Page:CAB Accident Report, American Airlines Flight 383.pdf/9

– 8 – The aircraft's gross weight at the time of the accident was computed to be 120,980 pounds with a center of gravity (c.g.) of 25.5 percent Mean Aerodynamic Chord (MAC). Both the weight and c.g. were well within the prescribed landing limits.

The aircraft was serviced with 3,358 gallons of kerosene jet fuel at LaGuardia for a total of 38,000 pounds of fuel prior to departure.

1.7 Meteorological Information

The following official United States Weather Bureau (USWB) observations at the Greater Cincinnati Airport were taken prior to and following the accident:

1858, record special, measured ceiling 1,500 feet broken, 4,000 feet overcast, visibility 7 miles, thunderstorm, temperature 58F, dewpoint 53F, wind 220 degrees 8 knots, altimeter setting 30.00 inches, thunderstorm began at 1855, thunderstorm northwest moving southeast, occasional lightning in cloud and cloud to cloud.

1903, special, measured ceiling 1,500 feet broken, 2,500 feet overcast, visibility 2 miles, thunderstorm, moderate rain showers, wind 260 degrees 8 knots, altimeter setting 30.01 inches, thunderstorm northwest moving southeast, occasional lightning in cloud and cloud to cloud.

1911, special, 1,000 feet scattered, measured ceiling 1,500 feet broken, 2,500 feet overcast, visibility 2 miles, thunderstorm, light rain showers, temperature 56F, dewpoint 52F, wind 300 degrees 12 knots, gusts to 17 knots, altimeter setting 30.01 inches, thunderstorm north moving southeast, occasional lightning in cloud and cloud to cloud, windshift 1904, aircraft accident.

Examination of the Cincinnati USWB telautograph record shows that the 1858 and 1903 surface observations were transmitted to appropriate FAA facilities which included the Tower and IFR room.

The following advisory was transmitted immediately preceding the above observations; Weather advisory 1815 E, thunderstorms in the vicinity of Cincinnati 1830-2000, possible surface wind gusts to 40 knots from the northwest.

The Cincinnati arrival radar controller stated that precipitation areas were visible on his radar scope during the time of the approach of AA 383. He stated that the heaviest precipitation area was located to the west of the airport moving generally southward with areas of lighter precipitation located to the north and northeast moving to the southeast. He also stated that at the time of the last AA 383 radar observation, at a position approximately two miles northeast of the field, the aircraft appeared to be at the leading edge of the lighter area of precipitation.

The radar meteorologist on duty at the Cincinnati USWB testified regarding the radar weather observations during the period 1800-1900. He stated that a line of showers and thunderstorms approximately 20 miles in width was observed on his radar scope. The line extended from about 80 miles west of the station to 110 miles northeast and was observed to have been moving from the northwest (320°) at a speed of 25 knots. A photograph of the radar scope taken at 1900:30 showed that the line of precipitation had reached the Cincinnati Airport.