NTSB raises safety issues with old planes

National Transportation Safety Board
Chairman Mark V. Rosenker has addressed an aviation
conference in California reiterating the agency’s concern
with aging aircraft.“We have investigated several accidents and incidents
that have highlighted the safety implications resulting from
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    During his speech in Palm Springs, California before
the Aging Aircraft Conference, he noted that there is no
single criterion that defines An aircraftas ‘old’.  The age
og an eircraft depends on a number of factors that include,
but are$not limited to the chronological age, number of
flight cycles, number of flight hours and the environment in
which the aircraft operates. Furthermore, determining the
overall health of an aircraft is complicated by the fact
that individual aircraft components can age differently in
different portions of the same aircraft and by the nature of
certain aging mechanisms, such as fatigue.

      Some common themes identified in each of these
accidents involving aging aircraft have been:
*    Unknown service histories as is the case with military
    surplus aircraft,
*    Poor fatigue design details.  The regulations did not
    require fatigue analysis for these airplanes,
*    Most older airplanes have no inspection program, and
*    The continued operation of airplanes beyond their
    useful lifespan.

      On April 28, 1988, one person was killed when the top
of the fuselage of Aloha Airlines Flight 243 separated from
the rest of the hull due to fatigue and corrosion.  As a
result of the NTSB’s investigation, the FAA’s Aging Airplane
Program was developed in 1991 to focus on regulatory
initiatives related to structural fatigue and corrosion.
      In 1996, when the center fuel tank of TWA flight 800
exploded, the Board’s investigation found that wiring found
in the wreckage had numerous cracks in the insulation that
were attributed to age, bringing to light the problem of
aging systems.

      The Safety Board began documenting numerous systems
problems in fleet aircraft starting in May of 1997, with the
TWA-800 investigation, and continued that documentation when
SwissAir flight 111 crashed in September 1998.


      In October of 1998, the FAA released the Aging
Transport Non-Structural Systems Program a concept based on
the 1991 aging structures program that followed the Aloha
737 accident.

      However, aging aircraft continue to be a problem.  The
in-flight separation of a wing from three Forest Service
firefighting aircraft occurred within a short timeframe
several years ago.  Most recently, during the ongoing
investigation of a Chalk’s Ocean Airways accident in Miami,
Florida in December 2005, it was discovered that the wing of
a Grumman Mallard seaplane, manufactured in 1947,  separated
from the aircraft in flight and the resulting accident
killed the 20 passengers and crew on board.

      “The Safety Board feels that the continued commercial
operation of these 50 to 60 year old airplanes that were not
certified to the standards of today’s modern airplanes is
not safe -all passengers should have the same level of
safety,” Rosenker said.  “The FAA should require records
reviews, aging airplane inspections, and supplemental
inspections for all airplanes operated under Part’s 121, 129
and 135 regardless of the year they were type certificated,
the number of passengers they carry or their maximum
payload, and has issued related safety recommendations to
that effect.”