Coming AD Limits Operations To Day VFR Conditions
In a Customer Technical Communication notice released this
week, Eclipse Aviation announced it has developed a fix for the
pitot/AOA probe system on the Eclipse 500 to address icing issues,
as ANN first reported in
Eclipse tells ANN the new configuration follows over 60 hours of
developmental flight testing, and incorporates changes in the
Pitot/AOA probe and aircraft tubing. The supplier for the pitot/AOA
probe incorporated a drain in the tip of AOA/pitot probe, as well
as added insulation and heater elements within the probe to keep
temperatures inside the probe above freezing at all times.
Eclipse says the fix was tested in one of its engineering flight
test aircraft at extremely low temperatures, "with complete
TSO documentation will be submitted by the supplier by the end
of this month, according to Eclipse. A unit is now installed on a
test aircraft for certification, which Eclipse hopes will be
completed within three weeks. Once certified, the new system will
be incorporated into the production line, and aircraft already in
the field will have the piece retrofitted through issuance of a
service bulletin. Eclipse aims to have the problem rectified
fleet-wide by September.
The fix comes following three reported pitot icing incidents in
Eclipse 500s in which pitot pressure was lost on both left and
right primary air data sources, resulting in the loss of airspeed
indications on the Primary Flight Displays (PFDs). All three
aircraft maintained airspeed readings through a third, independent
source, and recovered primary airspeed indications once the
aircraft descended into warmer air.
Through testing, Eclipse found a specific set of temperature and
humidity conditions which led to condensation inside the original
probe, which froze as the aircraft climbed to higher altitude.
FAA Says An AD Is Coming
Until the fix is implemented, however, it appears current
Eclipse owners will have to comply with increasingly tight
restrictions on flight operations in their planes.
Eclipse also notified customers of a pending Airworthiness
Directive from the FAA, limiting all flights to day Visual Flight
Rules (VFR) conditions that do not allow the moisture in the
pitot/AOA system to freeze.
This is more restrictive than the previous FAA approved
limitation, which required aircraft operations to be temporarily
limited to flights in Visual Meteorological Conditions (VMC) with
an Eclipse company pilot or Eclipse trained mentor pilot on board.
Under the coming AD, an Eclipse pilot would not be allowed to file
an IFR flight plan, or ascend above FL180.
"The good news is, we expected to have all our planes
retrofitted by early September," Eclipse spokesman Andrew Broom
told ANN. "For now, it's not affecting very many pilots -- and we
wanted to be on the forefront of this issue."