Three Surprises to Anticipate Ahead of a Jet Engine Overhaul

An aircraft engine is a complex piece of engineering comprised of thousands of parts working in harmony. Yet these are not the only moving pieces in a business aircraft engine overhaul process. External factors also play a significant role in the outcome.

Parts and rental engine availability, deciding when to plan the service, total cost, and customer communication all need to be accounted for in order to deliver a seamless engine overhaul experience.

The Value of Planning Ahead for An Aircraft Engine Overhaul

Unaccounted details before opening an engine — sheer surprises, in other words — can extend the overhaul turnaround time (TAT) in the MRO shop, according to Stefan Wriege, Head of External Communications, Civil Aerospace for Rolls-Royce.

The usual TAT in the shop is 65 days on average and Wriege adds that eliminating the uncertainties is instrumental to reducing overall costs and extended delivery times.

“For all those reasons, we introduced CorporateCare Enhanced, which offers comprehensive coverage for the full powerplant, including the engine and nacelle, eliminating surprise invoices for our customers,” he says. “No matter what, we cover the shop visit and customers never receive an invoice beyond their monthly CorporateCare Enhanced hourly fee.”

Rolls-Royce’s main engine refurbishment work involves scheduled hard-time and on-condition EMP inspections for its TAY, BR710, BR725, AE3007, and Pearl engines.

For Joost Groenenboom, Senior Director at ICF’s Aviation MRO practice in London, the most significant surprise for customers is the unpredictable nature of engine failures – or as with new generation engines, the shorter time on wing compared to older tech.

“Having proper trend monitoring processes and sufficient in-house technical expertise is crucial to ensure adverse trends are detected early on and the removal planning is robust,” Groenenboom says. (IFC is mainly focused on CFM56, V2500, GTF, and LEAP-type engines, which are used on some Boeing Business Jets and Airbus Corporate Jets.)

He adds that another surprise is the lack of shop slots and the extended TAT due to supply chain issues. “Latest generation engines (such as the LEAP/GTF) have significant technical issues, and supply chain issues means that slots are hard to come by and TAT is much longer than for older generation engines.”

While it can take many years of operation before an aircraft needs to hit the shop for an overhaul, once it is time, the complexity of the entire process often surprises clients, especially regarding when to start planning for the investment.

For Phil Stearns, Director of Sales and Marketing for Stevens Aerospace, “The time it takes to start the overhaul once it reaches the overhaul facility [is often the main surprise].

“There is an overall event backlog, a lack of parts, and a lack of additional qualified labour in the overhaul shops. Luckily, for the most part that continues to improve.”

Stevens Aerospace removes and replaces the engine for overhaul and hot section inspection. During the process, it works directly with OEMs and Directors of Flight, with onsite personnel overseeing overhauls while keeping all stakeholders informed.

Are Rental Engines an Option During Your Business Jet’s Overhaul?

Sean Lynch, Managing Director at Engine Assurance Program, a company handling a large fleet of TFE731 engines, notes that clients need to begin planning on an engine shop visit several months in advance with an engine program, while customers without a program should plan with the shop directly.

“It will be safe to assume for the non-engine program clients that they will be grounded for months without a rental engine,” he highlights.

The availability of rental engines is one of those ‘moving parts’ in the process that can make or break the experience, and being part of an engine program increases the possibility of obtaining one, and thus avoid a grounded aircraft.

“With limited models of rental engines and near-record flying hours since the pandemic, it is more important now to start the planning process early to get your engines scheduled with a provider, to get on the schedule, and try to get a rental engine reserved,” highlights Chris Bodine, Vice President and General Manager of StandardAero’s Augusta Business Aviation MRO Facility. 

Groenenboom also believes that overall availability and demand are impacting the rental engine pool. 

“Lease engines are options, but they are hard to come by because of increased shop TAT time and a general increase in demand – for example, traffic has increased resulting in more demand for aircraft, which increases the need for spares and slots in shops,” he says.

Suresh Narayanan, CEO of Jets MRO, agrees that the rental component is challenging. The company works on Bombardier, Cessna Citation and Dassault Falcon business jets, with internal work on heavy engines controlled by the OEM.

“Rentals are not available nearly enough in the business jet space like in the commercial space. You have to hunt for a tear-down opportunity to try and get a rental engine or be a larger operator with buying power.”

Rolls-Royce has loaner engines for customers opting for their CorporateCare Enhanced support program, with over 250 engine and nacelle lease assets available. “We even cover the removals and re-installs of both the loaner and customer original engine as well as transportation for both engines to and from the shop,” says Wriege.

Business Jet Overhaul: Costs, Parts Shortages & Timelines

The downtime surprises that often accompany today’s engine overhauls may stem from aircraft owners/operators not planning early enough to allow for shops to pre-plan ahead of the event, including allocating and securing the necessary manpower and parts.

Bodine reveals that engine repair and overhaul downtime varies depending on the work scope and engine models. “Typical turbine end (hot section) repairs take 14-21 days, and compressor (cold section) repairs are 30-45 days. But both type repairs can vary for downtime based on the material (parts) availability.”

Groenenboom specifies that TAT depends on the engine type. “We can say that older generation engines used to have a shop TAT of around 55-75 days. This has significantly increased, and particularly for the newer generation engines (such as the LEAP/GTF) it is even longer.”

Moreover, Bodine highlights the cost of performing these types of repairs and overhauls is mainly driven by the material (parts) that need to be replaced. 

“While everyone typically has an estimated cost and flat rate to perform these types of events, there are many instances where the material content is high, driving the pricing for the event higher than expected; some of those are corrosion and [hot end] parts that fail the inspection phase,” he says.

Narayanan believes there’s room for improvement regarding the overhaul provider’s initial proposed timelines. “Initial timelines are rarely hit, so there is no objective measure from the shops on timelines and their reported on-time performance, unfortunately, which is an industry gap we are trying to fix,” he shares.

Meanwhile, Lynch reckons that there seems to be a new parts shortage every quarter — everything from engine wiring harnesses and blades to simpler parts such as washers and bolts.

“Engine shop visit costs have increased almost 100% in the last four years,” he explains. “Engine shops used to offer free R&R and shipping which stopped a few years ago, adding substantially to the cost of every event.”

Furthermore, Lynch notes that the market has changed dramatically over the last two years, with parts shortages and supply chain issues pushing engine shop visits four to six months longer than usual.

Business Jet Overhaul: Managing Expectations

Often overlooked, the capacity to actively engage during the planning phase and throughout the entire overhaul process can make or break the customer experience.

Communication, planning, and scheduling are vital to the shop, and having a slot to take the engine and do the necessary planning, aircraft operators/owners can’t start planning and talking with the shop too early.

“Our MRO customer team holds pre-induction calls with the client to discuss the work scope of their engine(s) and provides weekly updates to avoid surprises during their shop visit,” Wriege says. “They provide a weekly status of the engine(s), scheduled release dates, and costs.”

Bodine recommends customers visit the facility, meet the team, and view the work in progress. But he adds that new technologies are playing a role in this engagement, especially for customers who don’t have the time to come and see their engine, or those based so far away that travel doesn’t make sense.

“We have built an online web-based system called mystandardaero.com that allows customers to access their work package from anywhere and receive any type of advice to review progress, approve work, and see a running tab on what they have spent to date.”

Along the same lines, Stearns mentions that all parties involved must invest in communication efforts to achieve an efficient overhaul – including the aircraft owner, the Director of Maintenance, the MRO shop, the engine program provider (where applicable), and the engine overhaul facility – with engagement sometimes starting a couple of years in advance.

“This is especially important when you are considering rental engines, which, depending on the engine model, may not exist or may only have a few available,” he says.

“Some [owners] will be asked to consider back-to-back overhauls, doing them one at a time due to only having one rental engine available.”

Jets MRO ran a customer survey, and ‘communication’ during the maintenance process was a key feedback item among the numerous aircraft operators polled. “We process communication directly from the production floor to the customer,” Narayanan explains. “No sales or customer reps.

“Our systems take worked hours and report directly into a fixed project update at fixed times for the customer.”

Groenenboom goes a step further adding the value of active engagement, sharing that communication between the MRO and the customer is a requirement. “The initial work scope will require several changes,” he says. “The customer will also need to approve additional costs and technical actions based on regulations, internal maintenance, and lease/contractual requirements.”

What are the Top Three BizAv Engine Overhaul Surprises?

With many moving parts and stakeholders involved, defining the top three surprises about the business aircraft engine overhaul process seems complex.

Yet, while there are competing priorities for the different aircraft owners/operators, whether you’re a sole private jet owner or a multiple business jet operator it is possible to establish downtime, rental engine availability, and cost as being the three biggest areas for potential surprises around the engine overhaul process.

Communication and planning are vital in eliminating unwanted shocks, and beginning these well ahead of the overhaul process is strongly advised.

“The planning needs to begin six to eight months before the event [at least],” Lynch says. “Focus on what you know –such as the life-limited components that you know will be cycling out and requiring replacement, along with the parts that always require replacement during shop events.”

As Wriege highlights, aircraft engines are highly complex pieces of technology consisting of approximately 20,000 parts that must work together to enable the powerplant to deliver efficient and reliable thrust.

“It takes many years of operation before an engine has to come in for engine overhaul,” he concludes, “but once it’s time, it is a complex undertaking which customers sometimes underestimate regarding scope and cost.”

More information from:
Engine Assurance Program: www.eap.aero
ICF: www.icf.com/work/transportation/aviation
Jets MRO: https://jetsmro.com
Rolls-Royce: www.rolls-royce.com/corporatecare
Stevens Aerospace: https://stevensaerospace.com
StandardAero: https://standardaero.com

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