CEN18LA199

NTSB accident investigation · Aeronca 58B · Tekamah, NE · May 28, 2018

Accident · Serious injuriesLimited investigationFinal report
Date
May 28, 2018, 09:30 local (14:30 UTC)
Place
Tekamah, NE
Injuries
2 serious
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N47252Aeronca 58B
Defining event
Enroute-cruise: Loss of engine power (partial)
Weather
Visual (VMC) · Day
Status
Completed · report December 16, 2019
Report
Approved by Office Director
NTSB office
Central Region
Parties
FAA Lincoln FSDO
FAA report
20180528006399A
Case key
97343

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 partial loss of engine power due to the formation of carburetor ice. Contributing to the accident was the pilot's failure to use carburetor heat and his decision to continue flight with reduced engine power rather than landing the airplane on suitable terrain.

Findings · 5

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.

Temp/humidity/pressure: conducive to carburetor icingEnvironmental issues › Conditions/weather/phenomena · Effect on operationAeronca 0-58B: 1 caseAll aircraft: 435 casesProbable cause
Engine fuel and control: fuel control/carburetorAircraft › Aircraft power plant · Incorrect use/operationAeronca 0-58B: 1 caseAll aircraft: 195 casesProbable cause
Use of equip/info: use of equip/systemPersonnel issues › Task performance · PilotAeronca 0-58B: 1 caseAll aircraft: 1,391 casesProbable cause
Terrain: rough terrainEnvironmental issues › Physical environment · Contributed to outcomeAeronca 0-58B: 1 caseAll aircraft: 442 cases

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 private pilot reported that, about 30 minutes after departing for a personal, local flight, he was conducting a tribute over a cemetery and noticed that the engine was not running properly, so he proceeded to fly toward an airport located about 8 nautical miles (nm) to the east. While en route to the airport, the engine stopped developing full power and had a maximum rpm of about 1,500. The airplane descended, and during the forced landing, it impacted a ditch about 3 nm from the airport, which resulted in substantial damage to the airplane. The pilot stated that he should have landed the airplane in a flat field when the opportunity was possible, instead he "kept flying into a situation where there were no options." Postaccident examination of the airframe and engine revealed no evidence of any preaccident mechanical malfunctions or failures that would have precluded normal operation. At the time of the loss of engine power, the airplane was operating in conditions conducive to carburetor icing at glide power. The pilot reported that he was not using carburetor heat. It is likely that, during the tribute, the pilot reduced engine power, resulting in a buildup in carburetor ice, which restricted the air and fuel flow and caused the reduced engine power. When the reduced engine power condition occurred, the pilot should have identified an appropriate forced landing site; however, he chose to continue to fly the airplane to an airport located about 8 nm away. When the engine lost total power, he had to make a forced landing on unsuitable terrain.

Factual narrative

On May 28, 2018, about 0930 central daylight time, an Aeronca 58B, N47252, impacted terrain during a forced landing near Tekamah, Nebraska. The pilot and passenger received serious injuries; and the airplane sustained substantial damage. The airplane was owned and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed at the time of the flight, which was not on a flight plan. The airplane departed about 0845 from Tekamah Municipal Airport (TQE), Tekamah, Nebraska, on a local flight. The pilot reported that he departed from his private airstrip located at his residence about 0700 and flew to TQE to pick up the passenger. While at TQE, he topped off the fuel and attached two American flags, which were about 3 ft X 5 ft in size, to the airplane's struts. He attached the flags because the flight was a "tribute flight" over two memorial services being held in the local area. The flight departed TQE about 0750 and proceeded to fly over Tekamah Cemetery, and then flew over to Summit Lake and circled it twice. They overflew some neighbors' homes and then went to the pilot's airstrip and landed around 0810. About 0830, he departed to fly over the Craig Cemetery at 0900, and he noted that the engine was running fine. However, while flying over Craig Cemetery, the pilot noticed the engine was not running properly, so he headed toward TQE, located about 8 nautical miles (nm) east, to drop off the passenger. He stated that the engine was getting worse en route to TQE and not developing full power, with maximum rpm around 1,500 rpm. Although the engine was not developing full power, he continued to fly to TQE, hoping he could make it to the airport. The airplane continued to descend, and it impacted a ditch located 3 nm from TQE during the forced landing. The pilot stated that he should have landed in a flat field when the opportunity was possible, instead he "kept flying into a situation where there were no options." A Federal Aviation Administration (FAA) inspector examined the wreckage at the accident site. He stated that there were flat bean fields located near the accident site, but the wreckage was found in a ditch. There were no apparent landing or skid marks leading to the ditch. The examination of the wreckage revealed that the wooden propeller blade tips were broken. The propeller spinner exhibited features consistent with torque. He was able to rotate the engine crankshaft one revolution. The carburetor was separated from the mount but was held on by the throttle cable. The flight controls exhibited continuity from the cockpit to the flight control surfaces. Fuel was present in the fuel tanks. The FAA inspector reported that he interviewed the pilot. During the interview, the pilot did not recall pulling carburetor heat ON. The pilot stated that he did not have a problem with carburetor icing before. The examination of the engine confirmeddrivetrain continuity when the engine was rotated. Thumb compression was observed on all four cylinders, although the compression on cylinders No. 1 and 2 appeared "weak." All magneto leads checked good and the engine timing was verified at 30° before top dead center (TDC). All spark plugs produced an electrical spark, although the spark plug gaps for No. 1B, 3T, 4B, and 4T were greater than .016 to 0.21 inch specified. The carburetor floats were checked for freedom of movement. The inspection of the throttle plate and throttle arm revealed no defects. At 0854, the surface weather observation at TQE was wind 260° at 3 kts; 10 miles visibility; few clouds at 8,500 ft; temperature 26° C; dew point 18° C; altimeter 29.92 inches of mercury. Based on the temperature and dew point about the time of the accident, the conditions were favorable for serious carburetor icing at glide power.

Aircraft

Registration
N47252
Reported as
Aeronca 58B
Category
Airplane
Serial number
058B-9843
Built
1944
Airframe hours
2,668
Engine
Continental O-170-3, 65 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · March 10, 2018
Departed
TQE · Tekamah, NE
Destination
TQE · Tekamah, NE
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
62
Injuries
Serious
Certificate
Private
Airplane ratings
Single-engine land
Medical
Class 3, With waivers/limitations
Last flight review
September 16, 2016
Seat
Rear
Restraint
Lap only
Flight hours
912.2 total · 153.6 in this make and model · 852.2 as pilot in command · 5.5 in the last 90 days · 1.7 in the last 30 days · 1.1 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
260° at 3 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
79 °F, dew point 64 °F
Altimeter
29.92 inHg
Observed at
TQE, 3 nm away

Docket · 7

The files NTSB released with the investigation on September 19, 2019, on NTSB’s docket system: statements, records, photos and specialists’ reports. 4.9 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.