# System Requirements Document (SRD) — MRT-X Tactical UAS

**Document:** SRD-MRTX-001
**Revision:** v1.0
**Date:** 3 June 2026
**Derived from:** ORL-MRTX-001, NAVAIR PMA-263 RFI Notice 243-26-024
**Prepared by:** Aerix Defense Systems (fictional) — Advanced Programs Group
**Distribution:** Notional / Unclassified test material

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> **FICTIONAL DOCUMENT — METHODOLOGY TEST INPUT**
>
> Fabricated test material for an academic methodology demonstration. Not a real proposal, not submitted to NAVAIR. Provides a citation-grounded airworthiness traceability engine with a derived requirements baseline to process. Per ADR-0006, the capstone does not respond to the RFI and the platform is not a proposed solution.

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## 1. Purpose and Conventions

This System Requirements Document (SRD) derives verifiable system requirements from the Operational Requirements List (ORL-MRTX-001) and the source RFI. Each requirement is tagged by type:

- **[DESIGN]** — a design/performance requirement defining what the system must be or do.
- **[AIRW]** — an airworthiness/safety requirement defining a condition the system must meet for flight clearance.

Requirements use "shall." Each carries a trace tag in the form `(← RFI-n / ORL-x)` identifying its parent. Verification method is noted as one of Inspection (I), Analysis (A), Demonstration (D), or Test (T).

This SRD is a clean derivation. It does not annotate where requirements conflict; conflicts present in the engineering baseline are left for the airworthiness traceability engine to surface.

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## 2. System-Level and Classification Requirements

**SRD-2.1 [DESIGN]** — The air vehicle shall be classified DoD UAS Group 2 based on operational maximum gross takeoff weight. *(← ORL-4.1)* — V: I

**SRD-2.2 [DESIGN]** — The air vehicle operational MGTOW shall be between 43 lb and 45 lb across all mission variants. *(← ORL-4.2)* — V: T

**SRD-2.3 [DESIGN]** — The airframe primary structure and rotor system shall be designed to a maximum gross weight of 55 lb. *(← ORL-4.3)* — V: A

**SRD-2.4 [DESIGN]** — Total system weight including air vehicle(s), GCS, launch/recovery equipment, batteries, and peripheral gear shall not exceed 75 lb. *(← RFI-2)* — V: T

**SRD-2.5 [DESIGN]** — The system shall achieve Technology Readiness Level 8 or higher at fielding. *(← RFI-21)* — V: A

**SRD-2.6 [AIRW]** — The system shall be developed toward a Navy airworthiness flight clearance under the applicable NAVAIR airworthiness process for Group 2 unmanned aircraft. *(← ORL-6.1)* — V: A

## 3. Mission Performance Requirements

**SRD-3.1 [DESIGN]** — The system shall provide not less than 2.5 hours endurance from takeoff to landing with a representative mission payload. *(← RFI-8 / ORL-5.1.1)* — V: T

**SRD-3.2 [DESIGN]** — The air vehicle shall sustain a cruise airspeed greater than 25 KIAS. *(← RFI-7)* — V: T

**SRD-3.3 [DESIGN]** — The system shall provide a line-of-sight datalink range of not less than 40 km. *(← RFI-9)* — V: T

**SRD-3.4 [DESIGN]** — The system shall conduct day and night RSTA operations. *(← ORL-5.1.2)* — V: D

**SRD-3.5 [DESIGN]** — A single GCS/operator shall control not fewer than two air vehicles simultaneously. *(← RFI-13 / ORL-5.1.4)* — V: D

**SRD-3.6 [DESIGN]** — The system shall operate as a cooperating swarm of 4 to 8 air vehicles. *(← ORL-5.1.4)* — V: D

**SRD-3.7 [DESIGN]** — Each air vehicle shall function as a mesh relay node for other air vehicles in the swarm. *(← ORL-5.1.5)* — V: D

**SRD-3.8 [DESIGN]** — Deployment and operation shall require no more than two operator/maintainers. *(← RFI-14)* — V: D

## 4. Payload and Sensor Requirements

**SRD-4.1 [DESIGN]** — The system shall provide a total payload capacity greater than 3.75 lb. *(← RFI-3)* — V: T

**SRD-4.2 [DESIGN]** — The baseline ISR variant shall carry a dual-mode gimbaled EO/IR payload providing UHD electro-optical imagery, HD infrared imagery, a laser rangefinder, and a laser designator. *(← RFI-4 / ORL-5.2.1)* — V: T

**SRD-4.3 [DESIGN]** — The EO/IR sensor shall achieve DORI Identification-level performance against a NATO-standard vehicle target of 2.3 m critical dimension at the slant range corresponding to 1500 ft AGL surveillance geometry. *(← ORL-5.2.2)* — V: A/T

**SRD-4.4 [DESIGN]** — The baseline ISR sensor turret mass shall not exceed 2.0 lb. *(← ORL-5.2.3)* — V: I

**SRD-4.5 [DESIGN]** — The payload architecture shall be open and modular, supporting SAR/GMTI (3.0–4.0 lb) and SIGINT/ES (1.5–2.5 lb) payload variants on the common airframe. *(← RFI-17 / ORL-5.2.4)* — V: D

**SRD-4.6 [DESIGN]** — The payload architecture shall support simultaneous operation of multiple intelligence (multi-INT) payloads. *(← RFI-6)* — V: D

**SRD-4.7 [DESIGN]** — The open modular payload architecture shall support integration of weapon payloads. *(← RFI-17)* — V: A

**SRD-4.8 [AIRW]** — Integration of any weapon payload shall be subject to weapon-system safety analysis and shall not be flight-released absent that analysis. *(← RFI-17 / ORL-6.1)* — V: A

## 5. Propulsion and Power Requirements

**SRD-5.1 [DESIGN]** — The air vehicle shall employ series-hybrid electric propulsion comprising a turboshaft-driven generator, a hybrid energy buffer, and four independently controlled electric rotor drives. *(← RFI-10 / ORL-5.3.1)* — V: D

**SRD-5.2 [DESIGN]** — The propulsion system shall operate on Jet-A, JP-8, or F-24 fuel. *(← ORL-5.3.2)* — V: T

**SRD-5.3 [DESIGN]** — Fuel shall be stored in integral wet-frame structure within the airframe booms. *(← ORL-5.3.3)* — V: I

**SRD-5.4 [DESIGN]** — The electrical system shall provide a 270 VDC primary bus and a 28 VDC secondary bus. *(← ORL-5.3.4)* — V: T

**SRD-5.5 [DESIGN]** — The turbogenerator shall provide continuous electrical output sufficient for cruise power demand with margin for energy-buffer recharge. *(← ORL-5.3.6)* — V: T

**SRD-5.6 [AIRW]** — The energy buffer shall provide sufficient stored energy for controlled descent and autoland following total loss of generator output. *(← ORL-5.3.5 / ORL-6.2)* — V: A/T

**SRD-5.7 [AIRW]** — The 270 VDC primary bus shall provide arc-fault detection and protection. *(← ORL-6.2)* — V: T

**SRD-5.8 [AIRW]** — Each electrical bus shall remain within its applicable MIL-STD-704 voltage envelope under normal, abnormal, and emergency operating conditions. *(← ORL-5.3.4 / ORL-6.2)* — V: T

**SRD-5.9 [AIRW]** — The fuel system shall provide containment of fuel under crash loads and fire protection appropriate to the wet-frame integral-tank architecture. *(← ORL-6.3)* — V: A/T

**SRD-5.10 [AIRW]** — Lithium battery installation shall meet applicable Navy lithium battery safety requirements, including thermal-runaway containment. *(← ORL-6.4)* — V: A/T

**SRD-5.11 [AIRW]** — The hybrid energy buffer (lithium-ion plus supercapacitor) shall provide fault isolation between storage elements such that failure of one element does not propagate to the other. *(← ORL-5.3.5 / ORL-6.2)* — V: A/T

## 6. Flight Control, Navigation, and Autonomy Requirements

**SRD-6.1 [DESIGN]** — The flight control system shall support operator-in-the-loop and semi-autonomous operation. *(← RFI-11 / ORL-5.4.1)* — V: D

**SRD-6.2 [DESIGN]** — Navigation shall use a GNSS-aided inertial navigation system with M-Code GPS and dual-antenna GNSS-derived heading. *(← RFI-12 / ORL-5.4.2)* — V: T

**SRD-6.3 [DESIGN]** — The system shall continue navigation in GNSS-denied conditions using inertial dead reckoning, computer vision, and/or visual-inertial odometry. *(← RFI-12 / ORL-5.4.3)* — V: T

**SRD-6.4 [AIRW]** — 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 shall execute flight termination if recovery is not achievable. *(← RFI-12, 3B.10 / ORL-5.4.4)* — V: D

**SRD-6.5 [AIRW]** — The system shall provide defined lost-GPS behavior, geofencing, and auto-land. *(← 3B.10)* — V: D

**SRD-6.6 [AIRW]** — Flight-critical functions shall provide defined behavior under single-point failures of propulsion, power generation, energy storage, flight control, and navigation. *(← ORL-6.2)* — V: A

**SRD-6.7 [AIRW]** — Autonomy-enabled flight-critical functions shall provide traceable software requirements, software design-assurance evidence, and configuration management appropriate to flight-critical software. *(← 3B.16, RFI-21 / ORL-6.1)* — V: A

**SRD-6.8 [AIRW]** — The air vehicle shall provide organic obstacle/threat detect-and-avoid capability sufficient for collision avoidance in swarm formation flight. *(← 3B.22 / ORL-5.1.4)* — V: A/T

**SRD-6.9 [AIRW]** — Lost-link behavior shall be defined for the mesh-networked context, distinguishing loss of the direct operator link from loss of all mesh relay paths. *(← ORL-5.1.5 / ORL-5.4.4)* — V: A

## 7. Communications Requirements

**SRD-7.1 [DESIGN]** — The primary datalink shall be a MANET tactical radio with multi-band agility. *(← RFI-5 / ORL-5.5.1)* — V: T

**SRD-7.2 [DESIGN]** — The datalink shall employ AES-256 encryption using FIPS 140-3 validated cryptographic modules. *(← RFI-5 / ORL-5.5.2)* — V: I

**SRD-7.3 [DESIGN]** — The system shall be TAK-compatible and support real-time ISR dissemination to U.S. Government furnished information systems. *(← RFI-19)* — V: D

**SRD-7.4 [DESIGN]** — The system shall operate in DDIL RF environments. *(← ORL-5.6.3)* — V: D

**SRD-7.5 [AIRW]** — Datalink loss or degradation in DDIL conditions shall not produce an uncommanded hazardous flight state. *(← ORL-6.2 / 3B.10)* — V: A/T

## 8. Environmental and Basing Requirements

**SRD-8.1 [DESIGN]** — The system shall provide vertical takeoff and landing from unprepared expeditionary sites and amphibious ship decks. *(← RFI-20 / ORL-5.1.3)* — V: D

**SRD-8.2 [DESIGN]** — The system shall operate in winds up to 25 KIAS. *(← RFI-15)* — V: T

**SRD-8.3 [DESIGN]** — The system shall operate in rainfall up to 0.75 in/hr. *(← RFI-16)* — V: T

**SRD-8.4 [DESIGN]** — The system shall operate across diverse global climates including hot, cold, humid, and high-density-altitude conditions. *(← ORL-5.6.1)* — V: T

**SRD-8.5 [AIRW]** — The system shall operate in salt-fog and shipboard environments without degradation of flight-critical function. *(← ORL-5.6.2)* — V: T

**SRD-8.6 [AIRW]** — The system shall meet applicable environmental qualification standards (MIL-STD-810H environmental, MIL-STD-461G EMI/EMC) for the shipboard and expeditionary operating environment. *(← 3B.47 / ORL-5.6.2)* — V: T

**SRD-8.7 [AIRW]** — The system shall define precipitation and icing conditions under which flight is permitted, and shall prohibit flight outside those conditions. *(← 3B.44)* — V: A

## 9. Reliability and Maintainability Requirements

**SRD-9.1 [DESIGN]** — The system shall provide built-in test (BIT/BITE), fault detection and isolation, and maintenance alerting. *(← 3B.54)* — V: D

**SRD-9.2 [AIRW]** — Built-in test and health monitoring shall provide the airworthiness evidence for software-defined bus protection and fault isolation in lieu of physical inspection. *(← 3B.54 / ORL-6.2)* — V: A

**SRD-9.3 [DESIGN]** — Components shall be line-replaceable at the operator/field level with non-specialized tooling where practicable. *(← 3B.56)* — V: D

## 10. Compliance Requirements

**SRD-10.1 [DESIGN]** — The system shall be NDAA-compliant (FY2020 §848, FY2023 §817, FY2019 §889, American Security Drone Act 2023) or shall document a credible, time-bound path to compliance. *(← RFI Section 1)* — V: A

## 11. Open Derivation Notes

The following are noted for the next requirements iteration and are not yet resolved into requirements:

1. The RFI states a propulsion preference for non-petroleum-based sources (fuel cell, renewable); the derived propulsion requirements (Section 5) reflect the engineering baseline rather than that preference. The basis for the divergence is documented in TS-MRTX-PWR-001.
2. The endurance requirement (SRD-3.1) is derived from RFI-8 and ORL-5.1.1; its verification basis against the series-hybrid fuel state is pending (see TS-MRTX-PWR-001 §8).
3. Acoustic and signature requirements (RFI 3B.46, 3A.13) are not yet derived; deferred pending mission-system input.
4. GCS-specific requirements (3A.9, 3B.64 human factors) are not yet decomposed; deferred to SRD v1.1.

## 12. Revision History

- **v1.0 (3 June 2026):** Initial SRD. Requirements derived from ORL-MRTX-001 and PMA-263 RFI Notice 243-26-024, tagged [DESIGN]/[AIRW], with inline parent trace tags and verification methods. Clean derivation; conflicts not annotated. Full RFI→ORL→SRD→criteria traceability matrix deferred.