NTSB Factual Report

On October 1, 2010, at 2100 central daylight time, a Maule MXT-7-180-A, N152HS, sustained substantial damage during a forced landing after a total loss of engine power near Magnolia, Arkansas. The private pilot and a passenger were not injured. The airplane was registered to and operated by Henderson State University (HSU), Arkadelphia, Arkansas. Night visual meteorological conditions prevailed and no flight plan was filed for the flight that departed Monroe Regional Airport (MLU), Monroe, Louisiana, approximately 2030, and destined for Texarkana Regional Airport (TXK), Texarkana, Arkansas. The cross country flight was conducted under 14 Code of Federal Regulations Part 91 as part of HSU's commercial pilot curriculum.

According to the pilot, he was at 2,500 feet about 15 miles south of Magnolia Municipal Airport (AGO), Magnolia, Arkansas, when he heard a knocking sound in the engine. He immediately proceeded toward AGO, declared an emergency, and noted that the oil pressure gage read "0" and the oil temperature gage was "high." When the airplane was about 5 miles south of the airport and at an altitude of 1,700 feet, the engine seized. The pilot noted a small clearing and landed on a private horse farm. He said there was no visible moon and it was very dark outside, which made it difficult to see the terrain and he subsequently collided with corral fencing before coming to a full stop.

A Federal Aviation Administration (FAA) inspector performed an on-scene examination of the airplane, which revealed that the nosegear of the airplane collapsed and was pushed aft and the top of the fuselage center section was damaged. The firewall, left horizontal stabilizer and elevator sustained substantial damage. A large amount of oil was noted on the under side of the engine and belly of the airplane.

Examination of the engine revealed there was a large hole in the top of the crankcase and the oil drain line for the #4 cylinder was not connected. A review of the engine logbook revealed that the #2 cylinder had been removed on the day of the accident, which would have required the #4 cylinder oil drain line to be disconnected. When the cylinder was placed back on the engine, the oil drain line should have been reconnected and properly torqued per the manufacturer's maintenance manual.

In a written statement, the mechanic that replaced the #2 cylinder said that after he replaced the cylinder he performed an engine run and checked for leaks. No leaks were observed. The mechanic placed the cowling back on the engine, completed the 100-hour inspection paperwork and returned the airplane back to service. He stated that all work was performed in accordance with the Maule inspection guide, Lycoming direct drive overhaul manual, and a 4,313-lb torque wrench.

The pilot held a private pilot certificate for airplane single-engine land. His last Federal Aviation Administration (FAA) first class medical was issued on August 20, 2007. The pilot reported a total of 128 hours, of which, 34 hours were in the Maule.

NTSB Probable Cause

The mechanic's failure to properly install an oil drain line after he replaced a cylinder, which caused the engine to seize in flight due to a lack of lubrication.