Report on the Examination of I Stage Compressor Blades

The damages suffered by I stage compressor blades of three aeroengines have been studied at the request of Indian Air Force

Investigation of aileron control cable failure of a Pushpak aircraft

This is an investigation on the failure of aileron control cable in a Pushpak aircraft carried out at the request of the Deputy Director General of Civil Aviation. The nature of failure is analysed

Synthesis and biological activity of α-glucosyl C24:0 and C20:2 ceramides

a-Glucosyl ceramides 4 and 5 have been synthesised and evaluated for their ability to stimulate the activation and expansion of human iNKT cells. The key challenge in the synthesis of both target molecules was the stereoselective synthesis of the a-glycosidic linkage. Of the methods examined, glycosylation using per-TMS-protected glucosyl iodide 16 was completely a-selective and provided gram quantities of amine 11, from which a-glucosyl ceramides 4 and 5 were obtained by N-acylation. a-GlcCer 4, containing a C24 saturated acyl chain, stimulated a marked proliferation and expansion of human circulating iNKT cells in short-term cultures. a-GlcCer 5, which contains a C20 11,14-cis-diene acyl chain (C20:2),induced extremely similar levels of iNKT cell activation and expansion

Enhanced priming of adaptive immunity by a proapoptotic mutant of Mycobacterium tuberculosis

The inhibition of apoptosis of infected host cells is a well-known but poorly understood function of pathogenic mycobacteria. We show that inactivation of the secA2 gene in Mycobacterium tuberculosis, which encodes a component of a virulence-associated protein secretion system, enhanced the apoptosis of infected macrophages by diminishing secretion of mycobacterial superoxide dismutase. Deletion of secA2 markedly increased priming of antigen-specific CD8+ T cells in vivo, and vaccination of mice and guinea pigs with a secA2 mutant significantly increased resistance to M. tuberculosis challenge compared with standard M. bovis bacille Calmette-Guérin vaccination. Our results define a mechanism for a key immune evasion strategy of M. tuberculosis and provide what we believe to be a novel approach for improving mycobacterial vaccines

Report on the Investigations on Failed Hydraulic Booster Jack

The fractured shaft of a hydraulic booster jack of a fighter aircraft is analysed to find out the cause of failure. This investigation was carried out at the request of the Court of Inquiry

Report on the examination of fracture of Cardon Shaft of R-11 engine and the examination of components from R-25 engine

This report deals with the examination of fracture of a cardon shaft of an R-11 engine and the examination of components of an R-25 engine involved in an accident. The failure of the cardon shaft was found to be due to torsion although it was not possible to establish the exact cause or origin of torsional failure due to severe rubbing of the fracture surface. Several components from an R-25 engine such as compressor blades, nozzle guide vanes and turbine blades and also metal scrappings were examined. No material foreign to the engine was found in these components. It was found that the H .P. and L.P : turbines had experienced excessive overheating

Report on the Analysis of Failure of a Gear and a Second Stage low pressure Compressor Blade

This report analyses the mode and cause of failure of a gear and a second stage low pressure compressor blade. The gear had failed at the gear tooth roots due to tooth bending fatigue probably caused by excessive loads on the gear tooth. The compressor blade had fractured at the root on the convex surface of the blade, almost at the mid-portion. The failure was found to be due to fatigue originating from inclusions present at critical locations near the blade root on the convex side

Examination of helicopter components

An analysis of the fracture surfaces of some of the components of helicopter (Z-3.74) has been carried out. This work was done at the request of the Court of Inquiry