The plane gains some altitude and then points it’s nose down enough for its Y_acc to be the same as g which is 9.8m/s^2. After it lost enough altitude it will point its nose up and regain the lost altitude, it’ll repeat the cycle for however long they want or the fuel allows them to. It’s pretty much the same as free falling but with the plane itself instead of parachutes.

@@Born2Losenot2win Thank you!

Mechanical engineering