# NTSB CHI04CA219: Lake LA4-200, N1056L, Oshkosh, WI, August 1, 2004

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Data collection · Final report
- Date: August 1, 2004, 10:30 local (15:30 UTC)
- Place: Oshkosh, WI
- Coordinates: 43.966667, -88.5
- Nearby events: https://openairdocs.org/map.md?lat=43.9667&lon=-88.5000&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report December 3, 2004
- Report: Approved by Office Director
- NTSB case key (mKey): 59941
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI04CA219
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59941/pdf
- Page: https://openairdocs.org/ntsb/CHI04CA219

## Probable cause

The unsuitable rough water conditions encountered during the attempted water takeoff.

## Sequence of events

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

- On ground/water encounter with terrain/water, takeoff - roll/run
  - unsuitable terrain or takeoff/landing/taxi area - encountered (cause)
  - terrain condition - water,rough (cause)

## Analysis

The amphibious airplane was damaged when it reportedly encountered a large wave during a water takeoff and subsequently impacted the water.

## Factual narrative

On August 1, 2004, about 1030 central daylight time, a Lake LA4-200 amphibian, piloted by a commercial pilot, sustained substantial damage during a water takeoff from Lake Winnebago near Oshkosh, Wisconsin.  The 14 CFR Part 91 personal flight was operating in visual meteorological conditions without a flight plan.  There were no injuries to the pilot or passenger.  The flight had originally departed from Cushing Field Airport near Newark, Illinois, about 0900, and was bound for the Seaplane Base at the annual Experimental Aircraft Association gathering in Oshkosh, Wisconsin.

The pilot reported that he landed mistook a harbor for the seaplane base and landed.  He said that after he realized that he was north of the seaplane base, he attempted to takeoff.  He said that during the water takeoff, he encountered a large wave that "launched" the airplane into the air prior to achieving takeoff speed.  He said that the airplane was damaged when the airplane came down and impacted the water.

## Aircraft

- Registration: [N1056L](https://openairdocs.org/aircraft/N1056L), registered now, S/N 649, built 1974 (OpenAirDocs)
- Reported make and model: Lake LA4-200
- Registry model: [Lake LA-4-200](https://openairdocs.org/model/lake-la-4-200) (registry code 5110310) (OpenAirDocs)
- Registry engine: [Lycoming IO-360-A1B](https://openairdocs.org/engine/lycoming-io-360-a1b) (registry code 41819, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 649
- Airframe hours: 720.5
- Engines: Lycoming IO-360-A1B 200 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Jack D. Lupei
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, July 10, 2004, 4.5 hours before
- Departed: Oshkosh, WI
- Destination: 0C8, NEWARK, IL

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 55; injuries: none; commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; last flight review September 22, 2002; flight hours: 668 total, 108 in this make and model, 469 as pilot in command, 4 in the last 90 days, 4 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day

## 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 20040801028269A](https://openairdocs.org/incident/20040801028269A), Aug 1, 2004: Conaer LA4200, Oshkosh, WI, Substantial damage. (-23) Aircraft hit large wave on takeoff run. Became airborne, landed hard. Prop strike to fuselage, internal damage to structure.

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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