BELL HELICOPTER TEXTRON CANADA 407
Norfolk, NE — January 5, 2018
Event Information
| Date | January 5, 2018 |
| Event Type | ACC |
| NTSB Number | CEN18CA072 |
| Event ID | 20180110X40647 |
| Location | Norfolk, NE |
| Country | USA |
| Coordinates | 42.02250, -97.41361 |
| Highest Injury | NONE |
Aircraft
| Make | BELL HELICOPTER TEXTRON CANADA |
| Model | 407 |
| Category | HELI |
| FAR Part | 091 |
| Aircraft Damage | SUBS |
Conditions
| Light Condition | NDRK |
| Weather | VMC |
Injuries
| Fatal | 0 |
| Serious | 0 |
| Minor | 0 |
| None | 3 |
| Total Injured | 0 |
Probable Cause
Maintenance personnel’s failure to properly secure the tail rotor drive shaft cover, which resulted in the cover departing the helicopter in flight.
Full Narrative
The pilot and two medical crewmembers were on a return flight to a hospital helipad. During the approach to the helipad, the crew heard a noise outside the helicopter. The medical crewmembers reported they felt a slight "shudder" on the helicopter but attributed it to the wind as they approached the helipad. The pilot heard the noise, but there was no effect on the controls or flight characteristics, so he continued the landing without further incident. After engine shutdown, the on-coming pilot noticed the helicopter's tail rotor drive shaft cover missing. A search of the surrounding area near the helicopter's approach path, located the missing cover.
An examination of the helicopter noted substantial damage to the tail rotor drive shaft.
The day prior to the accident, scheduled maintenance was performed on the helicopter's tail rotor pitch change mechanism, which required removal of the drive shaft cover. The cover was reinstalled, and no problems were reported during a subsequent pre-flight inspection.
It is likely the cover fasteners were not properly secured, after the cover was re-installed.
About This NTSB Record
This aviation event was investigated by the National Transportation Safety Board (NTSB). NTSB investigates all U.S. civil aviation accidents to determine probable cause and issue safety recommendations to prevent future accidents.