SEA93LA196

NTSB accident investigation · Aerospatiale SA-365-N2 · Ogden, UT · September 10, 1993

Accident · FatalLimited investigationFinal report
Date
September 10, 1993, 15:30 local (21:30 UTC)
Place
Ogden, UT
Injuries
1 fatal, 2 serious, 3 minor
Damage
Destroyed
Phase of flight
Maneuvering
Aircraft
N818RAerospatiale SA-365-N2
Weather
Visual (VMC) · Day
Status
Completed · report August 1, 1994
Report
Approved by Office Director
Case key
41764

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The pilot's failure to maintain proper altitude. A factor to the accident was glassy water.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

In flight collision with terrain/waterManeuvering
Terrain condition - water,glassyFactor
Proper altitude - not maintainedPilot in commandCause

Analysis

During a flight for the purpose of aerial photography, the helicopter was flying over glassy water conditions. The pilot had set the bug on the radar altimeter for 50 feet; however, while he was looking outside for reference, the helicopter descended below 50 feet. The pilot stated that he suddenly had a sensation of movement over the water, and just seconds before impact with the water, the pilot noted ten feet above water level on the radar altimeter.

Factual narrative

On September 10, 1993, at 1530 mountain daylight time, an Aerospatiale SA365N2, N818R, collided with the water in the Great Salt Lake while maneuvering 10 miles west of Ogden, Utah. Visual meteorological conditions prevailed at the time and no flight plan was filed for the corporate flight. The helicopter was destroyed and the certificated Airline Transport pilot and two passengers suffered minor injuries, two passengers were seriously injured, and one passenger was fatally injured. The flight had departed from the Ogden area on September 19, 1993, at 1330.

The pilot reported that the purpose of the flight was to take a camera crew up to produce aerial videography and still photos of the area's mineral extraction facilities. The helicopter had been flying in the area for approximately two hours at varying altitudes from 50 feet to 900 feet. While travelling back to the landing area, the camera director wanted to get one more shot of the water at low level. The pilot noted that the water was calm and glassy and provided no depth perception. The pilot set the decision height "bug" to 50 feet on the radar altimeter then began the descending right turn at 300 feet per minute and 95 knots. At 50 feet above water level, the pilot rolled to level flight and slowed the helicopter to 60 to 70 knots. The pilot was using outside reference while maneuvering and stated that he suddenly turned his attention to the radar altimeter when he felt the sensation of speed over the water and noted that the altitude read 10 feet. Approximately two seconds later the helicopter contacted the water surface. The helicopter pitched over and came to rest on its left side in four feet of water.

The pilot reported that there were no mechanical failures or malfunctions with the helicopter at the time of the accident.

Aircraft

Registration
N818R
Reported as
Aerospatiale SA-365-N2
Category
Helicopter
Serial number
6377
Airframe hours
462
Engine
Turbomeca ARRIEL 1C2, 724 horsepower, turbo shaft
Damage
Destroyed
Flight
Executive/Corporate · Part 91
Operator
American Stores
Registered owner
American Stores
Airworthiness certificate
Standard, Normal
Last inspection
Continuous airworthiness · August 28, 1993 · 12 hours before

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
43
Certificates
Commercial, Airline transport
Airplane ratings
Multi-engine land
Instrument ratings
Airplane, Helicopter
Medical
Class 1, Valid Medical--no waivers/lim.
Seat
Right
Flight hours
9,066 total · 233 in this make and model · 7,800 as pilot in command · 85 in the last 90 days · 50 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
20 statute miles
Lowest ceiling
None
Temperature
84 °F
Altimeter
30.00 inHg
Observed at
OGD, 23 nm away