WPR19LA049

NTSB accident investigation · Taylorcraft L 2M · Walla Walla, WA · December 21, 2018

Accident · No injuriesClass 3 · LimitedFinal report
Date
December 21, 2018, 13:30 local (21:30 UTC)
Place
Walla Walla, WA
Injuries
1 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N46147Taylorcraft L 2M
Defining event
Enroute: Fuel exhaustion
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Western Pacific Region
Parties
FAA-FSDO
FAA report
20181221022039A
Case key
98819

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 preflight planning, which resulted in a total loss of engine power due to fuel exhaustion.

Findings · 2

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 · PilotTaylorcraft L-2M: 1 caseAll aircraft: 719 casesProbable cause
Fluids: fuelAircraft › Fluids/misc hardware · Fluid managementTaylorcraft L-2M: 1 caseAll 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 pilot had just purchased the airplane. Before departing on the cross-country flight, he conducted preflight fuel planning based on the airplane’s total fuel capacity and the fuel consumption rate as reported by the previous owner (16 gallons and 4 gallons per hour, respectively). The pilot reported that, about 30 minutes from the destination, the fuel quantity gauges “showed low fuel,” but he thought he had adequate fuel onboard to reach the airport. About 15 minutes from the destination, the engine lost total power and the pilot performed a forced landing to a field. The airplane nosed down during the landing roll and came to rest upright, resulting in substantial damage to the engine firewall and mounts. An industry expert for the accident airplane make/model and engine configuration indicated that the airplane’s fuel consumption was likely about 6 gallons per hour and that the airplane had a total fuel capacity of 14 gallons. During a subsequent interview, the pilot reported that the loss of engine power was the result of fuel exhaustion. The pilot’s reliance on the information provided by the previous owner likely contributed to his exhaustion of the available fuel.

Factual narrative

On December 21, 2018, about 1330 Pacific standard time, a Taylorcraft L-2M airplane, N46147, was substantially damaged when it was involved in an accident near Walla Walla, Washington. The commercial pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that he departed with 16 gallons of fuel onboard and climbed to about 3,500 ft mean sea level (msl) at a 500 foot-per-minute (fpm) rate of climb. After experiencing about 30 minutes of rough air, the pilot climbed to 6,500 ft msl, also at a 500-fpm rate of climb, but could not find smooth air and returned to his original cruise altitude for the remainder of the flight. About 30 minutes from the destination, he noted that the fuel quantity gauges “showed low fuel,” but he thought that he had adequate fuel to make it to the airport. About 15 minutes from the destination, the engine "sputtered" and then lost all power. He verified that the oil temperature and pressure were normal and applied full throttle, rich mixture, carburetor heat, verified that the fuel selector was in the ON position, and that the magnetos were set to both. The pilot was unable to restore engine power and performed an off-airport landing to an open area. During the landing roll, the airplane nosed down and contacted the ground. Examination of the airplane revealed substantial damage to the engine mounts and firewall. The recovery team that responded to the accident site reported that the fuel tanks and header tank were void of fuel and that the fuel system was not compromised. The 1353 recorded weather observation at ALW included wind from 220° at 11 knots, 10 statute miles visibility, clear skies, temperature 06°C (43°F), dew point -01°C (30°F), and an altimeter setting of 30.13 inches of mercury. The potential for carburetor ice was graphed using a carburetor ice chart from the Federal Aviation Administration's Special Airworthiness Information Bulletin CE-09-35, "Carburetor Ice Prevention," published on June 30, 2009. According to the chart, the airplane was at risk of serious icing at glide power and may have been at risk of serious icing at cruise power. During a follow-up interview with the pilot, he reported that he may have experienced fuel exhaustion during the accident flight. According to the pilot, the previous owner informed him that the engine's average fuel consumption was 4 gallons per hour (gph); however, the pilot did not corroborate this information with another source, as the previous owner was experienced in building airplanes. Further, the owner also told the pilot that the airplane was equipped with two 6-gallon wing tanks and one 4-gallon header tank. The pilot fueled the airplane to capacity and completed his fuel performance computation based on a 16-gallon fuel capacity and 4 gph fuel consumption. The previous owner furnished the pilot with historical records for the accident airplane; however, a flight manual was notamong them. The pilot's total flight time en route was 2 hrs and 15 minutes, and he recalled leaning the fuel/air mixture out during cruise flight. A fuel performance computation was completed using the flight plan information provided by the pilot. The airplane was equipped with a Continental O-200, air-cooled, reciprocating engine. According to an industry expert, the fuel consumption for this make/model and engine configuration is 5-6 gph or more. Additionally, the total fuel quantity for the airplane was 14 gallons, as the header tank's capacity was actually 2 gallons, not 4 gallons. Based on these values, the airplane would have burned about 1.2 gallons in the approximate 12 minutes that elapsed during takeoff and while climbing to 3,500 ft, and then 6,500 ft at a 500 fpm rate of climb. This would have left the pilot with 12.8 total gallons of fuel for the remaining 2 hours and 3 minutes of flight, which equates to a fuel consumption of about 6.4 gph.

Aircraft

Registration
N46147
Reported as
Taylorcraft L 2M (No Series)
Category
Airplane
Serial number
L5567
Built
1943
Airframe hours
1,423
Engine
Continental O-200-A, 100 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · May 14, 2018 · 9 hours before
Departed
SZT · Sandpoint, ID
Destination
ALW · Walla Walla, WA
Flight plan
VFR
Equipment
Electronic flight bag or handheld device

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
23
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 1, With waivers/limitations
Last flight review
January 8, 2018
Seat
Front
Restraint
Lap only
Flight hours
276 total · 1 in this make and model · 171 as pilot in command · 5 in the last 90 days · 2 in the last 30 days · 1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
220° at 11 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
43 °F, dew point 30 °F
Altimeter
30.12 inHg
Observed at
ALW, 10 nm away

Docket · 6

The files NTSB released with the investigation on March 17, 2022, on NTSB’s docket system: statements, records, photos and specialists’ reports. 12.7 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.