Engineering & Research 415-D N3940H

Summary

On 6 September 2013 at about 21:54 local time, a Engineering & Research 415-D registered N3940H, operated by Ferren Larry, was involved in an accident near Beaver Falls, Pennsylvania, United States. 2 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

6 September 2013 at 21:54

Classification

Accident

Location

Beaver Falls, Pennsylvania, United States

Nearest airport

Beaver County Airport (BVI)

Coordinates

40.7700, -80.3914

Aircraft

Engineering & Research 415-D

Registration

N3940H

Category

Airplane

Year built

1947

Engines

1

Operator

Ferren Larry

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Beaver Falls → Clarksburg

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA13LA406

Nobody was injured.

The owner/pilot’s failure to follow engine manufacturer recommendations for engine oil changes and spark plug cleaning and rotating when operating the airplane with 100 low lead fuel, which resulted in carbon buildup in the engine and the total loss of engine power due to the No. 3 cylinder exhaust valve being stuck open.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

According to the pilot, he departed for a flight to his home base airport, and, while the airplane was climbing through 200 ft above ground level, the engine began to run roughly. While he was attempting to turn back toward the airport, the engine experienced a total loss of power, and he subsequently made an emergency landing in a nearby field. No anomalies were noted with the carburetor or the induction, ignition, and fuel systems; 100 low lead fuel was found in the header tank. A postaccident examination of the engine revealed that the No. 3 cylinder exhaust valve was stuck in the "open" position and that the Nos. 2 and 4 cylinder spark plugs were carbon fouled. Although an engine manufacturer service bulletin (SB) stated that 100 low lead fuel was an acceptable alternative fuel, it also indicated that "the amount of tetraethyl lead in these higher grade fuels has increased the lead build up and fouling of spark plugs." The SB noted that, when this type of fuel is used, "exhaust valve sticking could result from lead salt accumulation in the lubricating oil," and it recommended that "regular 50 hour oil changes be implemented to reduce such accumulation." The SB also recommended that the spark plugs be rotated every 50 hours of operation and cleaned and rotated every 100 hours. A review of the engine maintenance logbooks revealed that the airplane's most recent annual inspection was completed about 60 hours before the accident. No record was found indicating that the oil was changed after the annual inspection. Based on the condition of the exhaust valve and the spark plugs and the maintenance records, it is likely that the pilot did not follow the SB-recommended procedures, which resulted in the engine carbon buildup and the exhaust valve being stuck open.

Quoted verbatim from the NTSB record.