Individually Owned: 150,657
Corporate Owned: 137,281
Grinnell Regional Airport
Aircraft Accident/Incident Report
Grinnell, Iowa 50112
Tuesady, April 17, 2012 11:16 CDT
NTSB Narrative Summary Released at Completion of Accident
The helicopter began to vibrate as the pilot raised the collective for liftoff. The pilot lowered the collective and closed the throttle when the vibration began; however, he was too late in recognizing the onset of ground resonance, which resulted in a violent, uncontrollable oscillation and separation of the tail boom from the fuselage. Examination of the helicopter revealed no anomalies that would have precluded normal operation.
NTSB Probable Cause Narrative
The pilot's improper liftoff technique, which resulted in ground resonance, and the pilot's delayed recognition of the ground resonance.
Event Information
| Type of Event | Accident |
| Event Date | 4/17/2012 |
| Event Day of the Week | Tuesday |
| Time of Event | 1116 |
| Event Time Zone | Central Daylight Time |
| Event City | Grinnell |
| Event State | IOWA |
| Event Country | -- |
| Zipcode of the event site | 50112 |
| Event Date Year | 2012 |
| Event Date Month | 4 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 414236N |
| Event Location Longitude | 0924410W |
| Event Location Airport | Grinnell Regional Airport |
| Event Location Nearest Airport ID | GGI |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | 0.2 |
| Degrees magnetic from airport | -- |
| Airport Elevation | 1008 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1115 Central Daylight Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | GGI |
| Elevation of weather observation facility | 1008 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | CDT |
| 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) | 13 |
| Dew Point at event time (in degress fahrenheit) | 3 |
| Wind Direction (degrees magnetic) | 150 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 4 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.35 |
| 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) | 31427 |
| NTSB Notification Source | FAA-ACE-ROC |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | May 30 2013 4:58PM |
| User who most recently changed record | bowl |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N69HJ |
| NTSB Number | CEN12LA247 |
| 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 | HUGHES |
| Aircraft Model | 269A |
| Aircraft Series Identifier | UNDESIGNAT |
| Aircraft Serial Number | 580869 |
| Certified Max Gross Weight | 1670 |
| 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 6 2012 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | 3085 |
| ELT Installed | No |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Lowry Flying Service Inc |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Grinnell |
| Aircraft Owner State | IA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | -- |
| Operator is an individual? | No |
| Operator Name | Pilot |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | Grinnell |
| Operator State | IA |
| Operator Country | USA |
| 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 | -- |
| 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) | Personal |
| Second Pilot on Board | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | GGI |
| Departure City | Grinnell |
| Departure State | IA |
| Departure Country | USA |
| Departure Time | 1116 |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | GGI |
| Destination City | Grinnell |
| Destination State | IA |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Feb 4 2013 12:39PM |
| User who most recently changed record | galm |
| 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 | -- |