Engine Overhaul or Upgrade?

March 24, 2017
For the King Air 200, B200 and B200GT there are options.

Engines on an aircraft are almost always the most expensive component to maintain. When an engine is timed out, some aircraft owners don’t have any options other than to overhaul their current engines. For the King Air 200, B200 and B200GT, however, there are several options to upgrade for more speed, decreased time to climb, and better performance.

The Times & Inspections

Regardless of the model of engine that is on your aircraft, the intervals are 1,800 hours for hot sections and 3,600 hours for overhaul. If you are unfamiliar with the process, a Hot Section Inspection is not a full overhaul and does not incur near the cost. During a Hot Section Inspection, all hot section engine components are inspected to make sure they can generate enough power for efficiency and safety. This includes turbine blades, compressor inlet, CT shroud segments, and more.

During an engine overhaul, all portions of the engine are disassembled, cleaned, inspected, reassembled, tested (ensure the facility you will be using has an appropriate test cell to run the engine off wing through all parameters), and shipped back to the installation agency. The engine consists of four major sections as follows: Accessory Gearbox, Gas Generator section, Power Section, and Reduction Gearbox. Engine accessories that will also be overhauled at that time are as follows: fuel control unit, fuel pump, fuel nozzles, fuel flow divider, fuel oil heater, constant speed governor, heated tubes, and ignition unit. During the overhaul, and any mandatory service bulletins can be embodied. It is also a time when any optional service bulletins may be reviewed and completed if a customer elects to do so. Service centers at that time will also make recommendations of the bulletins that will benefit the customer. This is also a time when the engine mounts should be changed, engine hoses reviewed for life limit and changed if needed. A reputable service center will be able to explain to you and guide you through any items that must be done, as well as optional items that could be done at that time because of access and convenience.

 Overhaul or Upgrade

If your engine is due for overhaul, it can be difficult to navigate all of the options, especially if it is your first time going through the process. When starting the project, it is important to know what engines you currently have on your aircraft. This can vary based on the serial number of your airplane and whether it has already been upgraded or not. However, a general guideline is the King Air 200 was built with a PT6A-41, the B200 was built with a PT6A-42, and the B200GT was built with the PT6A-52. Once this is identified, it is important to work with a service center, preferably an authorized service center, who can manage your project throughout the entire process.

Working with an experienced service center provides you many benefits, the first being pricing. Since service centers provide dozens of engine overhauls each year, they have negotiated the best prices with both engine overhaul facilities and engine providers. In addition, they will be able to provide you with all pricing options and help weigh your cost-benefit analysis. They can also complete the engine removal and reinstallation in the most efficient and cost-effective manner. They can complete any other work you need during your downtime such as airframe inspection, paint, interior, or avionics upgrades. If a problem arises, the MRO facility has the ability to fix numerous engine issues and obtain the appropriate level of support with the overhaul or engine supplier. They will also stand behind the project, including honoring warranty issues.

If you are overhauling/upgrading for the first time, make sure to review the needs for your aircraft. Would you like to go faster, decrease time to climb, or increase performance? If the answer is yes to any of those questions, you should explore your upgrade options. The current available options are the PT6A-42, the PT6A-61, and the PT6A-52. Each option has different pricing and performance capabilities. Review the overhaul quote cost and ballpark estimate out-the-door costs and compare them to all of your upgrade options. In some cases, it may be more economical to upgrade. These comparisons can be done easily with a competent and trustworthy MRO representative.

Choosing Who Will Overhaul Your Engine

If you have weighed all of your options and decide an overhaul is the best decision for your aircraft, it is important to fully understand what facility is going to be right for you. There are a few factors to consider. Do you want a Pratt & Whitney approved facility? Are you OK using a facility that Pratt & Whitney does not support? Are you comfortable using PMA parts, or do you only want to use OEM parts? Does the company you are using have a long-standing history and good reputation?

As you can see there are many factors to consider when choosing an engine service center.

Working With a Service Center

If you have decided that you would like to work with an authorized service center, it is recommended to get at least two to three quotes and compare all items on the quote, not just price. This will ensure that you are making a fair comparison. Check to see if the engine overhaul facility will:

  • Give me a report of what was wrong with my engine
  • Fly me to see their facility and review my engine during the inspection progress
  • Have a good relationship with the MRO
  • Are they responsive to my questions
  • Have a good name in the industry
  • Reveal turn time
  • Provide loaner engine availability and price
  • Have a field service response team
  • Provide warranty hours and calendar limits
  • Have the ability to do repairs
  • Be able to use overhauled, repaired, or used parts to reduce cost

When you are faced with the challenge of overhauling or upgrading your engines, your options can seem overwhelming. With a little bit of education and some guidance from an authorized service center, you can go into the process better informed with less surprises.

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.