19971221044319A

Unregistered homebuilt impacted ground when right wing failed. Giving dual to his son sans CFI rating. (.19) on December 21, 1997, at 1520 central standard time, an unregistered amateur-built quicksilver GT-500 airplane was substantially damaged when it impacted the ground during an uncontrolled descent following the failure of the left wing. The local instructional flight departed from kitty hawk ultralight field, san antonio, Texas, and the accident occurred near the flight's destination, Bat Cave Field Airport, san antonio. The non-certificated instructor pilot, who was the owner of the airplane, received serious injuries and the student pilot who was the owner's son, sustained minor injuries. No flight plan was filed and visual meteorological conditions prevailed for the flight. The FAA inspector who examined the wreckage reported that the left wing strut appeared to have separated from the left wing at the strut-to-wing attach point. The inspector further reported that the airplane was equipped with a ballistic recovery systems (brs) parachute which had been deployed, and the lines of the parachute were found wrapped around the propeller of the pusher-mounted engine. (.4) during cruise flight, the left leading edge wing strut fitting failed, & the amateur-built aircraft, which was being operated as an ultralight vehicle under an exemption to title 14 CFR part 103, entered a left spin. The ultralight instructor pilot deployed the aircraft's emergency parachute, which inflated partially & slowed the aircraft's rate of descent. A witness observed the aircraft impact the ground in a nose down attitude at an estimated speed of 25 to 30 mph. Examination revealed the wing strut fitting failed due to improper installation of the 3 bolts, used to secure the fitting to the leading edge wing spar. The bolts had been inserted through the forward holes of the fitting, through holes in the tubular spar, but not through the rear holes of the fitting. This defect was not visible during preflight inspections; however, it could have been found during a condition inspection, since a zipper installed in the fabric lower wing surface provided access to examine the rear of the fitting with the aid of a flashlight & mirror. No record was found to indicate that a condition inspection had been performed on the kit-built aircraft, in accordance with provisions for usingthe '2-place training exemption.' The aircraft was first flown in February 1995 & had been owned by the pilot since June 1995. The main line, which fastened the ballistic recovery system (brs) parachute to the airplane, was found wrapped around the propeller drive shaft of the rear-mounted (pusher) engine. (Tty)unreg unltrlight expreienced structural failure of the left wing and crashed. San antonio, TX. (-23) on December 21, 1997, at 15:20 central time, an unregistered amateur-built quicksilver gt 500 airplane was substantially damaged when the left wing failed causing an uncontrolled descent impacting the ground. The pilot was not certificated. The wing failure was due to the improper installation of the strut to wing attach bracket.