Aviation Accident Summaries

Aviation Accident Summary CHI00LA034

HOULTON, WI, USA

Aircraft #1

N2005J

Taylorcraft F-21

Analysis

The pilot reported, 'The engine developed a bad noise and vibration so I turned it off and looked for a place to land.' He landed in a farm field and the landing gear collapsed during rollout. The inspection of the engine revealed the #1 connecting rod was detached from the crankshaft and the connecting rod cap was missing. One rod cap bolt was intact although bent, and no nut was found on the bolt. The other rod cap bolt was broken with the nut portion missing. The #1 cylinder crankshaft journal was inspected. No discoloring, significant scoring, or other damage was noted. The rod bolts and nuts for cylinders 2, 3, and 4 were inspected for proper installation and torque. All nuts appeared to be properly installed. The nuts were torque checked at 40 lbs. No nuts moved at this torque setting. The overhauled engine had been installed on the airplane on July 15, 1998. The airplane had been flown approximately 50 hours since the major overhaul.

Factual Information

On December 1, 1999, at 1105 central standard time, a Taylorcraft F-21, N2005J, was substantially damaged during an emergency landing in a farm field near Houlton, Wisconsin, after the airplane experienced a loss of engine power. The 14 CFR Part 91 personal flight departed Lake Elmo (21D), Minnesota, at 1040, on a local flight. The private pilot was not injured. Visual meteorological conditions prevailed and no flight plan was filed. The pilot reported he was returning to land at Lake Elmo. He reported, "The engine developed a bad noise and vibration so I turned it off and looked for a place to land. I was in farm country. Some smoke came into the cabin. I picked a clear field and landed wings level at stall speeds. The field was very rough. The wheels folded up and I slid 60 feet. Got out of the airplane after turning off the master." An Airworthiness Inspector from the Federal Aviation Administration inspected the airplane. He reported the inspection of the engine revealed that the case was broken in the area of the number #1 cylinder. He reported, "The #1 connecting rod was detached from the crankshaft and the connecting rod cap was missing. One rod cap bolt was intact although bent, [and] no nut was found on the bolt. The other rod cap bolt was broken with the nut portion missing. The #1 cylinder crankshaft journal was inspected. No discoloring was noted. No significant scoring or other damage was noted." The inspector reported, "The rod bolts and nuts for cylinders 2, 3, and 4 were inspected for proper installation and torque. All nuts appeared to be properly installed. The nuts were torque checked at 40 lbs. No nuts moved at this torque setting." The overhauled engine had been installed on the airplane on July 15, 1998. The airplane had been flown approximately 50 hours since the major overhaul. The airplane received an annual inspection on July 7, 1999. It had flown approximately 9 hours since the annual inspection.

Probable Cause and Findings

the mechanic failed to torque the rod cap bolt during the major engine overhaul. Factors relating to the accident included the rough field and the collapsed landing gear.

 

Source: NTSB Aviation Accident Database

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