FTW98LA053

The airplane was at 2,000 feet MSL on an IFR radar vector for the approach when the engine rpm surged, the oil pressure decreased, the electronic engine monitor indicated an over temperature condition on the #4 cylinder, and the engine started running rough and vibrating. The pilot shut down the engine, and declared an emergency, as the airplane descended into VFR conditions at 500 feet MSL. A forced landing was executed to a road with transmission lines and trees. During the landing flare and touchdown, the left wing of the airplane struck trees. This was the first flight following the annual inspection. The lower area of the fuselage was covered with oil and examination revealed that a 'line and B-nut at the turbocharger wastegate were loose.' The #4 cylinder was seized and the #4 rod bearing journal was damaged. On Nov. 8, 1996, the turbocharger had been overhauled and reinstalled. During the last annual inspection on Nov. 19, 1997, the mechanic had welded a patch on the turbocharger outlet elbow. An engine teardown revealed physical evidence of oil starvation.

On November 19, 1997, at 1440 central standard time, a Cessna 177RG single engine airplane, N88WC, impacted trees and terrain following a loss of engine power near Tomball, Texas. The aircraft was owned and operated by the instrument rated private pilot under Title 14 CFR Part 91. The private pilot, the sole occupant, received minor injuries and the airplane sustained substantial damage. Instrument meteorological conditions prevailed and the personal flight was operating on an IFR clearance. The flight departed Houston Gulf Airport, Houston, Texas, at 1410.

During personal interviews, conducted by the investigator-in-charge (IIC), and on the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the pilot reported that he received a weather briefing and filed an IFR flight plan for 4,000 feet MSL for a direct flight from the Houston Gulf Airport to the David Wayne Hooks Airport. The airplane was at 2,000 feet MSL on an IFR radar vector for the approach at the David Wayne Hooks Airport when the engine rpm's surged to 3,000 rpm and then returned to 2,000 rpm, the oil pressure decreased to 70 pounds, the electronic engine monitor indicated an over temperature condition on the #4 cylinder, and the engine started running rough and vibrating. The pilot shut down the engine and declared an emergency. The airplane descended into VFR conditions at 500 feet MSL. When the airplane was at 300 feet MSL the pilot observed a road for the forced landing; however, power lines and trees were in the approach path to the road. The airplane missed the power lines; however, during the landing flare the left wing of the airplane struck trees. This was the first flight following the annual inspection.

The FAA inspectors examined the airplane and found structural damage to the wings, fuselage, firewall, and stabilator. The lower area of the fuselage was covered with oil. Further examination by the FAA inspector revealed that a "line and B-nut at the turbocharger wastegate were loose." The #4 cylinder was seized and the #4 rod bearing journal was damaged.

A review of the maintenance records by the IIC revealed that the airplane was originally manufactured in 1974. A November 8, 1996, inspection stated that the mechanic had "removed the turb[ocharger] PN 465292-9001 SER PKR0113 and had unit overhauled by main turbo systems w[or]k order 16088, reinstalled, safetied v clamp, and torqued to specs." At the last annual inspection (tachometer reading 3,711.3 hours) on November 19, 1997, an aircraft maintenance entry stated that the mechanic had "welded patch on turbocharger outlet elbow."

An engine teardown conducted by the engine manufacturer representative at Williamsport, Pennsylvania, on May 6, 1998, under the surveillance of the FAA inspector, revealed physical evidence of oil starvation. The engine oil screen was contaminated with metal debris which "appears to be connecting rod bearing" and extruded bearing material was found in the oil sump. The damage to the #4 connecting rod bearing was "consistent with damage associated with the loss of engine oil lubrication."