N911MK
Registered owner: AVERA MCKENNAN, SD (owner ≠ operator)
Operators of this aircraft
Who operated this tail, and how firmly we know it.
Accident & incident history
Maintenance disclosures
THE PROBLEM APPEARS TO BE A PLUGGED SCAVENGE LINE DUE TO INTERNAL ENGINE COKING. THE RESULT COULD BE EXCESSIVE INTERNAL OIL PRESSURES CAUSING EXTERNAL DISCHARGE OF THE OIL, IN THIS CASE OUT THROUGH A VENT LINE. ALONG WITH THAT THERE WOULD BE A BYPASS OF OIL INTERNALLY THROUGH THE LABYRINTH SEALS (3) AND WOULD ALLOW THE OIL TO ENTER AND EXIT THE GAS GENERATOR ALLOWING FOR AN IGNITION SOURCE AND IGNITION. AT THAT POINT YOU WOULD HAVE AN IGNITION SOURCE AT THE GAS GENERATOR, BURNING OIL RUNNING DOWN THE SIDE OF THE ENGINE ALONG WITH VENTING OIL AVAILABLE DRAINING ONTO THE DECK AND ADDING FUEL (OIL) TO THE FIRE.
TWO CRACKS NOTED DURING PREFLIGHT INSPECTION ON THE LT HORIZONTAL STABILIZER LOWER SIDE. NO OTHER VISUAL INDICATION OF DAMAGE.
DURING FLIGHT, A SLIGHT 'SQUEAL' NOISE WAS HEARD FOLLOWED BY A BURNED RUBBER ODOR. THE AIR CONDITIONER WAS SWITCHED OFF, THE NOISE QUIT. ACFT MADE A PRECAUTIONARY LANDING AT A LOCAL AIRPORT. THE AIR CONDITIONER COMPRESSOR HAD LOCKED UP AND BURNED THE DRIVE BELT.
CABLE SHORTED, CAUSING FALSE FIRE WARNING INDICATION.
FUEL CONTROL FAILED UPON INSTALLATION. REMOVED AND REPLACED. (X)
SPRING CARRIER FAILED IN POWER TURBINE. METAL PICK-OUT AT BEARING MATING SURFACE. REMOVED AND REPLACED SPRING CARRIER.
UPON INITIAL TRANSCEIVER INSTALLATION, CIRCUIT BREAKER TRIPS WHEN TRANSMITTER BUTTON IS KEYED. REMOVED AND REPLACED.
TAIL ROTOR DRIVE AFTER INSTALLATION, PART WAS DETERMINED TO BE DEFECTIVE FROM FACTORY. END PLATE OUT OF LIMITS PER BHT 222 OMM.
TRANSMISSION TORQUE NEEDLE FLUCTUATES 20 - 30 PERCENT, FALLS TO ZERO, AND THEN RETURNS AND BEGINS TO FLUCTUATE AGAIN.
INDICATOR READS 10 PERCENT LOW, NR 2 ENGINE.
AS TRANSDUCERS WARM UP, PRESSURE DROPS OFF. WILL STAY AROUND 50 PSI.