Casualties unknown

2007-10-10: Flight Design Gmbh CTSW (N245CT) — Afton, WY

Afton, WY, US

On October 10, 2007, a Flight Design Gmbh CTSW (registration N245CT) was involved in an aviation accident near Afton, WY. Investigators recorded the probable cause as: The pilot's failure to correct the alignment of the airplane and his improper recovery from a bounced landing, resulting in exceeding the design stress limits that caused the right main landing gear to fail. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

During landing on runway 34, an airplane bounced and then landed hard on the right main gear, which tore off. The airplane veered right, struck the runway with the right wing, and nosed over.

Accident Overview

The pilot reported that after flying over the airport, he observed the wind sock, segmented circle, and wind-T indicating calm wind from the north. He conducted an approach to runway 34 with 30 degrees of flaps, maintaining 45 knots using elevator control without trimming for that speed. Sensing he was slightly low, he increased power until both VASI bars appeared white, then reduced power to idle. The airplane bounced, but the pilot stated it was "not hard enough to have a wheel fall off." He noted he was going straight down the runway into "a few knots of wind." On the subsequent touchdown, “the stub of the right main gear dug into the runway,” causing the airplane to veer to the right and depart the runway. The right wing struck the ground, and the airplane nosed over.

Instructor's Account

The flight instructor offered a different description. He characterized the pilot's performance in the traffic pattern as “somewhat ragged and less precise and exhibited tension,” noting that the pilot overshot his downwind-to-base turn by 20 degrees. The instructor took control to reestablish a stable approach, then returned control to the pilot. Threshold crossing airspeed was 55 knots. The pilot allowed the right wing to settle, inducing a right turn. The instructor attempted to recover but stated it was too late. The airplane “landed hard with the right wing low resulting [in] major ballooning. When the bottom fell out, the plane landed extremely hard on the right main gear [and] proceeded off the runway” at a 20 to 30 degree angle, nosing over in the grass.

Witness and Damage

The airport manager, who witnessed the accident, said the airplane was not aligned with the runway centerline when it landed hard. The impact tore off the right main landing gear. The airplane veered off the runway and nosed over. The right wheel was found on the left side of the runway, and the airplane came to a halt approximately 300 feet off the right side of the runway.

Laboratory Examination

A laboratory examination of the right main gear fracture revealed that “the fracture was overstress, consistent with bending from a hard landing impact. There was a compression buckle at the top and a tensile fracture at the bottom. There was also considerable plastic deformation, but no indication of pre-existing cracks or defects.” Steel type, wall thickness, yield strength, tensile strength, and hardness measurements met or exceeded specifications. The report concluded that the fracture was the “result of impact on landing.”

Manufacturer's Design

According to the airplane manufacturer, the gear assembly was designed in accordance with ASTM 2245 and successfully passed a drop test of 550 mm (21.7 inches) at a weight of 600 kg (1,323 pounds).

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20071029X01678. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.