An American Eagle Airlines Saab 340B+ dropped rapidly from flight level 115 (11,500ft/3,480m) to FL065 due to icing, the US National Transportation Safety Board (NTSB) reports.
The January 2 incident occurred as the aircraft (N390AE) was en route from San Luis Obispo, California to Los Angeles International (LAX). No injuries were reported among the 25 passengers, two crew and one flight attendant, and the aircraft landed without incident at its intended destination.
The NTSB says the crew reported a normal takeoff and initial climb, and at FL025 the captain gave control to the first officer with the aircraft’s autopilot engaged.
“As the airplane climbed through 11,000 feet mean sea level [FL110] the captain noted light rime ice accumulating on the windshield wiper blades and about 0.5in [13mm]-wide area of ice on the left wing,” says the NTSB’s preliminary report.
It adds: “The captain began to reach up to activate the manual de-ice boot system and the aircraft vibrated. The aircraft encountered ice and the windscreen immediately turned white.
“The clacker and stick-shaker activated and the captain took control of the airplane. The autopilot disengaged and the airplane began to bank to the left in a nose low attitude.”
American Eagle flight 3008 then began a rapid decent; the captain recovered at an altitude of around FL065. The rest of the flight was uneventful and the aircraft landed at LAX at 15:40 on schedule.
NTSB investigators note that the day before the incident, a flight crew reported that the timer light illuminated during an en route de-icing recheck, and that the de-icer failure light was later deferred “in accordance with the operator’s minimum equipment list”. An appropriate placard was placed next to the de-ice system control, and the auto cycling switch was put into the ‘off’ position.
“Initial examinations revealed the airplane’s deice system were operational; however, the deicer timer failure light illuminated,” adds the NTSB.
American Eagle was not immediately available for comment.
DARREN SHANNON / WASHINGTON, DC
Read the full text of the preliminary report.
Source: Flight International
