Cessna 195A N9859A

Summary

On 18 May 2012 at about 20:20 local time, a Cessna 195A registered N9859A was involved in an accident near Tipton, Pennsylvania, United States. One person was 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

18 May 2012 at 20:20

Classification

Accident

Location

Tipton, Pennsylvania, United States

Coordinates

40.6306, -78.3003

Aircraft

Cessna 195A

Registration

N9859A

Category

Airplane

Year built

1950

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

Old Bridge → Zelienople

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA12LA343

Nobody was injured.

A fatigue failure of a copper oil line, which resulted in a partial loss of engine power due to oil starvation.

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

Read the full NTSB narrative

The pilot stated that, during cruise flight, he noticed that the engine rpm began fluctuating and that, about 20 seconds later, the rpm dropped. The pilot immediately looked at the oil pressure gauge and observed that it was "reading zero." He then declared an emergency with air traffic control, and a controller informed him that the nearest airport was 15 miles south of his location. He brought the engine back to idle to keep it from seizing in case power would be needed later to avoid terrain, which was primarily mountain ridges with hills and narrow valleys, and set the propeller to low rpm. The pilot realized that he could not make it to the nearest airport and chose to land on a road in an industrial park. The landing was uneventful, but, during the landing roll, the airplane was substantially damaged when the left wing struck a standpipe and the airplane subsequently nosed over. Examination of the engine revealed that a 1/2-inch metal oil line had fractured at the rocker's scavenge oil tube adjacent to the coupling sleeve and nut. Further examination revealed that the metal oil line had failed in fatigue in the manufactured bend adjacent to the coupling sleeve, that it was at least 34 years old, and that it had probably been reused many times. The oil tube assembly also displayed a distinctive bend and compression at the bead end and a slight bend at the nut end that were not specified on the manufacturer's drawings and were consistent with the oil tube assembly being significantly bent to fit on the engine. The manufactured bends also displayed oval cross-sections not specified in the drawings. The oval cross-sections may have been produced by the original manufacturing process but were likely produced by bending at each reuse, which would have initiated bending fatigue. Cracks propagating from the fracture face at the centerline of the tube were also present. Hardness testing revealed that the tubing at the fractured bend was harder than a sample of tubing that had not been subjected to any bending and that it exceeded the specified maximum hardness. This testing indicated that the increased hardness of the tubing in the bend had been produced by the original manufacturing process and/or by subsequent work hardening (that is, the undesirable strengthening of a metal such as copper by plastic deformation).

Quoted verbatim from the NTSB record.