ANC94GA041

NTSB accident investigation · Grumman G21A · Mt. Fairweather, Canada · March 21, 1994

Accident · Minor injuriesFinal report
Date
March 21, 1994, 11:15 local (15:15 UTC)
Place
Mt. Fairweather, Canada
Injuries
1 minor, 2 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N741Grumman G21A
Weather
Visual (VMC) · Day
Status
Completed · report January 3, 1995
Report
Approved by Office Director
NTSB office
Alaska Regional Office
FAA report
19940321006189A
Case key
2454

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 pilot's improper decision in attempting to outclimb the rising terrain with the existing airplane climb performance. Factors which contributed to the accident were: the pilot's inadequate preflight of the airplane, the over maximum gross weight of the airplane, high terrain, high density altitude, the pilot's lack of recent flying experience, his overconfidence in his airmanship ability, questionable testing of the pilot's flying competency and proficiency, and the state of Alaska's inadequate oversight of the aviation program which allowed management to disregard their own regulations.

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.

In flight collision with terrain/waterClimb
Airframe - waterFactor
Aircraft preflight - inadequatePilot in commandFactor
Aircraft weight and balance - exceededPilot in commandFactor
Terrain condition - high terrainFactor
Weather condition - high density altitudeFactor
In-flight planning/decision - improperPilot in commandCause
Lack of recent experiencePilot in commandFactor
Overconfidence in personal abilityPilot in commandFactor
Inadequate certification/approval,airmanCompany/operator mgmtFactor
Inadequate surveillance of operationOther govt organizationFactor

Analysis

The state-operated amphibian was unable to outclimb rising terrain and impacted the margerie glacier, coming to rest at 9,650 ft MSL. Pilot had not flown since last proficiency check on 11/27/93. Pilot's checks were conducted by a civilian employee who reported directly to the pilot. Pilot did not perform weight & balance. Airplane 1,403 lbs over max gross weight. Additionally, 80 lbs of frozen water was found in the bilges of the hull. At the power and carb air temp settings used by the pilot, the airplane reached max performance at aprx 5,000 ft MSL. Investigation delegated to the U.S. By Canada.

Factual narrative

History of flight

On March 21, 1994, at approximately 1115 Alaska standard time, an amphibian Grumman G21A airplane, N741, collided with glacial terrain under controlled conditions. The airplane is registered to the State of Alaska, Department of Public Safety, and was being operated as a public use aircraft. Departing Juneau at 1030, the airplane was on a VFR flight plan in visual meteorological conditions at the time of the accident. The location of the accident site was at the 9,650 foot level of the Margerie Glacier, located on the west side of Mount Fairweather, in British Columbia, Canada. A commercial pilot and two persons were on board at the time, two were uninjured and the third, a passenger in the right pilot's seat, received minor injuries. The airplane sustained structural damage consistent with substantial damage.

The Grumman amphibian airplane, owned and operated as a public-use aircraft was assigned to the Alaska Department of Public Safety, and hangared at the Juneau Airport. The manager responsible for the division's aviation program oversight in his position as, the Deputy Commissioner of Public Safety for the State of Alaska, was the pilot-in-command. On the day of the accident, the aircraft was being flown on a mission to transport the pilot and an Alaska State Trooper Lieutenant to Anchorage and the Director of the State's Highway Safety Planning Department to Yakutat. Additionally, eighteen numbered and boxed items were on board described as evidence to be delivered to Anchorage in conjunction with a state criminal proceeding.

Investigators found that the aircraft had impacted in controlled flight, with wings level, in a climb, on a snowfield above the Margerie Glacier at a location approximately one mile, 070 degrees (true) from the 15,300 foot peak of Mount Fairweather. Hull marks in the snow field indicated that the first touchdown was at approximately the 8900 foot elevation and the airplane came to a stop at approximately 9650 feet. Retractable wing floats were extended and the snow field showed wing float marks following the second hull skip mark at approximately the 9000 foot elevation. The retractable main wheels were extended equally approximately beyond flush with the hull. Snow was packed behind the extended main wheels. It could not be determined whether the retractable wing floats remained extended for the flight or were jarred down on impact with the snow field.

The saddle of the snow field above the impact point was measured by recovery aircraft altimeter to be approximately 11,000 feet in elevation extending south to north between Mount Fairweather and Mount Root (12,680'). Accurate elevation or contour lines are not shown on the Juneau Sectional Aeronautical Chart for the snow fields between the peaks. Both of these peaks are "boundary peaks" marking the U.S. and Canadian borders. (Refer to Wreckage and Impact Information.) The aircraft came to rest inside Canadian territory.

Injuries to persons

The commercial pilot and the passenger in the rear of the airplane were uninjured. A second passenger in the airplane's copilot seat received back injuries not requiring hospitalization and as such were classified as minor injuries.

Damage to aircraft

The aircraft sustained little structural damage on the snow field during the gear-up landing. Investigators were unable to determine if any damage had occurred to the bottom of the amphibian's hull. Damage to the right horizontal stabilizer at the center of the right elevator hinge point involved the structure of that control surface and is classified as substantial damage. Subsequently the aircraft sustained further damage during salvage operations.

Personnel information

The pilot in command of the aircraft was Claude E. Swackhammer, who held a Commercial Pilot's Certificate and a Second Class Medical Certificate, with limitations of glasses for near and distant vision required. He said that he had flown "about 90 hours in the past year, in the Navajo and the Goose." (Piper PA-31-350 Navajo airplane and the Grumman G-21A).

Records of the department indicate the pilot flew 88.7 hours in the G-21A and 6.8 hours in the PA-31 during the 1993 and 1994 fiscal years. No flights were recorded after November 27, 1993 until the day of the accident. The Aircraft Manual of the Department of Public Safety requires all Department pilots to meet regulations of the Federal Aviation Administration for recent flight experience under FAR 61.57 and have flown within 90 days in order to act as pilot-in-command.

The pilot-in-command of the accident airplane served as the manager of the Department of Public Safety aircraft fleet.

Records provided by the State of Alaska indicated that the pilot had flown the accident aircraft most recently on November 27, 1993 on the occasion of a six month instrument check, and an annual multi-engine land and sea proficiency flight check. That check flight report indicated that 26 separate items were examined and were marked "satisfactory." No events or maneuvers were marked otherwise.

The check airman, as Aircraft Supervisor of the State of Alaska, Department of Public Safety, at Anchorage, is a civilian employee of the state and reports directly to Deputy Commissioner Swackhammer. State records showed that the same check airman had conducted satisfactory proficiency flight checks of the accident pilot in single and multi-engine airplanes on 11/27/93, 6/3/93, 5/27/93, 4/2/93, 11/4/92, and 10/8/92. No check flights were recorded between 1992 and 1985 where records of satisfactory check flights are once again recorded by the same check airman dating back to 1979. No unsatisfactory grades for maneuvers tested were recorded.

Investigators asked the accident pilot if he believed himself to be sufficiently current and proficient in the aircraft. He replied that he believed himself to be. He said that on the day of the accident that he did not use the aircraft checklists because he, "knew the airplane."

During an interview with the accident pilot, investigators learned that a preflight inspection of the airplane on the morning did not include a check of the weight and balance of the airplane or an examination or draining of the bilges for water. The pilot said that the airplane contained "about 300 gallons of fuel." He also said that he estimated the cargo to be "about 300 pounds, maybe a little more." No weight and balance calculations or forms were found in the aircraft.

Investigators were told that Federal Aviation Regulations applicable to preflight actions of a pilot in command (14 CFR Part 91.103 (b)(2)) regarding preflight duties apply to Department pilots under Section XIII of its own regulations.

The accident pilot told investigators that the flight, until the accident event was routine and conducted in visual meteorological conditions. He said that he flew the airplane so as to transit the glacier on Mount Fairweather, but that "a downdraft" prevented the airplane from climbing sufficiently to cross the mountain.

The accident pilot estimated the altitude needed to cross the glacier saddle to be 9000 feet, based on his knowledge of the sectional chart. (see Juneau Sectional Aeronautical Chart)

The pilot told investigators that he recognized from the airspeed indication and the passing terrain that the airplane was not climbing and as he neared the surface of the upsloping icefield he "decided to put it in straight ahead." He recalled the airspeed "around seventy (70 knots) and the VSI (vertical speed indicator) about 500 (feet per minute) down."

He was asked about engine power and settings. He said that the aircraft was performing normally, and that he had been cruising at about 10,000 feet enroute, using an engine RPM setting of 1800. The pilot told investigators that he "pushed the props up to about 1950 (RPM)" and that he had used "full th

Aircraft

Registration
N741
Reported as
Grumman G21A
Category
Airplane
Serial number
B-97
Airframe hours
8,773
Engine
P&W R986-SB/SB2, 450 horsepower, reciprocating
Damage
Substantial damage
Flight
Public aircraft · Public use
Operator
State Of Alaska, doing business as Department Of Public Safety
Registered owner
State Of Alaska
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · August 5, 1993 · 100 hours before
Departed
JNU · Juneau, AK
Destination
ANC · Anchorage, AK
Flight plan
VFR

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

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
51
Certificates
Commercial, Military, Flight engineer
Airplane ratings
Single-engine land, Multi-engine sea, Single-engine sea, Multi-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
3,500 total · 500 in this make and model · 3,400 as pilot in command · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
110° at 6 knots
Visibility
50 statute miles
Lowest ceiling
8,000 ft broken
Temperature
32 °F, dew point 18 °F
Altimeter
29.00 inHg
Observed at
YAK, 50 nm away

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 N741 · 1

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