SOW_1.pdf

STATEMENT OF WORK

I. GENERAL INFORMATION

Introduction

This project requires the design and fabrication of a pilot-controlled ejection system capable of releasing a scientific payload from an uncrewed aerial system (UAS) in emergency conditions.

The purpose of this system is to enhance operational safety and reduce the risk of aircraft- loss during USGS aeromagnetic survey missions conducted by the Energy and Minerals Mission Area.

Background

The Interdisciplinary Methods and Applications in Geophysics project, housed in the Geology, Geophysics, and Geochemistry Science Center, has been funded through the USGS Energy and Minerals Mission Area to develop an aeromagnetic uncrewed aerial system (A-UAS) system (AKA drone system) for very high-resolution magnetic data collection. The magnetic sensor payload is custom (patent pending), specifically engineered to reduce drag and motion, which increases the sensitivity of the sensor. The sensor payload hangs below a rotary-wing drone via a custom sling (patent pending) specifically engineered to reduce swing of sensor. The sling is required to be long to reduce the significant magnetic interference caused by the drone. This length increases the risk of an accident during flight, as the sling may become entangled with objects such as trees. Part of the risk mitigation is to increase the flight height of the drone to avoid obstacles. A second part of the risk mitigation, required by the Department of the Interior Office of Aviation Services (OAS), is to build a sensor ejection system that can be invoked by the pilot in case of an emergency.

Definitions/Applicable Documents

UAV platform: the uncrewed aerial vehicle (“drone”) itself, not including the sensor payload, sensor sling, or drop-release.

A-UAS: an aeromagnetic uncrewed aerial system that includes the sensor payload, the UAV to fly it, and the attachment system used to secure the sensor payload to the UAV.

Sensor payload: the housing and all sensors necessary for aeromagnetic data collection with a UAV system. The payload described herein includes instruments to measure the earth’s magnetic field, sensor orientation (inertial measurement unit, or IMU), a GPS, and an altimeter. It also includes a small computer to run the sensors, and a local power source for all of these devices (the sensor payload does not use power from the UAV).

Sensor sling: a rope system from which the sensor payload hangs below the UAV, the purpose of which is to increase the distance between the sensor payload and the UAV during flight. The sensor sling attaches to the sensor payload at the bottom, and the drop-release system at the top, and is 4.5 meters in length when fully deployed.

Drop-release: a mechanical system that clamps or secures the sensor sling to the UAV and is capable of releasing (ejecting) the sensor sling and sensor payload on command from the pilot.

Scope

The scope of this contract is to provide a pilot-controlled drop release mechanism capable of safely separating the sensor payload and sensor sling from the host UAV during emergency conditions. The work includes the development of a complete design, prototype fabrication, and performance testing sufficient to demonstrate safe and reliable operation. This project is limited in scale to two copies of a single prototype design rather than development of the UAV platform or sensor payload itself.

II. WORK REQUIREMENTS

A. Technical Requirements.

1. Design and Fabrication

1.1 Design Package

The Contractor shall develop a complete engineering design for the drop-release system and provide:

• Fully dimensioned, manufacturing-ready CAD files in a USGS-approved, non-proprietary format (such as STEP).

• A bill of materials (BOM) and assembly instructions sufficient for repeatable fabrication.

• Interface specifications for all mechanical, electrical, and software connections to USGS UAV.

1.2 Formal Design Review

The Contractor shall conduct a formal design review (FDR) with USGS prior to prototype fabrication. The review shall include presentation of the full design package and creation of an action-item log. All design-related action items identified by USGS shall be closed before prototype fabrication begins.

1.3 Single-Action Release

The drop-release system shall be activated by a single pilot command that results in complete release of the sensor payload and sling. No additional manual, mechanical, or electronic actions shall be required at the moment of release. Pre-flight arming is permitted but must visibly indicate armed status to the pilot.

1.4 Single‑Point Mechanical Release

The release mechanism shall employ a single mechanical actuation point (such as a single latch, cam, or actuator) that controls the complete separation of the sensor payload and sling. The design shall not rely on multiple independent latches, hooks, or motors whose individual failure could prevent a full release. All components involved in the release shall act through a unified mechanism to ensure that no more than one mechanical point of failure exists within the release path.

1.5 Attachment System Compatibility

The system shall be mechanically compatible with the 12 mm rail mount system used by the USGS National Uncrewed Systems Office (NUSO) Freefly Systems Alta-X Gen 1 and Gen 2 fleet. Mounting hardware shall comply with manufacturer-specified tolerances and load limits.

No modification of Freefly Alta-X 12mm rail hardware shall be required.

1.6 Payload Attachment System

The drop-release mechanism shall attach to the payload sling system at four separate equal distant points. The sling system attachment consists of four cord loops that must be allowed to slide freely through the attachment mechanism.

1.7 UAV Clearance

The assembled system shall not intrude into UAV takeoff or landing clearance envelopes and shall not restrict landing-gear articulation, propulsion, or sensor operation. Clearance shall be verified during fit-testing.

1.8 Mass and Center of Gravity

The system shall not exceed a maximum installed mass of 1.5 kg and shall not shift the UAV center of gravity outside the airframe limits specified in the applicable flight manual.

1.9 Reusability and Maintenance

The release mechanism shall be resettable and reusable for at least an estimated 2000 cycles without component replacement, excluding consumable items. Routine maintenance shall be possible without specialized tools.

1.10 Prohibited Technologies

The system shall not use pyrotechnic devices or any explosive-based release components. All actuation mechanisms shall be mechanical or electromechanical.

1.11 Materials

Within 4.5 meters of the sensor payload (the length of the fully deployed sling system), all structural and fastener materials shall be non-ferromagnetic or otherwise magnetically quiet so as not to degrade aeromagnetic data quality.

2. Integration and Interfaces

2.1 Handset and Command Integration

The system shall integrate with DOI-approved UAV hand flight controllers and shall use only switches or controls designated and approved by the DOI Office of Aviation Services. An Interface Control Document (ICD) shall describe all signal, power, communication, and status indicator functions.

2.2 Flight Control Software Integration

The system shall be compatible with DOI-approved Drone Amplified DA Flight flight control software. The Contractor shall provide integration documentation and demonstrate proper release functionality during ground and hover testing prior to flight testing.

2.3 Status and Feedback

Option line item: to be quoted separately.

If exercised, the system shall provide a clear, pilot-visible status indication (such as armed, ready, and released) via controller interface or physical indicator.

The system shall confirm a successful release within one second after the pilot command.

This option is subject to the availability of funds.

2.4 Power Interface

The system shall be either self-powered or use a UAV power bus. If UAV power is used, the system shall not exceed 120 watts power draw. The ICD shall describe protections for overcurrent, brownout, and electromagnetic compatibility.

3. Performance and Safety Requirements

3.1 Release Time

The system shall fully separate the payload and sling from the UAV within 0.5 seconds of the pilot release command under nominal operating conditions.

3.2 Load Capacity and Safety Factor

The system shall support a payload plus sling mass of 5 kilograms, accounting for static and dynamic flight loads.

3.3 Accidental Release Prevention

The system shall prevent inadvertent activation through mechanical and/or software safeguards.

In the event of command signal loss, the system shall default to a safe, non-release state.

3.4 Post Release Stability

Activation of the release mechanism shall not induce unsafe UAV behavior. Immediately after release, the UAV must remain controllable and within its manufacturer-specified flight envelope.

4. Environmental and Reliability Requirements

4.1 Operating Environment

The system shall operate reliably across temperatures of –20 to 50 °C, precipitation levels satisfying ingress-protection rating IP43 or equivalent standard, and wind conditions up to 20 mph typical of rotary-wing UAS missions.

4.2 Vibration and Shock

The system shall withstand vibration and shock conditions consistent with rotary-wing UAS operations, such as those described in MIL-STD-810 or an equivalent standard.

4.3 Ingress Protection

Critical components shall meet an ingress-protection rating of at least IP43 (the equivalent rating of the Freefly Alta-X).

4.4 Reliability

The system shall be constructed such that a mean time between failures (MTBF) of at least 500 hours is reasonably expected based on components, materials, and testing.

5. Fit-Testing and Verification

5.1 Pre-Fabrication Fit Check

The Contractor shall conduct an early fit check using a USGS UAV or twin model to validate mechanical interfaces and clearances. Any issues identified shall be corrected before final fabrication. The Government will provide reasonable access to a USGS Alta-X Gen 1 and/or Gen 2 aircraft for fit verification and integration testing.

5.2 Pre-Delivery Fit Check

The Contractor shall conduct a final fit verification on a USGS UAV or equivalent twin prior to delivery. All misalignments or clearance issues shall be corrected before flight testing. The Government will provide reasonable access to a USGS Alta-X Gen 1 and/or Gen 2 aircraft for fit verification and integration testing.

5.3 Ground Verification

The Contractor shall perform ground and flight verification of release actuation and reset, the electrical and software interface, and load capacity to confirm compliance with performance requirements. Payload for ground and flight tests may be a dummy payload of equal weight to the actual payload. The Government will conduct the flight operations and provide aircraft and pilot, contractor will attend, observe, and as necessary demonstrate / participate in drop-release integration and function.

6. Communication

6.1 Kick-off meeting

A web-based kick-off meeting shall be held to review the scope of work, expectations, and to address any initial questions or issues.

6.2 Ad-hoc meetings

In addition to formal project review meetings previously specified, ad-hoc meetings may be called for project updates or clarification of any issues that arise. This may include communications such as bi-weekly check-ins, as determined in the kick-off meeting.

B. Deliverables.

1. Prototype Hardware

The Contractor shall deliver the following physical components:

1.1 Two fully functional prototype drop-release mechanisms meeting all Technical Requirements in Part II.A.

1.2 All hardware, wiring, connectors, mounting brackets, and any ancillary components required for installation and operation on USGS Freefly Alta-X Gen 1 and Gen 2 UAV systems.

2. Design Documentation

The Contractor shall deliver a complete design package that includes:

2.1 Fully dimensioned, manufacturing-ready CAD files in a USGS-approved, non-proprietary format.

2.2 A bill of materials (BOM) listing all parts, materials, and specifications.

2.3 Assembly instructions sufficient for repeatable fabrication and maintenance.

2.4 An Interface Control Document (ICD) describing all electrical, mechanical, software, and communications interfaces required for integration with USGS UAV systems.

2.5 A brief user-level operating guide describing arming procedures, activation method, status indications, and reset steps.

3. Test and Verification Documentation

The Contractor shall deliver documentation showing completion and results of required testing, including:

3.1 Ground-test verification results demonstrating proper mechanical, electrical, and software behavior.

3.2 Load-test results confirming structural capacity and safety factor compliance.

3.3 Fit-testing reports documenting the outcomes of both required fit checks and any corrections made.

3.4 A flight-test report summarizing test-flight outcomes, including release performance, UAV stability observations, and confirmation that acceptance criteria have been met.

4. Final Report

The Contractor shall provide a final report summarizing the design, fabrication, testing activities, issues encountered, corrective actions taken, and final configuration of the delivered prototypes.

5. Delivery Schedule and Location

5.1 The Contractor shall provide a delivery schedule listing planned dates for:

• Completion of the design package

• Design review

• Prototype fabrication

• Fit checks

• Ground testing

• Flight testing

• Final delivery

5.2 All deliverables shall be shipped or electronically submitted to the U.S. Geological Survey at the following location or other location specified by USGS Contracting:

Geoffrey Phelps U.S. Geological Survey Geology, Minerals, Energy, and Geophysics Science Center 350 N. Akron Road, Building 19 Moffett Field, CA 94035

Electronic deliverables shall be provided in standard, non-proprietary formats unless otherwise approved by USGS.

6. Acceptance of Deliverables

Deliverables will be accepted by USGS upon verification that:

• Hardware meets the Technical Requirements in Part II.A, including

• 0.5-second release requirement

• Successful fit verification

• Successful ground testing

• Successful flight demonstration

• Delivery of all technical data

• Documentation is complete and consistent with delivered hardware and software.

• Required tests have been successfully completed and documented.

• Flight-test demonstration meets all acceptance criteria.

• All corrective actions identified by USGS have been addressed.

Optional Task Deliverables (If Exercised) If the Government exercises Optional Task 2.3, the Contractor shall provide all documentation, hardware, software integrations, and demonstrations associated with status‑indication and confirmation functionality, as required by Section 2.3.

III. SUPPORTING INFORMATION

Place of Performance.

Drop-release will be designed and manufactured in accordance with the contractor’s location and capabilities. Final testing of the drop-release mechanism will be at a location to be determined by

USGS.

B. Period of Performance July 1, 2026, to June 30, 2027. Optional Task 2.3 may be exercised at any point within the period of performance. Performance timelines associated with the optional task shall be negotiated at the time of exercise and subject to the availability of funds.

C. Special Considerations

1. Personnel must have expertise in mechanical and electrical engineering sufficient to design and build the prototype drop-release.

2. Data Rights, Safety, Environment.

3. Security/Privacy issues (ingress to Federal buildings, personnel clearances, computer security).

(note A/C = aircraft, ie: drone AKA UAV).