CEN18LA223

NTSB accident investigation · Aeronca 7BCM · Eureka Springs, AR · June 14, 2018

Accident · Serious injuriesClass 3 · LimitedFinal report
Date
June 14, 2018, 11:15 local (16:15 UTC)
Place
Eureka Springs, AR
Injuries
1 serious
Damage
Substantial damage
Phase of flight
Initial climb
Aircraft
N9098CAeronca 7BCM
Defining event
Initial climb: Loss of engine power (partial)
Weather
Visual (VMC) · Day
Status
Completed
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Central Region
Parties
Federal Aviation Administration (Little Rock FSDO)
FAA report
20180614007679A
Case key
97476

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 pilot’s failure to maintain adequate airspeed following a partial loss of engine power after takeoff for undetermined reasons, which resulted in the airplane exceeding its critical angle of attack and an aerodynamic stall at a low altitude.

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.

Not determinedNot determined › Not determined · Unknown/Not determinedAeronca 7BCM: 2 casesAll aircraft: 2,247 casesProbable cause
Performance/control parameters: airspeedAircraft › Aircraft oper/perf/capability · Not attained/maintainedAeronca 7BCM: 3 casesAll aircraft: 1,681 casesProbable cause
Use of equip/info: aircraft controlPersonnel issues › Task performance · PilotAeronca 7BCM: 11 casesAll aircraft: 9,295 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 was conducting his first flight in the airplane that he purchased earlier the same day. The pilot stated that he did not identify any anomalies during his preflight inspection of the airplane and that the fuel tank had been topped-off before the flight. He reported that the engine started normally and that he observed no anomalies during two separate engine run-ups that he completed before takeoff. He noted that he verified full engine speed, checked proper operation of both magnetos, and cycled the carburetor heat control during both engine run-ups. The pilot reported that after an uneventful takeoff, about 200 ft above ground level, the engine suddenly lost power. The pilot stated that the engine was partially running but was unable to produce enough thrust to sustain level flight. The pilot decided to return to the airport due to heavily wooded terrain ahead of the airplane's position. The pilot stated that he rolled the airplane into a steep left turn, and about halfway through the 180° turn, the airplane entered an aerodynamic stall at a low altitude. The pilot reported that the airplane impacted terrain in a left-wing-down, nose-down attitude. The forward fuselage, outboard left wing, and both wing struts sustained substantial damage during impact. A postaccident wreckage examination did not reveal any evidence of mechanical malfunction that would have precluded normal operation of the airplane or its engine during the flight. The fuel samples collected after the accident were free of contamination. The cause of the partial loss of engine power could not be determined with the available evidence. It is likely that when the pilot turned back to the airport after the engine lost partial power, he did not maintain adequate airspeed and exceeded the airplane’s critical angle of attack, which resulted in an aerodynamic stall. A review of available maintenance documentation revealed that the airplane did not have a current annual inspection. The pilot, who also held an aviation mechanic certificate with inspector authorization, did not apply for a ferry flight permit before the flight.

Factual narrative

On June 14, 2018, about 1115 central daylight time, an Aeronca 7BCM airplane, N9098C, was substantially damaged when it was involved in an accident near Eureka Springs, Arkansas. The private pilot sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The accident occurred during the pilot's first flight after he purchased the airplane earlier that morning. He stated that the previous owner had refueled the airplane with 100 low-lead aviation fuel before he arrived at Silver Wings Field Airport, Eureka Springs, Arkansas. The airplane fuel tank had about 13 gallons of fuel before the flight. The pilot stated that he did not identify any anomalies during his preflight inspection of the airplane and brief orientation of the cockpit. He reported that the engine started normally and that he observed no anomalies during two separate engine runups that he completed before takeoff. He noted that he verified full engine speed, checked proper operation of both magnetos, and cycled the carburetor heat control during both engine run-ups. The pilot noted that his intention was to takeoff from runway 34 and initially orbit the airport before continuing toward his destination. The pilot reported that he made an uneventful takeoff and the airplane climbed above the trees located at the end of the runway; however, shortly after clearing the trees, when the airplane was about 200 ft above ground level, the engine suddenly lost power. The pilot stated that the engine was partially running but was unable to produce enough thrust to sustain level flight. The pilot reported that he immediately decided to return to the airport because there was only heavily wooded terrain ahead of the airplane's position. The pilot stated that he rolled the airplane into a steep left turn, and about halfway through the 180° turn, the airplane entered an aerodynamic stall at a low altitude. The pilot reported that the airplane impacted terrain in a left-wing-down, nose-down attitude. An onsite examination of the airplane was completed by an airworthiness inspector with the Federal Aviation Administration (FAA). The FAA inspector reported that the forward fuselage, outboard left wing, and both wing struts sustained substantial damage during the accident. Flight control continuity was confirmed from the cockpit controls to the individual flight control surfaces. Fuel recovered from the fuel filter assembly and carburetor float bowl was blue in color, had the odor of 100 low-lead aviation fuel, and was not contaminated. The engine remained attached to the firewall through its mounts, but the carburetor had separated from the engine crankcase during impact. Internal engine and valve train continuity were confirmed as the engine crankshaft was rotated. Compression and suction were noted on all cylinders in conjunction with crankshaft rotation. The upper spark plugs were removed and exhibited features consistent with normalengine operation. Both magnetos produced spark as the engine crankshaft was rotated. The propeller remained attached to the engine crankshaft flange. Both propeller blades exhibited S-shape bends, blade twisting, leading-edge gouging, and chordwise burnishing. The postaccident examination of the airplane and engine did not reveal any evidence of mechanical malfunction that would have precluded normal operation. A review of available maintenance documentation revealed that the airplane had accumulated 0.75 hours since the last annual inspection that was completed on October 21, 2016. The pilot, who also held an aviation mechanic certificate with inspector authorization, did not apply for a ferry flight permit before the flight.

Aircraft

Registration
N9098C
Reported as
Aeronca 7BCM
Category
Airplane
Serial number
7BCM-372
Built
1947
Airframe hours
1,710.72
Engine
Continental C-85-12F, 85 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · October 21, 2016 · 0.75 hours before
Destination
PVT · Excelsior Springs, MO
Airport
55AR · Silver Wings Field Airport, runway 34, 1,900 × 65 ft, grass/turf
Equipment
None

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
75
Injuries
Serious
Certificate
Private
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
BasicMed
Last flight review
June 8, 2017
Seat
Front
Restraint
Lap only
Flight hours
2,000 total · 400 in this make and model · 10 in the last 90 days · 2 in the last 30 days · 0 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
230° at 11 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
88 °F, dew point 70 °F
Altimeter
30.05 inHg
Observed at
ROG, 20 nm away

Docket · 8

The files NTSB released with the investigation on March 10, 2021, on NTSB’s docket system: statements, records, photos and specialists’ reports. 4.2 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.