Bengaluru, Nov 8 (PTI) Hindustan Aeronautics Ltd (HAL) signed a Transfer of Technology (ToT) agreement with CSIR-National Aerospace Laboratories (NAL) on Wednesday, for the manufacturing of BMI Engine Bay Door for the series production of LCA – Tejas Mk1A.

Tejas Mk1A is an indigenous 4.5 generation, all weather and multi-role fighter aircraft for the Indian Air Force. HAL had requested for transfer of technology for the BMI Engine Bay Door, and the ToT agreement has been reached between it and HAL, CSIR-NAL said.

'With the signing of the technology transfer for BMI Engine Bay Door, HAL can directly produce these high temperature resistant composite parts for the series production of LCA Mk1A aircraft meeting the initial requirement of IAF squadrons,' it added.

Continuing with the indigenous development, for the first time in the country, CSIR-NAL said, it has developed manufacturing process technology of High Temperature Resistant Co-cured Composite Structures using Carbon-BMI Prepreg for the engine bay door where it can withstand the service temperature of about 200 degree C.

The processing of Carbon-BMI is very tricky, because the resin becomes very thin as viscosity reaches 8-10 centipoises at higher temperatures, it said. Hence, retaining the resin within laminate is a major challenge.

During the process it emits volatiles and moisture while curing, it further said, adding therefore, proper venting is necessary during the curing of these resins; otherwise, it may cause process-related defects such as voids and delaminations.

Noting that over the last three decades, CSIR-NAL has developed many critical technologies for the LCA – Tejas and continues to support this major national programme, NAL said, its Advanced Composites Division (ACD) has pioneered the design and development of composite structures using innovative and cost-effective manufacturing technologies including co-curing/co-bonding constructions.

The laboratory has played a pivotal role in the development of the composite parts for LCA-Tejas which include: Fin & Rudder, Wing Spars, Wing Fuselage Fairings, Fairings blocks, Centre Fuselage parts & Under carriage doors, it said.

The innovative technologies developed by CSIR-NAL not only reduces the cost but also improves the structural efficiency by minimising the number of mechanical joints, it said, adding that the innovations have resulted in more than 20 per cent cost savings and 25 per cent weight reduction in the parts of the LCA-Tejas. PTI KSU RS KSU ROH