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facility and one-of-a-kind “Engine Test Center.” The MRO facility operates a production floor for six engine product lines, engine accessories and component repair. It is expected to house at least 10 additional engine lines by 2019.
Next door, the engine test center is comprised of six engine test cells with the capability of testing up to 25,000 pounds of thrust. Each area is strategically designed to achieve quicker turn times and reduced cost. In addition, the company has nine regional turbine centers (RTC’s) and 50-plus field service reps from 27 dispatch locations (a map of facility locations can be found on their website, dallasairmotive.com).
“Our success with the PT6A stems from our ability to be close to customers through our RTC’s, F1RST Support field service team and valuable partnerships like the Pinnacle Air Network,” said Joe Capra, senior commercial director at Dallas Airmotive. “We all have the same goal: keep customers flying and minimize maintenance costs.”
Expectedly, Capra notes cost is almost always the top question and concern amongst PT6A owners. The good news, however, is those owners can significantly influence the life and operating cost of their engines through certain operating and maintenance practices. The bulk of those practices fall under two categories: following OEM recommendations and conducting preventative maintenance.
Follow OEM Recommendations
The Pilot Operating Handbook (POH) should be every operator’s go-to for engine operation guidelines. Adherence to OEM recommendations will lead to savings in both time and money when it comes to servicing the engine.
“Following the POH is extremely important,” said Capra. “When the parameters are continually exceeded, we often see those engines come in for shop visits related to degradation of the engine, usually as a result of exceeding engine temperature limits.”
This is because extended operation outside recommended power settings can result in hot section component distress and increase general engine wear and tear. Consequently, the engine may prematurely reach operating limits (adding cost).
Another frequented topic among PT6A owners is TBO extensions. This option potentially allows operators to achieve maximum usage out of their engine. Though appealing to some, there are several factors to consider. One being an aircraft operated beyond the manufacturer’s TBO is likely to appear less attractive in the used aircraft market. Additionally, operators should consider the potential toll on the engine’s health.
“Whenever this question comes up, we answer depending on the hours they fly,” said Capra. “If an operator is racking up lots of hours flying each month, an approved TBO extension may work without issues. However, if there is a greater amount of time between flying, the engine is likely susceptible to corrosion.”
Capra explains that in those particular cases, when the engines are serviced, what could otherwise have been a repairable part may now need to be replaced. Typically, Dallas Airmotive embraces a “repair versus replace” mentality. “But whether it’s a brand-new or used part, we provide customers with detailed options to fit their unique situation,” continued Capra. The basic Time Between Overhaul (TBO) and Hot Section Inspection (HSI) interval is published in the appropriate Service Bulletin for each PT6A engine model.
Preventative Maintenance
There are a number of preventative measures Dallas Airmotive recommends PT6A operators take in order to keep their engine its healthiest:
• Fuel nozzle maintenance – The No. 1 most “cost effective
insurance” against hot section distress is using conservative
fuel nozzle maintenance intervals;
• Borescope inspections – In conjunction with fuel nozzle
maintenance, monitor hot section condition for early detection of degrading conditions and costly repairs. Early detection may increase component reparability versus replacement;
• Oil analysis – Conduct periodic oil filter inspections looking for metallic and non-metallic debris. Look for signs contamination, darkening, unusual smell, carbon particles in the oil. With or without professional oil analysis, the regular monitoring of oil conditions is highly recommended;
• Compressor/turbinewashes–Mustbetailoredtotheaircraft operating environment (salt laden environment, and industrial pollution). This is frequently found to be one of the more neglected preventive maintenance measures;
• GPU starts (when possible) – Spools the engine faster during start for lower peak ITT. Extends hot section and starter life;
• Introduce fuel at peak Ng (not minimum stated in manuals) – Allows for maximum cooling airflow during engine start to
reduce hot section distortion and thermal distress;
• Pre-shutdown cool-down – As recommended by the OEM. Promotes thermal stabilization of hot section components
and helps prevent Compressor Turbine blade rub;
• Runengine(s)atleastonceeveryweek–ReferenceMaintenance
Winner Aviation
April 2018
TWIN & TURBINE • 17