Ercoupe 415 N99716

Summary

On 19 February 2017 at about 17:15 local time, a Ercoupe 415 registered N99716 was involved in an accident near Dawsonville, Georgia, United States. One person was on board and one had minor injuries. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

19 February 2017 at 17:15

Classification

Accident

Location

Dawsonville, Georgia, United States

Coordinates

34.3383, -84.0919

Aircraft

Ercoupe 415

Registration

N99716

Category

Airplane

Year built

1946

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Jefferson → Lafayette

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA17LA109

1 person had minor injuries.

A decrease in oil pressure due to the pilot's unintentional overfilling of the engine oil sump, and the pilot's subsequent decision to perform an off-airport precautionary landing, which resulted in impact with a tree.

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

Read the full NTSB narrative

The private pilot recently purchased the airplane and was returning it to his home airport. Before the flight, he added 1/2 quart of oil to the engine, bringing the oil level to between 3 1/2 and 4 quarts. About 30 minutes after departure, the pilot noticed that the oil pressure was dropping. He reduced engine power and turned the airplane toward the closest airport. The oil pressure continued to decrease, even though the engine continued to produce power, and the pilot chose to perform a precautionary landing on a road. Upon touchdown, the airplane skidded across the road until it impacted a tree and came to rest in a ditch. Examination of the engine revealed a hole in the oil sump consistent with impact damage, and oil was noted coming from the crankcase breather tube. In addition, oil was noted on the bottom of the airplane from the nose to the empennage. Even after the oil leaked from the broken oil sump and from the breather tube, the postaccident engine oil level was 3 1/2 quarts. A subsequent engine run demonstrated that the engine would experience a momentary drop in oil pressure indication if the oil sump was overfilled. The engine and the oil pressure gauge otherwise operated normally. Since the pilot lacked operational experience with the airplane, it is likely that he unintentionally overfilled the oil sump, which resulted in an interaction between the oil in the sump and the rotating crankshaft. The interaction likely resulted in air bubbles becoming entrained in the oil and a subsequent oil pressure fluctuation. Additionally, since he checked the oil level following a previous flight, it was likely that the oil had not fully drained back into the sump when the reading was taken. Considering that the oil pressure gauge operated normally after the accident, it is unlikely that the gauge was producing a faulty reading in flight.

Quoted verbatim from the NTSB record.