Individually Owned: 150,657
Corporate Owned: 137,281
Private Heliport Airport
Aircraft Accident/Incident Report
Darlington, Maryland 21034
Friday, July 29, 2011 16:30 EDT
NTSB Narrative Summary Released at Completion of Accident
The pilot of the helicopter stated that he conducted a light touchdown on the helipad and reduced engine power and applied collective friction for cooldown, per the helicopter’s checklist. About 1 minute after the touchdown, the helicopter began to vibrate violently. The pilot further reduced engine power, but the helicopter continued to vibrate until it fell apart. Before the day's flights, the pilot performed a preflight inspection of the helicopter, during which he visually inspected both forward and aft landing gear dampers and also squeezed them to confirm that they contained oil and were not leaking. He did not observe any anomalies during this inspection. The landing gear dampers were examined by the manufacturer after the accident, and during load testing three of the four dampers did not meet required specifications. The minority owner of the helicopter stated that, based on the helicopter's fuel consumption during the time since its last inspection, he believed that the helicopter was more than 50 hours overdue for a 100-hour inspection. He also stated that, on one occasion, he found the helicopter's Hobbs meter disconnected. The helicopter manufacturer’s maintenance instructions state that, "Incorrect fluid levels, improper pressure or inoperable valving will deteriorate the damping capabilities of the landing gear dampers. These conditions may result in ground resonance and destruction of the helicopter.”
NTSB Probable Cause Narrative
Inadequate maintenance of the helicopter's landing gear dampers, which resulted in a main rotor out-of-balance condition and ground resonance encounter.
Event Information
| Type of Event | Accident |
| Event Date | 7/29/2011 |
| Event Day of the Week | Friday |
| Time of Event | 1630 |
| Event Time Zone | Eastern Daylight Time |
| Event City | Darlington |
| Event State | MARYLAND |
| Event Country | -- |
| Zipcode of the event site | 21034 |
| Event Date Year | 2011 |
| Event Date Month | 7 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 393905N |
| Event Location Longitude | 0761413W |
| Event Location Airport | Private Heliport |
| 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 | 395 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1755 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | 204 |
| Weather Observation Facility ID | MTN |
| Elevation of weather observation facility | 24 |
| Distance of event from weather observation facility (units?) | 20 |
| Time Zone of the weather observation | EDT |
| Lighting Conditions | Dawn |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | 8000 |
| Sky/Lowest/Cloud Conditions | Few |
| 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) | 38 |
| Dew Point at event time (in degress fahrenheit) | 21 |
| Wind Direction (degrees magnetic) | 230 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 9 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.83 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | Minor |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | 1 |
| Injury Total None | -- |
| Injury Total Serious | -- |
| Injury Total All | 1 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 30062 |
| NTSB Notification Source | FAA Eastern ROC |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Jul 3 2012 5:51PM |
| User who most recently changed record | gots |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N39SH |
| NTSB Number | ERA11LA428 |
| 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 | SCHWEIZER |
| Aircraft Model | 269C |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | S1287 |
| Certified Max Gross Weight | 2050 |
| 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 | 3 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Aug 4 2010 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | 2907 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Irvin Smith III |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Smyrna |
| Aircraft Owner State | DE |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 19977 |
| Operator is an individual? | No |
| Operator Name | CVC Helicopter Service |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | Smyrna |
| Operator State | DE |
| Operator Country | USA |
| Operator Zip code | 19977 |
| 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) | Positioning |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | NA |
| Departure City | Bel Air |
| Departure State | MD |
| Departure Country | USA |
| Departure Time | 1600 |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | NA |
| Destination City | Darlington |
| Destination State | MD |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jul 3 2012 5:51PM |
| User who most recently changed record | gots |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |