Incident at WATSON LAKE YT (CYQH)
2003-08-01: Maintenance and Manufacturing reported that this leg, of a trip planned from Texas to Anchorage, Alaska, involved a flight from Fort Nelson, BC to Watson Lake, Yukon. Rain shower and some wind turbulence were reported enroute. N91663 a Wittman Tailwind amateur built aircraft, was enroute VFR Ft. Nelson to Watson Lake, Yukon at 6500 ASL, when the top 1/4 of the windshield cracked horizontally, from the edge to the center support attach screws. This portion of the windshield flapped for a few minutes until finally departing the aircraft. The pilot was easily able to maintain control of the aircraft, however, as the OAT was 40 F, conditions in the cockpit were quite cool. N91663 continued on to Watson Lake without further incident. Quite fortunately some identical material was found in Watson Lake and a new windshield was manufactured using the old windshield as a template. The windshield in this aircraft is a flat piece of material attached with screws over a slightly curved portion of the cockpit. It was thought by the pilot/builder that the original build plans did not allow the screw holes in the windshield to be oversized, to allow for expansion and contraction. This aircraft had only 60 TSN and this was the first cool weather the aircraft had encountered. As the crack had started from between two screw holes, the pilot/builder surmised that the tight screw holes did not allow the windshield to contract in the cool weather. The new windshield was made with slightly larger holes to preclude a recurrence of this event. On his return to the US, the owner is intending on bringin this deficiency in the windshield design to the attention of the manufacturer.
2003-07-29: N91563, a Whitman Tailwind W-8 Experimental Amateur Built, was enroute VFR from Fort Nelson to Watson Lake at 6,500 feet ASL when the windshield split in half perpendicular to the fuselage. Part of the windshield separated from the aircraft and fell to the ground. N91663 continued to Watson Lake without further incident.
2003-08-06: UPDATE TSB reported that the amateur built Whitman Tailwind W-8, registration N91663, was en route from Fort Nelson, BC. to Watson Lake, Yukon, VFR at 6500 feet ASL, when the right side of the windscreen fractured laterally across the middle, from the edge to the centre. The portion of the windscreen above the fracture popped up approximately two inches, and several minutes later a large section of the windscreen separated from the aircraft. The aircraft continued to Watson Lake and landed without further incident. Examination determined that the fracture line had originated at the right edge of the Plexiglas and had progressed laterally, between two screw holes. The screws that originally secured the windscreen had recently been replaced with screws of a larger diameter.
|Occurred At||- 19:30|
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