Aircraft Accident/Incident Report

Mesa, Arizona 85215
Wednesday, March 22, 2006 16:00 MST

NTSB Narrative Summary Released at Completion of Accident

The experimental category flight was being operated by the helicopter manufacturer under Title 14, CFR Part 91, when the accident occurred. The commercial certificated helicopter pilot was conducting a series of climbing and descending turns while a second helicopter, flying alongside, filmed the maneuvers. According to a safety representative for the helicopter manufacturer, all of the maneuvers were conducted within the normal limitations of the helicopter. The maneuvers were completed uneventfully, with no in-flight anomalies noted, and the helicopter returned to the manufacturer's base. While conducting a routine daily inspection of the helicopter in preparation for the next scheduled flight, maintenance technicians discovered damage to the main rotor hub's five pitch case assemblies, slightly aft of the upper damper cap. The damage was a result of the pitch cases striking the upper main rotor hub perimeter bolts. All five pitch cases were damaged beyond repairable limits, and were replaced. The safety representative for the helicopter manufacturer reported that the anticipated corrective action will be to increase the clearance between the pitch cases and the main rotor hub perimeter bolts by trimming additional material from the inboard and upper portion of the main rotor pitch case assemblies during the manufacturing process.

NTSB Probable Cause Narrative

The manufacturer's inadequate design clearance of the main rotor blade grip pitch cases, which resulted in damage to the pitch cases when they contacted main rotor perimeter bolts during maneuvering flight.

Event Information

Type of Event Accident
Event Date 3/22/2006
Event Day of the Week Wednesday
Time of Event 1600
Event Time Zone Mountain Standard Time
Event City Mesa
Event State ARIZONA
Event Country --
Zipcode of the event site 85215
Event Date Year 2006
Event Date Month 3
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 332739N
Event Location Longitude 1114342W
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 Pilot
Time of the weather observation
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID --
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation --
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) 20
Air Temperature at event time (in degrees celsius) 17
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) --
Variable Wind Indicator Variable
Wind Speed (knots) 10
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) --
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) 20470
NTSB Notification Source MD Helicopters Safety Departme
NTSB Notification Date Mar 28 2006 12:00AM
NTSB Notification Time --
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Oct 31 2006 8:45AM
User who most recently changed record NTSB\JOHB
Basic weather conditions Visual Meteorological Cond
FAA District Office Phoenix FSDO

Aircraft Involved

Aircraft #1

Aircraft Registration Number N912LH
NTSB Number ANC06LA038
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed Company VFR
Flight plan Was Activated? Yes
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name MD Helicopters, Inc.
Aircraft Model MD 900
Aircraft Series Identifier --
Aircraft Serial Number 900-00095
Certified Max Gross Weight 6500
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 8
Number of Engines 2
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Jan 1 2006 12:00AM
Airframe hours since last inspection --
Airframe Hours 77.04
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name MD Helicopters, Inc.
Aircraft Owner Street Address 4555 East McDowell Road
Aircraft Owner City Mesa
Aircraft Owner State AZ
Aircraft Owner Country USA
Aircraft Owner Zipcode 85215
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City --
Operator State --
Operator Country --
Operator Zip code --
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? --
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) Other Work Use
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code FFZ
Departure City MESA
Departure State AZ
Departure Country USA
Departure Time 1530
Departure Time Zone MST
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code FFZ
Destination City Mesa
Destination State AZ
Destination Country USA
Specific Phase of Flight Maneuvering
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Aug 2 2006 9:56PM
User who most recently changed record STAM
Since inspection or accident Time of Accident
Event Location Runway Number and Location NA
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --