DEN03FA099 · Agusta A109K2
Agusta A109K2 · Accident: airframe, component or system failure during initial climb
From Salt Lake City, UT to Salt Lake City International Airport (SLC)
Event
- NTSB case
- DEN03FA099
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 1 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Agusta A109K2
- Aircraft type
- Agusta A109
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N123RX
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From Salt Lake City, UTTo Salt Lake City International Airport (SLC), Salt Lake City, UT
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Initial climb
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Rotor system, tail rotor hub › Failure, total
- Rotor system, tail rotor hub › Fatigue
- Rotor system, tail rotor › Separation
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The helicopter flight crew had just finished rescuing a lost hiker and was preparing to return to their home base. The pilot informed the flight nurse that dispatch wanted them to proceed home because the helicopter was due its 25-hour inspection. The pilot mentioned that he first needed to return to the location where they picked up the hiker so he could get an altitude reading. Before taking off, search and rescue personnel warned the pilot of paragliders in the area. The flight nurse said the pilot acknowledged them, and then took off and proceeded southbound. The flight nurse said they were climbing out when she heard a loud noise. She said it seemed to come from beneath the helicopter. She said she heard the pilot say, "Oh no" and then the helicopter began spinning clockwise out of control. The flight nurse said she was being tossed around, but was trying to get into a position for the crash. Then the helicopter impacted the ground. The flight nurse said she got out through the front of the helicopter. She said she checked the paramedic and the pilot, and then went for the radio to call for help. She said that the engines were still running and she smelled fuel. At that point she noticed the tail rotor was missing. Several witnesses on the ground heard and saw the helicopter. The witnesses recalled the helicopter took off and made a right turn to proceed south. Some of the witnesses said they heard a loud bang. Most of the witnesses described the helicopter as doing a 360-degree counter clockwise turn, then the nose of the helicopter pitched up, the tail rotor came off, and the helicopter continued to spin and descend until it impacted the hillside. An examination of the helicopter's broken tail rotor trunnion showed four separate fatigue areas originating from the inner splines. The exam also showed that the fatigue occurred due to stresses that exceeded the design spectrum. Excessive heating was noted due to friction between the trunnion and blade grip bushings. The tail rotor trunnion had a published service life of 2,700 hours. At the accident, the trunnion had 698.0 total hours.
Probable cause
Fatigue of the tail rotor trunnion resulting in complete trunnion failure and subsequent tail rotor separation from the helicopter. Factors contributing to the accident were the low altitude, low airspeed, excessive tail rotor loading, and the worn tail-rotor blade grip bushings.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN03FA099
- Event ID
- 20030616X00878
- Case number
- DEN03FA099
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: local date, investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2003-06-08.
- API snapshot SHA-256: a8b88e5c4c6a68d5565af7864eb80d1aff77839aa85a24e2ec69dd9d6a810543; retrieved 2026-09-20T19:11:17.892Z.