During the Whirlwind course we were given a QHI demo of the effect of recovery from fast rearwards flight, in a backwards hover taxi. The old bird used to kick up her heels quite rapidly (about the only time it did anything rapidly).
I used rearwards translational lift during my time displaying the Puma HC1. One manoeuvre was to climb at full power from the hover whilst flying backwards at the fastest controllable speed. On reaching 450 feet agl, leveling off allowed the airflow to suddenly build under the horizontal stabiliser. Applying forward cyclic allowed the tail to rise (rather than the nose to drop) until the pitch attitude reached 90 degrees nose down. This was followed by a downwards vertical roll through 180 degrees, allowing the aircraft to be flown away in the opposite direction. A full 90 degrees nose down was needed, otherwise after the 180 degree roll the aircraft came out more nose down than vertical.
During one display practice the nose tucked right under to an estimated 120 degrees nose down at the top of the manoeuvre (estimated by the ground observer, my Squadron Boss) That one was bit exciting (you can't see the sky at all until you've rolled through and the ground is very rapidly approaching!) but at least after the 180 roll we were away from the vertical.