Aviation Inspection 101: Using Modern Videoscopes to Measure Tip Gap Clearance

Regular aviation inspection is essential to safe travel. Using a videoscope with precise measurement features can help prevent critical engine problems. One of the most inspection tasks made easier because of videoscopes is the tip gap clearance measurement.

The USA200 Series Borescopes offers a comparative measuring feature with a measuring probe.   The on screen measuring grid aids in identifiy the size of defects.    This system is also available in a 4mm diameter probe with the same comparative measuring probe tip.

Carrying out the tip gap clearance measurement is a challenging yet important task for aviation engine inspection. The technique requires the use of accurate placement of reference points to determine the status of the engine.

Tip Gap Clearance Measurement: An Overview

Tip gap clearance is a method that involves measuring the distance between the tip of the blade and the engine shroud. The technique is carried out to ensure a proper distance between the blade and the engine shroud, which results in efficient engine performance.

Measuring the distance between the tip of the blade and the engine is difficult. Conventional videoscopes are not suitable for this task since enlarging the inspection area means moving away from the target object. The furthest distance that the conventional videoscope can measure is about 0.8 inch or 20 mm. Accuracy decreases significantly beyond the distance because of which measuring tip gap clearance is not possible.

To get a precise and accurate measurement, you need to know the following:

  • Distance from the object to be measured
  • Size of the object to be measured

The above two factors can greatly affect the size of the measurement. You need to know how far away the tip from the object is prior to conducting the tip gap measurement. Modern videoscopes with high quality scopes can help measure the tip-to-target distance from the image with great accuracy.

Use of Modern Videoscopes for Tip-to-Gap Measurement

The latest videoscopes have features that allow measuring tip-to-target or Z distance within an image. This allows the video scope to display samples of the distance in real-time, thereby highlighting multiple Z values of the image.

Aviation technicians use a videoscope to get important details required for measurement that allows them to understand the surface profile. It helps them get accurate measurements of the tip gap clearance.

An important thing to remember when using a videoscope for performing the tip to gap analysis is that the angle between the videoscope device and the blade’s tip can cause incorrect perception about the clearance boundaries. To avoid this issue, a reference plane must be set at a specified surface and then the measurements should be taken perpendicular to the plane. Measuring the gap is easy after correctly defining the plane using this method.


Visualization of hard-to-reach positions is possible using a videoscope. The camera can go through the machine to perform an advanced inspection. Carrying out the tip gap analysis can help troubleshoot turbine problems that can lead to critical engine failure.

Contact USA Borescopes for modern videoscope for aircraft and helicopter engine maintenance. We specialize in providing high quality videoscopes with the latest technologies that can be used for advanced inspection of aviation engines.   Call one of our trained sales professionals at 931-362-3304.