ANC04LA038

NTSB accident investigation · Grumman G21 · Unalaska, AK · April 5, 2004

Accident · No injuriesLimited investigationFinal report
Date
April 4, 2004, 17:15 local (Apr 5, 2004, 01:15 UTC)
Place
Unalaska, AK
Injuries
9 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N22932Grumman G21
Weather
Visual (VMC) · Day
Status
Completed · report September 29, 2004
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
FAA, Anchorage FSDO, FAA, Anchorage FSDO
FAA report
20040404006449A
Case key
59015

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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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

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of control - on ground/waterLanding - roll
Ground loop/swerve - inadvertentCopilot/second pilotCause
Improper transition/upgrade trainingCheck pilotFactor
Landing gear,normal brake system - not installed
Supervision - inadequatePilot in commandCause
Inadequate surveillance of operationCompany/operator mgmtFactor
Lack of total experience in type of aircraftCopilot/second pilotFactor
Weather condition - crosswindFactor
Main gear collapsedLanding - 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
Reported as
Grumman G21
Category
Airplane
Serial number
B-139
Airframe hours
16,220
Engine
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

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
58
Injuries
None
Certificates
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
Role
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.

Other investigations on N22932 · 3

Matched to the same aircraft by N-number and date.