CEN22LA220

NTSB accident investigation · Grumman American Avn. AA-1B · River Falls, WI · June 1, 2022

Accident · Serious injuriesClass 3 · LimitedFinal report
Date
June 1, 2022, 12:15 local (17:15 UTC)
Place
River Falls, WI
Injuries
1 serious, 1 minor
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N6298LGrumman American Avn. AA-1B
Defining event
Approach-VFR pattern base: Fuel exhaustion
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Central Region
Parties
FAA FSDO
FAA report
20220601009939A
Case key
105171

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

On this page

Probable cause

The student pilot’s and flight instructor’s inadequate preflight fuel planning, which resulted in a total loss of engine power due to fuel exhaustion.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Planning/preparation: fuel planningPersonnel issues › Task performance · Student/instructed pilotGrumman American Avn. AA-1B: 5 casesAll aircraft: 719 casesProbable cause
Planning/preparation: fuel planningPersonnel issues › Task performance · Instructor/check pilotGrumman American Avn. AA-1B: 5 casesAll aircraft: 719 casesProbable cause
Fluids: fuelAircraft › Fluids/misc hardware · Fluid levelGrumman American Avn. AA-1B: 5 casesAll aircraft: 1,695 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The flight instructor and student pilot reported problems with the airplane’s engine shortly after takeoff. The flight instructor stated that the engine “quit abruptly” and “seized,” and the student pilot stated that the engine “locked up” and lost total power. The flight instructor assumed control of the airplane and made a forced landing in a field, which resulted in substantial damage to the airplane’s left wing. Postaccident examination of the airplane revealed no fuel remaining in the wing tanks and no evidence of a fuel spill. The fuel system was not compromised. According to the accident report submitted by the flight instructor they departed with 8 gallons of fuel and were flying for about 1 hour and 15 minutes. Postaccident examination revealed that the engine rotated freely, and compression was verified on all cylinders. Both magnetos produced spark when rotated. Thus, the engine likely lost power due to fuel exhaustion.

Factual narrative

On June 1, 2022, about 1215 central daylight time, a Grumman AA-1B airplane, N6298L, was substantially damaged when it was involved in an accident near St. Croix Riviera Airport (6WI2), River Falls, Wisconsin. The student pilot sustained minor injuries, and the flight instructor sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor reported that, during the accident flight, he and the student pilot performed two takeoffs and landings and that, on the third takeoff, the engine “quit abruptly” at an altitude of about 150 ft. The flight instructor stated that the engine appeared to have “seized instantly.” The student pilot reported that, during the initial climb after takeoff and when the airplane was about 150 to 200 ft above ground level, the engine “locked up” and lost total power. At that time, the flight instructor assumed control of the airplane and made a forced landing to a vacant field south of the airport, which was straight ahead of the departure runway. The airplane came to rest upright in the field, which resulted in substantial damage to the left outboard wing panel. Examination of the airplane at the accident scene found no fuel in the wing fuel tanks. A subsequent examination revealed that the fuel tanks were not breached and that the other fuel system components had no discrepancies. According to the accident report submitted by the flight instructor they departed with 8 gallons of fuel and were flying for about 1 hour and 15 minutes. The engine rotated freely, and compression was verified on all cylinders. Both magnetos produced spark when rotated.

Aircraft

Registration
N6298L
Reported as
Grumman American Avn. AA-1B
Category
Airplane
Serial number
AA1B0098
Built
1972
Airframe hours
2,986
Engine
Lycoming O-320, 150 hp, reciprocating
Damage
Substantial damage
Flight
Instructional · Part 91
Registered owner
Jft LLC
Airworthiness certificate
Standard, Normal
Last inspection
Annual · November 19, 2021
Departed
6WI2 · River Falls, WI
Airport
6WI2 · St Croix Riviera, runway 13, 1,700 × 100 ft, grass/turf
Equipment
Stall warning system, ADS-B

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
Flight instructor
Age
60
Injuries
Serious
Certificates
Airline transport, Flight instructor, Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Seat
Right
Restraint
Lap only
Flight hours
14,500 total · 10 in this make and model
Role
Student pilot
Age
39
Injuries
None
Certificate
Student
Medical
Class 3, With waivers/limitations
Seat
Left
Restraint
Lap only
Flight hours
38 total · 38 in this make and model · 5 as pilot in command · 29 in the last 90 days · 15 in the last 30 days · 2 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
Variable at 4 knots
Visibility
10 statute miles
Temperature
66 °F, dew point 45 °F
Altimeter
30.06 inHg
Observed at
KSTP, 14 nm away
METAR
SPECI KSTP 011203Z 00000KT 10SM BKN025 12/09 A3009 RMK AO2 T01220094= METAR KSTP 011653Z VRB04KT 10SM SCT050 19/07 A3006 RMK AO2 SLP177 T01890072=

Docket · 5

The files NTSB released with the investigation on November 8, 2023, on NTSB’s docket system: statements, records, photos and specialists’ reports. 40.3 MB in all.

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 N6298L · 1

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