Aerospace Endoscopes

Often for inspections we have to see inside things and this can be technically referred to as an endoscopy – something which is more familiar as a medical term, although is now widely used as a generic term in aircraft engineering. In general industry it is often called a borescope to get away from the medical conotations. As its name suggests, a borescope can inspect things through a hole. Their rigid design makes them ideal when straight-line access to the inspection area is possible.

Aircraft endoscopes are used to inspect aircraft engines, turbines, wall cavities, weapon systems and fuel injectors. They use an optical system to transmit an image from the lens at the inspection area back to the eyepiece. In some instances a still or video camera can be mounted on to the eyepiece to allow the inspection to be visually documented. The inspection area can also be illuminated by adding a fibre bundle which relays light from an external source.

The rigid nature of endoscopes ensures that they provide a high quality image with little distortion. Instrument diameters range from 0.9 mm (0.03 in) to 16 mm (0.6 in) with working lengths of up to 1.5 m (4.9 ft) although longer lengths are possible using extension tubes.

Some endoscopes offer a greater field of vision by attaching the lens to a swing prism. This can allow the user to adjust the direction of view from 55º to 115º and inspect a greater area in a shorter space of time.

Endoscopes ease of use offers a straightforward inspection solution with minimum set-up.

Aero engine inspection equipment and video probes 

Technology has changed our lives and changed the way in which we inspect things. Video technology has evolved greatly and we can now inspect and record in the narrowest of spaces using video probes. Video probes offer state-of-the-art technology to inspect pipe work of all sizes, ducting, wall / floor voids and many other areas – effectively places which are inaccessible to the human eye.

How can a small camera see in spaces that have no natural light? Video probes are fitted with lights which are either comprised of fibre optics or LED illumination. Fibre optic lighting tends to feature on smaller diameter instruments. Illuminated guides can offer light up to 50 m (164 ft) but the diameter of the guide is larger.

The key advantage of video probes is their ability to provide high resolution real-time video outputs, allowing us to see the cause of the problem and in some instances, solve it there and then if it is a blockage, by using retrieval tools to remove the obstruction. The footage can also be recorded or captured in still photographs.

The video probe’s control unit is where the sophistication becomes apparent. Simple systems offer controls for illumination, while higher end models incorporate features such as character generation, electronic zoom, picture comparison, video image storage and image transmission capability. They offer a flexible, compact and effective inspection solution.

Aerospace Fibrescopes

Aerospace fibrescopes are flexible inspection devices made of a fibre optic bundle and transmit an image from a lens at one end to the user’s eyepiece at the other end. The greater the number of individual fibres which are included in the bundle, then the better the resolution of the image.

Fibrescopes are constructed for tough industrial handling and are used in a variety of remote visual inspections, often in places which cannot be easily inspected by man. They are ideal for capturing bright, clear images from inside turbines, pipes, tanks, tightly packed equipment and other small or difficult to reach places.

They can either be articulating, non-articulating or semi rigid based designs. In some instances the eyepiece is replaced with a camera to capture and record what is being inspected. They can also be fitted with an additional fibre which allows light to be transmitted to the inspection lens from an external source.

Articulating fibrescopes use coherent image bundles (or guides) to transmit the image from the inspection site to the user’s eyepiece. This allows the user to control the lens by using knobs and levers on the handle. Depending on the diameter of the fibrescope either two or four way controls are available.

The diameter of an articulating fibrescope can be as small as 0.5 mm (0.019 in) and reach a length of up to 2.7 m (8.9 ft). A good articulating fibrescope has a range – how many degrees the working ends can move in any given direction – which exceeds 90º in any direction. The range generally reduces as the distance increases due to the tension on the wires and controls.