ROSELAWN, Ind. -- Three days after the crash of an American Eagle ATR72 commuter plane that killed all 68 on board, the airline's parent company issued a bulletin yesterday prohibiting some of the procedures used by the cockpit crew.
Marty Heires, a spokesman for the AMR Co., said the bulletin was "precautionary" and was not intended to imply that either the crew or the propjet plane were at fault.
The first prohibited procedure involved flying in a holding pattern with the plane's flaps extended.
Flaps -- flat metal slabs that can be extended back from the wings to increase their lift -- usually are extended only on takeoffs and landings.
Flight 4184 was flying at a speed of about 210 mph with its flaps extended at a 15-degree angle as the plane circled over Roselawn, descending slowly from 10,000 feet.
An alarm sounded, warning the pilot that damage to the flaps could occur at that speed, and he retracted them.
The second procedure prohibited in the bulletin is using the plane's autopilot during conditions in which ice can build up on the wings and fuselage, overburdening the aircraft.
Even the though the cockpit crew of Flight 4184 was aware of the icing hazard, the plane was being flown on autopilot in the holding pattern.
Mr. Heires said the flap advisory was not new and was simply upgraded from the "not recommended" list to the "prohibited" list. He said the autopilot advisory is new.
Even though the airline did not relay National Weather Service information about icing conditions to the cockpit crew -- the pilots of Flight 4184 were aware of them.
Recording devices recovered from the plane show that the propjet's de-icing equipment had been turned on more than 15 minutes before the crash. Why the pilot had the flaps deployed in the holding pattern is not clear.
However, sources close to the investigation believe that when he retracted them in response to the alarm, that is when Flight 4184's troubles intensified.
The ATR72 went into a stall, rolling over on its back and plunging 9,000 feet to the ground.