instrument meteorological conditions

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instrument meteorological conditions (IMC)

Meteorological conditions expressed in terms of visibility, the distance from clouds, and the ceiling, less than the minimums specified for visual meteorological conditions. In a control zone, a VFR (visual flight rules) flight may proceed under instrument meteorological conditions if and as authorized by air traffic control.
References in periodicals archive ?
Visual flight rules flight into instrument meteorological conditions: An empirical investigation of the possible causes.
ss ss Instrument meteorological conditions. n n Visual meteorological conditions.
As expected, IMC is significant with a positive coefficient at the 0.01 level, indicating that the severity of accidents goes up when pilots encounter instrument meteorological conditions. This supports the common sense notion that worse accidents are more likely to happen during bad weather than during good weather.
At the top of the range airspace and still in Instrument Meteorological Conditions (IMC), Titan 11 declared an emergency for Titan 13 and coordinated separate clearances.
The NTSB determined the probable cause(s) of this accident to include: "The noninstrument-rated pilot's decision to depart on and continue a flight over mountainous terrain into forecast instrument meteorological conditions, icing, and hazardous wind conditions that exceeded the airplanes performance capabilities and resulted in an uncontrolled descent and collision with terrain."
Investigators determined that the helicopter inadvertently entered instrument meteorological conditions (IMC), which caused the pilots to lose visual reference to the ground and become disoriented and lose control.
However, I can tell you that, when they hit your windscreen, combined with a setting sun in the west, you're basically IMC (instrument meteorological conditions).
Those radio and IFF malfunctions were minor irritants when flying in good weather, but added up to significant problems in solid instrument meteorological conditions (IMC).
According to the NTSB, "Although it is possible that the pilot may have experienced spatial disorientation, there was insufficient evidence to conclude that spatial disorientation contributed to the accident." The rather unhelpful probable cause finding: "The pilot's loss of airplane control while attempting to fly a missed approach procedure in instrument meteorological conditions."
So how can you provide positive aircraft separation to non-radar-equipped aircraft in Instrument Meteorological Conditions (IMC) during operational contingencies?
In fact, an IPC can be accomplished without filing an IFR flight plan, flying in instrument meteorological conditions (IMC), talking to ATC, operating in dense airspace (i.e., Class A, B, C or D), or checking the weather and its associated risks (if flying only in the local area with a view-limiting device and safety pilot under visual flight rules).
The FAA has a category devoted just to this problem--"Continued Visual Flight Rules (VFR) Flight into Instrument Meteorological Conditions (IMC)." It is one of the larger categories for civil-aviation mishaps.

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