Underwing Payload Hardpoint for MALE UAV

Project Overview

This project was undertaken as part of the Industry Ready Engineer program by Boeing India University Relations. The objective was to design and develop a robust, modular, and aerodynamically optimized Underwing Payload Hardpoint for a Medium-Altitude Long-Endurance (MALE) Unmanned Aerial Vehicle (UAV). This hardpoint is engineered to enhance the UAV's operational capability by supporting a variety of mission-specific payloads. The design was advanced through the Critical Design Review (CDR) phase, with all key requirements validated for compliance with safety, functionality, and performance specifications.

Project Objectives

1. Enhanced Payload Flexibility: Develop a hardpoint that supports a diverse range of payloads without compromising the UAV's aerodynamic stability or operational efficiency.
2. Modular, Adaptable Architecture: Ensure structural and electronic compatibility with various payload configurations, with provisions for straightforward integration and maintenance.
3. Standards and Safety Compliance: Conform to industry and regulatory standards, including SAE ARP4754A guidelines for functional safety and airworthiness, as required for UAV systems utilized in defense and surveillance.

Scope of Work

• Structural Design and Integration: Engineered load-bearing components and mounting brackets to secure the hardpoint to the UAV structure, ensuring structural robustness under operational stresses.
• Payload Retention and Release Mechanisms: Implemented high-precision latching actuators and proximity sensors to enable secure locking and controlled ejection of payloads. The actuation system was optimized to ensure quick response and reliability under varying load conditions.
• Electrical Interface Design: Established an electrical interface integrating with the UAV’s power distribution system and avionics, facilitating communication and control over payload release functions.
• Aerodynamic Optimization: Designed and integrated lightweight composite fairings to reduce aerodynamic drag, maintaining the UAV's endurance and minimizing impact on maneuverability.

Technical Approach

1. Pylon Interface and Structural Mount: Developed an aerodynamically contoured pylon to interface with the UAV wing, maintaining structural integrity while minimizing adverse aerodynamic impacts.
2. Main Load-Bearing Structural Member: Employed a central longitudinal structural member as the primary load path, ensuring even load distribution and resilience under static and dynamic loads.
3. Latching Actuators with Fail-Safe Mechanism: Incorporated dual latching actuators along the wing chord, equipped with a fail-safe mechanism to lock the payload in position in the event of power failure. Proximity sensors provide feedback on latch engagement and payload presence, enhancing reliability.
4. Adjustable Rails and Wiring Interface: Designed rails on the main structural member for adaptability, allowing reconfiguration to accommodate payloads of varying dimensions. A quick-disconnect wiring interface was incorporated to ensure reliable arming and data connections with the payload.
5. Aerodynamic Fairing and Drag Minimization: Developed composite fairings attached to the pylon to minimize drag. Computational Fluid Dynamics (CFD) analyses and wind tunnel simulations were used to validate aerodynamic performance.

Verification and Compliance

The design was rigorously tested and evaluated across multiple tiers to validate compliance with operational, environmental, and performance requirements:

• Load and Stress Analysis: Comprehensive Finite Element Analysis (FEA) was conducted on primary load paths, including structural members, bolts, and mounting brackets. The design was validated against critical load conditions such as maximum payload weight, emergency maneuvers, and gust conditions.
• Aerodynamic Efficiency: Drag analysis was performed using CFD and verified in a simulated operational envelope to ensure fairing design minimized aerodynamic penalties.
• Environmental and Operational Resilience: The hardpoint was designed to endure extreme environmental conditions, including vibration, shock loads, and high-temperature variations per MIL-STD-810G. Structural integrity was tested under the UAV's expected flight envelope, ensuring reliability across varying altitudes, accelerations, and speeds.

Key Achievements at the CDR Stage

• Requirement Compliance: Developed a detailed Requirements Compliance Matrix to trace design decisions and verify conformance with Tier-1, Tier-2, and Tier-3 requirements, encompassing payload capacity, power infrastructure, actuator reliability, and drag reduction.
• Failure Modes and Effects Analysis (FMEA): Conducted an FMEA to identify and mitigate potential failure points across structural, mechanical, and electronic components, addressing risks in high-stress scenarios to ensure mission safety.
• Prototype Viability and Risk Mitigation: Validated the design's readiness for prototyping by addressing key risk factors, including load distribution and actuator redundancy, thereby ensuring a high level of operational confidence.

Future Development and Certification

With the CDR complete, the next stages involve transitioning to prototype fabrication and testing. Full-scale verification would include environmental and structural testing under operational loads, with certification processes adhering to IMTAR (Indian Military Technical Airworthiness Requirements) and CEMILAC standards. This certification is essential for defense deployment, ensuring the system meets airworthiness and reliability standards for mission-critical applications.