# NTSB CHI92LA233: MBB BO-105, N30SV, Madison, SD, August 9, 1992

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: August 9, 1992, 13:26 local (18:26 UTC)
- Place: Madison, SD
- Coordinates: 44.000717, -97.099555 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=44.0007&lon=-97.0996&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 3 minor
- Status: Completed, report September 14, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 15509
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI92LA233
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15509/pdf
- Page: https://openairdocs.org/ntsb/CHI92LA233

## Probable cause

THE PILOT'S INADEQUATE VISUAL LOOKOUT AND INADVERTENT DESCENT.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- In flight collision with terrain/water, maneuvering
  - terrain condition - water
  - descent - inadvertent, pilot in command (cause)
  - visual lookout, inadequate (cause)

## Analysis

THE PILOT REPORTED HE ENTERED A SHALLOW RIGHT TURN ABOUT 200-300' ABOVE LAKE MADISON. HE SUDDENLY REALIZED HE HAD LOST CONSIDERABLE ALTITUDE AND WAS IN A STEEP RIGHT BANK. HE SAID HE ATTEMPTED TO LEVEL THE HELICOPTER AND GAIN ALTITUDE BUT STRUCK THE WATER. HE WAS UNAWARE OF ANY PRE IMPACT MECHANICAL DIFFICULTIES WITH THE HELICOPTER. A POST CRASH INSPECTION DID NOT DISCOVER ANY PREEXISTING MECHANICAL DEFICIENCIES.

## Aircraft

- Registration: [N30SV](https://openairdocs.org/deregistered/N30SV-1993-03-11), registration cancelled 1993-03-11, S/N S755 (OpenAirDocs)
- Reported make and model: MBB BO-105
- Registry model: [Messerschmitt-Boelkow-Blohm BO-105S](https://openairdocs.org/model/messerschmitt-boelkow-blohm-bo-105s) (registry code 5626006) (OpenAirDocs)
- Category: Helicopter
- Serial number: 755
- Airframe hours: 2000
- Engines: ALLISON 250-C20 420 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Business, Part 91
- Operator: Rocky Mountain Helicopters
- Registered owner: State St. Bank And Trust
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, July 21, 1992, 54 hours before
- Departed: SIOUX FALLS, SD
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 42; airline transport; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane, helicopter; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 7,835 total, 53 in this make and model, 2 in the last 90 days, 2 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 340° at 5 knots
- Visibility: 5 statute miles
- Lowest ceiling: 3,700 ft broken
- Temperature: 84 °F, dew point 75 °F
- Altimeter: 29.00 inHg
- Observed at: BKX, 23 nm away

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19920809029769A](https://openairdocs.org/incident/19920809029769A), Aug 9, 1992: Bolkms BO105A, Madison, SD, Substantial damage. Struck lake surface during low altitude descending turn. Indicates loss of VFR reference due haze and mirror effect

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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