Tucson, AZ, USA
N660T
Tingle Special
The airplane entered a torque roll to the left during the initial climb shortly after takeoff. Numerous pilot witnesses observed the composite airplane on takeoff roll when the airplane began to drift to the left of centerline. Some observed dust below the left wing from the left main landing gear tire rolling in the dirt. The airplane lifted off the ground in a nose high pitch attitude and rolled 90 degrees to the left in a knife-edge turn. The airplane then continued to an inverted position, descended at a 45-degree nose low pitch attitude, and impacted the ground. All of the witnesses indicated that the engine seemed to be at full power during the entire event. Measurements of tire marks on the runway and tire tracks in the dirt to the east of the runway, indicated that the pilot continued with the takeoff roll even though the airplane was well east of the runway centerline and even departed the runway surface to the east. According to the airplane kit manufacturer, takeoffs with more than 70 percent torque were not recommended until the airplane reached 100 knots indicated airspeed. The kit manufacturer added that if one were to takeoff with more than 70-percent torque, below 100 knots, there would not be enough rudder authority to offset the torque/p-factor of the 725-horsepower engine/propeller. There was no record in the FAA database of the airplane receiving an experimental airworthiness certificate nor was there an endorsement in the logbook indicating that the pilot/builder had flown the requisite 40 hours of test flights prior to carrying passengers. The airplane was destroyed by impact and fire damage. The FAA inspector who responded to the accident site reported finding no anomalies with the identifiable components that would have prevented normal flight.
HISTORY OF FLIGHT On November 19, 2005, at 0920 mountain standard time, a Tingle Special experimental airplane, N660T, impacted terrain on the departure end of runway 19 at the La Cholla Airpark in Tucson, Arizona. The airplane was destroyed and the pilot and his passenger were fatally injured. The airline transport pilot/owner operated the airplane under the provisions of 14 CFR Part 91 as a personal flight. The cross-country flight was departing at the time of the accident, and was destined for Carefree, Arizona. Visual meteorological conditions prevailed and a flight plan was not filed. According to the airpark members, the pilot and passenger had flown into La Cholla to attend a pancake breakfast that was taking place the morning of the accident. There were numerous witnesses to the accident, many of whom were pilots. Some observed the airplane on takeoff roll down runway 19 when the airplane began to drift to the left of centerline. Some observed dust below the left wing from the left main landing gear tire rolling in the dirt (some commented that they first believed a problem had developed with the left main landing gear). The airplane lifted off the ground in a nose high pitch attitude and rolled 90 degrees to the left in a knife-edge turn. The airplane then continued to an inverted position, descended at a 45-degree nose low pitch attitude, and impacted the ground. Witnesses reported that the airplane only obtained a total height of 40 to 150 feet above the ground before it began descending. All of the witnesses indicated that the engine seemed to be at full power during the entire event. PERSONNEL INFORMATION The pilot held an airline transport certificate with a multi-engine land airplane rating and type ratings in Airbus 310; Boeing 707, 720, 727, 737, 747, 757, 767; Cessna 500; Lockheed L-1011; and Learjet airplanes. He also held a commercial pilot certificate for single-engine land and sea airplanes. On May 31, 2005, he was issued a third-class medical certificate with a couple of limitations for corrective lenses. Review of records maintained by the Federal Aviation Administration (FAA) and the pilot's most recent logbooks showed that the pilot accumulated over 28,000 flight hours. His latest logbook began in November 2003, and had 33 total flight hours recorded for the accident airplane and an additional 10 hours were flown in a similarly built airplane. AIRCRAFT INFORMATION The amateur-built airplane (serial number 1) consisted of a composite structure with a low-wing design, incorporating a 725-horsepower Walter 601-D turboprop engine (serial number 851047) and an Avia V508B three-blade propeller (serial number 2062). Review of the airframe logbook revealed that the listed date of manufacture was November 11, 2003. On that date, the pilot/builder endorsed the logbook indicating that he inspected the airframe, engine, and propeller, and that they were determined to be in a condition suitable for flight. On November 11, 2003, a designated airworthiness representative (DAR) endorsed the logbook indicating that he inspected the airplane and found it compliant with the Federal Aviation Regulations. The endorsement indicated that Phase I and II operating limitations and instructions had been issued. The tachometer time indicated next to that endorsement was 0.6 hours. According to the FAA records, there was no experimental airworthiness certificate on file as being issued on the aircraft. Without the airworthiness certificate, the FAA could not confirm whether or not operating limitations had been issued for the airplane. An FAA inspector from the Scottsdale Flight Standards District Office (FSDO) assisted in gathering information on the accident airplane. The FSDO inspector interviewed the kit manufacturer, who reported that the pilot was the second owner of the accident airplane and that he purchased it as an uncompleted kit. The pilot then took the kit to California to have it completed. The DAR indicated that he had provided the pilot a set of operating limitations, which required that the aircraft undergo 40 hours of flight testing before passengers could be carried on board. The FAA inspector assisting in the investigation requested a copy of the operating limitations issued for the accident airplane, but did not receive a copy. A review of the pilot/builder's logbook revealed that he accumulated a total of 33 hours of flight time in the accident airplane. The hobbs meter at the accident site read 22 hours. Typically, a logbook endorsement would be required indicating that the airplane underwent its first phase of flight tests (first 40 hours). There was no endorsement in the aircraft logbooks indicating that he had flown the requisite 40 hours of flight testing usually required prior to carrying passengers. The engine logbook revealed that on November 12, 2002, the pilot/builder had completed an overhaul of the engine (the compliance method in which he conducted this overhaul was not noted). The endorsement for that overhaul indicated that the engine was run for 2.0 hours on an engine test stand. There were no additional maintenance entries for either the airframe or engine and no record of a 2004 condition inspection having been conducted. The FAA inspector spoke with the kit manufacturer. The kit manufacturer informed the inspector that takeoffs with more than 70 percent torque were not recommended until the airplane reached 100 knots indicated airspeed. The kit manufacturer added that if one were to takeoff with more than 70 percent torque, below 100 knots, there would not be enough rudder authority to offset the torque/p-factor of the 725-horsepower engine/propeller. METEOROLOGICAL INFORMATION Witnesses in the area indicated the weather was clear with light winds. Following the accident, the Oro Valley Police Department personnel contacted the Tucson International Airport (located 20 miles south of the accident site) and were informed that the winds were from the south at three knots. WRECKAGE AND IMPACT INFORMRATION Oro Valley Police Department personnel and the Scottsdale FSDO inspector documented the accident site with photographs and a wreckage diagram. Police department personnel also took measurements of a tire mark on the runway and a tire track in the dirt on the east side of the runway. The tire mark found on the runway started about 678 feet down the length of the runway and well east of the centerline. It stretched for about 134 feet, and was 6 feet west of the runway's east edge line at its beginning and continued south-southeast until the tire mark left the runway surface. The tire track in the dirt began about 1,112 feet down the length of the runway and about 12 feet east of the runway edge line, and lasted about 40 feet before it disappeared. Review of the wreckage diagram revealed that a number of trees were contacted by the airplane during the accident sequence. According to the police report, the tree branches were severed on an approximate 45-degree angle to the point of initial impact. The identified components not destroyed by fire consisted of the right wing, the elevator and rudder, two landing gear struts and their wheels, the nose landing gear, the engine, and two of the three propeller blades (one of which remained attached to the hub and came to rest near the initial ground impact mark, and the other came to rest approximately 500 feet southeast of the hub). Examination of the wreckage photos revealed that the airplane sustained significant impact and fire damage. The cockpit and left wing had been consumed by a post-crash fire and only burnt fabric remained as evidence of their existence. According to the FSDO inspector, who examined the wreckage at the accident site, remnants of all flight control surfaces of the airplane were identified at the accident site and no anomalies were noted that would have affected the airplane's normal operations. MEDICAL AND PATHOLOGICAL INFORMATION According to the Oro Valley Police Department report, both the pilot and passenger remained secured to their seats via the restraint systems, but the seats had been ejected from the airplane. A parachute remained attached to the passenger's seat and the pilot's parachute remained attached to him. The pilot's parachute rip-chord was snagged on a cactus branch near its final resting area, but the parachute did not deploy fully and was only slightly open. An autopsy and toxicological test were conducted on the pilot. The cause of death was attributed to blunt injuries sustained during the accident. Toxicological tests were negative for carbon monoxide, ethanol, and cyanide. An unquantified amount of metoprolol was detected in the pilot's blood and urine. ADDITIONAL INFORMATION The FAA's Flight Training Handbook (Advisory Circular - AC 61-21A) advises pilots regarding the elements that make up torque, or the left turning tendencies of the airplane. According to the AC, during the takeoff roll, there is an additional turning moment around the vertical axis due to the torque reaction from the engine and propeller. As the left side of the airplane is being forced down by torque reaction, more weight is being placed on the left main landing gear. This results in more ground friction, or drag, on the left tire than on the right, causing a further turning moment to the left. The magnitude of this moment is dependent on many variables. Some of these variables are: (1) size and horsepower of engine, (2) size of the propeller and the RPM, (3) size of the airplane, and (4) condition of the ground surface.
The pilot's excessive use of power during takeoff, which resulted in an inadvertent torque roll shortly after lift off. Also causal was the pilot's failure to abort the takeoff when directional control could not be maintained during the takeoff roll.
Source: NTSB Aviation Accident Database
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