Page 25 - EAA78.Newsletter.Archives.(February.2017-July.2021)

CHAPTER CHATTER, EAA Chapter 78
The lawyers say that a movable tail wing called a
stabilator, which tilts up and down to aid the pilot in
climbing or descending, is the cause of the crashes, and
that Piper has sought to conceal the design defect by
settling lawsuits with a stipulation that parties not
discuss settlement details. Like other claims against
Piper, Renick's case was settled.
Because the Piper stabilator is weakly reinforced, it is
uniquely vulnerable to a self-reinforcing vibration
called divergent flutter that can pulse through the
entire aircraft and within seconds cause it to break
apart. The lawyers contend that each crash exhibits the
telltale signs of 45-degree folds in the horizontal
stabilator, which occur as the stabilator first vibrates
and then bends under stress.
Courtesy NASA, Stillman Fires Collection, Prelinger Archives
The bending destroys the plane's aerodynamics, causing
it to plummet from the sky.
“We have had a number of experts look at this, and
all of them say the structure is too light and allows it
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to bend and change its airfoil,” said Arthur Wolk,
whose Center City-based firm has won more than $1
billion in jury verdicts and settlements in aviation
lawsuits. “It is my view that, given the history of
these airplanes, the stabilator needs to go. If you
have an engineering flaw, it will always rear its ugly
head until you fix it.”
Piper maintains that there is no merit to Wolk’s
allegations and that its aircraft are safe. The National
Transportation Safety Board has filed reports on more
than 200 midair breakups of Piper Cherokee, Saratoga,
and Seneca aircraft since the 1970s, and in the vast
majority of cases found that pilot error was the cause.
One common scenario, according to the NTSB: The
pilot flew into or near bad weather, causing the aircraft
to break apart.
But Piper points out that the NTSB never once has
found that a design defect was the cause of a crash of
these planes.
"All Piper aircraft are certified by the FAA," said Piper
spokeswoman Jacqueline Carlon. "We are unaware of
any lawsuit against Piper in which this supposed
'divergent flutter problem' has been identified by the
NTSB as the cause of the accident. If the NTSB or the
FAA thought there was such a problem, they would
surely communicate it to the public."
The NTSB findings are viewed with skepticism by
Wolk, himself an expert pilot certified to fly certain
types of military jets, who contends that the NTSB is
too in the thrall of aircraft manufacturers to objectively
examine the causes of aircraft mishaps.
“As long as the National Transportation Safety Board
continues to have the aircraft manufacturer as a party to
the investigation, pilot error will always be the primary
probable cause,” says Wolk, who flies his own Eclipse
500 twin-engine jet once a month to California, where
he has a second home.
Wolk is known as a tough litigator who doesn’t shy
away from difficult cases. He represented families of
victims of the USAir Flight 427 crash in Pittsburgh on
Sept. 8, 1994, that claimed 132 lives. Wolk lobbied
hard for the NTSB to find that a flaw in the plane's
rudder system caused the crash, while Boeing,
manufacturer of the Boeing 737 that went down, argued
pilot error was responsible. The NTSB eventually