Pratt & Whitney PT6A | Hot Section Inspection (HSI) not mandatory and TBO times of 8000 hrs!

As we are regularly selling Turboprop aircraft, we often get questions about the engine. Most of the Turboprop aircraft we sell are equipped with a Pratt & Whitney PT6A engine. One thing buyers mostly don’t know is that a Hot Section Inspection (HSI) on a PT6A engine, when you have an engine health monitoring system in place, is on-condition. With an TBO time of 4000 hours, the HSI is scheduled at 2000 hours. Although an HSI on a PWC PT6A engine is a relatively simple job, that can be performed on wing, you only get an indication of the engine health at that moment. 

According to Pratt & Whitney Canada Service Bulletin (P&WC S.B. No. 1403) the HSI frequency can be based on Engine Condition Trend Monitoring (ECTM). In short this means that if you don’t have a ECTM system on board, you need to perform an HSI at 2000 hours. When you have an Engine Condition Trend Monitoring (ECTM) system in place, it will constantly monitor the engine condition and records everything. From start to the shut-down of the engine, all parameters will be stored. Once there is an exceedance, it will record this, the company that is monitoring this data will send a message to the owner of this exceedance. Once an exceedance has been noted, it will be time to inspect the engine and look for the cause. And when you see a deterioration in performance, you can also decide to perform an HSI. We can easily say that an engine that is monitored by an ECTM system, gives more confidence to a buyer than one that is only on an HSI scheme.

Several aircraft owners are also asking us how they can reduce the overhaul cost of their engine. As most PT6A engines have a Time Between Overhaul (TBO)  of roughly 4000 hours, these owners become nervous when the TBO time is coming closer. With overhaul prices in the range of $225k / $430k, depending on the model, you can imagine their concerns. I always advise them to look more in-depth at the MORE Supplemental Type Certificate (STC), this MORE STC increases the TBO hours to 8000 hours which is interesting for many aircraft owners. 

If you are thinking to buy a Turboprop and need assistance, please contact us, we would be happy to assist. You can reach us at vincent@faaircraftsales.com.