Scud running
Encyclopedia
In general aviation
, scud running is a practice in which pilots
lower their altitude to avoid clouds or Instrument meteorological conditions
(IMC). The goal of scud running is to stay clear of weather to continue flying with visual, rather than instrument, references. This practice is widely accepted to be dangerous, and has led to death in many cases from pilots flying into radio towers and high tension wires; however, even instrument-rated pilots sometimes elect to take the risk to avoid icing or embedded thunderstorms in cloud, or in situations where the minimum instrument altitudes are too high for their aircraft.
Scud running is occasionally referred to as "maintaining visual contact with the ground while avoiding physical contact with it" or "if the weather's too bad to go IFR, we'll go VFR." A procedure under instrument flight rules (IFR), called a contact approach
, is often referred to as a form of "legalized" scud running.
The term gets its name from scud
, which is used to describe small, ragged, low cloud fragments that are unattached to a larger cloud base, and often seen with and behind cold fronts and thunderstorm gust fronts.
to remain 500 ft (152.4 m). below a cloud ceiling and to maintain 3 smi visibility. However, outside of airport control zones and major terminal areas, controlled airspace typically begins at 1200 feet (365.8 m) above ground level; below that is uncontrolled (class G) airspace, where (at that altitude) a pilot is required only to remain clear of clouds and to maintain 1 smi visibility.
General aviation
General aviation is one of the two categories of civil aviation. It refers to all flights other than military and scheduled airline and regular cargo flights, both private and commercial. General aviation flights range from gliders and powered parachutes to large, non-scheduled cargo jet flights...
, scud running is a practice in which pilots
Aviator
An aviator is a person who flies an aircraft. The first recorded use of the term was in 1887, as a variation of 'aviation', from the Latin avis , coined in 1863 by G. de la Landelle in Aviation Ou Navigation Aérienne...
lower their altitude to avoid clouds or Instrument meteorological conditions
Instrument meteorological conditions
Instrument meteorological conditions is an aviation flight category that describes weather conditions that require pilots to fly primarily by reference to instruments, and therefore under Instrument Flight Rules , rather than by outside visual references under Visual Flight Rules . Typically, this...
(IMC). The goal of scud running is to stay clear of weather to continue flying with visual, rather than instrument, references. This practice is widely accepted to be dangerous, and has led to death in many cases from pilots flying into radio towers and high tension wires; however, even instrument-rated pilots sometimes elect to take the risk to avoid icing or embedded thunderstorms in cloud, or in situations where the minimum instrument altitudes are too high for their aircraft.
Scud running is occasionally referred to as "maintaining visual contact with the ground while avoiding physical contact with it" or "if the weather's too bad to go IFR, we'll go VFR." A procedure under instrument flight rules (IFR), called a contact approach
Contact approach
A Contact Approach is an approach available to aircraft operating on an IFR flight plan, where the pilot may deviate from the published instrument approach procedure and proceed to the destination airport by visual reference to the surface....
, is often referred to as a form of "legalized" scud running.
The term gets its name from scud
Scud (cloud)
Scud clouds, a type of fractus cloud, are low, detached, irregular clouds found beneath nimbostratus or cumulonimbus clouds. These clouds are often ragged or wispy in appearance. When caught in the outflow beneath a thunderstorm, scud clouds will often move faster than the storm clouds themselves...
, which is used to describe small, ragged, low cloud fragments that are unattached to a larger cloud base, and often seen with and behind cold fronts and thunderstorm gust fronts.
US regulations
In the United States, most controlled airspace below 10000 ft (3,048 m). MSL requires a pilot flying under VFRVisual flight rules
Visual flight rules are a set of regulations which allow a pilot to operate an aircraft in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. Specifically, the weather must be better than basic VFR weather minimums, as specified in the rules of the...
to remain 500 ft (152.4 m). below a cloud ceiling and to maintain 3 smi visibility. However, outside of airport control zones and major terminal areas, controlled airspace typically begins at 1200 feet (365.8 m) above ground level; below that is uncontrolled (class G) airspace, where (at that altitude) a pilot is required only to remain clear of clouds and to maintain 1 smi visibility.