The U.S. Federal Aviation Administration (FAA) has announced it
plans to issue an Airworthiness Directive (AD) involving a
staggering 1,740 Robinson helicopters -- the fastest selling
and most popular helicopters in operation around the world.
The FAA says it is taking the action because improperly
lubricated and corroded bearings in R22 and R44 helicopter
pitch control assemblies are responsible for tail rotor
assembly failures, causing breakup and loss of control.
This AD program is one of the FAA's largest.
An AD is the aircraft industry equivalent of an automobile
recall, except that it has the force of law in the United
States.
Founded in 1973, Robinson Helicopters (Torrance, California)
is the world's
largest helicopter manufacturer, even though they only offer
two models: the 2-seat R22 and the 4-seat R44. The company,
with annual sales over USD $100 million,
operates out of a 260,000 square foot factory and employs
over 600 people. The factory is currently undergoing a
major expansion program.
In 2001, Robinson sold over 325 R22 and R44 helicopters;
in pre-recession 2000, the number was almost 400 units. Every year since
1987, the company has outsold all
other North American helicopter manufacturers combined.
The company has been manufacturing and
selling the R22 since 1979. Over 3,300 R22's have been
sold in 60 countries, including
China and Russia. 29 feet long, with a 25-foot twin
blade main rotor and weighing only 830 pounds
before fuel and passengers, it is the lightest and
least-expensive (approx. $200,000 with avionics)
helicopter made today.
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The four-seat Robinson R44
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The R44 was introduced in 1993, and has been the world's
best-selling helicopter every year since 1998. It is used
by private pilots, news, police, charter operators, surveyors,
ranchers and repair crews worldwide.
With a 6-cylinder Lycoming engine, the R44 has a 2400 pound
gross weight. It is 39 feet long, has a 33-foot, twin blade
main rotor and can cruise at 130 mph.
Robinson has always stressed its reliability and
safety record. The engines are downrated to reduce
stress and improve reliability; all wear parts
are designed to go 2,200 operating hours before
overhaul. Regarding the bearings,
Robinson says, "Teflon-lined, elastomeric and sealed
bearings eliminate most lubrication requirements."
Both helicopters have twin blade tail rotors; the
R22's is 42 inches in diameter, while the R44's is
58 inches in diameter. Both use the same
pitch control assembly.
The FAA's Airworthiness Directive involves the bearings
in that tail rotor pitch control assembly. According to
the FAA, "This proposal is prompted by reports of failure
of the tail rotor assembly due to improperly lubricated
bearings ... The actions specified by the proposed AD are
intended to detect corrosion of the bearings and prevent
bearing failure, breakup of the tail rotor assembly,
tail rotor contact with the tailboom, and subsequent
loss of control of the helicopter."
The AD would require inspecting the pitch control assembly
for roughness or binding of the pitch control bearings.
by hand-rotating the pitch control bearing housing. If the
housing does not rotate freely, the proposed AD would require
replacing the unairworthy pitch control assembly with
an airworthy unit.
The FAA estimates the AD affects 1,300 R22 and 440 R44
helicopters currently operating in the United States.
Following the AD, the pitch control bearings must
be inspected every 300 hours time-in-service (TIS)
or 12 months, whichever comes first.
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