For medium strength aircraft plywood ISI Mark is Mandatory as per BIS IS 709: 1974. This Indian Standard lays down the requirements, sampling and test procedures for medium strength aircraft plywood to be used in the construction, repair and maintenance of aircraft structure and aircraft related aerospace applications. The standard specifies the following critical quality parameters: dimensions, thickness tolerances, veneer quality, bonding strength, density, moisture content and mechanical properties, in order to ensure that the product has sufficient strength, durability and reliability under operating conditions. IS 709:1974 specifies the criteria for the selection of appropriate timber veneer and high-performance adhesive bonding systems which will enable consistent structural performance with an acceptable strength to weight ratio. This standard stresses in manufacturing a high level of manufacturing control and exhaustive testing for resistance to delamination, dimensional instability and mechanical stresses at operating conditions. It also covers marking, packing and labelling for product identification, traceability and checking of compliance. BIS certification as per IS 709:1974 guarantees that medium strength aircraft plywood meets national standards for quality and performance, ensuring safety, reliability, and suitability for aerospace applications.
