Weatherhill airport program · Published 14 October 2026 · Source-linked research, prepared with AI assistance. No airport trial results are reported.
Define success before collecting results
A credible fog pilot needs a specific hypothesis, a defined test volume and conditions under which the mechanism is expected to work. It also needs an agreed primary outcome and an analysis plan. Selecting the best-looking episode after testing cannot establish repeatable performance.
Weatherhill's existing FogLab direction uses a proposed 20% reduction in optical extinction as an initial screening target. That is a research target, not an achieved result or an airport requirement. The site-specific protocol must still justify its relevance, measurement method and uncertainty before the target is used.
Begin with controls and instrument stability
The proposed design compares powered treatment with the same apparatus unpowered, alongside independent background observations. Treatment periods should be randomized where the experimental design permits, with eligibility rules established in advance. Instrument checks and synchronized records are part of the experiment.
The team would measure optical conditions at several positions, weather variables, collected water and total system power. It would also record interruptions and maintenance. This helps distinguish a physical effect from changing ambient fog, airflow introduced by the apparatus, sensor contamination or selective exclusion of difficult periods.
Test the size and duration of the effect
A local change is only the beginning. The pilot must establish where the effect occurs, how it varies downstream and how long it persists while fog continues to arrive. The proposed report would show results across relevant conditions, including failures, rather than only average performance.
Sample size should follow the variability observed in preliminary work and the effect the study aims to detect. A fixed calendar period cannot guarantee enough suitable fog events. Schedule, statistical strength and seasonal exposure must therefore be considered together when the field stage is scoped.
A field report should retain the full event timeline so independent reviewers can examine transitions, interruptions and excluded periods as well as the selected analysis windows.
Include engineering and cost gates
The proposed evaluation accounts for total power, water handling, cleaning, component condition and downtime. Independent specialist review would examine installation requirements and compatibility before an airfield location is considered. A promising optical result still needs a workable and acceptable engineering system.
The decision gates are deliberately separate: reproduce the effect, demonstrate a useful spatial footprint, sustain it under relevant conditions, assess cost and determine whether airport evaluation is justified. Failure at any stage is useful information. The next investment should follow the evidence rather than a predetermined deployment date.
What a design partner would help shape
A partner could contribute the operational question, representative weather records, a suitable off-runway setting and access to qualified reviewers. Before testing, the collaboration would agree responsibilities, data rights, analysis methods and how findings can be communicated. No partner relationship is implied until agreed.
The initial deliverable is a pilot specification and decision framework. Any eventual operational study would require separate scope and authorization. Measured extinction or MOR improvements do not change runway minima, establish certified RVR performance or authorize aircraft movements.
Questions from airport teams
Has Weatherhill achieved the 20% target?
No result is claimed here. Twenty percent is a proposed optical-extinction screening target from the FogLab direction and would need to be justified in the final protocol.
Why start off-runway?
The mechanism, measurement method and engineering requirements should be evaluated before considering an operational airport setting. This produces evidence for a better-defined next decision.
How many fog events are needed?
There is no justified universal number. The protocol should determine sample requirements from variability, the target effect and the desired statistical strength, while accounting for suitable weather availability.
Sources & further reading
- WMO Statement on Weather Modification ↗World Meteorological Organization · Published June 14, 2025; technical assessment covers information through June 2024.
- Aeronautical Studies — Evaluating Effects on Air Navigation and Communication Facilities ↗Federal Aviation Administration · FAA consideration of physical, electromagnetic and line-of-sight effects on aviation infrastructure.
- Safety Management Systems for Airports and Airport Projects ↗Federal Aviation Administration · Airport safety-management and project safety-risk-management resources.
- Order 6560.10D — Runway Visual Range ↗Federal Aviation Administration · RVR definitions, visibility-sensor siting and use for aviation operations.