Pratt and Whitney’s PT6 engine is one of the most reliable and cost-effective engines ever built. However, pilots and people involved in the engine repair and overhaul business have become very much aware of the fact that the PT6 is not immune to increasing maintenance costs.

PT6 fuel nozzles are one part of the hot section maintenance that must be serviced on a regular basis. The design of the fuel nozzle and installation is simple and efficient. Unfortunately however, there is a good deal of misunderstanding surrounding the maintenance and required overhaul of the fuel nozzles.

It is recommended that the PT6 and PT6A fuel nozzles be checked on a regular basis with the first inspection focusing on damage to the tip, adapter and sheath. It is important that the nozzle tip is carefully cleaned using an ultrasonic cleaning machine. This procedure takes time and is one that should not be rushed. If cleaned improperly, the tip may need to be replaced, which is quite costly.

Next, a leak test should be performed. This test will reveal if there is any problem between the nozzle tip, lock tab and adapter assembly at the points of seal. Once the leak test is done, a flow check should be carried out. Be sure to note any odd spray patterns and identify where they originate from. Finally comes the sheath inspection which is done to see if it is calibrated correctly.