# NTSB LAX85LA201: Sederberg Bensen B-8M, N4544L, Lower Lake, CA, April 13, 1985

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: April 13, 1985, 14:47 local (22:47 UTC)
- Place: Lower Lake, CA
- Coordinates: 38.880748, -122.549392 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.8807&lon=-122.5494&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 24692
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX85LA201
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/24692/pdf
- Page: https://openairdocs.org/ntsb/LAX85LA201

## Sequence of events

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

- Loss of engine power, takeoff - initial climb
  - reason for occurrence undetermined (cause)
- Forced landing, descent - emergency
- In flight collision with object, descent - emergency
  - object - tree(s)
  - object - fence
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

FOLLOWING A NORMAL TAKEOFF WITH THE FUEL TANK ONE-HALF FULL, THE ACFT CLIMBED TO 1000 FT AGL AT WHICH TIME ENGINE PWR WAS GRADUALLY LOST. A GRND WITNESS REPORTED HEARING THE ENG SPUTTER OR MISS. THE PLT ATTEMPTED TO RETURN TO THE ARPT BUT HAD INSUFFICIENT ALTITUDE AND THE ACFT COLLIDED WITH A 50 TO 60 FT TALL TREE. THE REASON FOR THE LOSS OF ENG PWR IS UNKNOWN. THE PLT WAS THE BUILDER OF THE EXPERIMENTAL ACFT & HAD JUST REINSTALLED THE ENG PRIOR TO THE ACCIDENT.

## Aircraft

- Registration: [N4544L](https://openairdocs.org/deregistered/N4544L-1997-11-19), registration cancelled 1997-11-19, S/N 1 (OpenAirDocs)
- Reported make and model: SEDERBERG BENSEN B-8M (BENSEN B-8)
- Registry model: [Sederberg Stanton E BENSON B-8M](https://openairdocs.org/model/sederberg-stanton-e-benson-b-8m) (registry code 13021LN) (OpenAirDocs)
- Category: Gyroplane, amateur-built
- Serial number: 1
- Airframe hours: 75
- Engines: McCulloch 100-13 90 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Stanton Sederberg
- Airworthiness certificate: Special, Experimental (Special)
- Last inspection: Annual, September 26, 1984, 0 hours before
- Departed: 209, LOWER LAKE, CA
- Airport: 209, Pearce Fld, runway 30, 2,485 × 50 ft, dirt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; student; medical: class 3, valid medical--w/ waivers/lim; seat: center; flight hours: 82 total, 82 in this make and model, 70 as pilot in command, 8 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 75 °F

## 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 19850413015799A](https://openairdocs.org/incident/19850413015799A), Apr 13, 1985: Amtrbx BENSENB8M, Lower Lake, CA, Substantial damage. Power loss after takeoff. Turned back to runway and descended colliding with a tall tree. Undetermined malfunction.

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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