Although hoping to decrease delays, improve system
capacity, and modernize facilities, the ultimate goal of the
NAS Plan is to improve system safety. If statistics are any
indication, the beneficial effect of the implementation of
the plan may already be underway as aviation safety
seems to have increased in recent years. The FAA has
made particular emphasis to not only reduce the number
of accidents in general, but also to make strides in curtailing
controlled flight into terrain (CFIT) and runway
incursions as well as continue approach and landing
accident reduction (ALAR).
The term CFIT defines an accident in which a fully
qualified and certificated crew flies a properly working
airplane into the ground, water, or obstacles with no
apparent awareness by the pilots. A runway incursion is
defined as any occurrence at an airport involving an aircraft,
vehicle, person, or object on the ground that creates
a collision hazard or results in a loss of separation with an
aircraft taking off, attempting to take off, landing, or
attempting to land. The term ALAR applies to an accident
that occurs during a visual approach, during an instrument
approach after passing the initial approach fix (IAF), or
during the landing maneuver. This term also applies to accidents occurring when circling or when beginning a
missed approach procedure.
The NTSB released airline accident statistics for 2004
that showed a decline from the previous year. Twentynine
accidents on large U.S. air carriers were recorded in
2004, which is a decrease from the 54 accidents in 2003.
Accident rates for both general aviation airplanes and helicopters
also decreased in 2004. General aviation airplane
accidents dropped from 1,742 to 1,595, while helicopter
accidents declined from 213 to 176. The number of accidents
for commuter air services went up somewhat, from
2 accidents in 2003 to 5 in 2004. Air taxi operations went
from 76 accidents in 2003 to 68 accidents in 2004. These
numbers do not tell the whole story. Because the number
of flights and flight hours increased in 2004, accident
rates per 100,000 departures or per 100,000 flight hours
will likely be even lower.
Among the top priorities for accident prevention are
CFIT and ALAR. Pilots can decrease exposure to a
CFIT accident by identifying risk factors and remedies
prior to flight. [Figure 1-5] Additional actions on the
CFIT reduction front include equipping aircraft with
state-of-the art terrain awareness and warning systems
(TAWS), sometimes referred to as enhanced ground
proximity warning systems (EGPWS). This measure
alone is expected to reduce CFIT accidents by at least 90 percent. With very few exceptions, all U.S. turbine powered
airplanes with more than six passenger seats were
required to be equipped with TAWS by March 29, 2005.
Added training for aircrews and controllers is part of the
campaign to safeguard against CFIT, as well as making
greater use of approaches with vertical guidance that use
a constant angle descent path to the runway. This measure
offers nearly a 70 percent potential reduction.
Another CFIT action plan involves a check of groundbased
radars to ensure that the minimum safe altitude
warning (MSAW) feature functions correctly.
Like CFIT, the ALAR campaign features a menu of
actions, three of which involve crew training, altitude
awareness policies checklists, and smart alerting technology.
These three alone offer a potential 20 to 25
percent reduction in approach and landing accidents.
Officials representing Safer Skies—a ten-year collaborative
effort between the FAA and the airline
industry—believe that the combination of CFIT and
ALAR interventions will offer more than a 45 percent
reduction in accidents.