3.3 m/s flying machine. HELP

https://preview.redd.it/p1cowmmmb6jh1.png?width=3420&format=png&auto=webp&s=d337728cb171d070a4ce5c1a664c7e606cf0a086

https://preview.redd.it/96m0kc8sb6jh1.png?width=1708&format=png&auto=webp&s=600b2e12490ab1fe16b362d776ebfbffb9b17cb3

I Have this flying machine that travels at 3.3 m/s. I am trying to add an extension to make it bigger but I can't find anything that works ive tried something like this but it didn't work, can someone help me

https://preview.redd.it/5kc9af92c6jh1.png?width=1708&format=png&auto=webp&s=5cd038b3a51b7ad2604f6bc23327b2f55c63d3c0