Findlay, OH, USA
N333SV
Sadler Vampire
The airplane was an experimental amateur-built airplane that was a prototype for light sport aircraft certification. The flight test was conducted by the engine manufacturer, who also provided a pilot to fly the airplane. The pilot had not received flight instruction or a checkout in the airplane. The pilot learned to fly the airplane on his own by taxiing and performing local flights in the airport area. The pilot also had no training or experience in aircraft flight test. A larger radiator had been installed onto the airplane due to noted high engine temperature during previous flights. Prior to the accident flight, the pilot performed two taxi tests during which he performed short hops on the runway to get familiar with the aerodynamic forces that would be encountered during takeoff and landing. The engine temperature was reported as normal during this time. The pilot then attempted a takeoff for a flight that was to remain in the airport traffic pattern. Just after takeoff the airplane lost total engine power. The pilot attempted an engine restart without success, during which he did not hear the engine turn over. The pilot then executed a forced landing into a quarry located about 0.6 miles from the departure end of the runway. An examination of the reduction drive assembly needle roller bearing sidewall revealed a combination of wear and high temperatures leading to overstress. Circumferential wear marks on the separated cage sidewall and the presence of metallic debris suggested impingement of the rollers on the sidewall during engine operation. Heat tinting of the outer raceway in the vicinity of the failed sidewall and the cam that served as the inner raceway was also noted. The needle bearing malfunction could be attributed to misalignment of the needle bearing and insufficient lubrication.
On September 3, 2008, at 1257 eastern daylight time, a Sadler Vampire, N333SV, received substantial damage on impact with terrain during a forced landing and a post crash fire. The airplane experienced a total loss of engine power after takeoff from Findlay Airport, Findlay, Ohio. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 flight test was not operating on a flight plan. The pilot sustained minor injuries. The local flight was originating at the time of the accident. The airplane was certified as an experimental amateur-built airplane and was used as a prototype toward seeking certification as a light sport aircraft by its manufacturer. The pilot stated the engine previously experienced "slightly" high engine temperatures that had been reduced to the "normal operating range" with the installation of a larger radiator onto the airplane. The airplane was fueled from a portable fuel tank in the back of a pickup truck. This fuel tank did not have any sump drains or fuel filtration available. The pilot stated that there were no fuel sump drains available on the airplane and Federal Aviation Administration (FAA) inspectors did not note the presence of any fuel sump drains during their post accident examination of the wreckage. Additionally, the provided airplane checklist did not mention the sumping of fuel to check for contamination. The pilot performed a low speed taxi followed by a high speed taxi. He performed "short hops" to get used to the aerodynamics of the airplane for takeoff and landing. He then "felt confident" that everything was operating "well" enough to fly the airplane one time in the airport traffic pattern. The pilot used runway 07 (5,883 feet by 100 feet, asphalt) for the takeoff. He applied full throttle and obtained an engine speed of 5,100 revolutions per minute (rpm). He rotated the airplane at 65 miles per hour (mph), maintained 75 mph, and obtained a climb rate of about 200 feet per minute. He turned crosswind approximately 500 feet agl, and in the turn to the downwind leg, the engine experienced a loss of engine power while over Main Street. He attempted an engine restart but did not hear the engine turn over. He then turned his attention to executing a forced landing. He pitched the airplane to obtain 85 mph, which reportedly was the best glide speed. He stated that the glide ratio was "very poor" and knew that he could not return to the airport. He saw a quarry that he thought was his best option for a landing area because of the commercial area adjacent to the airport. Once he knew that he could reach the quarry, he allowed the airplane speed to increase to about 95-100 mph. As the airplane descended, the ridges in the lower part of the quarry, where he wanted to land, came into view. The airplane inadvertently touched down on the first ridge and bounced. The pilot wanted to avoid a stall so he pitched the airplane nose down. He then impacted a second ridge with trees and the airplane yawed left. He was unable to realign the nose of the airplane with the direction of travel. The airplane touched down and slid to a stop. According to the Findlay Police Department Report, the airplane's main landing gear wheels touched down on an upper ledge of the quarry and bounced off the edge before striking two small trees and a lower ledge in the quarry. The airplane's nose landing gear then struck the bottom of the quarry. The airplane travelled westbound an additional 135 feet before coming to rest. The pilot exited the airplane, and the airplane then caught on fire. The airplane wreckage was located approximately 0.6 miles north from the departure end of runway 36. The pilot, age 24, held a commercial pilot certificate with single-engine land, multiengine land, and instrument airplane ratings. He was issued a flight instructor certificate in May 2008. He accumulated a total flight time of 455 hours, 6 hours of which were reported in the make and model of accident the airplane. The pilot stated that he was hired by his brother-in-law, who was the engine manufacturer, as a test pilot which was also a way for him to accumulate flight time. The pilot stated that he did not receive an airplane checkout in the accident make and model airplane but learned to fly the airplane on his own. He stated that he got used to the airplane on airport taxiways and on flights limited to the airport area. The pilot had no previous aircraft flight test training or experience. The aircraft manufacturer stated that the airplane fuel system consisted of a single-fuel tank with a sump drain located on the gascolater, which was the low point in the fuel system. There was a metal to metal fuel shutoff valve, and excess fuel was ported back to the fuel tank near the fuel tank vent. The fuel cap was not vented. Cockpit engine water temperature indication is sensed at the outlet side of the engine cooling system prior to entering the radiator. The airplane was powered by a Rotamax 1300CG engine at the time of the accident. The model and serial number of the engine were obtained from company provided records that stated the engine was serial number 5, manufactured on October 15, 2007, and accumulated 52 hours. However, the Affidavit of Ownership for Experimental Aircraft, AC Form 80850-88, identifies the engine as a Rotamax R700, serial number 2-DC-R-S-N-G-004. The engine manufacturer stated the Rotamax 1300CG was the correct engine model for the airplane. Post accident disassembly of the installed Rotamax 1300CG engine and reduction drive assembly was conducted under the supervision of the Federal Aviation Administration. During the disassembly of the reduction drive assembly, multiple bearing failures were noted. The reduction drive assembly was then shipped to the National Transportation Safety Board Materials Laboratory for metallurgical examination. The metallurgical examination revealed one end of the rotor bearing journal exhibited a dark and discolored surface relative to the opposite rotor bearing journal on the shaft. Light colored lines from the needle rollers were visible on the surfaces of both rotor bearings. There were no indications of deformation (brinnelling) by the rollers on the inner raceways. Closer examination of the discolored rotor bearing journal revealed metal transfer on the bearing surface and pitting on one location. Similar light colored lines from roller bearings were noted on the main bearing journals. The complete circumference of one of the sidewalls had separated from the rest of the needle bearing cage. Upon removal of the sidewall, four needle rollers fell out of the cage due to damage and plastic deformation to which the cage had been subjected. It was not apparent whether this damage occurred before or after the sidewall separated from the cage. Small shards of metal were found on the rollers and the outer raceway. The outer housing was discolored on the side with the fractured cage sidewall and around the oil hole in the middle. A piece of metal debris was found inside the oil hole. The needle rollers showed signs of abrasive wear and damage to the ends of the rollers. A typical needle roller exhibited abrasive wear by third body particles at an end which was adjacent to the fractured cage sidewall. The diameter of the needle roller on this end is also reduced relative to its opposite end. A random sampling of five rollers produced an average reduction in diameter of 0.0064 inch +/- 0.0007 inch. The ends of the rollers next to the fractured cage sidewall were concave in profile with buildup of material around the edge. The opposite end of the roller ends possessed rounded edges. The fractured sidewall of the cage had concentric abrasion marks coincident with the location of the needle rollers. In between the rollers it appeared that two fractured ribs had been plastically deformed and pressed against the cage sidewall. In another location, there appeared to be buildup of metal debris on the fracture cage sidewall. Two ball bearings within the assembly had seized. The balls in one raceway of the double row ball bearing were clustered together creating an approximately 120 degree included angle of raceway in which there were no balls. There was no readily visible evidence that would explain the seizure of these bearings. Most of the bearings, once wiped of residue showed, a typical lightly scratched finish with some discoloration from heat from post crash fire.
A total loss of engine power due to the failure of the reduction drive assembly as a result of excessive wear and high temperatures. Contributing to the accident were the pilot's lack of total experience in the airplane and the unsuitable terrain for a forced landing.
Source: NTSB Aviation Accident Database
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