Casualties unknown

1999-07-26: Mooney M20B (N74523) — Hayward, WI

Hayward, WI, US

On July 26, 1999, a Mooney M20B (registration N74523) was involved in an aviation accident near Hayward, WI. Investigators recorded the probable cause as: Contact with the lake surface during a climbing left turn, attributed to glassy water conditions and dusk lighting which impaired depth perception. 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

A pilot executed a low approach over a lake, initiating a climbing left turn that resulted in the left wing striking the water surface due to glassy conditions and dusk lighting.

What happened

The pilot operated an aircraft on a flight that included a low approach over a body of water. Upon reaching the end of this approach phase, the pilot initiated a climbing left turn. During the roll to the left, the left wing made contact with the surface of the lake. Despite this incident, the pilot continued the flight and successfully returned to the departure airport without further complications.

The investigation

Following the event, the pilot provided a report detailing the circumstances leading to the wing strike. The pilot identified specific environmental factors that contributed to the difficulty in maintaining situational awareness during the maneuver.

Findings

The primary contributing factors cited by the pilot were the visual conditions present at the time of the accident. Specifically, the glassy water surface and the dusk light condition impaired the pilot's ability to accurately judge altitude and distance relative to the water. These conditions are known to create optical illusions that can lead to spatial disorientation or misjudgment of height above terrain.

Safety message

Pilots operating near large bodies of water during low-light conditions should exercise heightened caution. Glassy water surfaces can reflect the sky, removing visual depth cues and making it difficult to distinguish between the horizon and the water surface. This effect is exacerbated at dusk, where contrast is reduced. Pilots should rely on instruments rather than visual references when navigating over featureless terrain or water in such conditions.

Probable cause

Contact with the lake surface during a climbing left turn, attributed to glassy water conditions and dusk lighting which impaired depth perception.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X19224. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.