Optimus Prime gained a jet pack in his new alt mode.
After Smokescreen had placed the Forge of Solus Prime on Optimus' right hand, Optimus was resurrected in a new body that came with a built in jet pack. Optimus flew to Darkmount to take on Megatron and save to Ultra Magnus.
Megatron sliced half of Optimus's jet pack with his Dark Star Saber.
After Optimus sacrificed himself, his jet pack was last seen with him as he flew into the Core.