During my L1011 conversion at Palmdale in 1975, I hired a C150 and flew my lady friend to Tehachapi from Fox Field. We had a leisurely lunch and took off to retrun to Fox field. Climbing at 500 fpm coming through the gap at 4,500ft, ROC suddenly increased to 1500fpm with a rapid rise in altitude. I pitched down, increased power but the aircraft was still rising in a pitch down attitude. We fell out of it at 10,000ft. I was innocently asked by my girfriend during the inadvertent climb as to where we were going and my answer was I really don't know.
