The Emergency Lubrication (EMLUB) system of the helicopter was designed to
guarantee 30 minutes of continued safe flight in the event of total loss of the
dual oil lubrication system of the Main Gearbox (MGB).
Investigations on the EMLUB system have revealed an area of the flight
envelope in which the emergency lubrication Glycol pump’s performance is
different to that assumed during certification.
Consequently, even though the likelihood of using the EMLUB is extremely low
(no total loss of oil lubrication encountered on the Super Puma fleet), as the
continued safe flight of 30 minutes is not guaranteed in the whole flight
envelope, and pending a Eurocopter modification to the Glycol pump and
EMLUB pressure switches, an immediate landing or ditching is required as
soon as the EMLUB system is activated.
To address this potential unsafe condition, Eurocopter issued EC225
Emergency Alert Service Bulletin (ASB) No 04A010 to provide updated
Rotorcraft Flight Manual (RFM) emergency procedures.
For the reasons described above, this AD requires amendment of the RFM
emergency procedures section.
So now, the EC225 has lost its 30 minute "run dry" capability.