Sounds to me like you are turning your jets off late (or not turning them off properly). Make sure you are turning off your jets at a lower altitude, I used to get the jets firing intermittently due to limited oxygen at high altitude which causes the plane to spin. I started flying on rocket only above 10k and it fixed it. Best to bind an action group to turn them off at the same time. You should be able to hear them "popping" if this is what is causing the issue.