthiness requirement. An ELT maintenance program should be established so that Defence aircraft ELTs remain operable during their service life.
3.22 ELT maintenance requirements should be established and promulgated, and include as a minimum:
an ELT functional test at least every 12 months
corrosion inspection performed during each required battery change
battery change in accordance with the manufacturers guidelines followed by a functional check.
3.23 Capability requirement. Recorded data security risk assessments should be conducted on Defence aircraft flight recorder equipment, with associated controls identified, implemented and documented.
3.24 Flight recorder designs may not afford adequate protection against unauthorised access to sensitive information that may be processed by and recorded on flight recorder equipment. Consequently, a security assessment of the system and data recorded should be undertaken to identify potential implications of unauthorised access. Where potential security risks are identified, these should be evaluated and appropriate controls (eg design - installation of ‘zeroise’ features or data encryption; or procedural - requirements for disabling data recording functions during certain operational scenarios) should be implemented where warranted. Any protective measures implemented or required to be conducted during aircraft operations should be documented in the aircraft’s security program documentation (eg the aircraft specific Security Classification and Categorisation Guide).
3.25 Further guidance on implementing the flight recorder and locating equipment requirements prescribed in this chapter can be provided by the chapter sponsor.