Individually Owned: 150,657
Corporate Owned: 137,281
N/A Airport
Aircraft Accident/Incident Report
Columbus, Ohio 43215
Thursday, August 16, 2012 1:50 EDT
NTSB Narrative Summary Released at Completion of Accident
On August 16, 2012, at 0150 eastern daylight time, an MD Helicopters, Inc. 369E, N551CP, impacted terrain during a forced landing near Columbus, Ohio. The certificated commercial pilot and an observer, who was also a commercial pilot, were not injured. The helicopter sustained substantial damage. The helicopter was registered to the City of Columbus and operated by the Columbus Police Department under the provisions of 14 Code of Federal Regulations Part 91 as an aerial observation flight. Night visual meteorological conditions prevailed for the local flight that had originated from the Columbus Police Heliport (OH52), Columbus, Ohio.
The pilot reported that he leveled off at 1,500 ft mean sea level (msl) and had completed a turn to the west when he heard a "loud exploding noise" from the rear of the helicopter, followed by a long sustained "whining" noise coming from the engine and a constant warning tone in the background. The pilot saw that the gas producer (N1) and power turbine (N2) gauge needles were a falling "rapidly." The pilot performed an autorotation and touched down on a street where the helicopter slid and rotated counter-clockwise about 1 1/2 turns. The helicopter's tail fin, stabilizer, and tail rotor were broken off, and the main rotor blades were substantially damaged from contact with a utility pole adjacent to the street.
The helicopter was powered by Rolls Royce M250-C20B, serial number CAE-837045, turboshaft engine. The engine accumulated a total time of 4,667 hours and to cycles of 2,987. The engine was overhauled on May 25, 2011 and accumulated a total time since overhaul (TSO) of 1,023 hours and cycles since overhaul (CSO) of 529. During the last overhaul, new turbine wheel stages 1-4 were installed. The engine was removed on June 13, 2012 for a compressor bearing problem at TSO 832.1 hours and CSO 529.
The helicopter's engine was examined by a National Transportation Safety Board powerplants specialist. The N1 drive train turned free and continuous between the compressor and the starter generator pad. The N2 drive train was locked. The left-hand compressor discharge tube was undamaged. The right-hand compressor discharge tube was pierced in one location and dented in one location. The hole and dent locations and direction were in the plane of the 4th stage turbine rotor. The hole was located at the 6 o'clock to 9 o'clock location with reference to the tube and was about 2-1/2 inches long with the width varying from ½ inch to 1 inch. The edge material condition of the hole at 9 o'clock was 'petaled' inwards; consistent with a high-speed particle entering the tube and the edge material condition at the 6 o'clock location was 'petaled' outwards, consistent with a high-speed particle material exiting the tube. The dent location was between the 12 o'clock and 9 o'clock location with reference to the tube and was approximately 2 inches in axial length and 3 inches wide. There were two rectangular shaped impressions within the dent surface, each approximately 3/8 inch square.
The 3rd stage turbine nozzle was intact and undamaged. The 3rd stage turbine wheel was intact. The curvic coupling was undamaged. The outer shroud was intact; however, a 90-degree segment of the outer rim was heavily scored, consistent with contact against the shroud.
The 4th stage turbine nozzle was generally intact; however a 4-inch segment of the 4th stage turbine shroud was fractured in the plane of the 4th stage turbine wheel, consistent in location with the fracture of the exhaust collector housing. The 4th stage shroud showed heavy rotational scoring. All the nozzle vanes were present and undamaged. The 3rd stage turbine shroud showed heavy rotational scoring. The 4th stage turbine was missing one blade. The missing blade was fractured near the inner platform. An examination of the fracture surface showed high cycle fatigue. A 3-blade span of the related segment of the rim was also missing. The two adjacent blades were fractured near the tips. One adjacent blade was missing the entire rim segment and was twisted, while the other adjacent blade was partially attached to the remaining rim. All other blades were present and appeared to be undamaged. The curvic coupling was intact and undamaged.
The N2 bearing set consisted of the No. 3, No. 4, No. 5 and No. 6 bearings. The No. 5 bearing snap ring was found dislodged from its groove. The power turbine inner shaft was intact; however, the No. 6 bearing inner race was heavily deformed at the roller bearing contact surface.
NTSB Probable Cause Narrative
Not Yet Reported
Event Information
| Type of Event | Accident |
| Event Date | 8/16/2012 |
| Event Day of the Week | Thursday |
| Time of Event | 150 |
| Event Time Zone | Eastern Daylight Time |
| Event City | Columbus |
| Event State | OHIO |
| Event Country | -- |
| Zipcode of the event site | 43215 |
| Event Date Year | 2012 |
| Event Date Month | 8 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 395700N |
| Event Location Longitude | 0825860E |
| Event Location Airport | N/A |
| 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 | 151 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | 90 |
| Weather Observation Facility ID | CMH |
| Elevation of weather observation facility | 815 |
| Distance of event from weather observation facility (units?) | 8 |
| Time Zone of the weather observation | EDT |
| Lighting Conditions | Night |
| 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) | 21 |
| Dew Point at event time (in degress fahrenheit) | 16 |
| Wind Direction (degrees magnetic) | -- |
| Variable Wind Indicator | -- |
| Wind Speed (knots) | -- |
| Wind Velocity Indicator | Calm |
| Wind Gust Indicator | -- |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30 |
| 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) | -- |
| NTSB Notification Source | FAA |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Dec 9 2014 1:45PM |
| User who most recently changed record | galm |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N551CP |
| NTSB Number | CEN12TA550 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Public Use |
| Type of Flight Plan filed | Company VFR |
| Flight plan Was Activated? | Yes |
| Damage | Substantial |
| Aircraft Fire | Ground |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | MD HELICOPTER |
| Aircraft Model | 369 |
| Aircraft Series Identifier | E |
| Aircraft Serial Number | 0571E |
| Certified Max Gross Weight | 3000 |
| 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 | 4 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | -- |
| Airframe Hours | 4667 |
| ELT Installed | No |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | City of Columbus |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Columbus |
| Aircraft Owner State | OH |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | -- |
| Operator is an individual? | No |
| Operator Name | Columbus Police |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | Columbus |
| Operator State | OH |
| 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) | -- |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | Yes |
| Departure Airport Code | -- |
| Departure City | Columbus |
| Departure State | OH |
| Departure Country | USA |
| Departure Time | 150 |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | -- |
| Destination City | Columbus |
| Destination State | OH |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jul 24 2014 3:25PM |
| User who most recently changed record | galm |
| 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 | -- |