An HSI can help you save money by finding little issues before they develop into larger problems, requiring the replacement of parts. As mentioned above, there are scheduled and unscheduled HSI’s. With scheduled HSI’s, this is routine maintenance, that in the long run helps keep your aircraft running properly and catches things before they become a larger issue down the road.
For example, an HSI can reveal a minor crack. Thanks to the HSI, the technician can repair it with welding or grinding right away. If the crack is overlooked at an early stage, it can cause the entire component to need to be replaced later, therefore costing more money and even a delay in repair if you can't get the part.
The actual cost of the HSI depends on what information is uncovered. If the engine is in good shape, all you have to do is pay for the examination itself. However, if the HSI reveals that important components must be replaced, this can result in significant expenses.
An HSI is a perfect opportunity to inspect the engine's health since it is already in the shop. There are some easy maintenance activities you can do during an HSI that will bring additional benefits. External fuel and oil leaks can be checked for, as well as gearbox oil seals. Cases can also be inspected for corrosion, which is particularly vital for aircraft that operate near salt water.