At the beginning of the 1990s, there was a chronic lack of inspectors for towed equipment.
The training course for APK inspector level 2 includes many elements that are completely irrelevant to towed equipment, especially with regard to the engine, among other things. TRTA exerted a considerable amount of pressure to introduce the APK 3 inspector grade exclusively for heavy-duty towed equipment.
Both the training and the diploma were successfully realised, thereby lowering the threshold for trailer mechanics to become an APK inspector and ensuring that the number of inspectors rose again.