Computerized X-ray tomography is free from these shortcomings. This method allows to reach considerably higher sensitivity than X-ray one. Moreover, the geometrical correlations between the details are fully restored.

One of the wide classes of aircraft technique that causes crashes and malfunctions includes MICRO OBJECTS such as parts of control system aggregates, electronic assemblies, automatic systems. The computerized high resolution X-ray tomography (Microtomography) is the most informative method for the diagnostic of the state of faulty assemblies in this class of the aircraft technique. The results of the investigations and the development of the Microtomography system for small size aircraft assemblies testing, are described in this paper.

The system includes following parts: microfocal X-ray source, precision scanner, control personal computer, receiving TV-system based on the X-ray vidicon, projection data pre-processing system, the special processor for image reconstruction, the system for reconstructed tomograms processing and documenting.

The special feature of the microtomograph is that the special TV- camera as the radiation receiving system. The camera is based on the X-ray vidicon (40-160 kV) with 90 mm amorphous selenium target; it has an electromagnetic focal and the electron beam deviation systems. The camera works in he uninterrupted reading mode with 25 frames per second frame frequency and 625 or 1125 lines per frame, as well as in the increased accumulation duration mode (upto 1000 frames) with locked electron beam and the digital conversion and storage block plugged in the X-ray television installation. When using the accumulation mode the sensitivity for passed X-ray radiation is essentially increased because of low power of the microfocal source. The dynamic range of the receiving TV-system is from 0, 5 upto 10⁴. X-ray vidicon works effectively in the voltage range on the X-ray valve anode from 40 upto 250 kV.

The microfocal X-ray source with 150kV maximum voltage and 15 µm focus size is used.

The main technical data of the microtomograph: the object diameter - upto 50 mm; the object length - upto 50 mm; steel (aluminum) equivalent thickness - upto 15 (40) mm; positioning error (X, Y, Z) - 5 µm; angle positioning error - 1 min; spatial resolution - 20µm; pixel size - 0.1 mm (normal mode), 0.03 mm (high resolution mode); layer scanning duration - not more than 15 min.

Following operations are executed automatically:

• data collection system calibration;
• obtaining an observation image;
• scanning the object in the tomography mode;
• placing the data on the magnetic storage;
• tomogram reconstruction;
• image processing and analysis;
• documenting an observation image or a tomogram.

The results of aircraft MICRO OBJECTS testing adduced:

• forcing collector fuel burners;
• aggregate bearings;
• welded connections of the pipelines for fuel and special liquid feeding;
• non-metallic details.

A considerable economic effect equal to the cost of an aircraft at the minimum is expected yearly because of the installation of the tomography into the practice of the catastrophe causes investigations. This is possible owing to the elimination of the catastrophes and crashes causes, that were not detected before.