# Operational Requirements List (ORL) — MRT-X Tactical UAS **Document:** ORL-MRTX-001 **Revision:** v1.0 **Date:** 3 June 2026 **Prepared in response to:** NAVAIR PMA-263 RFI, Notice 243-26-024, 11 February 2026 **Prepared by:** Aerix Defense Systems (fictional) — Advanced Programs Group **Distribution:** Notional / Unclassified test material --- > **FICTIONAL DOCUMENT — METHODOLOGY TEST INPUT** > > This Operational Requirements List is fabricated test material for an academic methodology demonstration. "Aerix Defense Systems" is a fictional company. This is not a real proposal and not a response submitted to NAVAIR. It exists to provide a citation-grounded airworthiness traceability engine with a realistic requirements input to process. Per ADR-0006, the capstone does not respond to the RFI and the platform is not a proposed solution. --- ## 1. Purpose and Scope This Operational Requirements List (ORL) defines the capabilities, performance metrics, and operating conditions the MRT-X Medium Range Tactical Unmanned Aircraft System must satisfy to meet the mission need expressed in NAVAIR PMA-263 RFI Notice 243-26-024. The ORL is the parent artifact from which the system requirements baseline is derived. The ORL captures *operational* requirements — what the system must do and under what conditions — not design solutions. Where a configuration is named, it reflects the engineering team's concept of a system that can satisfy the operational need; it is not a constraint on the requirements themselves. ## 2. Mission Context The MRT-X supports U.S. Marine Corps Expeditionary Forces in Reconnaissance, Surveillance, and Target Acquisition (RSTA), patrolling, security and force protection, convoy operations, and operations in urban terrain. The system operates from amphibious ships and expeditionary advanced bases, in austere locations, across diverse global climates, day and night, including in degraded, denied, intermittent, and limited (DDIL) RF environments. The system is fielded as a cooperating swarm of 4–8 air vehicles sharing a common airframe and propulsion baseline, differentiated by mission payload. ## 3. Engineering Team of Record | Role | Engineer | Responsibility | |---|---|---| | Chief Engineer / Systems | M. Castellano | ORL structure, mission decomposition, cross-cutting requirements, class assignment | | Propulsion & Power Lead | D. Reyes | Turbogenerator, electrical architecture, energy storage, fuel system | | Flight Controls & Autonomy Lead | S. Okafor | Flight control, autonomy, lost-link behavior, GNSS-denied operation, swarm coordination | | Airworthiness & Safety Lead | J. Pell | Safety requirements, airworthiness compliance posture, emergency procedures | | Sensors & Payload Lead | L. Tran | EO/IR payload, DORI performance, mission sensors | ## 4. Sizing Evolution and Class Assignment The mission need as published assumes an air vehicle of less than 20 lb maximum gross takeoff weight (MGTOW), DoD UAS Group 1, with all-electric propulsion and not less than 2.5 hours endurance carrying the full RSTA sensor and communications payload. A battery-topology-versus-weight trade study (companion document TS-MRTX-PWR-001) was performed to validate the all-electric Group 1 concept. The trade study found that no current battery chemistry closes the endurance requirement within the Group 1 mass ceiling once the payload, datalink, navigation, and structure masses are accounted for. The energy storage mass alone, at the required endurance, exceeds the available mass budget. On the basis of that trade study, the engineering team adopted a **series-hybrid electrical architecture** in which a wet-frame auxiliary-power-unit-style turbogenerator provides continuous electrical power, supplemented by a hybrid energy buffer, and **reclassified the air vehicle to DoD UAS Group 2 (21–55 lb MGTOW)**. The airframe and rotor system are designed to a 55 lb gross-weight ceiling for growth margin and variant flexibility; nominal operational MGTOW is 43–45 lb across variants. **ORL-4.1** — The air vehicle shall be classified DoD UAS Group 2 based on operational maximum gross takeoff weight. **ORL-4.2** — The air vehicle shall maintain nominal operational MGTOW between 43 lb and 45 lb across all mission variants. **ORL-4.3** — The airframe primary structure and rotor system shall be designed to a maximum gross weight of 55 lb. ## 5. Operational Requirements ### 5.1 Mission Performance **ORL-5.1.1** — The system shall provide not less than 2.5 hours on-station endurance at cruise with the baseline ISR payload. **ORL-5.1.2** — The system shall conduct day and night RSTA operations. **ORL-5.1.3** — The system shall provide vertical takeoff and landing from unprepared expeditionary sites and from amphibious ship decks. **ORL-5.1.4** — The system shall operate as a cooperating swarm of 4 to 8 air vehicles under a single ground operator station. **ORL-5.1.5** — Each air vehicle shall serve as a mesh relay node, extending operator reach beyond direct line-of-sight to any single air vehicle. ### 5.2 Sensor and Payload **ORL-5.2.1** — The baseline ISR variant shall carry a dual-mode (EO and LWIR) gimballed sensor turret with laser rangefinder and laser designator. **ORL-5.2.2** — The sensor shall achieve DORI Identification-level performance against a NATO-standard vehicle target (2.3 m critical dimension) at the nominal operational slant range corresponding to 1500 ft AGL surveillance geometry. **ORL-5.2.3** — The sensor turret mass shall not exceed 2.0 lb for the baseline ISR variant. **ORL-5.2.4** — The system shall support SAR/GMTI and SIGINT/ES payload variants within the common airframe, with payload masses of 3.0–4.0 lb and 1.5–2.5 lb respectively. ### 5.3 Propulsion and Power **ORL-5.3.1** — The air vehicle shall employ series-hybrid electric propulsion: a turboshaft-driven generator supplying a high-voltage DC bus shared with a hybrid energy buffer, with four independently controlled electric rotor drives. **ORL-5.3.2** — The propulsion system shall operate on Jet-A, JP-8, or F-24 fuel. **ORL-5.3.3** — Fuel shall be stored in integral wet-frame structure within the airframe booms. **ORL-5.3.4** — The electrical system shall provide a 270 VDC primary bus for motor drives and energy buffer and a 28 VDC secondary bus for avionics, datalink, navigation, and payload. **ORL-5.3.5** — The energy buffer shall provide sufficient stored energy for controlled descent and autoland following loss of generator output. **ORL-5.3.6** — The turbogenerator shall provide continuous electrical output sufficient for cruise power demand with margin for energy-buffer recharge. ### 5.4 Flight Control and Navigation **ORL-5.4.1** — The air vehicle shall be controlled by a flight control system capable of autonomous and operator-in-the-loop operation. **ORL-5.4.2** — Navigation shall use a GNSS-aided inertial navigation system with dual-antenna GNSS-derived heading. **ORL-5.4.3** — The system shall continue navigation by inertial dead reckoning during GNSS outages of operationally representative duration. **ORL-5.4.4** — On loss of the command-and-control link, the air vehicle shall execute a defined lost-link contingency (return-to-home or pre-planned recovery) and, if recovery is not achievable, flight termination. ### 5.5 Communications **ORL-5.5.1** — The primary datalink shall use a mobile ad-hoc network (MANET) tactical radio with multi-band agility. **ORL-5.5.2** — The datalink shall employ FIPS 140-3 validated cryptographic modules. ### 5.6 Environmental and Operating Conditions **ORL-5.6.1** — The system shall operate across diverse global climates including hot, cold, humid, and high-density-altitude conditions. **ORL-5.6.2** — The system shall operate in salt-fog and shipboard environments without degradation of flight-critical function. **ORL-5.6.3** — The system shall operate in DDIL RF environments. ## 6. Safety and Airworthiness Posture **ORL-6.1** — The system shall be developed toward a Navy airworthiness flight clearance under the applicable NAVAIR airworthiness process for Group 2 unmanned aircraft. **ORL-6.2** — Flight-critical functions shall provide defined behavior under single-point failures of propulsion, power generation, energy storage, flight control, and navigation. **ORL-6.3** — The system shall provide fire protection and fuel-containment provisions appropriate to the propulsion and fuel architecture. **ORL-6.4** — Lithium battery installation shall meet applicable Navy lithium battery safety requirements. ## 7. Requirements Derivation Note System requirements (SRD-MRTX) will be derived from this ORL. Each ORL entry decomposes into one or more verifiable system requirements with assigned verification methods. The airworthiness traceability engine ingests this ORL and the derived requirements baseline to map each against the applicable airworthiness criteria corpus. ## 8. Revision History - **v1.0 (3 June 2026):** Initial ORL. Mission decomposition from PMA-263 RFI Notice 243-26-024. Class evolution from published Group 1 all-electric to Group 2 series-hybrid documented per battery trade study TS-MRTX-PWR-001. Operational requirements across mission, sensor, propulsion, flight control, communications, environmental, and safety domains.