Page:CAB Aircraft Accident Report, United Airlines Flight 227.pdf/17



Mr. George S. Moore

Director

Flight Standards Service

Federal Aviation Agency

Washington, D. C. 20553

Dear Mr. Moore:

Our investigation of the November ll, 1965, accident of United Air Lines Boeing 727, N7030U, at Salt Lake City, Utah, has progressed to the point where we believe specific recommendations are in order in regard to the routing of fuel and electrical lines through the fuselage. We will probably have additional recommendations later concerning other design and operational aspects; however, further investigation and study are required beforehand.

It has been established with reasonable certainty that the fire following impact resulted from fuel lines being broken by the failed right main landing gear. This component broke through the fuselage sidewall in the vicinity of fuselage station 1050 and severed the fuel lines to the No. 2 and No. 3 engines. Ignition of spilled fuel could have been caused by sparks from runway contact or by a broken and shorted generator lead, or both. As you well know, the fire which followed was devastating and resulted in the loss of 43 lives.

It is interesting to note that in this accident both main landing gears struck the sidewalls of the rear fuselage after being broken free from their attachments. This directly rearward path of both gears indicates that the aircraft was not yawed appreciably at the time of impact and, therefore, we believe it is indicative of the natural failure pattern for any straightforward hard impact. In the past there have been many cases of landing gears being torn from aircraft because of low approaches over dikes and other obstructions and because of landings short of runways followed by the curbing of the gear on the paved runway end. Since there is no reason to believe that the 727 will not be subjected to similar treatment, it is imperative to afford a higher-degree of survivability following such accidents. We, therefore, make the following recommendations: