# Propulsion & Fuel System Safety Report — MRT-X

**Document:** RPT-MRTX-PROP-001 | **Type:** Vendor substantiation
**Revision:** v1.0 | **Date:** 3 June 2026
**Prepared by:** Aerix Defense Systems (fictional) — D. Reyes, Propulsion & Power Lead
**Verifies against:** SRD-MRTX-001 §5; MIL-HDBK-516C propulsion/fuel sections

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> **FICTIONAL — METHODOLOGY TEST INPUT.** Not a real safety report. Contains deliberately planted gaps.

## 1. System Description

The MRT-X uses a series-hybrid propulsion architecture: a ~3.5 hp small turboshaft engine drives a ~2 kW generator feeding the 270 VDC bus. Four electric motors drive the rotors. The turbine provides no mechanical path to the rotors. Fuel (JP-8) is stored in integral wet-frame tanks within the airframe booms.

## 2. Propulsion Safety Analysis

The turbogenerator is single-string. Loss of generator output is mitigated by the energy buffer, which provides controlled descent and autoland (SRD-5.6). Turbine hot-section is shrouded; exhaust is routed away from structure. Fuel shutoff is commanded on flight termination.

Generator continuous output (2 kW) exceeds measured cruise electrical demand (1.6 kW) with margin for buffer recharge, satisfying SRD-5.5. Demonstrated in ground run (see §4).

## 3. Fuel System Safety Analysis

Fuel is contained in integral boom structure (wet-frame). Tank venting is provided. Fuel quantity is sensed for CG management as fuel burns. Fire protection is provided by material selection and routing of fuel lines away from the hot section.

Crash-load fuel containment is provided by the airframe structure. The wet-frame design integrates fuel containment with primary structure; the structure is designed to the 55 lb gross-weight load cases.

## 4. Ground Test Results

Turbogenerator ground run: 2 hr continuous, output held at 2.0 kW, no thermal exceedance. Fuel system leak check: pressure-decay test passed at 1.5× operating pressure. Bonding and grounding verified.

## 5. Compliance Summary

The propulsion and fuel system is assessed compliant with the applicable safety requirements for the proposed envelope.

## 6. Revision History

- **v1.0 (3 June 2026):** Initial report. Propulsion and fuel safety analysis with ground-test substantiation.

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### [INTERNAL — NOT PART OF REPORT] Planted gaps in this document

- **PG-PROP-1:** §3 **asserts** crash-load fuel containment is "provided by the airframe structure" but presents **no crash-load analysis or test** — no impact case, no fuel-retention test, no rupture analysis. SRD-5.9 requires containment under crash loads; this is an unsubstantiated claim. The wet-frame integral architecture is exactly the configuration MIL-HDBK-516C fuel criteria (written for discrete tanks) cover poorly. (Category: GAP + unsubstantiated claim.)
- **PG-PROP-2:** The report **never addresses the RFI non-petroleum propulsion preference** (RFI-10). It substantiates a JP-8 turbine as if petroleum propulsion were uncontested. A certification official tracing to the RFI should flag that the propulsion concept contradicts a stated source preference with no rationale in this report. (Category: CONTRA with source / missing rationale.)
- **PG-PROP-3:** §2 fire protection is described qualitatively ("material selection and routing") with **no fire test, no fire-zone designation, no fire-detection/suppression analysis** for a JP-8 system with a hot turbine in close proximity. (Category: unsubstantiated.)
- **PG-PROP-4 (clean element / control):** §2 generator margin (2.0 kW vs 1.6 kW demand) **is** substantiated by ground run — this should verify cleanly. Engine should NOT flag SRD-5.5.