By Mike Saathoff
Director of Sales Operations & Engine and Accessory Sales for Elliott Aviation
Throughout the lifetime of an aircraft, engines are likely the most expensive parts of an aircraft to maintain. Unfortunately, there is no simple solution that applies to every make and model of engine. With so many variables, including engine manufacturer, engine programs, parts obsolescence, maintenance history, pedigree, and more, it can be easy to make a costly mistake when entering an aircraft transaction.
Fully understanding your variables and knowing the right questions to ask your service center is critical to making the right decisions for what will be the best solution for your aircraft and mission.
1. Engine Times and Cycles
Engines are valued based on the life remaining of the engines. The life remaining of the engine is based on the engine overhaul and inspection requirements. Within those requirements are the time or cycle limited components. All of these items are based on times or cycles, so the importance of correct times and cycles cannot be stressed enough.
In reviewing the engines, make sure the seller has current and up-to-date times and cycles of each engine, including APUs (if applicable). These are primarily tracked and documented with a flight log. Make sure all cycle limited components are tracked. Numerous items inside a turbine engine are tracked independently and have varying cycle limited replacement or overhaul requirements.
Having someone who is familiar with logbook research on engine items can not only ensure your times and cycles are accurate but can help verify numerous other items that, if handled improperly, could be costly mistakes. These items can include: if the aircraft engines are up-to-date on service bulletins (and if not, why?), inconsistencies in engine times, and repetitive issues within an engine.
2. Is it on a Program?
There are many engine programs in the industry. Some examples are JSSI (Jet Support Services, Inc), Honeywell MSP (Maintenance Service Plan), Pratt & Whitney ESP (Eagle Service Plan), Williams TAP (Total Assurance Program), and more.
With each program, there are many variables and options. Some programs are highly customizable for the customer. They can vary from covering a portion of the major events to covering every possible expense the engine might incur.
When purchasing an aircraft that is on an engine program, make sure you fully understand what is and what is not covered. Ask for a copy of the current engine maintenance agreement, and review this agreement with your engine representative or the program representative. When reviewing the agreement, ask the following questions: Is the existing contract transferable? What are my monthly costs? What items are completely covered? What items will I be responsible for at small and large engine events? Does it cover normal inspections and discrepancies? Do I have to use a particular service provider to complete the service, or are there advantages to using certain providers?
3. Maintenance History and Cost
One item that some owners overlook is the engine maintenance history. Primarily, have they been maintained by a reputable facility that properly follows maintenance guidelines?
Like many other items, much of this information can be acquired with thorough logbook research. The same facility consistently services most aircraft. Consider if that facility has a good track record for the type of aircraft you are purchasing.
In order to establish any upcoming maintenance costs on the engines, you should be able to use all of the information gathered from the logbook research and supply that to your preferred maintenance provider. They should be able to provide you with a ballpark estimate of the upcoming maintenance costs on your engines based on estimated utilization.
Aircraft owners need to understand where the engine is in its current lifecycle and what upcoming events are coming due. This can be evaluated by estimating your usage of the aircraft. You can then discuss any potential upcoming expenses with your planned maintenance provider or agency providing the pre-buy.
4. Location and Operation
The primary location of the aircraft during operation can have a major impact on the engine life and costs. Has it been operated in an extremely sandy environment, corrosive environments such as sea salt air, or significant pollution areas? Has it been exposed to the elements for a significant amount of time? All of these can make a difference on the internal condition of the engine.
An even more significant concern is if the engine has been run through a complete cycle recently and on a consistent basis. A complete cycle would be running the engines long enough to get them in the appropriate operating temperatures for long enough to meet the engine needs. Some of these needs are to ensure oil sufficiently coats all internal components requiring it and to heat up all areas to remove contaminants. Each engine will have its own particular requirements for calendar limits between cycles. Consult engine manufacturers' manuals for this information. Many times this is tracked in the engine logbook or flight log.
Trend monitoring is another way to understand how the engine has been operated. Many of the current generations of avionics systems have digital trend monitoring that will track all parameters through all engine operations. Additionally, many other aftermarket or manual tracking methods can be used in the same manner.
5. Understanding the value of the currently installed engines
All of the above items have factors in determining what your aircraft engines are worth and can positively or negatively impact. A large factor in the process is who has completed the major events on the engine when it is off wing. Was it a factory-authorized facility, and are they reputable?
Make sure you understand if the current engines have had modifications and if those modifications have an effect on the airframe warranty. Items like aftermarket parts, what facilities are supporting the engine, and parts obsolescence all factor into the value of the engine and the cost of repairs.
Another resource in the process would be an independent ASA Accredited aircraft appraiser. ASA Accredited appraisers deal with valuing aircraft every day and are the most knowledgeable professionals in the industry to determine aircraft values.
Do You Have the Needed Info to Make the Decision?
Fully understanding aircraft engines during a transaction can be difficult and time-consuming. However, working with an experienced maintenance provider and broker-dealer to explain all the parameters will make a significant difference in your comfort level with your decision. Ultimately, you have to make the decision that will be best for you. Do your research, talk to reputable shops and talk to other operators.
Never feel pressured into making a decision without fully understanding all of your available options. Weigh the pros and cons, and when you come to a conclusion, you will know that you made the right call!
Want to know more about our engine capabilities? You can find that here.
Mike Saathoff has over 20 years of experience in corporate aircraft maintenance. He has held several service technician and quality control positions with Elliott Aviation and currently serves as the Director of Sales Operations & Engine and Accessory Sales. He has an Airframe and Powerplant and Inspection Authorization license with the FAA. You can email him at msaathoff (at) elliottaviation.com