Endoscopes have a variety of useful applications in industry for penetrating and viewing locations which are not otherwise directly accessible.  For example, to inspect the inside of a jet engine without disassembling it, an endoscope may be inserted through an entry port into the engine, thereby permitting the viewer to look inside.  The ability to inspect the inside of an engine is an especially important way of assessing damage, structural integrity, repair status, and general operability. 
The endoscope is generally inserted through an external opening in the structure to be inspected, such as a bleed or igniter port for a jet engine.  Since the precise interior location may not be directly reached from the external port, a means may be provided to guide the endoscope to the desired position.  In some circumstances, the interior location may be reached using a rigid, preformed guide tube through which the endoscope may be inserted and guided to its destination.  However, when the pathway is one which would not permit access via the rigid guide tube, an alternate means must be devised for guiding the flexible endoscope, past obstacles and gaps, to the desired target.  In particular, difficulty was experienced in inspecting specific areas of the 731 series engine manufactured by Garrett General Aviation Division of Allied Signal Aerospace Company.