Part 108 BVLOS Landing Logic: Autonomous Site Selection and Terrain Data

Regulatory watch

Federal rulemaking discussions for Part 108 Beyond Visual Line of Sight (BVLOS) operations are focusing on software assurance and automated contingency landing logic. When long-range aircraft experience catastrophic propulsion degradation or loss of link, regulators want predictable, deterministic off-field landing behavior.

Key regulatory themes to track across federal policy updates include:

• Autonomy assurance benchmarks: Policy groups are evaluating software integrity standards for autonomous decision-making algorithms, particularly systems that select emergency touchdown points without human intervention.
• Autonomous landing site selection (ALSS): Regulators are examining how aircraft detect and reject hazardous terrain, water hazards, and non-participating people when return-to-launch profiles are unachievable.
• Contingency airspace reservation: Frameworks are defining how uncrewed traffic management systems broadcast active emergency descent corridors to nearby crewed and uncrewed aircraft in real time.

Verify all official rulemaking publications, advisory circular drafts, and open comment periods directly through official FAA portals.

Waivers and approvals

FAA safety assurance teams evaluating complex BVLOS petitions and linear infrastructure routes are placing heightened scrutiny on forced-landing reliability over remote terrain.

Applicants are currently being asked to demonstrate:

• Sensor blinding mitigations: Quantitative test data proving that optical or LiDAR-based ground scanning systems can safely identify clear terrain during adverse lighting, such as low-angle sun glare or heavy shadows.
• Surface slope and obstacle rejection: Evidence that onboard algorithms correctly identify and avoid sloped surfaces, standing water, and tree canopies during unguided emergency descents.
• Kinetic footprint containment: Documented energy dissipation models showing that the aircraft and its payload will remain within the pre-calculated ground risk buffer during steep contingency glide profiles.

Compliance risk

Enterprise UAS programs often manage standard operations well, but they frequently fail safety audits due to outdated surface data and unmonitored autonomy defaults:

• Stale Digital Elevation Models (DEMs): Flying over corridors using outdated surface elevation maps that fail to reflect recent construction, utility pole additions, or forest canopy changes, compromising automated low-altitude emergency routes.
• Autonomy fallback configuration drift: Ground control software or firmware updates silently resetting automated emergency descent actions from dynamic site selection back to unguided vertical descent.
• Unlogged manual flight overrides: Field crews taking manual stick control during anomalous automated descents without recording the root cause or filing an internal safety management report.

Three things to do this week

1. Audit surface elevation datasets: Verify that all digital elevation models and terrain obstacle maps loaded into your flight management software match the current physical environment of your operational corridors.
2. Review emergency sensor-fault logic: Check manufacturer documentation and bench test records to confirm how your aircraft executes emergency landings if primary optical or surface-scanning sensors degrade mid-flight.
3. Check FAA rulemaking notices: Monitor official FAA communication channels for updates on autonomous software assurance standards and Part 108 public engagement sessions.