# NTSB ANC98LA038: Grumman G-21, N22932, Dutch Harbor, AK, April 15, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 15, 1998, 11:45 local (19:45 UTC) - Place: Dutch Harbor, AK - Coordinates: 57.790527, -152.39923 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=57.7905&lon=-152.3992&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 9 uninjured - Status: Completed, report September 28, 1999 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 3130 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC98LA038 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/3130/pdf - Page: https://openairdocs.org/ntsb/ANC98LA038 ## Probable cause The pilot-in-command's failure to identify the swells prior to landing. A factor was the water swells. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - On ground/water encounter with terrain/water, landing - terrain condition - water (contributing factor) - unsafe/hazardous condition - not identified, pilot in command (cause) ## Analysis The pilot landed the seaplane in a protected bay in order to wait for the weather to improve at his destination. He said the wind and seas were calm; however, during landing, the seaplane encountered a swell. The seaplane porpoised, and the left horizontal stabilizer contacted the water. ## Factual narrative On April 15, 1998, at 1145 Alaska daylight time, a Grumman G-21 amphibious seaplane, N22932, sustained substantial damage during a water landing five miles northwest of the Unalaska Airport, Dutch Harbor, Alaska. There were no injuries to the airline transport certificated pilot, or the eight passengers. The flight was operated by Peninsula Airways, Inc., of Anchorage, Alaska, as scheduled commuter flight number 323. The flight was a return leg from Akutan, Alaska, and departed at 1120. Instrument meteorological conditions prevailed at the Unalaska Airport, and the flight was holding in visual meteorological conditions outside the Class-E surface area. The pilot stated during a telephone interview with the NTSB investigator-in-charge on April 15, 1998, that after holding for 15 minutes, he decided to land on the water in a protected bay to wait for improved weather. He reported the winds and seas as calm. After landing, the seaplane porpoised on a swell which the pilot had not identified. The left horizontal stabilizer struck the water during the porpoise and was damaged. The passengers were transported to Dutch Harbor via a rescue boat, and the seaplane was water taxied to the harbor. ## Aircraft - Registration: [N22932](https://openairdocs.org/aircraft/N22932), registered now, S/N B-139, built 1946 (OpenAirDocs) - Reported make and model: Grumman G-21 - Registry model: [Grumman G-21A](https://openairdocs.org/model/grumman-g-21a) (registry code 3951204) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-985 series](https://openairdocs.org/engine/pratt-whitney-r-985-series) (registry code 52008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: B-139 - Engines: P&W R-985 450 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Registered owner: Peninsula Airways, Inc. - Airworthiness certificate: Standard, Normal - Departed: AKUTAN, AK - Destination: DUT, AK - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; airline transport; airplane ratings: single-engine sea, multi-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 7,136 total, 83 in this make and model, 6,862 as pilot in command, 83 in the last 90 days, 53 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: 2,500 ft broken - Temperature: 34 °F - Altimeter: 29.00 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 19980415006889A](https://openairdocs.org/incident/19980415006889A), Apr 15, 1998: Grumav G21, Unalaska, AK, Substantial damage. Unable land amphibian at dut. Landed on wataer to await clearing. Porpoised on a swell damaged horizontal stabilize. (From .4) the pilot landed the seaplane in… ## Other investigations on N22932 (3) 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. - [NTSB ANC04LA038](https://openairdocs.org/ntsb/ANC04LA038), Apr 5, 2004: Grumman G21 (N22932), Unalaska, AK, substantial damage. Probable cause: The inadvertent ground loop/swerve by the second pilot during the landing roll, and the first (check) pilot's inadequate supervision of the second pilot, which resulted in a loss of control and… - [NTSB ANC93IA026](https://openairdocs.org/ntsb/ANC93IA026), Jan 7, 1993: Grumman G-21A (N22932), Akutan, AK, incident, minor damage. Probable cause: THE INCIDENT WAS CAUSED BY THE PILOTS IMPROPER COMPENSATION FOR THE WINDS. FACTORS WERE THE MICROBURST, THE ROUGH WATER, AND THE PILOT'S INADEQUATE EVALUATION OF THE WEATHER CONDITIONS. - [NTSB LAX79FA084](https://openairdocs.org/ntsb/LAX79FA084), Sep 17, 1979: Grumman G-21A (N22932), Avalon, CA, substantial damage, 1 fatal 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.