Aircraft Accident/Incident Report

Blair, Nebraska 68008
Thursday, June 23, 2011 12:55 CDT

NTSB Narrative Summary Released at Completion of Accident

The pilot was conducting an aerial observation flight in a helicopter when he felt a high vibration in the tail rotor system in conjunction with a sharp jerk in the anti-torque pedals. The pilot autorotated to a wet field and the helicopter subsequently rolled over. A postaccident examination of the helicopter revealed that a pitch link retaining bolt had come loose from the pitch link attachment horn. The bolt and its associated hardware separated in flight and the bolt hole where the pitch link attached was elongated. According to the helicopter’s preflight inspection checklist, the pitch link should have been checked before flight for binding or looseness; however, the pilot could not recall if he actually checked it. The helicopter underwent a 100-hour maintenance inspection two weeks before the accident. At that time, the maintenance manual required an inspection in which the pitch links would have to be disconnected then reassembled. Since the pitch link retaining bolt and its associated hardware were never recovered, it could not be determined if the pitch link assembly had been properly installed or torqued at the last inspection. The pitch link failure occurred about 14 hours after this inspection. The Federal Aviation Administration reported that they were not aware of any instances prior to this accident where the tail rotor pitch link assemblies became loose and failed prematurely after proper installation.

NTSB Probable Cause Narrative

The failure of a tail rotor pitch change link due to the retaining bolt becoming separated in flight. Contributing to the accident was the pilot’s inadequate preflight inspection.

Event Information

Type of Event Accident
Event Date 6/23/2011
Event Day of the Week Thursday
Time of Event 1255
Event Time Zone Central Daylight Time
Event City Blair
Event State NEBRASKA
Event Country --
Zipcode of the event site 68008
Event Date Year 2011
Event Date Month 6
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 413226N
Event Location Longitude 0960824W
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 1252 Central Daylight Time
Direction of event from weather observation facility (degrees) 330
Weather Observation Facility ID OMA
Elevation of weather observation facility 984
Distance of event from weather observation facility (units?) 10
Time Zone of the weather observation CDT
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height 3300
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling --
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 21
Dew Point at event time (in degress fahrenheit) 14
Wind Direction (degrees magnetic) 310
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 14
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 29.89
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) 29622
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 Feb 2 2012 1:15PM
User who most recently changed record bowl
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N5694A
NTSB Number CEN11LA414
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 ENSTROM
Aircraft Model F-28C-2
Aircraft Series Identifier --
Aircraft Serial Number 491-2
Certified Max Gross Weight 2600
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 100 Hour
Date of Last Inspection Jun 9 2011 12:00AM
Airframe hours since last inspection 14
Airframe Hours 3706
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type Unknown
Aircraft Owner Name P AND N CORPORATION
Aircraft Owner Street Address 1710 MARION AIRPORT RD
Aircraft Owner City MARION
Aircraft Owner State IA
Aircraft Owner Country USA
Aircraft Owner Zipcode 52302-9626
Operator is an individual? No
Operator Name P AND N CORPORATION
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address 1710 MARION AIRPORT RD
Operator City MARION
Operator State IA
Operator Country USA
Operator Zip code 52302-9626
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) Aerial Observation
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code PMV
Departure City Plattsmouth
Departure State NE
Departure Country USA
Departure Time 1230
Departure Time Zone CDT
Destination Same as Local Flt --
Destination Airport Code --
Destination City Blair
Destination State NE
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jul 5 2012 2:02PM
User who most recently changed record broda
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 --