Eurocopter AS 350/355/EC130 - Astar/Twinstar/Ecureuil
Maintenance Inspection Authority
Maintenance Inspector 20
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Diverted; Flight Crew Landed in Emergency Condition
Human Factors; Environment - Non Weather Related; Aircraft
The aircraft had sat for 30 days at a small airport. The pilot arrived and departed with the intent to fly to [an airport several states away]. Whether the aircrafts' protective covers were installed has not been determined. After 30 minutes of flight; the low 'Oil Pressure' light illuminated. The pilot made a precautionary landing near a farm house. Upon opening the engine cowl; oil was everywhere. The engine had lost 4 quarts in the short flight. Most of the oil residue was around the Bleed Valve opening. A Mechanic was dispatched and found the engine case breather tube was blocked. This had caused the engine interior to become pressurized and vent the oil out the labyrinth seals. The tube was cleaned and reinstalled. A maintenance run was performed and the aircraft was put back in service for the continuation of the flight. The aircraft is operated on a Part 135 certificate. According to FAR PT 135.415 Par. (A)16. This event should be reported to the PT 135 Certificate Administrator (FSDO). This was not done. This has happened on two prior operations by this company where aircraft have made precautionary landings and declared an inflight emergency for priority landings. Management is aware of this and the procedure is contained in the company's Emergency Procedures Manual. Suggestions: company wide training on the correct procedures to follow in an event. Failure to follow published procedures.
Mechanic reports being dispatched being sent to repair a helicopter that landed in a field due to loss of oil quantity and pressure. The Mechanic found the engine case breather tube blocked causing engine oil to vent through the labyrinth seals.