HAL signs ToT with CSIR-NAL for BMI Engine Bay Door for Series Production of LCA-Tejas

Navratna Defence PSU Hindustan Aeronautics Ltd (HAL) signed a Transfer of Technology (ToT) agreement with CSIR-National Aerospace Laboratories (CSIR-NAL), Pune, on 8 November 2023. The agreement aims to manufacture BMI Engine Bay Door for the series production of Light Combat Aircraft (LCA) — Tejas Mk1A, an indigenous 4.5 generation, all weather and multi-role fighter aircraft for the Indian Air Force.

Over the last three decades, CSIR-NAL has developed many critical technologies for the LCA-Tejas and continues to support this major national programme.

Advanced Composites Division (ACD) of CSIR-NAL has pioneered the design & 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 developing the composite parts for LCA-Tejas, which include Fin & Rudder, Wing Spars, Wing Fuselage Fairings, Fairings blocks, Centre Fuselage parts, & Undercarriage Doors. The innovative technologies by CSIR-NAL reduce the cost and improve structural efficiency by minimising the number of mechanical joints. The innovations have resulted in more than 20% cost savings and 25% weight reduction in the parts of the LCA-Tejas.

In continuation to the above indigenous development, for the first time in the country, CSIR-NAL 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 °C. The processing of Carbon-BMI is very tricky because the resin becomes very thin as viscosity reaches 8-10 centipoises at higher temperatures. Hence, retaining the resin within the laminate is a major challenge. During the process, it emits volatiles and moisture while curing. Therefore, proper venting is necessary during the curing of these resins; otherwise, it may cause process-related defects such as voids and delaminations.

Furthermore, HAL has requested for transfer of technology for the BMI Engine Bay Door, and the ToT Agreement has been entered between HAL & CSIR-NAL in the presence of Mr Anbuvelan S, CEO (HC), HAL and Dr Abhay A Pashilkar, Director, CSIR-NAL. With signing the agreement, 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.

Direct Benefit: 

•    The Value of Transfer of Technology (ToT) of BMI Engine Bay Door for series production of LCA-Tejas Mk1A with License Fee of Rs 4.42 Crores and Royalty payment of Rs 62.44 lakhs (Total LCA-Mk1A aircraft order from IAF to HAL is 83 nos). The Royalty is payable till the last part is manufactured by the HAL. 

•    The total ToT & Royalty value of about Rs 5.05 crores to be realised by CSIR-NAL from the development of BMI Engine Bay Door composite parts for LCA-Tejas from HAL.

•    This is the second-highest ToT value in the history of NAL. Earlier, the high-value ToT of Fin & Rudder to HAL was during Aero India in February 2023 with a license fee of Rs 12.98 Crores and a royalty payment of Rs 6.37 crore for 83 aircraft.