Failure analysis of undercarriage door operating lever of an aircraft

Suresh Kumar, M and Madan, M and Venkataswamy, MA and Sujata, M and Bhaumik, SK (2007) Failure analysis of undercarriage door operating lever of an aircraft. Project Report. National Aerospace Laboratories, Bangalore, India.

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A failed undercarriage door-operating lever of an aircraft was sent to the laboratory for analysis. The lever was found to have fractured in three locations, one in each arm of the lever. The link rod had fractured in the tubular section near one of the ends. Fractographic study revealed that all the fractures except the one on the long arm of the lever were caused due to sudden overload on the component. The fracture on the long arm showed presence of a fatigue crack. The crack was located in one of the webs of the arm and had a depth of 4 to 5 mm. Analysis suggests that in spite of the presence of this fatigue crack, the component had adequate strength to sustain the normal operating load. Hence, the presence of this fatigue crack appears to be coincidental and does not appear to have played any role in the present failure. In view of this, it is concluded that the door-operating lever has failed due to overload on the component, possibly due to malfunctioning/problems elsewhere in the system. It is suggested that the source (s) of overload on the component be identified and corrective measures incorporated to prevent recurrence of similar failure. No metallurgical abnormalities in the material or corrosion were found to be responsible for the failure.

Item Type: Monograph (Project Report)
Uncontrolled Keywords: Aircraft;Undercarriage door-operating lever;Fatigue;Overload
Subjects: AERONAUTICS > Aeronautics (General)
CHEMISTRY AND MATERIALS > Chemistry and Materials (General)
Depositing User: Ms. Alphones Mary
Date Deposited: 26 Jul 2011 05:21
Last Modified: 26 Jul 2011 05:21

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