Aviation Accident Summaries

Aviation Accident Summary LAX04LA038

Saticoy, CA, USA

Aircraft #1

N102RC

Cathaway RV-6A

Analysis

The airplane traversed through a small stream, collided with a berm, and nosed over during a forced landing in a dry riverbed following a loss of engine power. Witnesses heard the airplane flying overhead before the crash and reported that the engine was sputtering. No fuel was found in the airplane's fuel tanks during recovery of the airplane from the accident site. During the engine examination, a B-nut for the carburetor fuel inlet line was discovered loose at its attach point. Fuel staining was evident on the fuel line fitting, the fuel line itself, and the airbox situated directly below the fuel line. An internal examination of the engine was conducted, with no obvious mechanical anomalies found. The B-nut was indexed so that it's position could be re established, then it was tightened to facilitate an engine ground run. The engine started and ran normally, both with and without the electric fuel pump, during the ground run. The B-nut was loosened to its original position. The electric boost pump was activated, with copious amount of fuel leaking out of the loose fuel line fitting.

Factual Information

HISTORY OF FLIGHT On November 7, 2003, about 1515 Pacific standard time, an experimental Cathaway RV-6A, N102RC, came to rest inverted after attempting to land in a sandy riverbed near Saticoy, California. The pilot/owner/builder operated the airplane under the provisions of 14 CFR Part 91. The airplane was destroyed. The pilot, the sole occupant, sustained fatal injuries. Visual meteorological conditions prevailed for the local area flight that departed the Santa Paula Airport (SZP), Santa Paula, California, about 1500. No flight plan had been filed. According to a witness at the Santa Clarita Regional Golf Course, a red and white airplane flew overhead around 1515. He said that it appeared to be going into Santa Paula. He said the engine was sputtering, and he watched for a while until it dropped below his horizon. He said about a 1/2 hour later there were helicopters flying around the area where he last saw the airplane. Other than the engine sputtering, the witness indicated that the airplane appeared to be under control. Another witness called the Ventura County Medical Examiner's office and reported seeing the airplane prior to the accident flying over the riverbed, and that the engine was "cutting in and out." PERSONNEL INFORMATION A review of Federal Aviation Administration (FAA) airman records revealed the pilot held a commercial pilot certificate with an airplane single engine land rating. The pilot also held a repairman experimental aircraft builder certificate. It contained the limitation: Inspection certificate for experimental aircraft make Cathaway Russ G, Model RV- 6A, serial number 1. The pilot held a third-class medical certificate issued on June 10, 2003. It had no limitations or waivers. An examination of the pilot's latest logbook indicated an estimated total flight time of 851 hours. He logged 3 hours in the last 90 days, and 1 hour in the last 30 days. The pilot's logbook indicated that from April 11, 2002, until October 20, 2003, he logged 31.5 hours in accident make and model. AIRCRAFT INFORMATION The airplane was an experimental single engine Cathaway RV-6A, serial number 1. A review of the airplane's logbooks revealed a total airframe time of 95.6 hours at the last annual inspection. An annual inspection was completed on April 22, 2003. An entry in the Aircraft logbook dated October 20, 2003, recorded a total airframe time of 100.5 hours. During the inspection of the accident airplane, investigators noted that the Hobbs hour meter read 101.2, and the tachometer read 83.07. A Textron Lycoming O-360-A1A engine, serial number L-33643-36A, was installed on the airplane. WRECKAGE AND IMPACT INFORMATION The airplane came to rest in a sandy area of the Santa Clara River, east of Saticoy Bridge on Highway 118, on a westerly heading. Witness marks on the ground, similar in distance to the airplane's landing gear, were observed in the sand. The marks traversed in an easterly direction, traveling across a small stream, and up an embankment to a berm. The inverted airplane was on the other side of the berm at Global Positioning System (GPS) coordinates of 34 degrees 16.96 minutes north and 119 degrees 09.02 west. MEDICAL AND PATHOLOGICAL INFORMATION The Ventura County Medical Examiner, Ventura, California, conducted an autopsy on the pilot on November 8, 2003. The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed a toxicological analysis from samples obtained during the autopsy. The results of the analysis of the specimens were negative for carbon monoxide, cyanide, volatiles, and tested drugs. TESTS AND RESEARCH Recovery personnel from Ray's Aviation, Santa Paula, California, indicated that there was no fuel recovered from the airplane. The National Transportation Safety Board investigator-in-charge (IIC), an FAA inspector, and a manufacturer's representative from Textron Lycoming, a party to the investigation, examined the wreckage at Ray's Aviation on December 5, 2003. A visual examination of the airframe revealed no obvious mechanical malfunctions. The propeller was a 2-bladed fixed pitch wooden propeller manufactured by Pacesetter; model 200. The propeller remained attached at the crankshaft flange, and the spinner remained attached to the propeller. One propeller blade had no damage to it. The other propeller blade sustained a fracture along the trailing edge that was about 7 inches in length. The fracture was repaired utilizing an adhesive to facilitate an engine ground run. A visual examination of the engine revealed that the fuel inlet line to the carburetor had been leaking, which was further evidenced by fuel staining of the fitting, and of the fiberglass airbox directly underneath the fuel inlet line. Investigators indexed the B-nut with an ink pen, and noted that the fitting could be hand tightened 1 1/4 turns (clockwise), and additionally wrench tightened a 1/2 turn. The remaining engine fuel lines were in place and secure at their respective fittings. There were no other obvious mechanical malfunctions noted with the engine. The engine manufacturer removed the spark plugs. The electrodes were mechanically undamaged and displayed coloration consistent with normal operation when compared to the Champion Aviation Check-A-Plug chart AV-27. The cylinders were borescoped and examined with no mechanical deformation on the valves, cylinder walls, or internal cylinder head noted. Thumb compression was obtained in firing order during manual rotation of the crankshaft establishing mechanical continuity throughout the rotating/reciprocating group and accessory section. Investigators noted that the magneto's remained attached to their respective mounting pads on the engine. The manufacturer's representative established that the magneto to engine timing was within the manufacturer's specification; Left magneto - 26 degrees before top dead center, right magneto - 25 degrees before top dead center. Investigators reinstalled the spark plugs, and attached their respective leads to conduct an engine ground run. Prior to starting the engine, investigators tightened the carburetor fuel inlet line, and activated the fuel boost pump. Investigators noted that the fuel pressure indication fell within the normal operating range. Investigators started the engine, and noted the oil pressure indication was within the normal operating range. Once the engine stabilized, above idle, the electric fuel boost pump was deactivated. The engine continued to run smoothly with no anomalies noted, and a normal fuel pressure indication was noted on the fuel pressure gauge inside the cockpit. After a warm-up period established the engine at a normal operating temperature, the throttle was advanced to 1,600 revolutions per minute (rpm). A magneto check was conducted with a drop noted to be within the manufacturer's specifications; 75 rpm drop recorded for both the left and right magneto. After completion of the engine ground run, and shutdown, investigators placed the carburetor fuel inlet line B-nut attachment back to its original position, and activated the electric fuel boost pump. Investigators noted copious amounts of fuel leaking from the fuel line.

Probable Cause and Findings

A loss of engine power due to fuel exhaustion as a result of a loose B-nut fitting for the carburetor fuel inlet line, which allowed fuel to leak out.

 

Source: NTSB Aviation Accident Database

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