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.
NTSB analysis
Prior to the accident flight, the pilot indicated that he was aware of the thunderstorm activity along his route of flight and that he anticipated deviating around the weather as necessary. While enroute to his destination, the pilot requested and was provided both weather information and pilot reports from other aircraft by air traffic control (ATC). Upon encountering an area of thunderstorm activity that extended east-to-west across the route of flight, the pilot reported encountering significant turbulence, and then downdrafts of 2,000 feet per minute. He then requested a course reversal to exit the weather before he declared an emergency and advised ATC that the airplane was upside down. There were no further transmissions from the pilot and radar contact with the airplane was lost. Review of radar data revealed that the pilot had deviated south and then southwest when the airplane entered a strong and intense echo of extreme intensity. Visible imaging revealed 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. This was indicative that the airplane had penetrated the main core of the cumulonimbus cloud, which resulted in an inflight breakup of the airplane. 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 aircraft's flight path; therefore the final penetration of the intense portion of the storm was likely unintentional.
Text from the NTSB. Open the NTSB docket for ERA09FA389 for the full record.
Event
- Date
- Jul 8, 2009
- Type
- Accident
- Place
- Gulf Of Mexico
- Highest injury
- Fatal
- Fatal injuries
- 5
- Weather
- Instrument (IMC)
- Light
- Day
Cessna 421C
- N-number
- N4467D
- Category
- Airplane
- Damage
- Destroyed
- Operating rule
- Part 91 (general aviation)
- Purpose of flight
- Executive or corporate
From the NTSB aviation accident database: N-registered aircraft, events since 2008, data through Oct 28, 2026. The file is published monthly, so the latest weeks are incomplete and recent records can change. The official source is the NTSB aviation investigation search. CheckAero is independent and not affiliated with the NTSB.