Embraer EMB145, Operation Manual

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SUPPLEMENTARY
PROCEDURES
ENVIRONMENTAL
AIRPLANE
OPERATIONS
MANUAL
1-02-79
Page
26
Code
01 REVISION 41
Copyright © by Embraer. Refer to cover page for details.
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LIGHTNING STRIKE
Even though the airplane is adequately protected against lightning
strikes effects, operating procedures should be established in an
attempt to avoid such phenomenon.
Avoid penetration of thunderstorms. In-flight lightning avoidance is
closely associated with thunderstorm avoidance. Maintain visual
contact with thunderstorms during the daytime and lightning at night.
Check the radar for precipitation, review all available types of weather
information, examine other pilot reports and follow ATC instructions.
Even with a good weather report received and understood, pay close
attention to those storms that develop rapidly along the route in a
given area and that cannot be predicted. While enroute, constantly
update the previous weather briefing through radio contact and
airborne equipment for actual storm avoidance.
Remember that radar detects only liquid droplets, not the cloud itself.
Only rain suspended in the cloud will produce a radar echo, which may
lead to occasional encounters with hail and lightning.
Circumnavigate the detected thundercloud or area, if possible by more
than 25 miles when traffic conditions permit. Flying over the top of the
thunderclouds is preferable.
Be aware that lightning can strike an airplane miles away from the
extreme side of a developed thunderstorm. Reports of airplane
receiving strikes in clear air at 25 or more miles from the nearest storm
are common.
The following paragraphs summarize the conditions in which strikes
are most common:
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Meteorological conditions: incident reports show that an airplane
must be within or beneath a cloud to receive a strike, or in or near
regions of precipitation. Incident reports show that in over 80% of
the strikes, the airplane was within a cloud and experiencing some
precipitation and turbulence. But other strikes may occur in a cloud
where there is no precipitation nearby, in clear air reasonably
distant from a thundercloud, during snowstorms and in clouds over
erupting volcanoes. Flight through or in the vicinity of cold front,
warm front, stationary front, unstable air or squall line are indicators
of imminent lightning strikes. Incident reports also show that
lightning strikes occur most commonly under light or heavy
turbulence conditions.
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Flight regime: Takeoff, climb, level flight, descent or approach.