What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
On 6/24/19 at approx 1720 hrs a member of the gainesville police department and a civilian instructor took off for an NVG training flight. The training began with some un-aided hover work, then NVG. After conducting a few normal approaches, emergency procedures including stuck pedals and hydraulics off landings were practiced. The first full down autorotation flare was higher than normal, which is common under NVG?s. the autorotation was debriefed. The instructor took the controls to demonstrate a few things that needed improvement. The instructor demonstrated an autorotation at different airspeeds and the different descent rates with a power recover. The instructor advised he would demonstrate an autorotation at 60 knots all the way to the ground. The instructor entered a straight in autorotation at 60 knots at 800 feet above ground slightly left of the taxi way, corrected. The descent was relatively normal. Flight instruments were observed to be RPM 100%, N1 stable, airspeed 60 KTS and the aircraft was slightly out of trim which the instructor announced and corrected. The flare was initiated at 75 feet and 55 knots. The helicopter was slightly off centerline, corrected and the flare was otherwise normal. At approximately 15 feet an initial pitch pull was initiated and started leveling the aircraft. During the cushioning phase of the autorotation, everything seemed normal until the first contact with the taxiway. As the aircraft touched down slightly heels first and as it rocked slightly forward it seemed to grab and started to oscillate uncontrollably. The nose then dropped. Student observed: upon touching the ground, he immediately felt like we were driving down a pot-hole filled dirt road and after several quick bumps, up and down while skidding across the taxiway, felt a massive whip forward and to the left followed by several more throws in a counter clockwise motion, the throws became more intense. The instructor believing he had pylon whirl lowered the collective and attempted to steer through it. The vibrations and throws then subsided. Observed damage to the tail boom, isolation mount and the upper cowling around the rotor mast of helicopter.
As the FAA filed it
ON 6/24/19 AT APPROX 1720 HRS A MEMBER OF THE GAINESVILLE POLICE DEPARTMENT AND A CIVILIAN INSTRUCTOR TOOK OFF FOR AN NVG TRAINING FLIGHT. THE TRAINING BEGAN WITH SOME UN-AIDED HOVER WORK, THEN NVG. AFTER CONDUCTING A FEW NORMAL APPROACHES, EMERGENCY PROCEDURES INCLUDING STUCK PEDALS AND HYDRAULICS OFF LANDINGS WERE PRACTICED. THE FIRST FULL DOWN AUTOROTATION FLARE WAS HIGHER THAN NORMAL, WHICH IS COMMON UNDER NVG?S. THE AUTOROTATION WAS DEBRIEFED. THE INSTRUCTOR TOOK THE CONTROLS TO DEMONSTRATE A FEW THINGS THAT NEEDED IMPROVEMENT. THE INSTRUCTOR DEMONSTRATED AN AUTOROTATION AT DIFFERENT AIRSPEEDS AND THE DIFFERENT DESCENT RATES WITH A POWER RECOVER. THE INSTRUCTOR ADVISED HE WOULD DEMONSTRATE AN AUTOROTATION AT 60 KNOTS ALL THE WAY TO THE GROUND. THE INSTRUCTOR ENTERED A STRAIGHT IN AUTOROTATION AT 60 KNOTS AT 800 FEET ABOVE GROUND SLIGHTLY LEFT OF THE TAXI WAY, CORRECTED. THE DESCENT WAS RELATIVELY NORMAL. FLIGHT INSTRUMENTS WERE OBSERVED TO BE RPM 100%, N1 STABLE, AIRSPEED 60 KTS AND THE AIRCRAFT WAS SLIGHTLY OUT OF TRIM WHICH THE INSTRUCTOR ANNOUNCED AND CORRECTED. THE FLARE WAS INITIATED AT 75 FEET AND 55 KNOTS. THE HELICOPTER WAS SLIGHTLY OFF CENTERLINE, CORRECTED AND THE FLARE WAS OTHERWISE NORMAL. AT APPROXIMATELY 15 FEET AN INITIAL PITCH PULL WAS INITIATED AND STARTED LEVELING THE AIRCRAFT. DURING THE CUSHIONING PHASE OF THE AUTOROTATION, EVERYTHING SEEMED NORMAL UNTIL THE FIRST CONTACT WITH THE TAXIWAY. AS THE AIRCRAFT TOUCHED DOWN SLIGHTLY HEELS FIRST AND AS IT ROCKED SLIGHTLY FORWARD IT SEEMED TO GRAB AND STARTED TO OSCILLATE UNCONTROLLABLY. THE NOSE THEN DROPPED. STUDENT OBSERVED: UPON TOUCHING THE GROUND, HE IMMEDIATELY FELT LIKE WE WERE DRIVING DOWN A POT-HOLE FILLED DIRT ROAD AND AFTER SEVERAL QUICK BUMPS, UP AND DOWN WHILE SKIDDING ACROSS THE TAXIWAY, FELT A MASSIVE WHIP FORWARD AND TO THE LEFT FOLLOWED BY SEVERAL MORE THROWS IN A COUNTER CLOCKWISE MOTION, THE THROWS BECAME MORE INTENSE. THE INSTRUCTOR BELIEVING HE HAD PYLON WHIRL LOWERED THE COLLECTIVE AND ATTEMPTED TO STEER THROUGH IT. THE VIBRATIONS AND THROWS THEN SUBSIDED. OBSERVED DAMAGE TO THE TAIL BOOM, ISOLATION MOUNT AND THE UPPER COWLING AROUND THE ROTOR MAST OF HELICOPTER.
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 N911GV · 1
Matched to the same aircraft by N-number and date.