IRAN, Inspect and Repair As Necessary, can be a periodic procedure requested by a conscientious owner, or can be required after a prop strike or an inadvertent over speeding or overheating of the turbine in a normal operation.
We here at Turbine Power Technologies have, with over 40 years of experience working with turbines and experimental aircraft, developed many new ways to enhance the performance and durability of the Walter engine. This includes metal and ceramic coatings on the combustion area of the turbine which mitigates heat damage and promotes more even burning of the fuel. After a prop strike or overheating of the engine, we often need to replace power and compressor blades in different sections of the engine. See the section on Borescope Inspections.
We at TPT have a new, state-of-the-art balancing machine for getting the shafts perfectly balanced. This is extremely important because of the high speeds involved within the turbines.
We also have a state-of-the-art balancing machine for the power turbine.
We are able to modify the engines slightly to bring down high temperatures and to increase the power. By adjusting the fuel system properly, and this is an extremely common problem with used Walter turbines, we can get the most power and efficient fuel delivery to the engine.
Our test stand, third generation, state-of-the-art, allows us to make adjustments during both high and low torque operation of the engines. It is easy to induce and identify any potential problems with the engine on the test stand.
The routine IRAN of a Turbine includes:
- Studying the logbook history of the turbine
- Dismantling the turbine completely
- Cleaning and inspecting all turbine parts
- Checking the hour-limited/cycle-limited replacement time for turbine parts
- Repairing or replacing turbine compressor blades in the 1st and 2nd stages
- Repairing or replacing compressor turbine blades
- Replace compressor thrust bearing and compressor turbine bearing
- Assembling the turbine shaft completely and balancing the same
- Repair the outer combustion chamber and the fuel manifold
- Repair air-back-wall diffuser blades
- Repair or replace the compressor stator blades
- Repair the inner combustion chamber and apply a metal and ceramic coating thereto
- Repair the compressor turbine nozzle and apply a metal and ceramic coating thereto
- Replace the deflector plate, if needed
- Replace thermocouples, if needed
- Replace the spark plugs and test the starting torches
- Repair or replace power turbine blades
- Assemble the power turbine shaft and balance it
- Examine the front and rear gearboxes
- Examine the exhaust system
- Clean all screen filters in an ultrasonic cleaner
- Dismantle and clean and inspect all turbine valves
- Reassemble the turbine completely
- Inspect all of the turbine accessories and repair or replace, if needed
- Replace the stator generator brushes and, if needed, replace the bearing
- Strip and apply new paint to gearboxes
- Test run turbine on test stand for approximately two hours with different power settings while adjusting FCU and prop governor
- Preserve the fuel system with preservative oil
IRAN of a Propeller generally includes:
- Examining the logbook history of the propeller
- Dismantling the propeller completely and cleaning all parts
- Inspecting propeller parts and repairing or replacing defective or worn parts if necessary
- Remove any old paint or coatings from the parts and apply new
- Replace all bearing balls
- Replace the complete seal and o-ring
- Assemble the propeller completely
- Balance the propeller on the test stand