Liability Disclaimer

1. Phase 1 Analysis Limitations

The current Phase 1 analysis operates under the following constraints:

• 2D ray-casting analysis: Geometry is projected onto a vertical plane aligned with the tower-to-runway bearing.
• Flat-earth assumption: No terrain elevation modeling. Ground is assumed to be at zero elevation everywhere.
• No atmospheric refraction: Light propagation is modeled as straight lines; atmospheric bending is not accounted for.
• No earth curvature: For distances under 20 km, curvature effects are negligible, but not explicitly modeled.
• No Part 77 imaginary surfaces: FAA obstruction surfaces are not computed or displayed in Phase 1.
• User-supplied tower position accuracy: Analysis is only as accurate as the tower coordinates you provide. See section 3 for more on this risk.

2. Phase 2 Planned Enhancements (Not Yet Available)

Phase 2, when released, will introduce:

• 3D analysis: Full three-dimensional geometry accounting for tower elevation, building height, and runway threshold elevation.
• Terrain integration: USGS elevation data for accurate ground modeling along the line of sight.
• Earth curvature and refraction: ITU-R recommended methods for atmospheric bending.
• Part 77 imaginary surfaces: Computation and visualization of FAA obstruction surfaces.

Even with Phase 2 enhancements, results will remain preliminary and non-stamped. Phase 2 analyses will support professional engineering review but will not substitute for it.

3. Phase 3 Stamped Reports (Future)

Phase 3, expected in the future, will introduce stamped reports digitally signed by a licensed Professional Engineer. Only Phase 3 stamped reports are authorized for submission to the FAA or use as authoritative in regulatory or permitting processes.

Phase 1 and Phase 2 reports carry no PE stamp and must not be represented as if they do.

4. Prohibited Uses

You must not use this tool's output as authoritative for:

• FAA Form 7460-1 (Notice of Proposed Construction or Alteration) submission
• FAA aeronautical study determinations or airspace determinations
• OE/AAA (FAA's Office of Obstruction Evaluation / Airports District Offices) submissions
• Building permits, zoning variances, or local government approvals
• Life-safety analysis or critical infrastructure decisions
• Regulatory determinations of any kind without prior Professional Engineer review and official FAA submission through proper channels

Any attempt to use this tool's preliminary output in place of these formal regulatory processes is the sole responsibility and liability of the user, not the tool provider.

5. Your Responsibilities

You agree to:

• Verify all inputs carefully: Double-check building coordinates, dimensions, height, tower position, and runway configuration before submitting analysis.
• Understand tower coordinate limitations: The tool includes a seed database of tower positions for major US airports. These are approximate and sourced from public FAA data. Do not assume they are exact without independent verification. See BUILD_LOG.md for notes on the accuracy and scope of the seeded database.
• Engage a licensed Professional Engineer: Before making any final decisions, submit your analysis to a PE licensed in your jurisdiction for review.
• File formal FAA notices: It is your responsibility — not the tool's — to submit FAA Form 7460-1, aeronautical study requests, and all required documentation to the FAA through official channels.
• Obtain required permits and approvals: Contact your local building department, zoning board, and airport sponsor for all necessary permitting.

6. Disclaimer of Warranty

THE TOOL AND ALL ANALYSES ARE PROVIDED "AS IS" AND "AS AVAILABLE" WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED.

We disclaim all warranties, including but not limited to:

• Merchantability
• Fitness for a particular purpose
• Accuracy, completeness, or reliability of results
• Non-infringement of third-party rights
• Uninterrupted or error-free operation

Under no circumstances shall the tool provider, its officers, directors, employees, or agents be liable for any indirect, incidental, special, consequential, or punitive damages, including loss of profits or data, even if advised of the possibility of such damages. The tool provider's total liability is capped at the greater of (a) $100, or (b) the amount you have paid for the Service in the preceding 12 months.