In Lee Smiths April 2014 article on Visual Area Protection, I think there is an error. The diagram indicates that the 20:1 slope is the same as standard three degree VDA. My memory, Lee Smiths original Danger Below MDA? from March 2013, and my math indicate that 34:1 is the same as a three degree slope.
The standard three-degree Visual Descent Angle (VDA) is approximated by a 20:1 slope (arctan(1/20) ≈ 2.86 degrees), not a 34:1 slope, which is typically for obstacle clearance.
Effective NEXRAD radar interpretation requires considering not just color intensity, but also storm movement, stage, and the aircraft's altitude relative to the storm, as a single image is insufficient for a complete assessment.
An aircraft's maneuvering speed (Va) decreases with lighter weight because less G-force is required to stall the wing, ensuring the wing stalls (unloads) before structural damage in turbulent conditions.
ARCTAN(Height/Base)=Angle In Lee Smith’s April 2014 article on Visual Area Protection, I think there is an error. The diagram indicates that the 20:1 slope is the same as standard three degree VDA. My memory, Lee Smith’s original “Danger Below MDA?” from March 2013, and my math indicate that 34:1 is the same as a three degree slope.
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