IAI1125 (Astra)
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 90; Flight Crew Total 10765; Flight Crew Type 2300
Aircraft Equipment Problem Less Severe
Air Traffic Control Issued New Clearance; Flight Crew Diverted; General Declared Emergency; General Maintenance Action
Aircraft
As flight neared destination; indications via the annunciator panel indicated a growing problem with the main hydraulic system including hydraulic levels (interment light display); illumination of left main 'Hyp Pump' light; intermittent activation of the auxiliary hydraulic pump to compensate for fluctuating main hydraulic pressure and intermittent illumination of right 'Hyd Pump' light. Aircraft QRH was consulted by Captain sitting in right seat as Pilot Not Flying and appropriate section referenced indicating only crew action necessary was to 'monitor' pressure. There was no requirement per the QRH for landing as soon as practical or possible; so flight continued toward the destination. At one point; perhaps 30-35 minutes out; the 'Hyd Level' light illuminated on the annunciator panel indicating to the crew a worsening problem with the main hydraulic system. Prior to this; the crew decided to divert to the nearby international airport since the runways were longer and more services were available rather than continue to the flight's destination. Once the 'Hyd Level' light illuminated and believing the aircraft was experiencing what would become a total loss of main hydraulic pressure/system and given this was a Part 135 passenger-carrying flight; the Captain; in consult with the First Officer; declared an emergency and so notified Center in order to receive priority handling. Center acknowledged and cleared the aircraft direct. The hydraulic system did not worsen from that point; there was no total loss of any aircraft hydraulic system; the aircraft's auxiliary hydraulic system performed as designed and intended and the landing; roll-out; braking and taxi-in were normal. There was no aircraft damage; crew or passenger injuries. Aircraft was followed by emergency vehicles to parking at the FBO and shut down. Passengers disembarked to their final destinations and the aircraft was turned over to Maintenance.
IAI1125 Captain experiences a main hydraulic system leak in cruise and elects to divert to an airport with longer runways. The main system continued to function normally throughout the approach and landing with a low quantity indication.