Aircraft Accident/Incident Report

San Luis Obispo, California 93401
Tuesady, May 18, 1999 17:30 PDT

NTSB Narrative Summary Released at Completion of Accident

The instructor stated the student entered a practice autorotation at 1,400 feet (600 feet agl) to a landing site on top of a hill about 800 feet high. As the flare was initiated at 40 to 50 feet, the instructor mentioned to the student that the cyclic trim was engaged. When the student unexpectedly reached forward and tried to push the trim control knob in, he inadvertently pushed forward on the cyclic control. The instructor said this pitched the nose of the helicopter down and resulted in a bleed off of main rotor rpm. When the low rotor horn and warning light came on the instructor took control of the helicopter and rolled in throttle. The lowest rpm he recalls seeing was slightly above 90 percent. He made a left turn to avoid hitting the hill and encountered a strong downdraft due to the gusty winds. The helicopter touched down on the left skid during the turn and rolled over twice.

NTSB Probable Cause Narrative

The student's inadvertent and uncoordinated application of forward cyclic during an autorotation flare, which resulted in a loss of main rotor rpm; and the flight instructor's inadequate supervision.

Event Information

Type of Event Accident
Event Date 5/18/1999
Event Day of the Week Tuesday
Time of Event 1730
Event Time Zone Pacific Daylight Time
Event City SAN LUIS OBISPO
Event State CALIFORNIA
Event Country --
Zipcode of the event site 93401
Event Date Year 1999
Event Date Month 5
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport
Event Location Nearest Airport ID
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness Partial - limited by pilot
Investigator's weather source Weather Observation Facility
Time of the weather observation 1717 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 270
Weather Observation Facility ID SBP
Elevation of weather observation facility 209
Distance of event from weather observation facility (units?) 5
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height 1000
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 13
Dew Point at event time (in degress fahrenheit) 11
Wind Direction (degrees magnetic) 300
Variable Wind Indicator Unknown
Wind Speed (knots) 17
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 24
Altimeter Setting at event time (in. Hg) 29
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Minor
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor 2
Injury Total None --
Injury Total Serious --
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 1617
NTSB Notification Source --
NTSB Notification Date May 18 1999 12:00AM
NTSB Notification Time 2035
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Jan 10 2001 10:04AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N8558N
NTSB Number LAX99LA186
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Robinson
Aircraft Model R22A
Aircraft Series Identifier R22A
Aircraft Serial Number 0466
Certified Max Gross Weight 1370
Aircraft Category Helicopter
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 2
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection May 7 1999 12:00AM
Airframe hours since last inspection 48
Airframe Hours 9536
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name HELIPRO, INC.
Aircraft Owner Street Address 945B AIRPORT DR
Aircraft Owner City SAN LOUIS OBISP
Aircraft Owner State CA
Aircraft Owner Country
Aircraft Owner Zipcode 93401
Operator is an individual? --
Operator Name
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address
Operator City
Operator State
Operator Country
Operator Zip code
Operator Code
Owner has at least one certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Instructional
Second Pilot on Board Yes
Departure Point Same as Event Yes
Departure Airport Code SBP
Departure City
Departure State
Departure Country
Departure Time 1630
Departure Time Zone PDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 10 2001 12:26PM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --