Weather Decision Making: Go or No-Go?
Why Weather Decision Making Matters
The 178-Second Reality
Research by the University of Illinois found that VFR pilots who entered simulated IMC without instrument training lost control in an average of 178 seconds. Most believed they could maintain control for much longer. Do not become a statistic. If you cannot see the horizon, you cannot maintain control without instruments and training.
Understanding METARs: Your Weather Snapshot
Key METAR Elements for VFR Pilots
Understanding TAFs: Looking Ahead
Plan for the Worst
When reading TAFs, plan your flight around the worst conditions forecast, not the best. If a TEMPO period shows conditions below your personal minima, either plan to avoid that time window or have robust alternates and contingencies in place.
Personal Minima: Know Your Limits
The Personal Minima Contract
Write your personal minima down and keep them in your flight bag. Before every flight, check the conditions against your minima. If conditions do not meet your criteria, the decision is already made. This removes the temptation to rationalise or make exceptions in the moment.
Marginal VFR: The Danger Zone
Common Weather Hazards in the UK
Fog and Mist
Low Cloud
Wind
Turbulence
Rain
Showers and CB Clouds
In the UK, showers often develop from cumulonimbus (CB) clouds that may not be obvious from the ground. These bring rapidly changing conditions, severe turbulence, hail, and potentially microbursts. Give shower clouds a wide berth and never attempt to fly underneath a CB.
Getting Good Weather Information
The Go/No-Go Decision Process
Weather Decision Essentials
- VFR into IMC is one of aviation's deadliest scenarios - respect weather absolutely
- Learn to decode METARs and TAFs quickly and accurately
- Establish written personal minima that exceed legal requirements
- Marginal VFR is the danger zone - when in doubt, do not go
- Use multiple weather sources: Met Office, SkyDemon, actual observations
- Follow a systematic go/no-go process and never let pressure override judgement
The Courage to Say No
An Aviation Truism
"It is better to be on the ground wishing you were in the air than in the air wishing you were on the ground." This old saying captures perfectly the essence of weather decision making. The ground is patient; it will still be there when the weather improves.