# NTSB CHI08CA298: Lake LA-4, N1147L, Algonac, MI, August 23, 2008 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 23, 2008, 14:15 local (18:15 UTC) - Place: Algonac, MI - Coordinates: 42.609405, -82.530639 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.6094&lon=-82.5306&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi: Ground collision](https://openairdocs.org/ntsb-events/200) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report January 22, 2009 - Report: Approved by Office Director - Parties: FAA-Detroit FSDO - NTSB case key (mKey): 69542 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI08CA298 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/69542/pdf - Page: https://openairdocs.org/ntsb/CHI08CA298 ## Probable cause The amphibious airplane's collision with submerged debris during taxi for takeoff, and the resulting damage to the hull. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Fuselage: plates/skins (aux fuselage)](https://openairdocs.org/ntsb-findings/01035330): Aircraft › Aircraft structures · Damaged/degraded (probable cause); cases with it: [Lake LA-4, 1 case](https://openairdocs.org/ntsb-findings/01035330/cases.md?model=5110302), [All aircraft, 4 cases](https://openairdocs.org/ntsb-findings/01035330/cases.md) - [Object/animal/substance: hidden/submerged object](https://openairdocs.org/ntsb-findings/03022052): Environmental issues › Physical environment · Effect on equipment (probable cause); cases with it: [Lake LA-4, 1 case](https://openairdocs.org/ntsb-findings/03022052/cases.md?model=5110302), [All aircraft, 36 cases](https://openairdocs.org/ntsb-findings/03022052/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Taxi: Ground collision](https://openairdocs.org/ntsb-events/200) (defining event); cases with it: [Lake LA-4, 1 case](https://openairdocs.org/ntsb-events/200/sequence.md?model=5110302), [All aircraft, 618 cases](https://openairdocs.org/ntsb-events/200/sequence.md) ## Analysis The pilot reported that after departure he proceeded to a nearby lake in order to practice water takeoffs and landings. After landing, the water conditions became too rough to safely takeoff. The pilot elected to water taxi to a bay area near an island for smoother conditions. He stated that as he crossed near the southern tip of the island, the airplane struck a submerged object. He estimated the airplane's speed at the time as approximately 6 miles per hour. He steered the airplane toward deeper water; however, after about 3 minutes his feet were under water. He subsequently taxied into water about 3 feet deep and came to rest with the landing gear down. He noted that the airplane normally sat about 18 inches deep in the water. The depth finder did not alert him to the presence of the submerged object prior to the collision. ## Factual narrative The pilot reported that after departure he proceeded to a nearby lake in order to practice water takeoffs and landings. After landing, the water conditions became too rough to safely takeoff. The pilot elected to water taxi to a bay area near an island for smoother conditions. He stated that as he crossed near the southern tip of the island, the airplane struck a submerged object. He estimated the airplane's speed at the time as approximately 6 miles per hour. He steered the airplane toward deeper water; however, after about 3 minutes his feet were under water. He subsequently taxied into water about 3 feet deep and came to rest with the landing gear down. He noted that the airplane normally sat about 18 inches deep in the water. The depth finder did not alert him to the presence of the submerged object prior to the collision. ## Aircraft - Registration: [N1147L](https://openairdocs.org/aircraft/N1147L), registered now, S/N 309, built 1964 (OpenAirDocs) - Reported make and model: LAKE LA-4 - Registry model: [Lake LA-4](https://openairdocs.org/model/lake-la-4) (registry code 5110302) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 309 - Airframe hours: 2452 - Engines: LYCOMING O&VO-360 SER 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 22, 2008 - Departed: DET, Detroit, MI - Destination: Algonac, MI - Airport: DET, Coleman A Young Muni ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; injuries: none; private; airplane ratings: single-engine land, single-engine sea; medical: class 3, with waivers/limitations; seat: left; flight hours: 348 total, 102 in this make and model, 1 in the last 90 days, 1 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 170° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Observed at: DET, 15 nm away 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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.