Casualties unknown

1999-08-04: Cessna 170B (N4448B) — Casper, WY

Casper, WY, US

On August 4, 1999, a Cessna 170B (registration N4448B) was involved in an aviation accident near Casper, WY. Investigators recorded the probable cause as: The pilot's failure to maintain directional control during the landing rollout, which resulted in a ground loop and runway departure, due to his decision to land on a runway other than the one cleared by air traffic control. 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

An aircraft departed the runway side during landing after a cross-country flight due to a ground loop. The pilot landed on the wrong runway despite clearance for another, encountering crosswinds that contributed to the loss of directional control.

What happened

The incident occurred while the aircraft was concluding a cross-country flight and attempting to land. The pilot had received explicit clearance from air traffic control to land on runway 8. However, the pilot executed the landing on runway 3 instead.

During the rollout on runway 3, the aircraft lost directional control and departed the side of the paved surface. The primary mechanism for this departure was identified as a ground loop, a condition where the aircraft pivots sharply around its main landing gear due to insufficient steering control or excessive yaw.

The investigation

Investigators examined the weather conditions at the time of the accident to determine their role in the loss of control. Wind data indicated that the wind was blowing from 090 degrees with a speed of 14 knots.

Based on the orientation of runway 3 relative to the wind direction, calculations showed a headwind component of 7 knots and a crosswind component of 12 knots. These lateral wind forces likely complicated the pilot's ability to maintain alignment with the runway centerline after touching down.

Findings

The sequence of events suggests that landing on a runway different from the one cleared by air traffic control introduced unnecessary complexity to the approach and rollout. Combined with the 12-knot crosswind component, this error likely exceeded the pilot's ability to maintain directional control, resulting in the ground loop and subsequent departure from the runway.

Safety message

Pilots must strictly adhere to assigned runway clearances. Landing on a runway other than the one cleared can lead to unexpected configuration issues or environmental factors that compromise safety. Additionally, crosswind landings require precise control inputs to prevent ground loops, especially when the aircraft is not aligned as anticipated.

Probable cause

The pilot's failure to maintain directional control during the landing rollout, which resulted in a ground loop and runway departure, due to his decision to land on a runway other than the one cleared by air traffic control.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X19482. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.