CROMAN CORP

Operated by Croman Corporation (per NTSB report)

A total loss of engine power due to the failure of the No. 2 engine’s stage 1 turbine blades as a result of an unreported hot start two days earlier.

Operated by CROMAN CORP (per NTSB report)

The improper installation of the fore/aft primary servo by maintenance personnel, which resulted in the attaching hardware backing out and which subsequently rendered the helicopter uncontrollable. Contributing to the accident was the company’s quality control personnel to identify the improper installation before certifying the helicopter for flight.

Operated by CROMAN CORP (per NTSB report)

A loss of power to the No. 2 engine due to the failure of the accessory gearbox drivetrain. Also causal was the pilot’s inability to release the external longline due to the use of a safety wire across the coupling of the quick-disconnect mechanism, which interfered with his efforts to land. Contributing to the accident was the repair facility’s failure to maintain a clean environment, which resulted in the inadvertent introduction of a contaminant during the engine overhaul/repair process.

Operated by CROMAN CORP (per NTSB report)

The pilot’s failure to maintain clearance from a tree during an aerial firefighting flight.

Operated by CROMAN CORP (per NTSB report)

Operated by Croman Corporation (per NTSB report)

Operated by CROMAN CORP (per NTSB report)

the loss of power in all engines due to the pilot's inadequate in-flight decision to continue flight with fuel level below the landing minimums specified in the flight manual, which resulted in the unporting of the fuel supply line and fuel starvation. A contributing factor was the blocked fuel ejector pump in the aft fuel tank and an inadequate maintenance level on the helicopter's fuel system.

Operated by CROMAN CORPORATION (per NTSB report)

THE PILOT INITIATING FLIGHT INTO KNOWN ADVERSE WEATHER. FACTORS WERE: LOW CEILING, FOG, AND TURBULENCE.

Part: PRESSURE SWITCH — INTERMITTENT (HYD SYSTEM) · airframe 35,784 hrs

WHEN TESTING HYD SYS USING MOGEN AND SELECTING PRIMARY OFF, IT WOULD NOT. AFTER THE THIRD SELECTION TO OFF, IT FINALLY TURNED OFF SECURING PRESSURE TO PRIMARY WITH A CAUTION LIGHT ILLUMINATED. FURTHER CHECKS OF THE INTERLOCK SYSTEM WERE NORMAL. ON THE PREVIOUS FLIGHT 12 MAY, 2015 AUX HYDRAULICS WERE SECURED ON SHORT FINAL, SIMULATING AN INFLIGHT SYSTEM FAILURE, NOT ACTUAL, AND AT THIS TIME ON SHORT FINAL THE PRIMARY SYSTEM STARTED CYCLING ON AND OFF CAUSING BUFFETING AND VIBRATIONS IN THE CYCLIC CONTROL. AUX HYDRAULICS WERE IMMEDIATELY RESTORED AND AN UNEVENTFUL LANDING PERFORMED. UPON REACHING PARKING AND MAINTENANCE CHECKS PERFORMED ALL SYSTEMS OPERATED NORMAL. ON 13 MAY, 2015 AFTER FURTHER TROUBLESHOOTING MAINTENANCE TECHS ISOLATED THE FAULT TO BE THE PRIMARY HYDRAULICS PRESSURE SWITCH. REPLACEMENT WITH AN O/H UNIT RETURNED THE SYSTEMS TO NORMAL OPERATION.

Part: BEARING — FAILED (ASSORY DR GRBOX)

THE ENGINE LOST FUEL AND OIL PRESSURE IN-FLIGHT AND QUIT. THE ACCESSORY DRIVE GEARBOX PINION SHAFT BEARINGS FAILED AND ALLOWED GEAR DISSENGAGEMENT TO FAILURE POINT. SUBMITTER RECOMMENDS REPLACING BEARINGS AT 3,600 HOURS TT.