What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Weather was clear and calm.
Aircraft engine suffered mechanical failure, causing loss of power.
Pilot autorotated aircraft to vacant field.
Main rotor blades severed the tail boom from the rest of the airframe.
Pilot's statement indicated that: approximately 5 NM wnw of kapg an engine chip caution illuminated. The pilot made a brief advisory radio call on the company frequency to the lead aircraft indicating the need to land as soon as practicable as no audible engine operational characteristics had changed. Very shortly after making the company advisory radio call, the pilot reported hearing engine noise change abruptly. A ?grinding? Noise could now be heard emanating from the aft section of the aircraft. This ?grinding? Noise was initially accompanied by the smell of engine oil, which eventually became smoke in the aft section of the passenger compartment. With the presence of smoke and the potential for an inflight aircraft fire, the pilot initiated an emergency decent-to-land to a suitable landing area. During the decent the engine noise and smoke in the aft section of the cabin intensified and began moving to the forward section of the cockpit. The pilot opened the forward air vent, and repositioned the forward door mounted vents in an attempt to reduce the amount of smoke / obscuration in the cockpit, to no avail. Now in an emergency decent, with rotor RPM being one of the pilot's primary concerns, he continued in a normal autorotative angle of decent to his intended point of landing. At approximately 75-50 fat (ail) the pilot initiated a flare to slow the aircraft and prepare for the possibility of a loss of engine power. Descending through the flare altitude the pilot leveled the aircraft and prepared for landing, at the same moment a significant change in engine power was observed indicating that the engine had failed. Simultaneously the cockpit smoke intensified to the point that the pilot lost visual reference with the ground he initiated ?pitch? Pull to slow the rate of decent. The aircraft impacted the ground in a generally level attitude and during the ground run the front portion of the kids (toe) dug into the ground causing the aircraft to pitch (nose) down, in an effort to minimize the likelihood of rolling the pilot applied aft cyclic to keep the aircraft level. After a few moments, the pilot rolled the throttle from ?fly? To ?cut-off? And after the blades stopped rotating, the pilot exited the helicopter.
Engine teardown revealed 2 things.
1. A piece of debris from a fractured air intake at the combustion chamber.
And
2. A separated rigid oil line at a connector. The line that pulled out from the connector nut appeared to have an insuficiently flared end, allowing the line to separate from the connector nut, causing an oil starvation condition.
As the FAA filed it
WEATHER WAS CLEAR AND CALM.
AIRCRAFT ENGINE SUFFERED MECHANICAL FAILURE, CAUSING LOSS OF POWER.
PILOT AUTOROTATED AIRCRAFT TO VACANT FIELD.
MAIN ROTOR BLADES SEVERED THE TAIL BOOM FROM THE REST OF THE AIRFRAME.
PILOT'S STATEMENT INDICATED THAT: APPROXIMATELY 5 NM WNW OF KAPG AN ENGINE CHIP CAUTION ILLUMINATED. THE PILOT MADE A BRIEF ADVISORY RADIO CALL ON THE COMPANY FREQUENCY TO THE LEAD AIRCRAFT INDICATING THE NEED TO LAND AS SOON AS PRACTICABLE AS NO AUDIBLE ENGINE OPERATIONAL CHARACTERISTICS HAD CHANGED. VERY SHORTLY AFTER MAKING THE COMPANY ADVISORY RADIO CALL, THE PILOT REPORTED HEARING ENGINE NOISE CHANGE ABRUPTLY. A ?GRINDING? NOISE COULD NOW BE HEARD EMANATING FROM THE AFT SECTION OF THE AIRCRAFT. THIS ?GRINDING? NOISE WAS INITIALLY ACCOMPANIED BY THE SMELL OF ENGINE OIL, WHICH EVENTUALLY BECAME SMOKE IN THE AFT SECTION OF THE PASSENGER COMPARTMENT. WITH THE PRESENCE OF SMOKE AND THE POTENTIAL FOR AN INFLIGHT AIRCRAFT FIRE, THE PILOT INITIATED AN EMERGENCY DECENT-TO-LAND TO A SUITABLE LANDING AREA. DURING THE DECENT THE ENGINE NOISE AND SMOKE IN THE AFT SECTION OF THE CABIN INTENSIFIED AND BEGAN MOVING TO THE FORWARD SECTION OF THE COCKPIT. THE PILOT OPENED THE FORWARD AIR VENT, AND REPOSITIONED THE FORWARD DOOR MOUNTED VENTS IN AN ATTEMPT TO REDUCE THE AMOUNT OF SMOKE / OBSCURATION IN THE COCKPIT, TO NO AVAIL. NOW IN AN EMERGENCY DECENT, WITH ROTOR RPM BEING ONE OF THE PILOT'S PRIMARY CONCERNS, HE CONTINUED IN A NORMAL AUTOROTATIVE ANGLE OF DECENT TO HIS INTENDED POINT OF LANDING. AT APPROXIMATELY 75-50 FAT (AIL) THE PILOT INITIATED A FLARE TO SLOW THE AIRCRAFT AND PREPARE FOR THE POSSIBILITY OF A LOSS OF ENGINE POWER. DESCENDING THROUGH THE FLARE ALTITUDE THE PILOT LEVELED THE AIRCRAFT AND PREPARED FOR LANDING, AT THE SAME MOMENT A SIGNIFICANT CHANGE IN ENGINE POWER WAS OBSERVED INDICATING THAT THE ENGINE HAD FAILED. SIMULTANEOUSLY THE COCKPIT SMOKE INTENSIFIED TO THE POINT THAT THE PILOT LOST VISUAL REFERENCE WITH THE GROUND HE INITIATED ?PITCH? PULL TO SLOW THE RATE OF DECENT. THE AIRCRAFT IMPACTED THE GROUND IN A GENERALLY LEVEL ATTITUDE AND DURING THE GROUND RUN THE FRONT PORTION OF THE KIDS (TOE) DUG INTO THE GROUND CAUSING THE AIRCRAFT TO PITCH (NOSE) DOWN, IN AN EFFORT TO MINIMIZE THE LIKELIHOOD OF ROLLING THE PILOT APPLIED AFT CYCLIC TO KEEP THE AIRCRAFT LEVEL. AFTER A FEW MOMENTS, THE PILOT ROLLED THE THROTTLE FROM ?FLY? TO ?CUT-OFF? AND AFTER THE BLADES STOPPED ROTATING, THE PILOT EXITED THE HELICOPTER.
ENGINE TEARDOWN REVEALED 2 THINGS.
1. A PIECE OF DEBRIS FROM A FRACTURED AIR INTAKE AT THE COMBUSTION CHAMBER.
AND
2. A SEPARATED RIGID OIL LINE AT A CONNECTOR. THE LINE THAT PULLED OUT FROM THE CONNECTOR NUT APPEARED TO HAVE AN INSUFICIENTLY FLARED END, ALLOWING THE LINE TO SEPARATE FROM THE CONNECTOR NUT, CAUSING AN OIL STARVATION CONDITION.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.
Other reports on N9159F · 2
Matched to the same aircraft by N-number and date.