As the Rotodome was positioned outside the Aircraft at a height of 5 metres carrying a total weight of 750 kgs. the quality assurance of the assembly was very critical.

First a 1/5th size of the actual component was manufactured with known induced defects for destructive and non-destructive test purpose.

The following non-destructive tests were carried out.

Ultrasonic C-scan

The ultrasonic C-scan testing is the most widely used test for the evaluation of large composite components. The system is capable of performing through transmission of pulse echo tests producing a permanent attenuation record in the from of a C-scan read out. The component under testing will be fixed between two Transducers, one transmitter and another receiver, which are mounted with water jet nozzles for achieving the sonic coupling between the transducer and the component under evaluation. The ultrasonic signal is plotted on an X-Y recorder. The movement of the probe on the surface of the component is synchronized with the position of the plotter on the X-Y recorder & the complete surface of the component will be displayed. This presentation shows both surface image of the defect and the exact contour of the defect in the component (i. e. cross section of defect).

The ultrasonic C-scan test could not be performed on such a large components in the case of radome. Hence a replica of the component with the same cross-section was made out of the same materials and process of fabrication and curing and ultrasonic C- scan was performed the detail methodology has been demonstrated.

X-ray radiography

The Rotodome was mounted on a stand and a portable X-ray equipment with a movable stand was positioned to align with the major areas of inspection. Totally 60 shots were taken in insert bonded area to check the bonding between inserts and nomex core with foaming adhesive. The image of the insert position was recorded on a X-ray film.

The results of the ultrasonic and X-ray radiographs were compared with the acceptance requirements for the airbone composite structures. The studies resulted in the final acceptance of this largest advanced composite structure produced in the country from Glass/Epoxy Prepregs.