Podcast: The Impact Of GTF Engine Issues

Aviation Week Network’s James Pozzi, Sean Broderick and Dan Williams discuss the impact of technical issues related to the GTF engine powering Airbus A320neo aircraft on the global fleet and aftermarket.

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Rush Transcript

James Pozzi:

So, welcome to the MRO podcast. I'm James Pozzi, MRO editor for the EMEA Regions, and today we are talking engines and specifically the Pratt & Whitney PW1000G program, also known of course as the geared turbofan. It's an engine program whose variance power several current narrow-body aircraft in the global fleet.

So, since entering into the service in 2016 as a new generation engine option to rival CFM International's LEAP Program, Pratt Whitney's GTF engine family now powers more than 1,600 aircraft, according to the manufacturer’s figures it released in summer, 2023. But in recent years, the engine program has been beset by several technical issues which have hampered its momentum in the market, and this has affected everything from OEM production rates and delivery volumes to operators, among other things.

So, joining me today to discuss this topic, are my colleagues, Sean Broderick, who is senior air transport and safety editor at Aviation Week, and Dan Williams who is senior manager of fleet, flight and forecast data at Aviation Week. Gents, welcome and thanks for joining me today.

Sean Broderick:

Thanks for having us.

James Pozzi:

So Sean, just starting off with yourself then, what are some of the more recent technical issues that we are reading about of course, and what mandates or inspection requirements have been issued to fix them? So, I think maybe starting first, perhaps maybe, how did we get to this place to start with, would be a welcome summary?

Sean Broderick:

Sure, James. So, on the Geared Turbofan program, as you pointed out, it's had issues really since its entry into service, and we can now clearly divide those issues into two categories. The first one is what Pratt has called a durability issues. Those were a series of specific things, knife-edge seals, combustor problems that are created issues and are still creating issues on some in-service airplanes. Basically parts that weren't lasting as long as Pratt thought they would. Had a series of those. Pratt is about at the end of the line with... Well, I'd give it maybe another year and they'll be at the end of the line with in-service disruptions linked to those parts. Affecting airplanes around the globe. More acute issue in severe severe environments. Think of the Middle Eastern and Indian Airlines have had a huge problem with this.

The second set, the one that's been getting... Or the second issue, really, that's been getting the headlines recently, it's a manufacturing problem that they had with certain parts, high pressure turbine, stage one and stage two discs. This issue traces back to a March, 2020 incident that happened on a Vietnam Airlines V2500 powered engine. Stay with us, and we'll get to the Gear Turbo fans real quick. But started out with V2500 engines. They narrowed the issue to a handful of discs. They thought it was about 30 V2500 discs that had a problem. So Prat said, and the regulators agreed, pull them out of service. In September, 2021, the FAA came out with an AD covering geared turbofans. So, between March '20 and September 2021, Pratt did a little more analysis, "This quality issue doesn't affect just V2500s, also geared turbofan discs too. About 60 of them."

Pratt went back again and looked at its analysis and found that it's not just 60, but it's more like 2,100 discs that have a problem. So, we went from pulling discs out of service to be safe, to an inspection program. This they finalized in October, 2022, the FAA directive. That directive, based on Pratt's

recommendations, operators were safe doing inspections on their discs at every scheduled shop visit. So, a little bit of added inconvenience, but not really any added service interruption.

Well, fast forward to December, 2022 when we had another in-service incident, this one with an A320neo, and it was a high-pressure compressor, seven stage blade rotor failure. Different problem, but it sent Pratt again back to its data analysis and risk analysis, and they realized that their inspection intervals that they recommended on the problem stage one and stage two high pressure turbine discs, were not good enough.

So, that's where we are now. They identified two tranches of discs that need immediate inspections. One of them is found on about 200... 201 engines, actually, as Pratt's August 4th service bulletin said, and there's going to be another set that needs inspections. Well, the first set, the 200 need inspections now. Pratt said get them out of service by September 15th. The second set is going to need the same inspections within about a year. These inspections are all coming, most of them are coming, most of them, not all, are coming before scheduled maintenance visits. Some of them happen to coincide with scheduled maintenance visits, but most of them are going to be unexpected by operators, and it's going to create some in-service interruptions.

So, the latest headlines focus on those 1200 discs, but this problem dates all the way back three years now, more than three years. It's really about how Pratt has been taking, has been reexamining its risk analysis, its data analysis, it's some of the service records on these parts that have come back in, and figured out that this metal powder contamination that started the whole process, an internal problem within a Raytheon company has grown into a situation where they got to manage it. So, that's where we are right now.

James Pozzi:

Thanks for summarizing all those issues and that timeline in the space of four to five minutes. Very well done with that.

Dan, in terms of numbers, what are you seeing in terms of the... We talked about the technical issues, but what kind of impact has this had on the GTF-powered aircraft in the global fleet in terms of numbers and maybe with operators as well? What are you seeing there?

Dan Williams:

So with the GTF, the issue is predominantly but not exclusively an Airbus A320 issue. There's still ongoing investigations regarding the GTFs that are on the Embraer E2 and the A220. So, I'm going to part the A220 and the E2 to one side, not because they're any less important, however, there is obviously a lot less of them, for starters. However, when we just look at the A320 family, then there are about 1,338 if I'm being about precise, GTF-powered A320 family. About, just over a little over 900 of them were built in between that timeframe that Pratt and Whitney have said that the engines are affected. So, the timeframe is from quarter four, 2015, the engine build, and through to the end of quarter three, 2021.

Now, we have to take a little bit of a leap of faith here and we have to therefore assume that an aircraft that came off the production line within those same quarters, will have potentially affected engines. So, I am going to caveat some of my numbers with that, because the reality is if an engine was built the very last day of quarter three, 2021, then it's not going to be rolling out onto an aircraft 'till quarter four. But I digress.

So, that brings us to a little over 900 aircraft. So, that is two thirds of all GTF-powered A320 family aircraft potentially could be affected. Now obviously the A320 family, they've got two engines on them

and it probably can be a case thereof, that either both engines are impacted, or one engine can be impacted. I believe that RTX, therefore Pratt, have said that 55 of those engines already are off wing. Now, some of those may be already off wing due to the other durability issue, because when we look at the aircraft that are affected, Indigo, Air China, GoAir, Go First, are some of the most impacted operators that have these aircraft.

Now, compounded with the first durability issue, they were already impacted anyway. So, the second issue might impact those operators less, ironically, because they've already got the engine of wing. So, it's going to be those operators that operated in slightly less harsh environments. So, we're talking things like Lufthansa, Spirit, All Nippon, Turkish Airlines. These have all got 30-plus aircraft in fleets that could be impacted. So, this is going to be felt quite quickly throughout the system. As Sean has said, some of them need to be done right away, now. Now, depending on how many spare GTFs there are in the system, that could have an impact going onto utilization of those aircraft long-term, because as we already know, and we've talked about many times, even including previous podcasts that we've done with Guy on the GTF and the durability issue, there isn't a lot of breathing room within that engine fleet, the spares fleet.

So, it is going to have an impact. The only, I don't have to say saving grace, is that we are coming to the end of the northern hemisphere's summer schedule. Now, it is naturally at a time the operators will either de-fleet because they start retiring aircraft, or they start maintenance on their fleet. So, it might just mean some headaches for the operations manager at airlines who have to potentially keep some other aircraft going a little bit longer to compensate for that, or pull maintenance a little bit sooner and just suck up capacity loss.

James Pozzi:

Yeah, interesting, the possible outcomes there. Going to the aftermarket, and back to Sean, we know Pratt have a pretty extensive global network of partners and various engine shops across the world, but of course capacity has been at a premium in MRO over the last few years, that's fair to say, and even before then perhaps, but do you see any issues related to this in carrying out the required inspections for the GTF engine in a timely fashion? Do you see any problems there with the MRO network?

Sean Broderick:

Yeah, you nailed it. They were already, as Dan said, already dealing with unexpected overhauls or restorations because of the teething problems. So we're what, seven years out from the first deliveries of those engines. They started ramping up in '17, '18, '19 as Dan's numbers said. So, you're just getting into the first scheduled overhauls for the busiest of those motors. Well, the durability issues created a backlog that Pratt didn't expect. This issue was only going to exacerbate that. Now they're working to get more capacity online, but as you well know, that takes time. Because these inspections can't be done on wing, you have to have an overhaul slot. So, you're talking, in today's world, 50, 60 days is the total turn from the time it leaves the airplane wing to the time it gets back. So, that's going to create issues for any operator that has these. Pratt spare engines, not a lot laying around, already have issues getting enough engines to Airbus for the new production line.

So, you add it all up, and it's a tremendous challenge. The big thing that we don't know, and none of it's in the documents that Pratt has released, we don't know what they're using, or if they're even using a flight-hour threshold for this. All they've done, is identified engines by serial numbers and as Dan said, the 145 of them are on wing, about 55 of them are already off wing, according to what Pratt had at the beginning August. So, we don't know if it's going to be, they get the initial 200 in, they do the inspections, will they need to do another thousand within a year? Will they need to do more? Will they

need to do fewer? What happens after that? That we really don't know and Pratt really doesn't know. Again, a very important, as Dan pointed out, this is all A320neos right now. Haven't even gotten in to the PW1100s, haven't gotten to the 1500s and the 1900s. However, Pratt has said because of the service life on most of those engines and the availability of spares, they don't expect near as much interruption for the 220s and the E195 E2 fleets as we're seeing on the A320neos.

James Pozzi:

Okay, sure. Finally, maybe going back to starting again with Sean and then getting Dan's input, what is the land like currently in relation to the GTF and its LEAP rival? Obviously that's a program that's had its own technical problems as well over the last few years certainly, but how have the technical issues of both programs impacted the overall landscape of the narrow-body engine segment, and perhaps taking into account the predecessor engines, of course, the VT 500 and the CFM56 family engines?

Sean Broderick:

The LEAP has had some issues, but I don't think they're in the same league, especially now with this latest issue coming here. The LEAP has had some issues in some of the more harsh environments. They've had a few other issues to fuel coking, but nothing that has created the level of disruption as acute or as long as we've seen on the geared turbofan side. Both OEMs will say that if you look at the previous iterations of the engine, so the CFM56 and the V2500, that it did take time to get to a level of durability where we are now. The operators don't agree.

One of the big problems is the sheer number of airplanes being pushed out with these engines vis-a-vis their predecessors. They're just more being delivered now, earlier on in the program, if you look at the first 10 years, let's say. So, any problem that ripples through the fleet, is naturally going to be a bigger problem on these newer generation ones, current generations ones than the last generation ones. But I mean for the OEMs, the engine OEMs, it really doesn't matter this iteration versus the last iteration. What matters is, are their customer's airplanes flying like they expected? In Pratt's case, they are absolutely not. CFM has a few issues, but Pratt has major issues that are... Again, we're at least a year from seeing any level of normalcy in the A320neo fleet powered by GTFs. I think that's safe to say, and it could be longer.

James Pozzi:

Cool. Dan, any thoughts to add?

Dan Williams:

Yeah, I mean, it poses the interesting question of future orders. When you have the A320 that has the option, historically... Okay, like Sean says, these are new, but generally, historically the split is about 55, 56% in favor of LEAP. Now, what's going to happen going forward, is if you are a LEAP customer, you're going to buy LEAP. But if you are a GTF customer or an existing GTF customer, the cost to change to start using LEAPs is too much to suck up, so you'll buy GTFs.

However, those operators, new operators of the A320neo family that haven't yet made an engine selection, it poses a question of what do they do. Which then poses other headaches throughout the system, because if they say, "Well, we look at GTF and it's not been quite as reliable as everybody would've hoped." It's an impressive engine. Everybody thought they'd have an issue with the gear part of the engine, and actually so far that's been doing pretty well. However, if they turn around and say, "Okay, well we're going to order LEAPs," which is absolutely fine, it's their decision to do, then that can

become a capacity issue on producing LEAPs. Because if everybody all of a sudden pivots to wanting leaps and the split goes from 55, 56-ish percent current LEAPs, to 70% LEAPs in service, then that's going to create headaches for CFM alone.

So, it's going to be interesting to see how over the coming, probably not immediately, but however, over the coming 18 to 24 months, these new customers to the A320neo family, what their engine choices are, and likewise the lessors, because obviously the lessors invest heavily in buying large fleets, so will hedge their bets, as it were, and probably we may find them going towards more LEAPs. But then with the crazy orders for 500 aircraft, for example, for Indigo who already have GTFs, I would imagine that they've carried on taking GTFs, and Pratt and Whitney are doing their best to work through this system. Again, this is something that they've inherited, courtesy of a powder coatings issues from a supplier. Yes, it is an RTF-owned supplier, but it's come from a supplier. It's not necessarily entirely their... I don't say fault, I don't mean it like that, but it's an oversight on quality, which, let's face it, Pratt and Whitney are not the only company within the industry right now that are having oversights on quality issues.

Sean Broderick:

Sounds like a topic for another podcast.

James Pozzi:

Well, it's certainly something we can get back to, I think in six months time or maybe around then, and see where the land lies then. Because yeah, it's certainly a very, very, very interesting topic. Yeah, Sean and Dan, thank you for your insights today for getting those insights on the engine programs and joining us on the podcast.

So, thank you as well for listening, and don't miss the next episode, by subscribing to the MRO podcast wherever you listen to podcasts. One last request, if you're listening in Apple Podcasts and want to support this podcast, please leave us a star rating on [inaudible]. Thank you.

Sean Broderick

Senior Air Transport & Safety Editor Sean Broderick covers aviation safety, MRO, and the airline business from Aviation Week Network's Washington, D.C. office.

James Pozzi

As Aviation Week's MRO Editor EMEA, James Pozzi covers the latest industry news from the European region and beyond. He also writes in-depth features on the commercial aftermarket for Inside MRO.

Daniel Williams

Based in the UK, Daniel is the Manager of Fleet, Flight and Forecast data for Aviation Week Network. Prior to joining Aviation Week in 2017, Daniel held a number of industry positions analyzing fleet data.