Abstract: A flexible helmet bag including an integrated first compartment for holding a pilot's helmet and a second compartment for safely carrying and containing an electronic device that includes a battery capable of thermal runaway. The second compartment is configured to contain a mobile device, for example, a tablet computer, a laptop, and a smart phone. the second compartment includes a first flexible wall coupled to a second flexible wall to forming a cavity therebetween. The third wall can include a fiberglass material positioned adjacent to the cavity, an aramid material, and a silica fabric material or a carbon fiber material positioned between the fiberglass material and the aramid material. The fourth wall can include a fiberglass material positioned adjacent to the cavity, an aramid material, and a silica fabric material or a carbon fiber material positioned between the fiberglass material and the aramid material.