Air travel safety has come a long way. And technology is partly to thank
According to industry statistics, airplanes are the safest way to get
from Point A to Point B. Driving a car is positively hazardous in
comparison. In 1950, 17 out of every one million commercial airline
passengers worldwide died. But since the mid-1970s, that figure has
fluctuated around one in a million, and the U.S. average is .3 per
And technology plays a role in that safety record.
”Our aviation system is so robust with backups that a single problem
almost never winds up hurting someone,” says Christopher Hart, the
Federal Aviation Administration’s (FAA) systems administrator for System
To keep it that way, FAA investigators pore over wreckage from every
accident to determine what went wrong and what steps to take to ensure it
never happens again. But crashes now are so rare, and the circumstances
so unique, that they offer little guidance.
”There is so little predictability in how the next accident will occur
that it is hard to predict where an intervention should be to prevent
accidents,” adds Hart.
To further improve safety, therefore, it is necessary to look at
potential, rather than actual problems.
One way is to use simulations. Airplane manufacturers extensively use
computer modeling to see how their equipment performs under various
weather conditions and load factors. Another method is to look at small,
but common, mechanical anomalies which could lead to problems down the
”We are trying to get smarter and look at events that happen relatively
frequently, but are innocuous by themselves because of the robustness of
the systems,” says Hart. ”But if they are part of the links in an
accident chain, we can stop those links before they cause an accident.”
Achieving this requires overcoming two barriers.
The first is that the potentially useful data is held by thousands of
different entities, including private and national airlines,
manufacturers, maintenance companies, air traffic controllers, trade
associations, labor unions and air forces. It would be useful, for
example, to be able to aggregate the Boeing 747 maintenance records of
all airlines that fly the plane so common problems could be identified
and corrected, rather than each airline being limited to the information
on the few 747’s in its own fleet. But these groups dont necessarily
want to share detailed information about their operations, whether due to
competitive advantage or fear of law suit.
The other barrier is that most of the data is unstructured, making it
difficult to compare and analyze.
To address these shortcomings, the FAA facilitated the creation of the
Global Aviation Information Network (GAIN) in 1996. GAIN is a voluntary
international membership organization composed of public and private
entities from more than 50 countries. It is structured around the
philosophy that ”the collection, analysis, and sharing of safety
information using advanced technologies in a just culture environment
will illuminate safety concerns and permit identification and
implementation of cost-effective mitigations.”
While getting its members to openly share information still has a long
way to go, progress is being made in developing analytical tools
specifically designed to analyze safety information.
”The airline industry generates two types of data — digital data from
flight data recorders and textual data generated from reports written by
pilots and others,” explains Hart. ”Several entities are looking at the
digital data, so our main focus has been on the free text data where not
as much work has been done.”
To fill this hole, GAIN’s Analytic Methods and Tools Working Group has
sponsored the creation of several tools to analyze the text information.
To date, each of these has been used by a single airline.
One of these tools was a proof of concept done by Southwest Airlines
using the PolyAnalyst tool from Megaputer, Inc. of Bloomington, In. Hart
says PolyAnalyst was selected, in part, because of its ability to analyze
small data sets.
”One of the issues with text mining software is the volume of
information needed to provide a valid analysis,” he says. ”Some of the
software requires quite a large number of data inputs to develop
relationships between words and terminology in the data set, but the
Megaputer tool is more applicable to smaller data sets than other
The six-week test involved reports from Southwest’s pilots, detailing any
abnormal occurrences during different flight phases. These reports are
filed in an Oracle database containing 63 structured fields. It also has
an unstructured field allowing input of up to 4,000 words of free text
for pilots to give a narrative description of the incident.
The existing system for analyzing the material in the database was a
time-consuming manual process which relied on the analyst’s memory and
was prone to human error.
PolyAnalyst analyzed both the text and structured data of 2,000 database
records, and generated graphic depictions of the types of anomalies for
each type of aircraft in use. The user could click on any of the data
points in the graph to drill down to the individual pilot reports to get
all the details.
While it is helpful for an individual airline to have such safety
information, the real benefit will come when airlines start sharing this
”Individual airlines have a certain quantity of data that they keep to
themselves, so the Megaputer tool is only being applied to data from one
airline,” says Hart. ”If we are successful in pooling data from other
airlines it will be more successful.”
This is where GAIN’s other data sharing project comes into play.
Hart stresses that the FAA is not trying to get the airlines’ data.
Instead, GAIN is working on creating a method where the raw data remains
on the servers of each of its members, but they pool non-identifiable
”We are not only looking at what happens at the airline level, but at
the system level — airlines, plus air traffic control systems, plus the
maintenance network,” he says. ”The foundation for that will be what
the individual entities are finding from programs like Southwest’s.”