This article deals with the data reduction technique using the principal component analysis applied to the carbon fiber-reinforced plastic panels for structural health monitoring approaches. Two carbon fiber-reinforced plastic panels subjected to damage and repair coincide with typical aircraft repair procedures found in the aircraft structural repair manual. The panels were simulated with 30 mm diameter of partial and full penetration damages using a diamond-coated router. The data (50 observations) were captured for the undamaged, damaged, and repaired conditions by placing lead zirconate titanate smart sensors at 100 mm across the damaged and repaired structures. A time-based data response was captured for post analysis during the interrogation on the structure at each condition. The raw data were captured in a Lamb waveform, and the interested features were extracted using Morlet wavelet analysis to evaluate the Condition Structural Index and Amplitude-Based Assessment for each condition retrieved from the Gaussian-like distribution. The results were evaluated using the principal component analysis technique in order to distinguish the characteristic of the undamaged, damaged, and repaired conditions. The results showed that in all cases considered, it was possible to distinguish the conditions of undamaged, damaged, and repaired states with promising accuracy and repeatability of the data.

In this paper, manufacturing process of aircraft radome via closed mold with vacuum infusion process is presented. Closed mold is needed to get smooth inner and outer surface. The radome mold was formed from the original part of the aircraft Duke 60 Beachcraft. The closed mold is made from fiber glass/polyester composite via hand lay-up technique. Tooling grade vinyl ester gel coat is applied on the mold to produce fine smooth surface and protection. Later, the radome part is fabricated with vacuum infusion and the consistency of thickness is achieved.

The preliminary analysis of laminate composite was conducted to analyse the optimal number of layers for aircraft radome application. In this work, the ESAComp software was used for preliminary analysis to predict the displacement during the flight operation. The ESAComp is a finite element software used for preliminary and conceptual design for composite layers. Flax fibre, glass fibre and epoxy resin were applied as the hybrid composite laminate design. The laminate construction consists of flax as the center laminate and sandwiched between glass fibre. Both fibres have the same weave pattern which is twill 2/2 and 200 gsm. The material properties for each materials were obtained from technical data sheet and used as input value for ESAComp. This software was used to analyse a single ply engineering constant by conducting fibre/matrix micromechanics analysis. The value of engineering constant of single ply for each material is then used for laminate analysis. It has range from 4,6 and 8 layers with 20%, 30% and 40% of fibre content on a flat panel with the size of 300 mm x 300 mm. The panel were fixed on each edges and under aerodynamic pressure load plus safety factor of two. Based on the result of analysis, minimum layer required is at least 6 layers if acceptance displacement is 0.1 mm. Therefore, experimental works on 6 layers hybrid laminate will be carried out to determine other requirement for aircraft radome application.

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Aviation accidents still hit the news even though the growth of technological advancement on commercial aircraft avionic systems has been impressive. Hence, one of the objectives of this study is to plot the time-based graph of commercial aviation accidents, with direct consequence from avionics instrumentations in the period of two decades, from 1996 to 2015. The second objective is to analyse two main aircraft manufacturers, Boeing and Airbus, in determining specific model of its kind that significantly involved in avionics-related instrumentation as one of the contributing factors that leads to the incidents or accidents. The third objective is to identify which avionics system that most frequently involved in aviation incidents, for both manufacturers. The final objective is to examine the main probable cause that has the highest percentage in those accidents within the said time frame. The method of collecting data is by doing comparative analysis from reliable official websites of four well-known bodies such as National Transportation Safety Board (NTSB), Federal Aviation Administration (FAA), Aviation Safety Network and Flight Safety Foundation. Results show that misfortune occurrences are directly associated with avionics within the said two decades, which mainly involved Autopilot and Flight Management System (FMS) (14% each), meanwhile the aircraft model Boeing 737 carries the highest percentage of avionics-related incidents or accidents. Nonetheless, 67% of the misfortune occurrences within the scope of study are mainly due to human error instead of technology.

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In this paper, a short review on the void and moisture content studies of fiber reinforced composites for both, synthetic and natural based fibers are presented. The review summarized the research papers in which include experimental and theoretical works that related to the void and moisture content studies. In addition to that, this review paper highlighting a few research studies conducted in literature on the effects of the void and moisture on the mechanical performances of the composite. Few common measurement methods used for the void and moisture determination are discussed here. The aims of this short review, mainly to capture the trend ranging from the recent five years back and summarize the various studies and also to compare and conclude the most common method for the determination of the void and moisture content. This paper is mainly providing a baseline in the selection of the methods for the future work of the author’s work with regard to the reduction of the presence of voids and moisture occur during the impregnation process of fiber reinforced composites, especially when using natural-based fiber.

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