Engineering & Research 415-D accident near Beaver Falls, Pennsylvania, September 6, 2013
On September 6, 2013 at about 9:54 pm local time, a 1947 Engineering & Research 415-D, registered N3940H, was substantially damaged in an accident during initial climb near Beaver Falls, Pennsylvania (Beaver County Airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
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.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 6, 2013 · about 9:54 pm local time
- Place
- Beaver Falls, Pennsylvania · Beaver County Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Engineering & Research 415-D, built 1947 · all 415-Ds on the register
- Registration
- N3940H · registry record · serial 4641
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Aircraft maintenance event during prior to flight
- Loss of engine power (total) during initial climb defining event
- Off-field or emergency landing during emergency descent
- Collision with terrain or object (not controlled flight into terrain) during landing (flare/touchdown)
The NTSB's findings
- cause Personnel issues › Task performance › Maintenance › Scheduled/routine maintenance › Pilot
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Damaged/degraded
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Malfunction
Pilot
- Certificate: airline transport pilot
- Ratings: single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 31,603 hours in all; 31,603 in this make and model
- Last flight review: October 10, 2012
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 2,219 hours
- Last inspection: annual inspection, October 2, 2012; 60 hours since
- Maximum gross weight: 1,260 lb
- Seats: 2
- Landing gear: fixed
- Engine: Cont Motor A&C75 SERIES (piston); 0 hours total
The flight
- Departed from: BVI Beaver Falls PA at 9:54 pm
- Destination: CKB Clarksburg WV
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 72°F (22°C), dew point 37°F (3°C)
- Altimeter: 30.18 inHg
- Observation at 9:47 pm from BVI
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number ERA13LA406.