Visibility: Reading the Visibility Group
Visibilidad: cómo leer el grupo de visibilidad
10 SM visibility
Decode a standard visibility group, including fractional values and the 'less than'/'greater than' prefixes, and explain why visibility is a required check for VFR flight.
Visual flight rules depend entirely on a pilot being able to see far enough to navigate visually and avoid other traffic and terrain — visibility is one of the specific numbers that can make a flight legal or not legal to conduct under VFR.
Teach It / Enséñalo
ENTIENDE
El GRUPO DE VISIBILIDAD sigue al grupo de viento e informa la visibilidad horizontal predominante en millas estatutarias, terminando en la unidad literal "SM." Un valor de número entero como "10SM" significa 10 millas estatutarias de visibilidad. La visibilidad fraccionaria se escribe usando una barra, como "1/2SM". Dos prefijos pueden modificar el número informado. Un prefijo "M" significa que la visibilidad es MENOR que el valor indicado. Un prefijo "P" significa que la visibilidad es MAYOR que el valor indicado. La visibilidad es uno de los valores específicos que determina si el vuelo VFR (Reglas de Vuelo Visual) es legal en un espacio aéreo dado — cada clase de espacio aéreo tiene sus propios mínimos de visibilidad y separación de nubes.
¿Tiene sentido?
AVIATION WORDS · Palabras de aviación
DILO EN INGLÉS · SAY IT IN ENGLISH
“The visibility group tells you how far a person can see, in statute miles, and whether that's a whole number, a fraction, or 'less than'/'greater than' a stated value.”
Ejemplo guiado
In the course's example METAR, "10SM" tells a pilot: 10 statute miles of prevailing visibility — well above the minimum required for VFR flight in nearly every airspace class, giving the pilot a quick, reassuring answer to "can I see far enough to fly visually right now?"
Real Aviation Application / Aplicación real en aviación
Checking visibility against the specific airspace's VFR minimums is a real, required step of every VFR preflight weather briefing — it's not just useful information, it's one of the actual legal gates a pilot must clear before a flight can proceed under visual flight rules.
Ask Your Teacher / Pregúntale a tu maestro
- What are the actual VFR visibility minimums for the different airspace classes?
- Why is visibility measured in statute miles instead of nautical miles like most other aviation distances?
- What real-world conditions typically cause a 'less than' visibility report like M1/4SM?
HAMPTON'S .02 CENTS
Statute miles versus nautical miles is worth calling out explicitly here — students who've already learned that most aviation distances use nautical miles sometimes assume visibility does too, and the exception is easy to miss if it's not pointed out directly.
It Would Behoove You… Continue to the next lesson: the Clouds group, the "C" in WWW VCT DAR.
Standards Alignment
CLASSROOM: METAR Fundamentals
FAA: FAA Aviation Weather Handbook (FAA-H-8083-28), Chapter 6; 14 CFR § 91.155 — Basic VFR Weather Minimums
CERTIFICATION: Private Pilot, Part 107
SOURCES: Aviation Weather Handbook (FAA-H-8083-28); 14 CFR § 91.155 — Basic VFR Weather Minimums