Aviation Accident Summaries

Aviation Accident Summary ATL99LA087

BRUCE, MS, USA

Aircraft #1

N1994J

Cessna T188C

Analysis

The pilot finished spraying a field, pulled up and turned the spray pump off, when the engine lost oil pressure and the pilot heard a loud noise. Smoke came out of the cowling and the engine lost power approximately 50 feet above the ground. The pilot elected to perform a forced landing to a cotton field. During the landing roll, the airplane traveled through some small trees and brush, and came to a stop across a ditch. Examination of the engine revealed that the engine experienced lubrication distress to the number 2 connecting rod bearing and journal. The number 2 connecting rod was supplied oil from the number 2 main bearing. The number 2 main bearing was shifted in the crankcase bearing saddle, which restricted the oil feed to the number 2 connecting rod. As a result, the number 2 connecting rod failed.

Factual Information

On May 14, 1999, at 1100 central daylight time, a Cessna T188C, N1994J, collided with the ground during an emergency landing in Bruce, Mississippi. The airplane was operated by the commercial pilot under the provisions of Title 14 CFR Part 137, and visual flight rules. Visual meteorological conditions prevailed at the time of the accident and no flight plan was filed for the local agricultural application flight. The pilot was not injured and the airplane sustained substantial damage. The flight departed Bruce, Mississippi, at 0900. According to the pilot, he had just finished spraying a field. As he pulled up out of the field and turned the spray pump off, the airplane lost oil pressure and the pilot heard a loud noise. Smoke came out of the cowling and the engine lost power approximately 50 feet above the ground. He engaged the fuel boost pump at that point, but was unable to regain power. The pilot elected to land in a nearby cotton field. The pilot stated that he did not have enough room to stop and the airplane subsequently traveled through some small trees and brush and came to a stop across a ditch in another cotton field. According to the FAA, the pilot stated that he had to keep decreasing the propeller pitch to keep the RPM up during the agricultural application. The FAA noted that the propeller could only be turned 180 degrees in either direction by hand during field examination of the accident. A pool of oil underneath the airplane was also noted by the FAA. Inspection of the engine revealed an outward protruding cracked area the size of a dime near the number three cylinder, and a hole, approximately two inches in diameter in the top of the crank case adjacent to the number 2 cylinder. The FAA stated that while looking through the hole in the crank case, it was noticed that the connecting rod was not connected to the crank shaft and the area where the connecting rod connects to the crankshaft was dry. Teardown and examination of the engine by Teledyne Continental Motors in Mobile, Alabama, and observed by the NTSB revealed that the engine experienced lubrication distress to the number 2 connecting rod bearing and journal. The number 2 connecting rod is supplied oil from the number 2 main bearing. The number 2 main bearing was shifted in the crankcase bearing saddle, which restricted or obscured the oil feed to the number 2 connecting rod. As a result, the number 2 connecting rod failed, which resulted in its disconnection from the crankshaft journal. The engine interior was damaged as a result of the number 2 connecting rod failure.

Probable Cause and Findings

The loss of lubrication to the number 2 connecting rod due to the shifted bearing that resulted in the total loss of engine power.

 

Source: NTSB Aviation Accident Database

Get all the details on your iPhone or iPad with:

Aviation Accidents App

In-Depth Access to Aviation Accident Reports