On March 15, 2007, at night, a Boeing 767-300, operated by United Airlines, experienced a bird strike after take-off from Chicago O'Hare International Airport, Chicago, Illinois. The airplane encountered a flock of ducks about 800 feet above ground level (AGL) resulting in the complete failure of the left engine. The crew was able to land the airplane safely.
This is an extract from the official accident report (CHI07LA093) published by the National Transportation Safety Board (NTSB), USA:
According to the captain, the landing lights illuminated the birds for "less than a second" before the airplane impacted them. There were multiple bird strikes in the vicinity of the cockpit. The left engine then experienced a series of compressor stalls and there were 3 or 4 "bangs" before the first officer retarded the throttle, The engine stabilized around the mid throttle position for a few seconds. The first officer adjusted the throttle again and then there was one more "bang" after which the engine flamed out. The left engine was secured and they continued flying towards Lake Michigan climbing to 5,000 feet mean sea level. There were no problematic right engine indications. The flight crew then executed an approach to and performed an overweight landing on runway 32 where it landed without further incident.
In the Wreckage and Impact Information section, the Report states:
All 38 fan blades were in place in the fan disk. One fan blade, [...], identified as blade 1, was fractured approximately in line with the midspan shroud. Most of the fractured fan blade's fracture surface was at an angle to the surface of the blade except for a section of the fracture in the centre of the blade that was smeared and had heat discolouration. Fan blade 1, inboard from the fracture, had a large radius bend on the leading edge that curled back opposite the direction of rotation. [The report provides further detailed description of the damage to the left engine resulted from the birdstrike].
The bird remains collected from the engine as well as biological remains that were found at the departure end of runway immediately after the incident were submitted for identification. All collected remains recovered during the disassembly of the engine together with the bird remains found on the runway were identified as canvas back ducks.
The Report provides no conclusion or recommendations.