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NTSB Report
November 17, 1991 · Robinson R22 Mariner R22 Marine · N4072U
Ocala, FL
Overview
Report Status
Probable Cause
Event Type
Accident
Date
November 17, 1991
Injury Outcomes
2 injuries (2 minor injuries)
Location
Ocala, FL
Aircraft
Robinson R22 Mariner R22 Marine
Tail Number
N4072U
Operator
Drax
Injuries
Minor
Aircraft Damage
Substantial
NTSB Number
MIA92LA031
PILOT INITIATED PRACTICE AUTOROTATION. AT 500 FEET ALTITUDE RECOVERY WAS ATTEMPTED BY INCREASING COLLECTIVE AND INCREASING THROTTLE. LOW ROTOR SPEED WARNING WAS HEARD AND ENGINE DID NOT ACCELERATE. PILOT LOWERED COLLECTIVE AND CONTINUED AUTOROTATION TO THE GROUND AT WHICH TIME A HARD LANDING WAS MADE. POSTCRASH EXAMINATION OF THE AIRCRAFT BY FAA INSPECTORS REVEALED NO EVIDENCE OF FAILURE OR MALFUNCTION OF THE AIRCRAFT ENGINE. THE ENGINE WAS OPERATED AFTER THE ACCIDENT WITH NO EVIDENCE OF FAILURE.
NTSB Probable Cause
THE PILOT-IN-COMMAND'S IMPROPER USE OF COLLECTIVE CONTROL AND THROTTLE DURING RECOVERY FROM AN AUTOROTATION WHICH RESULTED IN LOSS OF ROTOR RPM AND A SUBSEQUENT HARD LANDING.
Full Narrative
PILOT INITIATED PRACTICE AUTOROTATION. AT 500 FEET ALTITUDE RECOVERY WAS ATTEMPTED BY INCREASING COLLECTIVE AND INCREASING THROTTLE. LOW ROTOR SPEED WARNING WAS HEARD AND ENGINE DID NOT ACCELERATE. PILOT LOWERED COLLECTIVE AND CONTINUED AUTOROTATION TO THE GROUND AT WHICH TIME A HARD LANDING WAS MADE. POSTCRASH EXAMINATION OF THE AIRCRAFT BY FAA INSPECTORS REVEALED NO EVIDENCE OF FAILURE OR MALFUNCTION OF THE AIRCRAFT ENGINE. THE ENGINE WAS OPERATED AFTER THE ACCIDENT WITH NO EVIDENCE OF FAILURE.
Flight
Event TypeAccident
Event Time16:00 EST
Nearest Airport0nm N
Runway0
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftRobinson R22 Mariner R22 Marine
Tail NumberN4072U
Aircraft CategoryHeli
DamageSubstantial
OperatorDrax
Operating RulePart 91
Engines1
Engine TypeReciprocating
Engine DetailsLycoming · O-320-B2C · Reciprocating · 131
Seats2
People & Injuries
Injury Summary2 injuries (2 minor injuries)
Fatal0
Serious0
Minor2
Uninjured0
Total2
Crew 1Age 38 · Second Class
Conditions
ConditionsVMC
LightDaylight
Wind80° @ 6 kt
Visibility10 sm
CeilingNone
Temperature / Dew Point57
Altimeter30.00 inHg
Observation Time20:45
Weather SourceWFAC