EASA issued an emergency AD for AgustaWestland AW139


EASA issued airworthiness directive on AW139 helicopters, this was quickly followed by the FAA, Transport Canada and Australia CASA

EASA acted swiftly last week
after preliminary findings of the recent accident of an AW139 in Brazil. Other
safety agencies quickly followed with emergency ADs for the tail rotor blades
of AW139 and AB1319 helicopters. Soon after the accident Brazil grounded all 18 Brazilian
registered AW139s.

The airworthiness directive
(AD) requires the inspection of AW139 and AB139 tail rotor blades with 25
flight hours after the date of the AD and then at intervals no longer than 25
flight hours between inspections. The AD imposes a new life limit on the tail
rotor blades of 600 hours time in service or 1,500 flight cycles, whichever limit occurs first.

EASA issued an AD in early
2011 regarding the inspection of tail rotor blades, setting the inspection
limits. The new AD supersedes that earlier AD and retains the repetitive
inspections along with the new life cycle limits. For tail rotor blades for
which the number of flight cycles cannot be determined, EASA requires that the
number of flight hours accumulated by the blade since its first installation on
a helicopter must be multiplied by four to determine the replacement time for
that blade. EASA requires that blades that have exceeded the hours/flight
cycles limit be replaced within five flight hours or 30 days after the
effective date of the AD.

The FAA AD differed slightly
but still requires operators to inspect and replace tail rotor blades. It also
requires replacement of blades that have exceeded the newly revised life limits
within five hours time-in-service, rather than the first occurring of five flight
hours or 30 days.

These ADs are described by
EASA and FAA as “interim actions” and that further AFs might be issued later.