Premium On Safety - Issue 16, 2015 - 1

ISSUE 16 yEAR 2015


Best Practices: Can We (Still) Land There? 03
Flight Vis: Partnering With Your Local Airport for Safety 04
Lessons Learned: Wrapping It Up 05
ASI Message: Success Expectation 05
SMS Corner: Six Ways to Lose Money 06
USAIG Safety Posters 08

Greetings! Aviation mishap stats
and news headlines tell us that
despite ongoing efforts to lower the
rate of runway excursions, aircraft
continue to leave runways in ways
other than intended-far too often.
We need to keep the pressure on
reversing that trend, and to that end
the topic of braking action reports
and related concerns is a focus
in this issue. The FAA's recently
updated AC 91-79A is a succinct
summary of runway excursion risk
factors and defenses that should be
integrated in operating practices.
It's a perfect companion read to
the articles in here. Looking for
relatively low-cost/high-gain ideas
to boost safety and efficiency in
the New Year? David Miller's article
describes how outreach with airport
and air traffic authorities at their
home airfield benefited GEICO's
flight department and the airport
community. Fly smart and fly safe.

Paul Ratté
Director of Aviation Safety
Programs, USAIG

The finer Points of Runway
Braking Action Reporting

Are you Prepared for Slippery Winter Runways?

way surface. Many factors contribute to the loss
of friction. Besides the common culprits of standing water, slush, or ice, even a light coating of
moisture on the surface from recent rainfall may
lead to hydroplaning on landing-similar to what
drivers frequently experience on highways.
A runway's downward slope, or landing with
even a slight tailwind,
When considering the suitability of landing on a slick may significantly
decrease the effectiveness of aircraft braking
runway, flight crews seek information about braking
systems and even thrust
reversers. Lateral or
action, defined by the Greek term Mu (pronounced
"cornering" forces may
also come into play due
"mew") as the coefficient of friction between the
to crosswinds acting on
the aircraft, or as the
landing gear tire and the paved runway surface.
pilot uses nosewheel
steering to maintain the centerline or turn onto a
loss of braking action on landing. According to
taxiway. Lastly, the runway paving material also
a report by the Flight Safety Foundation, runway
contributes to this metric, as does any grooving
overruns accounted for fully half of all runway
into the hard concrete or asphalt surface.
excursion accidents between 1995 and March
Generally, runway braking action information
2008. In many of those cases, an arriving airis conveyed through four terms: good, medium
craft departed the runway surface due to a lack
(or fair), poor, and nil. The first and last terms are
of adequate deceleration on rollout.
When considering the suitability of landing on a easy to define; "medium" and "poor" represent
slight and significant reductions in braking and/
slick runway, flight crews seek information about
or directional control, respectively, often based
braking action, defined by the Greek term Mu
on a Mu reading. This information typically comes
(pronounced "mew") as the coefficient of friction
from air traffic control (ATC) personnel at the
between the landing gear tire and the paved runWinter's arrival across the northern hemisphere
brings the likelihood that not all our runways will
be dry and warm in the coming months.
Unless one limits flying solely to sunny and
clear days over the windswept deserts of Arizona
or New Mexico, it's likely that most pilots will
have had at least some experience with the

(continued on page 2)


Table of Contents for the Digital Edition of Premium On Safety - Issue 16, 2015