A method for ultrasonic inspection of a test object, comprising the steps of: - defining a coordinate system of the test object based on at least a first, a second and a third spatially separated position at a surface of the test object; - selecting, relative to the coordinate system of the test object, a plurality of spaced apart positions for delimiting a test area of the test object, the test area being an area of the test object which is to be inspected; - positioning a transducer of an ultrasonic measuring device at each of the plurality of positions to enclose the test area by a plurality of transducers, wherein each of the transducers comprises a transmitter for transmitting an ultrasonic wave pattern signal and a receiver for receiving an ultrasonic wave pattern signal; - transmitting, by means of the transmitter of each of the plurality of transducers, an ultrasonic wave pattern into the test object, along the surface of the test area enclosed by the plurality of transducers; - receiving, by means of the receiver of each of the plurality of transducers, the ultrasonic wave pattern signal transmitted by the transmitter of the remaining plurality of transducers; - acquiring an ultrasonic reference wave pattern signal for a reference area of a reference object, the reference area being provided with a plurality of transducers of an ultrasonic measuring device having a respective position within a coordinate system of the reference object corresponding to the plurality of positions of the test area within the coordinate system of the test object, the ultrasonic reference wave pattern signal being acquired by transmitting an ultrasonic wave pattern from a transmitter of each of the plurality of transducers arranged on the reference object to a receiver of each of the remaining transducers arranged on the reference object, wherein the test area of the test object and the reference area of the reference object correspond to each other in shape and structure; and - comparing the received ultrasonic wave pattern signal from the test object with the acquired ultrasonic reference wave pattern signal of the reference object for detecting a defect in the test object. - defining a coordinate system of the test object based on at least a first, a second and a third spatially separated position at a surface of the test object; - selecting, relative to the coordinate system of the test object, a plurality of spaced apart positions for delimiting a test area of the test object, the test area being an area of the test object which is to be inspected; - positioning a transducer of an ultrasonic measuring device at each of the plurality of positions to enclose the test area by a plurality of transducers, wherein each of the transducers comprises a transmitter for transmitting an ultrasonic wave pattern signal and a receiver for receiving an ultrasonic wave pattern signal; - transmitting, by means of the transmitter of each of the plurality of transducers, an ultrasonic wave pattern into the test object, along the surface of the test area enclosed by the plurality of transducers; - receiving, by means of the receiver of each of the plurality of transducers, the ultrasonic wave pattern signal transmitted by the transmitter of the remaining plurality of transducers; - acquiring an ultrasonic reference wave pattern signal for a reference area of a reference object, the reference area being provided with a plurality of transducers of an ultrasonic measuring device having a respective position within a coordinate system of the reference object corresponding to the plurality of positions of the test area within the coordinate system of the test object, the ultrasonic reference wave pattern signal being acquired by transmitting an ultrasonic wave pattern from a transmitter of each of the plurality of transducers arranged on the reference object to a receiver of each of the remaining transducers arranged on the reference object, wherein the test area of the test object and the reference area of the reference object correspond to each other in shape and structure; and - comparing the received ultrasonic wave pattern signal from the test object with the acquired ultrasonic reference wave pattern signal of the reference object for detecting a defect in the test object.