Not sure about that, if there is no additional thrust the aircraft will be decelerating because it's running "uphill", pulling the gravity vector forward. It'll

Not sure about that, if there is no additional thrust the aircraft will be decelerating because it's running "uphill", pulling the gravity vector forward. It'll be balanced, so you don't "feel" acceleration or deceleration. It's the same in a car, if you are coasting in neutral and encounter a hill, even though the car will be slowing down there is no "perceptible" longitudinal acceleration because it's caused by gravity (equally acting on the car and the occupant), just like in space or one of those zero-G flights. There would be an increase in drag when pitching up, that would also cause deceleration.