CFI-to-CFI Newsletter - Volume 11 Issue 2 - 33

LESSONS LEARNED
indication on the cockpit display, effectively giving
you a picture of where the storm was located in
the recent past-not at the moment. That is why
it's prudent to use datalink weather for strategic
decisions only, to plan ahead-not tactically to
avoid weather when you're already close to it.
Depending on your datalink weather provider,
when first received, the radar mosaic will be at
least five to seven minutes old as compared to
what is observed directly outside of the cockpit.
Be aware that in rare cases, it may be 20 minutes
old from when the weather was detected and the
image was created, broadcasted, and received in
the cockpit due to the datalink service delivery
method or disruptions in the datalink broadcast.
So, it's always a good idea to look out the window
and visually avoid any bad weather.
Also keep in mind that when talking to ATC about
the weather, ARTCC radar depicts precipitation
only, described as moderate, heavy, or extreme.
Their radar image refreshes every four to five
minutes and it does not show turbulence or clouds.
If ATC reports moderate or severe precipitation,
it implies that hazards like severe downdrafts,
turbulence, and hail may be present.

One more thing, be aware that if a system moves
at a speed greater than 15 or 20 knots, has cloud
tops that are higher than 30,000 feet, and if a
convective sigmet is issued for the area, these
are all signs indicating severe weather that is no
match for aircraft or pilot. So, if you encounter
convective activity, turn around or fly at least
20 miles away from the storm to avoid extreme
weather like downdrafts, hail, and severe
turbulence that can hurt you and your aircraft.
As a stark reminder of the dangers that storms
present and the reason to use datalink weather
strategically, not tactically, you might want to watch
ASI's Accident Case Study: Time Lapse, which
highlights this problem. The study examines a pilot's
mistake of relying on datalink weather displays
to navigate around quickly developing weather
systems with fast moving convective activity
(airsafetyinstitute.org/ACS/timelapse).

WEATHER OR NOT:
THUNDERSTORM CHALLENGE
Test your thunderstorm avoidance strategy. Be
prepared to deal with pop-up thunderstorms,
deteriorating weather, on-board and ATC radar
realities, and fuel concerns. You'll make critical
go/no-go decisions on a 300-nm route and
experience where your decisions lead. You'll even
have the option to try different flight paths to see
various decision outcomes (airsafetyinstitute.
org/weather-or-not-thunderstorms).
-MS

Machteld Smith is an aviation technical writer
for the AOPA Air Safety Institute. She holds a
commercial pilot certificate with multiengine,
instrument, and seaplane ratings. She loves flying
seaplanes and the adventure of landing on rivers and
lakes! Email: machteld.smith@aopa.org
Sponsored by

http://www.airsafetyinstitute.org/weather-or-not-thunderstorms http://www.airsafetyinstitute.org/weather-or-not-thunderstorms https://www.aopa.org/lms/courses/weather-or-not-thunderstorms/strategy/index.html http://www.airsafetyinstitute.org/ACS/timelapse https://www.aopa.org/about/aopa-partners/siriusxm-aviation

CFI-to-CFI Newsletter - Volume 11 Issue 2

Table of Contents for the Digital Edition of CFI-to-CFI Newsletter - Volume 11 Issue 2