United Airlines 611

By Patrick Mondout

Just after 7pm on July 19, 1970, United Air Lines Flight 611 (Philadelphia to Rochester, New York), a Boeing 737-222, crashed shortly after taking off from the Philadelphia International Airport. Among 55 passengers and six crewmembers, 17 passengers were injured, one seriously, and one crewmember received minor injuries - but there were no fatalities.

The takeoff roll and lift-off were reported normal in every respect. At the point in the climb where the landing gear is normally retracted, the flightcrew heard a loud explosion, following which the aircraft veered right.

The captain stated, "I advanced power on both engines without any response and then made the decision to attempt to land on the remaining runway." The aircraft touched down hard on the departure runway and continued off the end and across the blast pad. The aircraft came to rest, 1,634 feet past the end of the runway.

The loud explosion was that of the #1 engine failing. Disassembly of the engine revealed a contained failure within the turbine area. A first-stage turbine blade failed in flight which caused cessation of engine rotation prior to ground contact. Disassembly of the right (No. 2) engine and functional testing of its components revealed that it was in an operable condition at the time of the accident.

United Airlines United 737-222 A Boeing 737-222 just like the one involved in this accident seen here in Pittsburgh in August 1971. Image courtesy of AirNikon. Find more of his photos at Airliners.net

All the evidence developed during the investigation demonstrated that the #2 engine was operating in the air, during the thrust reversing cycle, and until the engine impacted the ground. The 737 is designed to allow for one of the two engines to fail during takeoff. It would have had enough power to gain altitude and then turn back and land at the airport.

The National Transportation Safety Board determined that the probable cause of this accident was the termination of the takeoff, after the No. 1 engine failed, at a speed above V2 (a point at which the aircraft should take off and well beyond the point - V1 - where a flight can safely be aborted) at a height of approximately 50 feet, with insufficient runway remaining to land safely. The captain's decision and his action to terminate the takeoff were based on the erroneous judgment that both engines had failed.

Source: National Transportation Safety Board (NTSB) report NTSB-AAR-72-9.

United Airlines 611 at a Glance
Airline	United Airlines
Date	July 19, 1970, 7:07pm
Flight number	611
Registration Number	N9005U
Crew Fatalities	0 of 6
Passenger Fatalities	0 of 55
Total Fatalities	0 of 61

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