Aviation Accident Summaries

Aviation Accident Summary LAX95LA277

PRESCOTT, AZ, USA

Aircraft #1

N163J

JENKINS LONG E-Z

Analysis

About midway down the runway, the pilot initiated the first of three abortive attempts to rotate and climb out. After each attempt the aircraft settled back onto the runway. The pilot aborted his takeoff but did not have sufficient stopping distance remaining. The aircraft overran the runway and collided with a fence. Before departure, the pilot performed a runup and then went through a verbal checklist which included mixture rich. The plans supplier recommends an engine leaning procedure be followed prior to takeoff when density altitude exceeds 5,000 feet. The computed density altitude was 7,771 feet. The computed gross takeoff weight was 1,546.8 pounds, which exceeded the plans supplier recommendation of 1,325 pounds. The runway has a 1.0 percent upslope. The weight of the aircraft placed it off of the takeoff distance performance planning charts. No discrepancies were found during an examination of the aircraft. The engine was started and exercised to full power.

Factual Information

On August 2, 1995, at 2040 hours mountain standard time, a homebuilt Long E-Z, N163J, collided with an airport fence while on takeoff from Ernest A. Love Field, Prescott, Arizona. The aircraft sustained substantial damage. The commercial pilot sustained fatal injuries and the sole passenger received serious injuries. The aircraft was operated as a personal flight by the owner. The flight originated in Oshkosh, Wisconsin, and was continuing to the final destination of La Verne, California. Visual meteorological conditions prevailed at the time and no flight plan was filed. The tower operator reported that after clearing the aircraft for takeoff on runway 21L, he observed it about midfield when the pilot initiated the first of three abortive attempts to rotate and climb out. After reaching approximately 10 feet agl on each try, the aircraft abruptly settled back onto the runway with a perceptible bounce. After the last attempt, the aircraft overran the departure end of the runway and collided with a chain link fence. The aircraft came to rest on a golf course about 1,000 feet from the end of the runway. The passenger reported that the pilot received an in-person weather briefing from the Prescott flight service station (FSS) prior to departure. He related that the pilot said the airport elevation, temperature, and aircraft weight was of no concern because they had taken off from Winslow, Arizona, earlier and they had become airborne after a 2,800-foot takeoff roll. Before takeoff, the pilot went through a verbal check list which included the item "mixture-rich." He also stated that both he and the pilot were wearing seat belts and shoulder harnesses. He remembered two abortive attempts to takeoff followed by abrupt descents back to the runway. On takeoff, everything sounded fine but after liftoff, instead of climbing, the aircraft went back down on the runway. He said he had no memory of subsequent events. A postaccident inspection of the aircraft was conducted by an FAA inspector. He reported that he found the throttle in the idle position, the mixture in the idle cutoff position, and the carburetor heat in the "full on" position with the magneto switch on "both." The altimeter Kollsman's window was set to 30.10 inHg, which corresponded with the setting that had been provided by the air traffic control tower (ATCT) at the time of the accident. He also noted that there was no visible damage to one of the two wooden propeller blades with minor leading edge damage to the other. The fuel selector was positioned on the left tank. After leveling the aircraft, the fuel gauges for both the left and right tanks each indicated 12 gallons. The aircraft total time, time since last inspection, and pilot flight times were estimated based on a combination of the aircraft and the pilot logbooks. According to a witness statement provided by the airport service lineman, the pilot had specifically requested refueling with 8 gallons of 100LL aviation fuel to be pumped into each of the two main tanks. The actual refueling was 8 gallons into the left and 8.1 gallons into the right. A fuel sample was taken from the aircraft fuel tank by the FAA inspector. He stated that it was similar in color and odor to aviation fuel. A density altitude of 7,771 feet was computed based on the field elevation of 5,042 feet, the current reported altimeter setting of 30.10 inHg, and temperature of 85 degrees Fahrenheit. The aircraft's gross takeoff weight was computed based on the empty weight of the aircraft (945.8 pounds including oil); fuel load of 24 gallons at 6.0 pounds per gallon; pilot weight of 199 pounds according to the current medical certificate; and the passenger reported weight of 255 pounds. The passenger reported the weight of luggage to have been about 3 pounds. The pilot was seated in the front. The resulting gross takeoff weight was 1,546.8 pounds. According to the plans supplier, the maximum gross weight should not exceed 1,325 pounds unless the provisions specified in the owner's manual are met, and then the maximum gross weight may be increased to 1,420 pounds for takeoff only. The plan suppliers provisions are appended to this report. The pilot took off on runway 21L, which has a 1.0 percent upslope. The plans supplier stated that performance planning is also a factor in high gross weight and/or high density altitude takeoffs. Rotation prior to obtaining best angle of climb airspeed results in higher induced drag and consequently, increases the distance required to accelerate to best angle of climb airspeed. When plotted, the weight of the aircraft placed it off the right side of the plans supplier's takeoff distance performance planning charts. As a result, no minimum lift-off or best angle of climb airspeeds were computed for this report. The performance planning charts are appended to this report. The plans supplier recommends an engine leaning procedure be followed prior to takeoff when density altitude exceeds 5,000 feet. After the accident, the aircraft was recovered and stored in a hangar operated by Aero Mechanics at Ernest A. Love Field. A portable battery was connected to the engine in an effort to start and run. The Lycoming representative who was present during the engine run reported that initially the engine would not start. Upon determining that the magneto switch had been damaged by impact forces and was causing the ignition to short circuit, the magnetos were then wired directly into the ignition circuit, thus bypassing the switch. The engine was started without difficulty and produced a static output of about 2,350 rpm at full throttle. The plans supplier reported that the static rpm obtained was in the normal range. An autopsy was conducted by the Yavapai County Coroner and toxicological samples were collected and forwarded to Civil Aero Medical Institute (CAMI). CAMI reported the toxicological screening was negative.

Probable Cause and Findings

the pilot's failure to properly lean the engine for best power, his premature rotation of an over gross aircraft on an uphill runway, and his delay in aborting the takeoff.

 

Source: NTSB Aviation Accident Database

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