Aviation Accident Summaries

Aviation Accident Summary LAX00LA179

DELANO, CA, USA

Aircraft #1

N9QV

Cone QUESTAIR VENTURE

Analysis

On the landing roll the airplane veered to the left and departed the runway with the right wheel hitting a concrete storm drain causing the airplane to nose over and come to rest inverted. The pilot reported that the attachment for the nose landing gear yoke had broken off. A 500-foot skid mark was found on the runway. The nose landing gear underwent a metallurgical examination. The fracture surfaces observed exhibited fractures consistent with overload stresses. There were no manufacturer design or material defects noted.

Factual Information

On April 29, 2000, at 1300 Pacific daylight time, a Cone Questair Venture, N9QV, nosed over inverted after landing at the Delano Muni Airport, Delano, California. The experimental homebuilt airplane, operated by the owner under the provision of 14 CFR Part 91, sustained substantial damage. The private pilot and sole passenger received serious injuries. Visual meteorological conditions existed for the personal flight and no flight plan had been filed. The flight originated from the Santa Monica Muni Airport, Santa Monica, California, at 1200, and was scheduled to terminate at the accident airport. The pilot stated that on the landing roll the airplane violently veered to the left. He attempted to correct with right rudder and the airplane departed the runway with the right wheel hitting a concrete storm drain causing the airplane to nose over, and came to rest inverted. The pilot further reported that the attachment for the nose gear yoke was later found broken off. WITNESS INFORMATION An officer from the Delano City Police Department interviewed the pilot. The pilot told him that he had realigned himself with the runway for landing. After touchdown he began to use the rudder control to maintain runway alignment prior to braking. The pilot stated that he thought he had been struck by a gust of wind that pushed him off the runway, and that he never had a chance to apply the brakes. WRECKAGE AND IMPACT INFORMATION When the officer arrived at the scene, he found the airplane lying inverted about 85 feet west of runway 32. He stated that the bearing of the airplane was southwesterly in relation to the runway. Due to cockpit damage he was unable to document dial and switch positions. He indicated that the propeller was "severely distorted." Due to wing damage, the officer was unable to determine the position of the flaps. The fuel cells were found ruptured with no fuel remaining inside. The rudder and elevators were found separated from the tail section of the airplane. The officer observed that the landing gear was in the down position. He noted that the nose landing gear was a castor type with no wheel braking devise. He further noted that the nose landing gear moved and rotated freely. The officer stated that he found debris where the airplane came to rest, as well as skid marks on the runway that were approximately 500-feet in length. METALLURGICAL EXAMINATION The engine mount with attached nose wheel components, including the deploy/retract linkage assembly, axle with sleeves, machine screw, and washer were sent to the Safety Board's metallurgical laboratory in Washington, D.C., for further examination. The metallurgist indicated that the deploy/retract linkage consists of the yoke at the upper end and a drag link at the lower end that form an angled structure aft of the nose gear strut. A motorized screw and linkage assembly assists the movement of this component. The linkage assembly connects between the screw and the deploy/retract arm, which is attached to the right side of the yoke axle. A fractured piece of the upper end of the drag link was found. The fracture surface was matte gray in appearance. The area adjacent to the drag link was bent and twisted. The axle section exhibited deformation and tears in an upward direction with the axle. The frame of the engine mount was bent upward in the location where the yoke attaches to the frame. The frame was also found fractured at the left attach point for the yoke axle. The metallurgist found no evidence of any preexisting cracks in the tested components. He further indicated that the overall fracture and deformation on the components was consistent with excessive loading of the yoke and drag link assembly in compression. The examination of the components revealed no structural design or materials flaws. ADDITIONAL INFORMATION According to the Venture website http://www.wallacecompany.com/venture_assoc/index.html at low speeds, the rudder will not steer the airplane, unless the builder has modified the airplane. The brake and steering controls are a combined assembly. According to a Federal Aviation Administration inspector, this type of airplane has a history of runway departures due to problems controlling the hydraulic nose wheel steering/brake system. He indicated that the system could trap pressure in the assembly prior to landing, which causes an uncommanded turn after the nose wheel compresses during the landing roll.

Probable Cause and Findings

Loss of directional control during landing for undetermined reasons.

 

Source: NTSB Aviation Accident Database

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