Corrosion Monitoring of Aircraft Based on the Corrosion Prognostic Health Management (CPHM) System

Abstract

The article presents methods to monitor the actual state of aircraft’s airframe, in particular, the onset of corrosion. The greatest emphasis is put on the “Corrosion Prognostic Health Management” CPHM system. Authors discuss corrosion detection using NDT methods as well as the possibilities of forecasting methods for estimating the onset of corrosion basing on the data gathered by means corrosion sensors. Based on the results of the previous research and analyses, authors focus on monitoring the internal microclimate and the factors causing corrosion in the aspect of damage tolerance operation of the aircraft. The results of the preliminary studies giving credibility to the concepts of predicting corrosion onset in the aircraft structure are presented. Preliminary results of tests carried out in supervised flights are also presented. The final part of the article presents the concept of modernizing the corrosion field site in order to use it in hermetic and non-hermetic tests of aircraft spaces.

Qualitative to Quantitative Non-Destructive Evaluation: A Concept for D-Sight Inspections of Aircraft Structures

“…The severity of corrosion remains difficult to evaluate. This is confirmed in several publications [6,11], where the evaluation of a progress of a corrosion process is performed based on a comparison of the image of the D-Sight inspection with a reference image of such an inspection representing a healthy structure or historical data of a tested structure.…”

“…From a variety of NDT techniques approved in the aviation sector for the testing of aircraft structures for corrosion [5], including well-known NDT techniques, such as ultrasonics, radiography, infrared thermography and eddy current testing [6], one can distinguish a double-pass retroreflection optical NDT technique with the commercial name D-Sight™. The D-Sight technique was developed in the late 1980's, for optical inspection of surface and subsurface defects in the automotive and aerospace industries [7].…”

“…The D-Sight technique was developed in the late 1980's, for optical inspection of surface and subsurface defects in the automotive and aerospace industries [7]. Its numerous advantages, which include the possibility of fast and sensitive inspection of large surfaces in a very fast way and independence on the properties of source light, this technique has been applied in non-destructive inspection (NDI) of aircraft structures over last three decades until nowadays [6,[8][9][10][11][12]. Despite the wide applicability of the D-Sight technique in inspection of aircraft structures, the technique remains mainly qualitative, which means that the output of inspection is an image with visible corrosion spots on a tested structure.…”

Automated Identification of Hidden Corrosion Based on the D-Sight Technique: A Case Study on a Military Helicopter

“…Because hidden corrosion, even at high severity, is barely visible to the naked eye, NDT-based approaches are necessary for sensing and detection. According to the literature [ 2 , 3 , 6 , 10 , 11 ], the following NDT techniques are used most often in such inspections: X-ray radiography/tomography, ultrasonography, eddy current testing, thermography, and shearography. However, their application is often biased by a certain amount of uncertainty in detecting hidden corrosion spots because of the low magnitude of the resulting deformations and the specificity of the application of particular techniques.…”

Monitoring of Hidden Corrosion Growth in Aircraft Structures Based on D-Sight Inspections and Image Processing

“…The usage of the latter techniques is defined by their high sensitivity to corrosion as well as their high probability of detection and quantification of corrosion [ 19 ]. A comparative study presented in [ 20 ] shows that in aircraft maintenance practice, many of the mentioned methods are applied simultaneously or in various combinations. Nevertheless, to reduce the costs and duration of inspections, some NDT techniques are favorable.…”