N49TJ Hughes 369HS accident

NTSB CHI04LA017 · 2003-10-21 · Evansville, MN

Summary

The helicopter was substantially damaged during an in-flight collision with a lake while conducting an aerial application pass. The local flight was operating from a temporary load site near the lake shoreline. The pilot stated: "The conditions were calm winds, sun coming up over the trees to the east, glassy water condition. During the spray run I must [have] lost my depth perception with the water surface and allowed the skids to contact the water. The aircraft decelerated rapidly ... [and] water came up over the bubble as the aircraft pitched forward." The pilot also noted that he should have "looked at the trees along the shoreline for a vertical reference instead of at the water. With glassy water it is hard to judge distance." He reported there were no malfunctions with the aircraft or engine prior to the accident.

Full narrative

On October 21, 2003, at 0845 central daylight time, a Hughes 369HS helicopter, N49TJ, piloted by a commercial pilot, was substantially damaged during an in-flight collision with Lake Christina near Evansville, Minnesota. The pilot was conducting an aerial application pass over the lake at the time of the accident. The flight was operating under 14 CFR Part 137 and was not on a flight plan. Visual meteorological conditions prevailed. The pilot sustained minor injuries. The local flight was operating from a temporary load site near the lake shoreline.

The pilot reported in his written statement that he departed from the load site about 0840. This was his sixth spray load of the day. He stated: "The conditions were calm winds, sun coming up over the trees to the east, glassy water condition. During the spray run I must [have] lost my depth perception with the water surface and allowed the skids to contact the water. The aircraft decelerated rapidly. ... Water came up over the bubble as the aircraft pitched forward."

After the accident, the pilot noted that he should have "looked at the trees along the shoreline for a vertical reference instead of at the water. With glassy water it is hard to judge distance."

The pilot reported no malfunctions with the aircraft or engine prior to the accident.

Probable cause

The pilot's misjudgment of clearance from the surface of the lake during the aerial application pass. The low altitude operation, glassy water, and his visual perception were contributing factors. The National Transportation Safety Board determined the probable cause of this accident.

Circumstances

Event type: Accident
Highest injury: Minor
Weather conditions: Visual Meteorological Cond
Light condition: Day
Sky condition: OVC
Ceiling (ft): 9000
Visibility (sm): 10
Wind direction: 340
Wind speed (kt): 3
Temperature (F): 46
Distance from field: 0.0

Aircraft

Registration	Make	Model	Damage	FAR part
N49TJ	Hughes	369HS	SUBS	137

Sequence of events

#	Occurrence	Phase
1	230	Cruise

Findings

Finding
19200	factor
24583	factor
24577	cause
31210	factor