# NTSB ANC04LA038: Grumman G21, N22932, Unalaska, AK, April 5, 2004 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 4, 2004, 17:15 local (Apr 5, 2004, 01:15 UTC) - Place: Unalaska, AK - Coordinates: 53.900276, -166.543609 - Nearby events: https://openairdocs.org/map.md?lat=53.9003&lon=-166.5436&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 29, 2004 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA, Anchorage FSDO, FAA, Anchorage FSDO - NTSB case key (mKey): 59015 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC04LA038 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59015/pdf - Page: https://openairdocs.org/ntsb/ANC04LA038 ## 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 substantial damage to the airplane. Factors associated with the accident are the second pilot's improper upgrade/transition training by the company check airman, the second pilot's lack of experience in the accident type airplane, the operator's lack of surveillance of the training process, and a crosswind. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - on ground/water, landing - roll - ground loop/swerve - inadvertent, copilot/second pilot (cause) - improper transition/upgrade training, check pilot (contributing factor) - landing gear,normal brake system - not installed - supervision - inadequate, pilot in command (cause) - inadequate surveillance of operation, company/operator mgmt (contributing factor) - lack of total experience in type of aircraft, copilot/second pilot (contributing factor) - weather condition - crosswind (contributing factor) - Main gear collapsed, landing - roll - terrain condition - runway ## Analysis A recently qualified captain was landing an amphibious, tailwheel airplane in a near direct crosswind of 7 gusting to 14 knots on a hard-surfaced runway at the conclusion of a scheduled commuter airline flight. The new captain (second pilot) was being observed and trained by the pilot-in-command check airman, who occupied the right seat pilot station. The right seat station was equipped with all flight controls, but did not have brake pedals. During the landing roll, the airplane ground looped to the right, and the left main landing gear collapsed, resulting in substantial damage to the fuselage. A review of the second pilot's training records and interviews with FAA personnel, disclosed that the second pilot had not received adequate transition training to the accident type airplane, and had a total of 1.8 hours in the accident type airplane at the time of the accident, which included all training and a flight check. The second pilot had accrued about 7 hours of tailwheel experience over 7 years prior to beginning his training on the accident type airplane. His received only 3 wheel landings, instead of the minimum of 12, in the accident type airplane during his transition training. Postaccident inspection of the airplane and maintenance records disclosed no evidence of any preaccident mechanical problems. ## Factual narrative On April 4, 2004, at 1715 Alaska daylight time, a tailwheel-equipped amphibious Grumman G21 airplane, N22932, sustained substantial damage when the left main landing gear collapsed following a loss of control while landing at the Unalaska Airport, Unalaska, Alaska. The two airline transport certificated pilots, and the seven passengers, were not injured. The Title 14, CFR Part 135 scheduled commuter flight was operated as Flight 325 by Peninsula Airways, Anchorage, Alaska, doing business as PenAir. The flight departed Akutan, Alaska, at 1645, en route to Unalaska. Visual meteorological conditions prevailed, and a visual flight rules (VFR) flight plan was in effect. According to information received from the operator's vice president, and from the NTSB Pilot/Operator Aircraft Accident Report submitted by the flight crew, the pilot-in-command of the flight was a check airman observing and instructing a recently upgraded captain during his initial operating experience. The new captain was the pilot flying, and occupied the left seat at the time of the accident. The check airman occupied the right seat pilot's station which was equipped with all flight controls, but did not have brake pedals. The airplane made an uneventful wheel landing touchdown on runway 30, but during the latter portion of the landing roll, as the tailwheel touched the runway, the airplane swerved hard to the left. The pilot flying indicated he applied full right brake, full right rudder, and differential power to arrest the turn. The airplane began a turn towards the center of the runway, and the rudder and differential power were neutralized. The airplane continued turning sharply to the right, and as the nose of the airplane passed approximately 20-25 degrees right of the runway centerline, the left main landing gear collapsed. The airplane slid on its fuselage for about 40 feet, before coming to rest on the runway. Reported wind conditions at the time of the accident were 7 knots gusting to 14 knots, from 027 degrees magnetic, or nearly a direct right crosswind. Discussions with the operator's vice president, and a review of digital photographs provided by the operator, disclosed that the airplane received structural damage to the bottom and right side of the fuselage. Interviews with and documents supplied by the FAA assistant principal operations inspector for the operator, disclosed the flying pilot had received an abbreviated level of transition training for the G21 airplane prior to receiving his G21 captain's check ride from the company check airman. The company check airman who administered the check ride and the flight training was the non-flying captain on the accident flight. According to the FAA inspector, the flying pilot had not met the operator's prescribed (and FAA approved) minimum training requirements for a G21 captain. He noted that only two of the four required training flights were completed, that only three of the required 12 wheel landings were accomplished, and that prohibited simultaneous flight checking and flight training were conducted. The FAA inspector indicated that prior to commencement of training in the G21, the flying pilot had accrued approximately 7 hours total tailwheel experience, collected over approximately 7 years. He received 1.8 hours of flight training in the G21, which included .1 (6 minutes) allocated for completion of the entire flight check requirements. A review of the airplane's maintenance records disclosed no evidence of any significant preaccident mechanical problems with the airplane, and no evidence of any preaccident mechanical anomalies were reported by the operator during the postaccident inspection. ## Aircraft - Registration: [N22932](https://openairdocs.org/aircraft/N22932), registered now, S/N B-139, built 1946 (OpenAirDocs) - Reported make and model: Grumman G21 - 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 - Airframe hours: 16220 - Engines: Pratt & Whitney R-985-AN-14B 450 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Registered owner: Peninsula Airways, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, February 9, 2004, 30 hours before - Departed: KQA, Akutan, AK - Destination: DUT - Flight plan: VFR - Airport: DUT, Unalaska, runway 30, 3,900 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; injuries: none; airline transport, commercial; airplane ratings: single-engine land, multi-engine sea, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; last flight review March 19, 2004; seat: right; flight hours: 20,000 total, 3,500 in this make and model, 116 in the last 90 days, 43 in the last 30 days, 5 in the last 24 hours - Co-pilot; injuries: none ## Weather - Conditions: Visual (VMC), Day - Wind: 27° at 7 knots, gusting 14 - Visibility: 7 statute miles - Lowest ceiling: 2,000 ft broken - Temperature: 36 °F, dew point 43 °F - Altimeter: 29.12 inHg - Observed at: PADU ## 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 20040404006449A](https://openairdocs.org/incident/20040404006449A), Apr 4, 2004: Grumav G21A, Unalaska, AK, Substantial damage. (-23) The flying pilot at the time of the accident was the second-in-command (SIC), [privacy data omitted]. [privacy data omitted] Had received a 14 CFR, part… ## 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 ANC98LA038](https://openairdocs.org/ntsb/ANC98LA038), Apr 15, 1998: Grumman G-21 (N22932), Dutch Harbor, AK, substantial damage. Probable cause: The pilot-in-command's failure to identify the swells prior to landing. A factor was the water swells. - [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.