This Mikoyan (grenivich... No idea how to spell it) 21 variant ( also known as the (Y)E-7PD) is a STOL version of the MiG-21 used in vietnam. This plane came about when the soviets wanted to test out the short take off capabilities and was only named the Mig-21PD after the trsting was finished. This aircraft is an experimental aircraft and has little information written about it that is easily accessed, but i have found some sources that seem to be reliable. The in hame model doesnt have a forward mounted wngine like the real engine has but the inlet helps with the take off procedure... I have also tested that the STOL feature does work by not using it, testing the stock model amd comparing take off length. Thank you to @thomin for the stock Mig-21 as it really sped up the process of making one. Please dont forget to rate and comment!