HARVIELL, MO, USA
N48484
Schweizer G-164B
THE PILOT REPORTED THAT DURING THE TAKEOFF ROLL ON THE 35TH AND LAST FLIGHT OF THE DAY, RPM ON THE TURBOPROP ENGINE WAS OBSERVED IN THE LOW GOVERNING RANGE, INCAPABLE OF TAKEOFF THRUST. HE SELECTED REVERSE THRUST WITH NO RESULT, AND INTENTIONALLY GROUND LOOPED THE AIRPLANE TO AVOID IMPACT WITH OBSTRUCTIONS. THE PILOT REPORTED THE OIL SUPPLY LINE TO THE PROPELLER GOVERNOR HAD BECOME DISCONNECTED. DISASSEMBLY AND TESTING OF THE ENGINE, FUEL CONTROL AND GOVERNOR FAILED TO REVEAL ANY OTHER DISCREPANCIES.
HISTORY OF FLIGHT On July 18, 1994 at 1820 central daylight time, a Grumman G-164B, N48484, operated as an agricultural application airplane by RH and RH, Inc., of Malden, Missouri, sustained a loss of power during takeoff. This was the 35th and last flight of the day. The pilot stated that during his takeoff roll, with throttle and condition lever in the full forward position, a lack of acceleration occurred, and the percentage gauge read 96% (incapable of takeoff power). He placed the throttle in the reverse thrust position to abort the takeoff, with no result. He stated he intentionally ground looped the airplane to avoid impact with trees and a ditch at the end of the runway. Visual meteorological conditions existed at the time of the accident and no flight plan was filed. The flight operated under 14 CFR Part 137, and was originating from a private farm strip near Harviell, Missouri. The pilot reported that he found the oil line to the high speed governor loose. PERSONNEL INFORMATION The airline transport rated pilot reported having accumulated approximately 40,000 hours of total flight time, and estimated 20,000 in this make and model airplane. He was 70 years of age at the time of the accident and held a current Class 2 medical certificate with the limitation of "must wear corrective lenses." AIRCRAFT INFORMATION The airplane was a Schweitzer/Grumman G-164B, serial number 43B, with a Garrett TPE 331-1-151A turboprop powerplant, serial number P-92136, rated at 665 shaft horsepower. This installation includes a full feathering, reverse thrust (BETA) propeller. The last 100 hour inspection was performed on May 1, 1994. The last annual inspection was performed 214 hours prior to the accident. AERODROME INFORMATION The grass agricultural airstrip from which the airplane was departing was approximately 2500 feet long, 40 feet wide, and the runway was oriented north and south. There were trees and a ditch at the departure end of the runway. WRECKAGE AND IMPACT INFORMATION The FAA Investigator in Charge arrived on scene 22 hours after the accident. The scene had not been secured prior to his arrival. There were many footprints and tire tracks in the vicinity of the aircraft upon his arrival. The airplane came to rest approximately 2000 feet from the point of initiation of the takeoff roll, 60 feet off the west side of runway 18, on an approximate heading of 270 degrees magnetic. The left main wheel was located 30 feet to the south of the airplane, on the west side of the runway. The right lower wing and spar was broken in an upward direction at the wing root. The left lower wing was broken at the root and came to rest deformed upward. The inboard wing struts on both sides were broken in a lateral direction. The tail wheel remained attached, and was oriented at 90 degrees to the fuselage. The chemical hopper and spray equipment were crushed upwards, and the chemical nitrogen fertilizer was spilled. The engine remained attached to the engine mounts. All 3 propeller blades were at a feathered (90 degree) position. All 3 exhibited uniform bending opposite the direction of normal rotation. The propeller pitch control linkages and dome exhibited metal fractures and deformation opposite the direction of normal rotation. The engine did not exhibit external damage. The exhaust did not exhibit signs of turbine blade failure or any marks on the internal surfaces. The propeller pitch control lever pointer was indexed at 21 degrees. The fuel line to the fuel control was removed, and fuel was present in the fuel supply line. The main fuel tank was ruptured, and no fuel remained within that tank. Engine controls and linkages were intact, secure and appeared normal according to the FAA IIC. Fuel control indexing appeared normal, according to the FAA IIC. Flight controls and linkages were continuous and free to move. SURVIVAL ASPECTS The aircraft was equipped with a seat belt and shoulder harness. Livable volume was maintained within the cockpit. Injuries to the pilot were a single head laceration. The pilot was able to egress the airplane unassisted. TESTS AND RESEARCH CONDUCTED The engine (serial number P92136) was disassembled on August 16, 1994, at Intercontinental Jet, Inc., in Tulsa, Oklahoma, and witnessed by Mr. C. E. Wilcox of the FAA Flight Standards District Office (SW-FSDO-15). No mechanical anomalies were discovered. The small amount of fuel remaining in the fuel filter housing was light brown in color. The quantity was insufficient for analysis. His statement is attached. The engine fuel control (serial number 858992) was then sent to the Woodward Governor Company and underwent an "As Received" functional test. No malfunctions which would have caused a power loss were observed. Some fuel leakage was observed during the test (5-10 drops per minute), and the flight idle fuel flow was within specification. The acceleration and max power fuel flows were approximately 2% below specification. The cause of this was not determined as the components were tested but not disassembled. Woodward Governor Company stated that "the lean shift in the acceleration and power lever schedules could have caused a fuel limited condition, but could not have caused the propeller to go to feather."
the separation of the oil supply line to the propeller governor, which resulted in the propeller inadvertently going into feather. Factors were the pilots intentional ground loop of the airplane to avoid impacting obstructions at the end of the runway.
Source: NTSB Aviation Accident Database
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