Standard Operating Procedures
L410 UVP-E20
Document No.:
SOP-L410-1
Page 6 - 3
Rev: 1
Date: JAN 18
Prepared by: LA
Checked by: CLS
6.5 Avoidance of Thunderstorms and Associated Hazards
Company policy is that Captains will try to avoid severe turbulence; particularly that associated
with cumulonimbus activity whenever possible.
Take off and landings should not be attempted when cumulonimbus activity is present within 5
nm of an airfield. All cumulonimbus activity should be avoided by at least 5 nm, and this should
be increased to 10 nm for any thunderstorm identified as severe or giving an intense radar echo.
Regard as extremely hazardous any cumulonimbus with tops higher than 35,000 feet whether
the top is visually sighted or determined by radar.
Vivid and frequent lightning indicates the severity of a thunderstorm. A lightning strike can
puncture the skin of an aircraft and can damage communication andnavigation equipment. In
addition it can damage engine components and has been suspected of igniting fuel vapors
and causing explosion. It can cause permanent errors in the magnetic compass.
Hail may be encountered in clear air several miles from a thunderstorm, usuallyon the downwind
side of an anvil. Rain at the surface does not mean the absence of hail aloft. Anticipate the
possibility of hail with any thunderstorm.
Captains must also be aware of the possibility of windshear associated with microbursts from
large cumulonimbus and large cumulus. If encountered near the ground, these can have
catastrophic results.
WARNING
Susi Air aircraft are not to attempt a takeoff or an approach when there is a
windshear alert or a preceding aircraft has reported windshear until the
condition causing this condition has ceased (i.e. thunderstorm over the
airport).
Summary of Contents for L410 UVP-E20
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