Saab 340B – N394AE – Air Crash Data

Incident Overview

Date: Friday 11 February 2005

Aircraft Type: Saab 340B

Owner/operator: American Eagle Airlines

Registration Number: N394AE

Location: Los Angeles, CA – ÿ United States of America

Phase of Flight: Unknown

Casualties: Fatalities: 0 / Occupants: 31

Component Affected: The airplane’s meteorological information and flight release.The airplane’s meteorological information and flight release.

Investigating Agency: NTSBNTSB

Category: Accident

During an approach to landing, an airplane encountered moderate turbulence at 5,000 feet mean sea level (msl). The flight attendant was knocked unconscious and sustained serious injuries. The aircraft was approximately 7 minutes from landing, and the flight attendant was completing his pre-landing checklist. Following regaining consciousness, he was able to get to an empty passenger seat. A deadheading flight attendant assumed the incapacitated flight attendant’s duties. Review of weather data indicated moderate turbulence was possible below 10,000 feet msl, and the meteorological data showed this was the expected condition for the flight. The airline’s weather provider issued an AIRMET Update 6, which was effective for the flight. However, the flight release contained information for AIRMET Update 3, which did not include the critical SIGMET Yankee, and the meteorologist did not issue a SIGMEC due to diminished forecasted turbulence. The NWS canceled the SIGMET Yankee at 1630, and the pilot reports (PIREPS) indicated that moderate turbulence had diminished. Consequently, the meteorologist did not issue a SIGMEC, leading to the absence of the turbulence information on the flight release.During an approach to landing, an airplane encountered moderate turbulence at 5,000 feet mean sea level (msl). The flight attendant was knocked unconscious and sustained serious injuries. The aircraft was approximately 7 minutes from landing, and the flight attendant was completing his pre-landing checklist. Following regaining consciousness, he was able to get to an empty passenger seat. A deadheading flight attendant assumed the incapacitated flight attendant’s duties. Review of weather data indicated moderate turbulence was possible below 10,000 feet msl, and the meteorological data showed this was the expected condition for the flight. The airline’s weather provider issued an AIRMET Update 6, which was effective for the flight. However, the flight release contained information for AIRMET Update 3, which did not include the critical SIGMET Yankee, and the meteorologist did not issue a SIGMEC due to diminished forecasted turbulence. The NWS canceled the SIGMET Yankee at 1630, and the pilot reports (PIREPS) indicated that moderate turbulence had diminished. Consequently, the meteorologist did not issue a SIGMEC, leading to the absence of the turbulence information on the flight release.

Description

The airplane encountered turbulence at 5,000 feet mean sea level (msl) during an approach to landing and the sole flight attendant was knocked unconscious and sustained serious injuries. The airplane was about 7 minutes from landing, and the flight attendant was completing his before landing checklist when turbulence was encountered. After regaining consciousness a few seconds later, he was able to get to an empty passenger seat. A deadheading flight attendant assumed the incapacitated flight attendant’s duties. Review and analysis of available weather data and forecast products showed that airman’s meteorological information (AIRMET) Update 6 was issued by the National Weather Service (NWS) and in effect for the flight for occasional moderate turbulence below 12,000 feet. A review of the meteorological data showed that the airplane was operating in conditions that would have supported at least moderate turbulence below 10,000 feet msl. The weather packet included in the flight release provided to the flight crew by the airline’s dispatch prior to the flight contained information for AIRMET Update 3; however, AIRMET Update 6 (valid for the accident flight) was not listed. Information contained on the release indicated to the crew that no moderate or greater turbulence was present along the route of flight. At the time of the accident, the airline’s contract weather provider evaluated current meteorological data and staff meteorologists used their judgment of the weather to issue a SIGMEC (significant meteorological conditions, a company issued advisory) based on the current weather conditions. NWS-issued SIGMET Yankee was canceled at 1630 because the current pilot reports (PIREPS) indicated that previously forecasted turbulent conditions had diminished. Although an AIRMET was in effect at the time of the accident for moderate or greater turbulence, there were no other supporting indicators to the airline staff meteorologist that moderate or greater turbulence was present along the route of flight. Due to the cancellation of the SIGMET and the lack of additional supporting information for moderate or greater turbulence, the meteorologist did not issue a SIGMEC. Therefore, the turbulence information was not on the flight release provided to the flight crew. Probable Cause: the in-flight encounter with turbulence.