5 fatalities

2009-07-08: Cessna 421C Golden Eagle III (N4467D) — Q4 Aviation — New Port Richey, United States of America

New Port Richey, United States of AmericaFlight

On July 8, 2009, a Cessna 421C Golden Eagle III (registration N4467D) operated by Q4 Aviation was involved in an aviation accident near New Port Richey, United States of America in flight. 5 people were killed. Investigators recorded the probable cause as: The pilot’s decision to operate into a known area of adverse weather, which resulted in the inadvertent penetration of a severe thunderstorm, a subsequent loss of control, and in-flight breakup of the airplane. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A).

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781196649Data APIEditorial standards

A pilot aware of thunderstorms along the route encountered a severe storm, reported turbulence and downdrafts, declared an emergency stating the airplane was upside down, and then lost contact. Two debris fields were found, indicating an inflight breakup.

Flight Details

Prior to the accident flight, the pilot indicated awareness of thunderstorm activity along the route and anticipated deviating around the weather as necessary. During the flight, the pilot requested and received both weather information and pilot reports from other aircraft via air traffic control (ATC).

Weather Encounter

Upon encountering an area of thunderstorm activity that extended east-to-west across the route, the pilot reported significant turbulence and then downdrafts of 2,000 feet per minute. He requested a course reversal to exit the weather before declaring an emergency and advising ATC that the airplane was upside down. No further transmissions were received from the pilot, and radar contact with the airplane was lost.

Radar and Weather Analysis

Radar data review revealed that the pilot had deviated south and then southwest when the airplane entered a strong and intense echo of extreme intensity. Visible imaging showed that the echo was located in an area of a rapidly developing cumulonimbus cloud with a defined overshooting top, indicating the storm was in the mature stage or at its maximum intensity. Two debris fields were later discovered near the area where the cumulonimbus cloud had been observed, indicative that the airplane had penetrated the main core of the cloud, resulting in an inflight breakup. Near the heavier echoes, the airplane's airborne weather radar may have been unable to provide an accurate representation of the radar echoes along the flight path; therefore, the final penetration of the intense portion of the storm was likely unintentional.

Probable cause

The pilot’s decision to operate into a known area of adverse weather, which resulted in the inadvertent penetration of a severe thunderstorm, a subsequent loss of control, and in-flight breakup of the airplane.