Individually Owned: 150,657
Corporate Owned: 137,281
Brown Field Airport
Aircraft Accident/Incident Report
San Diego, California 92154
Tuesady, November 8, 2011 14:25 PST
NTSB Narrative Summary Released at Completion of Accident
During an instructional flight, a practice autorotation was initiated with the intention of performing a power recovery. The student maintained directional control while the certified flight instructor (CFI) adjusted the rotor rpm. The student initiated the power recovery, but the engine did not respond. The student then relinquished control of the helicopter to the CFI, who attempted to cushion the landing, but the helicopter landed hard.
The helicopter's engine was equipped with a float-type carburetor, and the weather conditions provided for the possibility of serious carburetor icing at glide power. The accumulation of carburetor ice likely resulted in the loss of engine power. Neither the CFI nor student applied carburetor heat during the autorotation, nor they did not monitor the carburetor temperature gauge during the maneuver. During the postaccident examination of the engine, no mechanical failures or malfunctions were revealed which would have precluded normal operation.
The CFI's flight experience in piston-powered helicopters was limited to the 6 hours of training he had provided in the accident helicopter, with his prior rotorcraft experience occurring exclusively in turbine-powered helicopters. This was also the first time he had performed an autorotation in the accident helicopter.
NTSB Probable Cause Narrative
The flight instructor's inadequate supervision of the student pilot during a simulated autorotation and the pilots’ failure to use carburetor heat while operating at reduced engine power while in carburetor icing conditions, which resulted in a loss of engine power.
Event Information
| Type of Event | Accident |
| Event Date | 11/8/2011 |
| Event Day of the Week | Tuesday |
| Time of Event | 1425 |
| Event Time Zone | Pacific Standard Time |
| Event City | San Diego |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 92154 |
| Event Date Year | 2011 |
| Event Date Month | 11 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 323420n |
| Event Location Longitude | 1165848w |
| Event Location Airport | Brown Field |
| Event Location Nearest Airport ID | SDM |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | 0 |
| Degrees magnetic from airport | -- |
| Airport Elevation | 526 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1453 Pacific Standard Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | SDM |
| Elevation of weather observation facility | 526 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | PST |
| 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) | 18 |
| Dew Point at event time (in degress fahrenheit) | 3 |
| Wind Direction (degrees magnetic) | 290 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 8 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.15 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | METAR KSDM 082253Z 29008KT 10SM CLR 18/03 A3015 RM |
| 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) | 30067 |
| NTSB Notification Source | FAA Operations Center |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Jul 4 2012 3:49PM |
| User who most recently changed record | stam |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N4251A |
| NTSB Number | WPR12LA029 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | BELL |
| Aircraft Model | 47D1 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 110 |
| Certified Max Gross Weight | 2200 |
| 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 | Oct 3 2011 12:00AM |
| Airframe hours since last inspection | 10 |
| Airframe Hours | 4727 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | Unknown |
| Aircraft Owner Name | ERNESTO A MERUELO |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | San Diego |
| Aircraft Owner State | CA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 92102 |
| Operator is an individual? | Yes |
| Operator Name | Kieran S Twomey |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | San Diego |
| Operator State | CA |
| Operator Country | USA |
| Operator Zip code | 92118 |
| 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 | Yes |
| Departure Point Same as Event | Yes |
| Departure Airport Code | SDM |
| Departure City | San Diego |
| Departure State | CA |
| Departure Country | USA |
| Departure Time | 1320 |
| Departure Time Zone | PST |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | SDM |
| Destination City | San Diego |
| Destination State | CA |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jul 4 2012 3:48PM |
| User who most recently changed record | stam |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 26L |
| Runway Length | 3180 |
| Runway Width | 75 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |