Aging Aircraft; Structural Failure
AGING AIRCRAFT: STRUCTURAL FAILURE
Introduction
1. The term ‘Aging Aircraft’ generally applies to the aircraft getting older in its operational service. An aircraft begins to ‘Age’ as soon as it first flies and various effects begin to occur. However, the term is usually applied to the issues which can begin to arise as the time-since-new becomes significant. Aircraft design methodologies and approved maintenance schedules take account of the effects of the continued use of aircraft. Non Destructive Inspection (NDI) methods and other inspection / repair technologies are routinely established nowadays. However, keeping older jet aircraft in an airworthy condition has been found to present special difficulties. Special emphasis is needed to apply continuous effort in recognition of significant issues arising directly from age of aircraft as these pose fatal threats.
Structural Failure Due to Aging
2. The main causes for the structural failure of an aircraft due to aging are briefly discussed as following.
(a) Metallic Corrosion. The deterioration of the surface of a metal due to a chemical reaction is called metallic corrosion. This occurs because metals come in contact with electrolyte mostly contaminated water. As it arises, it may go undetected and result in loss of integrity of metallic structures. Since metallic corrosion is directly related to structural integrity, there is a dire need to look into the ground environment where an aircraft is usually parked and the typical flight environment. Improved inspections including the use of Non-Destructive Testing (NDT) and the management of any corrosion found through effective repair techniques, mapping technologies and recording are neutralizing this aging cause. Also the use of protective coatings and surface treatments are being utilized to minimize the effects of metallic corrosion.
(b) Structural Fatigue. Structural Fatigue is the process where a compound begins to develop cracks
Introduction
1. The term ‘Aging Aircraft’ generally applies to the aircraft getting older in its operational service. An aircraft begins to ‘Age’ as soon as it first flies and various effects begin to occur. However, the term is usually applied to the issues which can begin to arise as the time-since-new becomes significant. Aircraft design methodologies and approved maintenance schedules take account of the effects of the continued use of aircraft. Non Destructive Inspection (NDI) methods and other inspection / repair technologies are routinely established nowadays. However, keeping older jet aircraft in an airworthy condition has been found to present special difficulties. Special emphasis is needed to apply continuous effort in recognition of significant issues arising directly from age of aircraft as these pose fatal threats.
Structural Failure Due to Aging
2. The main causes for the structural failure of an aircraft due to aging are briefly discussed as following.
(a) Metallic Corrosion. The deterioration of the surface of a metal due to a chemical reaction is called metallic corrosion. This occurs because metals come in contact with electrolyte mostly contaminated water. As it arises, it may go undetected and result in loss of integrity of metallic structures. Since metallic corrosion is directly related to structural integrity, there is a dire need to look into the ground environment where an aircraft is usually parked and the typical flight environment. Improved inspections including the use of Non-Destructive Testing (NDT) and the management of any corrosion found through effective repair techniques, mapping technologies and recording are neutralizing this aging cause. Also the use of protective coatings and surface treatments are being utilized to minimize the effects of metallic corrosion.
(b) Structural Fatigue. Structural Fatigue is the process where a compound begins to develop cracks