Staudacher S-300D2 N112KG

Summary

On 7 July 2000 at about 23:00 local time, a Staudacher S-300D2 registered N112KG was involved in an accident near Kenosha, Wisconsin, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

7 July 2000 at 23:00

Classification

Accident

Location

Kenosha, Wisconsin, United States

Coordinates

42.6192, -87.8299

Aircraft

Staudacher S-300D2

Registration

N112KG

Category

Airplane

Engines

1

Operator

Not recorded

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CHI00LA189

Nobody was injured.

The fatigue failure of the rod end bearing and the separation of the aileron. A factor was the inadequate design change by the aircraft designer.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot was performing a 1/2 snap roll when the left aileron departed the airframe. The aircraft was still controllable and an uneventful landing was made. The spherical rod end bearing that was used for the center aileron hinge had broken and a subsequent metallurgical was performed. Energy dispersive spectroscopy (EDS) examination revealed "... only iron and manganese consistent with plain carbon steel. There were no appreciable amounts of chromium, nickel, or molybdenum as might be expected with an AISI 4130 or AISI 8420 material." The report also states that the "... microstructure and hardness is typical of a normalized or annealed, medium carbon steel." The metallurgical report states that the rod end fracture was due to "... reverse bending fatigue (from cycling about its lateral axis) initiating at the root of the shank threads." The aircraft designer said that the accident aircraft had a different style rod bearing installed than the original design. The designer stated that he believed that the new rod end bearing shank was made of the same material and heat treat as the original. The specification for the original rod end bearing shows that the shank is to be made from AISI 4130 or AISI 8420 steel.

Quoted verbatim from the NTSB record.