Aircraft Accident/Incident Report

Mendon, Utah 84325
Friday, May 7, 2010 17:32 MDT

NTSB Narrative Summary Released at Completion of Accident

The certified flight instructor (CFI) and student pilot departed on a local area training flight and found a suitable area to perform practice autorotations. During the first autorotation, the engine experienced a loss of power. The CFI assumed control of the helicopter and the student attempted to restart the engine. During the touchdown, the right skid caught on the terrain, and the helicopter rolled to the right. The CFI indicated that it appeared the grass-covered terrain was flat and would make a good emergency landing spot; however, upon touchdown he realized that the terrain was rough. A post accident examination and test run of the engine by a Federal Aviation Administration (FAA) inspector did not reveal any operational anomalies with the helicopter. Disassembly of the magnetos revealed evidence of internal arcing. The magneto manufacturer and engine manufacturer had issued service bulletins related to the inspection of the magnetos every 100 hours and 500 hours. The 500-hour inspection required that the magnetos be removed from the engine, disassembled, inspected, and serviced. According to the FAA inspector, review of the maintenance records for the helicopter showed that neither service bulletin had been complied with.

NTSB Probable Cause Narrative

A loss of engine power due to a failure of the magnetos as a result of inadequate maintenance.

Event Information

Type of Event Accident
Event Date 5/7/2010
Event Day of the Week Friday
Time of Event 1732
Event Time Zone Mountain Daylight Time
Event City Mendon
Event State UTAH
Event Country --
Zipcode of the event site 84325
Event Date Year 2010
Event Date Month 5
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 414319N
Event Location Longitude 1115611W
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 --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1750 Mountain Daylight Time
Direction of event from weather observation facility (degrees) 80
Weather Observation Facility ID LGU
Elevation of weather observation facility 4457
Distance of event from weather observation facility (units?) 5
Time Zone of the weather observation MDT
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 11
Dew Point at event time (in degress fahrenheit) -13
Wind Direction (degrees magnetic) --
Variable Wind Indicator --
Wind Speed (knots) --
Wind Velocity Indicator Calm
Wind Gust Indicator --
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.18
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 2
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 27988
NTSB Notification Source FAA Com Center
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Feb 4 2011 7:01PM
User who most recently changed record stam
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N393LE
NTSB Number WPR10LA232
Missing Aircraft Indicator --
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 HELICOPTER
Aircraft Model R22 BETA
Aircraft Series Identifier --
Aircraft Serial Number 4393
Certified Max Gross Weight 1370
Aircraft Category Helicopter
Aircraft Registration Class --
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 Annual
Date of Last Inspection Apr 22 2010 12:00AM
Airframe hours since last inspection 45
Airframe Hours 1000
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type C91
Aircraft Owner Name MOUNTAIN RIDGE HELICOPTERS LLC
Aircraft Owner Street Address 164 BERGER LN
Aircraft Owner City MURRAY
Aircraft Owner State UT
Aircraft Owner Country USA
Aircraft Owner Zipcode 84107-4713
Operator is an individual? No
Operator Name MOUNTAIN RIDGE HELICOPTERS LLC
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address 164 BERGER LN
Operator City MURRAY
Operator State UT
Operator Country USA
Operator Zip code 84107-4713
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation --
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 No
Departure Point Same as Event No
Departure Airport Code LGU
Departure City Logan
Departure State UT
Departure Country USA
Departure Time 1700
Departure Time Zone MDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code LGU
Destination City Logan
Destination State UT
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Feb 4 2011 7:01PM
User who most recently changed record stam
Since inspection or accident Last Inspection
Event Location Runway Number and Location N/A
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --