November-December 2022 - 16

WINTER WEATHER OPERATIONS
with visual observation of known
landmarks, but human estimation is
subjective and prone to error. Without
reliable, accurate visibility information,
airports cannot operate safely - nor
at full capacity.
Categorized airports must have
instrumented meteorological optical
range (MOR) measurements and
a system calculating runway visual
range (RVR), the essential factor
for enabling air traffic control and
pilots to make the correct operational
decisions. Visibility, or MOR, can
be measured with two approved technologies:
transmissometer and forward
scatter, with transmissometer technology
like Vaisala's LT31 transmissometer.
Forward scatter technology, such
as Vaisala's FD70, is, in addition to the
meteorological visibility (MOR), able
to measure the drop size distribution
and velocity of falling hydrometeors
and offer present weather detection of
conditions that were previously hard
to identify.
These advances enable automated
weather observation platforms to accurately
identify real-time conditions
in an autonomous operating mode,
delivering detailed particle-by-particle
analysis that allows for highly
reliable frozen-liquid differentiation.
The capability to differentiate between
frozen and liquid particles and other
precipitation identification is essential
for visibility and present weather,
including RVR.
Wind Shear: Addressing
Shifts in Wind Patterns
From wind shear and microbursts
to gust fronts and wind shifts, wind
remains one of the most dangerous
- and difficult to assess - weather
ABOUT THE AUTHOR
KARI LUUKKONEN
Kari Luukkonen has a long experience
in various roles in Vaisala. Over the
last five years, he has been managing
Vaisala's offering for aviation systems
and services. His work includes driving
the development of the overall weather
offering to meet the current and future
needs of the aviation market.
hazards. While it may not be the first
weather event that comes to mind
when addressing winter storms, the
sudden change in the direction or
velocity of wind, also known as wind
shear, is an essential consideration.
Most commonly resulting in delays
and cancellations, wind shear can also
quickly create dangerous situations
during takeoff and landing when aircraft
might not be able to withstand
severe wind-caused disruptions to
their flight paths.
While there is no mandate to
measure or detect wind shear, failure
to do so effectively can put lives at
risk and lead to crippling financial
damages. Consequently, the impact
of wind shear should be accounted for
since it occurs at a height and under
flying conditions in which aircraft are
most vulnerable.
The best aviation weather management
systems for wind shear incorporate
a combination of up to three
measurement technologies: a low-level
wind shear alert system (LLWAS),
weather radar and scanning wind
lidar. LLWAS measures average wind
speed and direction using a network
of remote ultrasonic sensors fixed
around runways and along approach
and departure corridors. In addition,
weather radar, used during precipitation,
can measure the wind field from
the entire aerodrome and beyond.
Scanning wind lidar, used in clear sky
16 \ AIRPORT BUSINESS / NOVEMBER/DECEMBER 2022
Vaisala's FD70 is able to measure the
drop size distribution and velocity of
falling hydrometeors and offer present
weather detection of conditions that were
previously hard to identify.
VAISALA
conditions, provides wind shear detection,
3D wind information and wind
inversion detection that can measure
the entire field, from the runway and
its approach and take-off areas.
With real-time detection of wind
shear, decision-makers can predict
wind changes to prevent accidents
and make runway changes to improve
airport efficiency.
Embracing Innovation
in Aviation
From maintaining scheduled operations
to keeping employees and travelers
safe, decision-makers with precise
and timely weather information can
adapt, rapidly react to changing conditions
and reduce disruptive delays.
Technological advances have opened
the door for airport decision-makers
to measure and detect severe weather
and take the proactive steps necessary
to minimize delays and cancellations
while keeping operations running as
safely and smoothly as possible. With
the right aviation weather solutions
in place, airports can not only be
prepared for winter weather but have
the information on hand to address
any severe weather event throughout
the year. 
November-December 2022

Table of Contents for the Digital Edition of November-December 2022
