BOEING 757-222UNITED AIRlNES INC

On September 26, 2011, 1637 mountain daylight time, a Boeing B-757-222, registration number N526UA, operated by United Airlines (UAL) as flight 909, and powered by two Pratt & Whitney PW2037M turbofan engines, experienced a left engine (No. 1) bird strikeF following touchdown on runway 35R at the Denver International Airport (DEN), Denver, Colorado. According to the flightcrew, after initial touchdown and the application of full reverse thrust, two hawks were observed on the centerline of runway 35R and shortly thereafter impacts were felt on the fuselage. The airplane was towed to the gate using a tug where the passengers deplaned normally. The incident flight was a 14 CFR Part 121 domestic passenger flight from Chicago O’Hare Airport (ORD) to DEN. Examination of the airplane revealed only minor gouging of the fuselage while the No. 1 engine inlet cowl exhibited multiple impacts, gouges, and through-holes. Examination of the No. 1 engine revealed that all the fan blades were extensively damaged, three fractured transversely across the airfoil at or near the mid-span shroud, but no penetration or breaches were observed in any of the engine cases. The bird remains recovered within the No. 1 engine were identified as coming from a female Red-Tailed Hawk. An intact bird that struck the side of the No. 1 inlet was also identified as a Red-Tailed Hawk but was not sexed. Comparing the airplane and engine damage to the requirements for bird ingestion and engine debris containment at the time the engine and airplane were both certificated revealed that the engine complied with the bird ingestion and containment requirements set forth in Parts 33.77 and 33.19 and the airplane complied with the containment requirements set forth in Parts 25.903.