The maintenance assembly, for workers to perform maintenance activities within a gas turbine engine, is capable of being arranged within a cavity, generally around a combustor, accessible from a manhole of the gas turbine engine. The maintenance assembly includes a platform, and an inflatable member cooperatively configured to the platform. The inflatable member is at a normal condition, when placed outside of the cavity, being at a deflated position and is at a working condition, when arranged within the cavity, being at inflated position so as to accommodate a shape coordinating the cavity in such a manner that the platform is advance within the cavity up to a predetermined level to enable the workers on the platform to reach at a predetermined position within the cavity to perform the maintenance activities.