Bell 407 N302LE

Summary

On 12 December 2006 at about 04:17 local time, a Bell 407 registered N302LE, operated by CJ Systems Aviation Group, Inc., was involved in an incident near Raytown, Missouri, United States. 4 people were on board and nobody was injured. The aircraft was slightly damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

12 December 2006 at 04:17

Classification

Incident

Location

Raytown, Missouri, United States

Coordinates

39.0493, -94.4902

Aircraft

Bell 407

Registration

N302LE

Category

Helicopter

Engines

1

Operator

CJ Systems Aviation Group, Inc.

Operating rule

Part 135: Air Taxi & Commuter

Phase of flight

Not recorded

Route

Clinton → Kansas City

Aircraft damage

Minor

Weather

VMC

Light

Night/Bright

NTSB number

CHI07IA042

Nobody was injured.

The loss of engine power during cruise flight due to third stage turbine wheel blade fatigue and subsequent separation, which resulted in an emergency landing.

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

Read the full NTSB narrative

The air ambulance helicopter executed an emergency landing on an elementary school parking lot following a loss of engine power. Night visual meteorological conditions prevailed at the time of the incident. The pilot stated that he heard a bang and got a low frequency vibration during cruise flight. The helicopter received minor damage due to internal engine components exiting the engine collector and exhaust stack. Examination of the third stage turbine wheel noted high cycle fatigue features on the fracture surface of one of the blades. The fatigue initiated at the trailing edge of the airfoil and propagated 0.515 inch before a fast fracture separation. Although a small area of porosity was observed in the microstructure adjacent to the fracture, it did not intersect the fracture surface, and no evidence of porosity was observed on the fracture surface. Chemistry and hardness were as specified. Given the high cycle features, good material properties, and lack of a stress-concentrating defect at the origin, the fatigue could be secondary to some other event that produced unusual loading or vibrations in the blade.

Quoted verbatim from the NTSB record.