# NTSB ANC19LA051: Lake LA-4-200, N6672L, Girdwood, AK, September 3, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: September 3, 2019, 13:15 local (21:15 UTC) - Place: Girdwood, AK - Coordinates: 60.968887, -149.119445 - Nearby events: https://openairdocs.org/map.md?lat=60.9689&lon=-149.1194&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration - NTSB case key (mKey): 100243 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC19LA051 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100243/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100243 - Page: https://openairdocs.org/ntsb/ANC19LA051 ## Probable cause The pilot's loss of directional control while landing, which resulted in a runway excursion and collision with terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Incorrect use/operation (probable cause); cases with it: [Lake LA-4-200, 3 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=5110310), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Lake LA-4-200, 4 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=5110310), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Lake LA-4-200, 2 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=5110310), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) ## Analysis According to the pilot, the landing gear and flaps failed to retract after departure. After verifying that the hydraulic pump circuit breaker had not opened and noting that the hydraulic pressure gauge indicated zero, he was able to successfully retract both the landing gear and wing flaps using the emergency hydraulic hand pump. Upon arrival at his destination, he again used the hand pump to extend both the landing gear and wing flaps. After touchdown, he applied the wheel brakes in an effort to slow and steer the airplane, but the airplane did not slow down. The airplane exited the side of the runway, proceeded down an embankment, and came to rest on its left wing and hull sustaining substantial damage to the left wing and fuselage. Postaccident examination of the brake and flight control systems revealed no preaccident mechanical malfunctions or anomalies that would have precluded normal operation. Although the pilot reported the failure of the airplane's landing gear and wing flap hydraulic system, it was independent of the brake system and therefore was not examined. ## Factual narrative On September 3, 2019, about 1315 Alaska daylight time, an amphibious Lake LA-4-200 airplane, N6672L, sustained substantial damage following a runway excursion at the Girdwood Airport (AQY), Girdwood, Alaska. The private pilot was not injured. The airplane was registered to, and operated by, a private individual, under the provisions of 14 Code of Federal Regulations Part 91 when the accident occurred. Visual meteorological conditions prevailed and no flight plan had been filed. The flight departed Merrill Field (MRI), Anchorage, Alaska at 1230 destined for AQY. According to the pilot, after departing PAMR the landing gear and flaps failed to retract, so he verified that the hydraulic pump circuit breaker had not opened and noted that the hydraulic pressure gauge indicated zero. He utilized the emergency hydraulic hand pump and was able to successfully retract both the landing gear and wing flaps. Upon arrival at AQY, the hand pump was once again utilized to extend both the landing gear and wing flaps. After touchdown, in an effort to slow and steer the airplane, the wheel brakes were applied but did not work properly. The airplane exited the runway, proceeded down an embankment and came to rest on its left wing and hull, sustaining substantial damage to the left wing and fuselage. According to the Lake LA-4 Owner's Manual, the airplane is equipped with a castering nose wheel, which requires differential braking for directional control. The hydraulic system is used to operate the landing gear, flaps, and longitudinal trim, and is composed of an integral pump and electric motor, pressure limit switch, accumulator, and reservoir, interconnected by necessary piping, check valves, and restrictors. The brake system is independent of the hydraulic system. An examination of the brake and primary flight control systems revealed no preaccident mechanical malfunctions or anomalies that would have precluded normal operation. The closest official weather observation station to the accident site was Portage Glacier (PATO), Whittier, Alaska, located about 20 miles southeast of the accident site. At 1253, a METAR was reporting, in part, wind, variable at 6 knots; visibility, 10 statute miles; clouds and sky condition, overcast clouds at 5,000 ft; temperature, 55°F; dew point, 52°F; and an altimeter setting of 30.08 inches of mercury. ## Aircraft - Registration: [N6672L](https://openairdocs.org/deregistered/N6672L-2020-12-11), registration cancelled 2020-12-11, S/N 435, built 1970 (OpenAirDocs) - Reported make and model: Lake LA-4-200 - Registry model: [Lake LA-4-200](https://openairdocs.org/model/lake-la-4-200) (registry code 5110310) (OpenAirDocs) - Registry engine: [Lycoming I0360 SER A&C](https://openairdocs.org/engine/lycoming-i0360-ser-a-c) (registry code 41511, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 435 - Year built: 1970 - Airframe hours: 2333.3 - Engines: Lycoming IO-360 A1B6 200 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 8, 2019 - Departed: MRI, Anchorage, AK - Destination: AQY, Girdwood, AK - Airport: AQY, Girdwood, runway 20, 2,095 × 60 ft, gravel - Equipment: ADS-B, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 81; injuries: none; private; airplane ratings: single-engine sea, single-engine land; medical: class 3, with waivers/limitations; last flight review July 7, 2019; seat: left; restraint: 3-point; flight hours: 1,438 total, 756 in this make and model, 1,380 as pilot in command, 15 in the last 90 days, 9 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: 5,000 ft overcast - Temperature: 55 °F, dew point 52 °F - Altimeter: 30.07 inHg ## 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 20190903014659A](https://openairdocs.org/incident/20190903014659A), Sep 3, 2019: Lake LA-4-200, Girdwood, AK, Substantial damage. Airman departed mri, climbed to 700FT, selected gear up, observed unsafe gear indication, checked light and hydraulic pressure and observed low pressure, at… ## Docket (1 files) The files NTSB released with the investigation on November 13, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100243. 672 KB in all. - Photos (item 1, .PDF, 5 photos, 672 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40477966&FileExtension=.PDF&FileName=Photos-Master.PDF 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.