Abstract: In ultrasonic echo testing to detect flaws in manufactured articles, raw materials and such it is desirable to maintain a predetermined spacing and relative orientation of the ultrasonic transducer and the surface of the tested article. Thus, automatic scanning of the article by repetitively translating the transducer across its surface is difficult or impossible if the article surface is anything other than flat. Herein, a plurality of satellite transducers are mounted with and around a primary transducer on a motor-adjustable articulated transducer head in ultrasonic test equipment so as to receive part of the main beam echo and thereby produce respective distance signals, which signals are used by control apparatus to control the transducer head adjustment motor and thereby regulate the primary transducer position relative to the tested article.