Hey everyone, I’ve been working on the Project Spearhead proposal in alignment with AIP-006. I’m creating this forum thread to discuss the proposal and get your feedback.
It’ll be great if you review it carefully and provide your comments by next Monday, March 9th; so that we have the final discussion during the community call and create the Snapshot proposal after.
Thank you in advance.
1. Project Summary
Project Spearhead is a multi-purpose 25 kg MTOW hybrid fixed-wing VTOL unmanned aerial vehicle (UAV) platform. The project aims to develop an aircraft platform equipped with electric motors for VTOL capability and a pusher internal combustion engine for cruise flight.
Spearhead will primarily target:
- Long-endurance rural surveillance missions
- Limited payload / emergency cargo missions
The core focus of the project is to develop and validate:
- Aircraft sizing & structural integrity
- Hybrid propulsion (internal combustion cruise + electric VTOL)
- Generator integration and energy management
- Transition flight control
- Internal combustion engine vibration mitigation
- Long-range telemetry, possibly beyond conventional RF limits
The aircraft will be fully usable for endurance missions and limited cargo operations, but it will not be optimized as a final commercial product. The intent is to build a capable platform and the internal know-how required for larger systems.
2. Project Scope
2.1 Hybrid Powertrain Development
Develop and validate:
- Gasoline engine integration
- Generator architecture
- Battery charging strategy in cruise
- Power distribution and monitoring
- Engine and generator failure handling
Special attention will be given to vibration isolation and avionics protection from engine-induced vibration.
2.2 Transition Flight Architecture
Design and test:
- Hover-to-cruise transition
- Cruise-to-landing transition
- Control logic and tuning
- Aerodynamic balance between stall speed and transition time
Trade-offs between wing size, stall speed, and battery mass will be studied.
2.3 Long-Range Telemetry
Investigate and test:
- Extended-range RF systems
- Potential satellite-based communication solutions (e.g., compact satellite terminals)
- Latency implications for BVLOS operations
The objective is to remove telemetry range as the primary operational limitation.
2.4 Platform Modularity
Spearhead will be designed as a platform that can support internal/external payload compartment.
2.5 Safety & Failure Modes
As the platform operates at significant distances and weights, the following safety options will be studied:
- Power System Redundancy: Evaluation of backup power delivery if the generator or internal combustion engine fails during cruise.
- Emergency Recovery Protocols: Options for autonomous flight termination or recovery procedures will be explored for high-latency or lost-link scenarios.
- Environment Awareness: Investigation into computer vision or sensor-based systems to identify safe areas for emergency maneuvers or landings.
3. Project Timeline
Phase 1: Electric Flight Validation (March-June 2026)
Prototype 1 to test the structural integrity and system validation.
- Platform: Full airframe (cockpit, tail, wings).
- Propulsion System: Equipped only with electric VTOL motors.
- Power: High-discharge flight batteries (no internal combustion engine or generator).
- Key Objectives:
- Validate vertical takeoff and hover stability.
- Test control surface authority (ailerons, elevator, rudder) during forward flight.
- Verify airframe structural integrity under real flight loads.
- Test the wing detachment system.
Phase 2: Hybrid Integration (July-October 2026)
Merging the propulsion systems and solving the mechanical noise.
- Integration: Installation of the internal combustion pusher engine, fuel system, and cooling system.
- Ground Testing: Static fire runs to:
- Verify internal combustion engine readiness.
- Measure engine temperature and evaluate cooling system effectiveness.
- Measure real-world vibration data using onboard IMUs.
- Key Objectives:
- Integrate internal combustion engine and related systems.
- Execute VTOL-cruise transition.
- Achieve cruise flight.
- Evaluate battery sizing.
- Tune the flight controller’s notch filters to ignore engine-induced noise.
Phase 3: Beyond Visual Line of Sight Flight (November 2026-January 2027)
Testing phase for VTOL-cruise transition. Breaking the telemetry limitation. Achieving BVLOS flight. Integrating obstacle avoidance system.
- Hardware: Integration of obstacle avoidance system. Integration of the long-range telemetry system. Evaluation of RF or satellite based options.
- Flight Profile: Transitioning from short-range testing to long-range linear paths.
- Key Objectives:
- Achieve consistency on flight mode transition.
- Measure latency and command-link reliability over long-range telemetry system.
- Evaluate autonomous “Link-Loss” protocols and recovery behaviors.
- Validate the “Environment Awareness” and obstacle avoidance systems.
Phase 4: Operational Tailoring (February-March 2027)
Finalizing the platform for specific mission profiles.
- Configurations: Testing the modular “Cargo” vs. “Surveillance” pods.
- Safety & Failure Modes: Integration and validation of failure modes during cruise flight.
- Key Objectives:
- Finalize the “Performance Manual” for customers (max payload vs. max range).
- Formalize the transition of “Spearhead Know-How” into the larger 500 lb cargo project.
4. Budget Cap
The project requires a budget to compensate skilled engineers specialized in research and development, real-world hardware testing, prototype construction, and flight tests.
- Labor Costs: $28,000/month
- Hardware Costs: $7,000/month
- Total: $35,000/month
Labor and hardware-related expenses will vary from month to month; thus, the stated budget includes a margin. Note that this is the maximum spending cap, actual monthly expenses are expected to often be lower. The project will end at the end of March 2027.
A multisig wallet will be established after approval to receive funds. The seats on the multisig will be; Project Lead (alperenag) and GBC.
5. Governance
This document will be presented in the GitHub repository upon project approval.
6. Project Lead
I, alperenag, will be responsible for leading the Project Spearhead team, overseeing the technical direction, coordinating development activities, and ensuring successful achievement of milestones and objectives.
7. Project Team
I, alperenag, will assemble the project team under the approved Project Spearhead budget upon project approval.
8. Deliverables
- Prototype UAVs: Development and refinement of UAV prototypes through each project phase.
- Engineering Reports: Prepared for each major milestone, clearly outlining technical specifications, decisions, and current project status.
- Design Files: CAD models, PCB layouts, and software repositories accessible for community collaboration.
- The “Performance Manual”: Data-backed charts for different configurations.
- Meeting Summaries: Documentation of meeting attendance, key decisions, and action items recorded and shared via GitHub.
- Structured Documentation: Documents assigned unique identifiers for transparency, consistency, and version control for logging the know-how achieved during the project.
- Operational UAV: Development of a mission-capable, long-endurance hybrid fixed-wing VTOL platform ready for diverse operational scenarios.
9. Project Requirements
9.1. Structural Integrity
- Airframe:
- The aircraft SHALL be a fixed-wing quadplane (VTOL) configuration with a maximum take-off weight (MTOW) of 25 kg.
- The airframe SHALL be designed for Modular Transportability, allowing the wings to be detached for transport in a vehicle.
- Landing Gear:
- The aircraft’s landing gear SHALL be shock-absorbing and support the full MTOW during landing, including in hard-landing scenarios.
9.2. Propulsion System
- eVTOL Motors:
- The eVTOL motors SHALL provide a thrust-to-weight ratio of at least 1.5:1 to ensure safe hover and transition, even with full payload.
- Internal Combustion Cruise Engine:
- The aircraft SHALL be equipped with a puller or pusher configuration internal combustion engine for forward flight.
- The IC engine MAY be integrated with an electric starter to start the motor in flight.
- The IC engine MAY be integrated with an electric generator to provide mid-flight battery charging.
- Cooling System:
- The aircraft SHALL incorporate an active or passive cooling system for the IC engine capable of maintaining safe operating temperatures during sustained cruise.
9.3. Power & Energy Management
- Battery System:
- The aircraft SHALL use a high-discharge battery to handle the peak current demands of VTOL takeoff and transition.
- Generator Integration:
- The generator MAY be capable of powering the avionics and recharging the buffer battery during forward cruise.
- Kill Switches:
- The aircraft SHALL have independent hardware kill switches for the High-Voltage and Low-Voltage systems.
- Telemetry:
- The system SHALL provide real-time telemetry on fuel levels, battery state of charge (SoC), and generator output.
9.4. Flight Control & Navigation
- Flight Controller:
- The aircraft SHALL utilize a Pixhawk-standard flight controller running firmware capable of quadplane transition logic.
- Transition Logic:
- The flight control system SHALL automate the transition between hover and cruise modes based on airspeed and altitude parameters.
- Sensors:
- The aircraft SHALL include redundant GPS and a radar/laser altimeter for precise terrain following and landing.
- Obstacle Avoidance:
- The aircraft SHALL be equipped with a front-facing computer vision or sensor-based system for obstacle detection.
9.5. Telemetry & Communication
- Long-Range Telemetry:
- The aircraft SHALL support real-time telemetry up to 200 km.
- Redundancy:
- The aircraft SHALL maintain a secondary short-range RF link for local takeoff and landing operations.
- Latency Management:
- The flight system SHALL be tuned to handle the latency implications of long-range BVLOS (Beyond Visual Line of Sight) operations.
9.6. Performance & Endurance
- Range:
- The aircraft SHALL be capable of a total flight range exceeding 200 km in hybrid cruise mode.
- Endurance:
- The aircraft SHALL provide at least 4 hours of flight time in hybrid configuration.
9.7. Payload
- Capacity:
- The aircraft SHALL be capable of carrying a modular payload of up to 3 kg.
- Mounting:
- The payload bay SHALL utilize a quick-release system and provide 12V power feeds.
- Data Integration:
- The payload system SHALL support CAN bus or Ethernet integration for high-bandwidth data transmission
9.8. Safety & Maintenance
- Failure Modes:
- The aircraft SHALL have programmed “Link-Loss” and “Engine-Out” autonomous recovery protocols.
- Health Monitoring:
- The system SHALL provide real-time monitoring of remaining fuel, internal combustion engine temperature, ESC and battery health.
- Pre-Flight Diagnostics:
- The aircraft SHALL include a pre-flight diagnostics system to battery levels, GPS accuracy, radar altimeter functionality, and sensor health before each flight.
- Heading Indicator LEDs:
- The aircraft SHALL include LEDs with predefined colors around it to indicate its direction.