Premium On Safety - Issue 13, 2014 - 6

LESSoNS LEARNED

PART 1 of 4

Where the Wreckage Is Buried
By DAVID JACK KENNy

and database management expertise
you've got to spare. If you have a sweet
tooth for writing queries in a relational
DBMS language, or think somebody
in your IT department suffers from an
excess of free time, you can download the
entire NTSB database along with reasonably complete documentation, update it
weekly and refresh it monthly, and
take advantage of the wealth of
detail captured in fields that aren't
accessible via the public search
page. Be advised, though, that
not all the linkages between the
18 individual tables are intuitively
obvious.
Aside from database programming, there are two alternatives.
The NTSB search page (ntsb.
gov/aviationquery/) covers all
aircraft, but the interface makes
many inquiries surprisingly awkA fine grasp of the subtleties of
ward. (Looking for King Air accidents caused by structural icing?
49 CFR Part 830 is needed here,
You've got some work to do.) The
particularly the exclusion of damage Air Safety Institute's (ASI) accident search page (aopa.org/asf/
limited to engines, propellers, skins, ntsb/search_ntsb.cfm) has preprogrammed some of the most frequently requested searches, but is
fairing, landing gear, brakes, etc.
restricted to airplanes of no more
than 12,500 pounds. It covers helicopof the trade can help you find what you
ters of all sizes, but searches for specific
need with only the necessary minimum of
types of helicopter accidents haven't yet
muddling around.
been implemented.
Actually, there's one step before the
The ASI database does have one
first one, which is determining whether the
advantage you won't find on the official
occurrences of interest necessarily qualify
as accidents. A fine grasp of the subtleties NTSB site: Aircraft make-and-model designations have been standardized. The
of 49 CFR Part 830 is needed here, particularly the exclusion of damage limited to NTSB relies on whatever the investigators
initially entered into their reports. This
engines, propellers, skins, fairing, landing
isn't a big deal with Cessnas, but if you're
gear, brakes, etc. If today's topic is the
after one of those models that's changed
expense of unintended gear-up landings,
names and corporate owners frequently
the accident data significantly understate
over the years, you'd better do your homethe problem.
work and be prepared to search for all
If you're after something really catathose different designations. Aerostars,
strophic, though-the kind of event that
for example, can show up with the manuleads to funerals, lawsuits, and total-loss
facturer listed as "Smith," "Smith, Ted,"
insurance claims-the accident database
"Piper," or "Aerostar Aircraft Corporation."
is the place to go. How far you want to
None of those catch every record-and a
go depends on how much time, ambition,
Whether you're looking for the perfect
case study to drive home the point of the
next safety standdown or trying to put
together a comprehensive accident review
for the models you operate, the first step
is always finding the relevant accidents.
This isn't generally difficult, but it's not
always straightforward, either. A few tricks

search specifying "Aerostar" as the manufacturer also turns up everything from
a Yak-52 to hot-air balloons. (To be fair,
these have become more consistent in
recent years' reports.)
Searching for specific types of accidents
can also be tricky. ASI's pre-programmed
keyword searches are helpful if they
happen to be directed to the subject
you're pursuing. The NTSB offers nothing between general searches specifying
time periods, models, purposes of flight,
etc., and free-text searches, which require
guessing at the phrasing used in the official narratives. There is some consistency
to that, and practice gives you a feel for it.
Still, the logic used to define complex criteria-say, descents below MDA in actual
IMC-isn't easy to pin down and often
doesn't return what you'd expect. To make
sure nothing gets overlooked, it's usually
best to run a series of broad inquiries-
noting the results of each and detailing
their intersections-then make notes after
screening every individual report. (The
"search tips" on the NTSB help page do
help, but only up to a point.)
Accident locations are another potential
bugaboo. The listed city and state are those
nearest the accident site-which may be
across state lines. Major airports aren't
always in the same states as the cities they
serve; accidents at Cincinnati's international airport come up labelled "Covington,
Kentucky." City names don't necessarily match within states, either, and can
also change over time: most accidents at
Providence International through 2001 are
listed under "Warwick, Rhode Island."
The guiding principle to searching both
systems is to not assume you've found
everything until you've exhausted all possibilities. The burden's on you to imagine
where things could hide, turn over all the
rocks, and look hard at whatever scurries
out. And after that? Stay tuned.
David Jack Kenny is manager of aviation
safety analysis for the Air Safety Institute,
an instrument-rated commercial pilot, and
owner of a Piper Arrow.

http://www.ntsb.gov/aviationquery/ http://www.ntsb.gov/aviationquery/ http://www.aopa.org/asf/ntsb/search_ntsb.cfm http://www.aopa.org/asf/ntsb/search_ntsb.cfm

Premium On Safety - Issue 13, 2014

Table of Contents for the Digital Edition of Premium On Safety - Issue 13, 2014