Agusta A109K2 N123RX

Summary

On 8 June 2003 at about 02:12 local time, a Agusta A109K2 registered N123RX was involved in an accident near Salt Lake City, Utah, United States. 3 people were on board and one died, one had minor injuries. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

8 June 2003 at 02:12

Classification

Accident

Location

Salt Lake City, Utah, United States

Coordinates

40.7239, -111.7206

Aircraft

Agusta A109K2

Registration

N123RX

Category

Helicopter

Engines

2

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Salt Lake City → Salt Lake City

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

DEN03FA099

1 person died.

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.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full 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.

Quoted verbatim from the NTSB record.