Kirk Thornburg, Spirit Airlines vice president for technical operations Spirit Airlines
Kirk Thornburg, Spirit Airlines vice president for technical operations

Spirit Airlines Considers Another Hangar, MRO Support For New Destinations

Ultra-low-cost carrier Spirit’s high operational tempo creates unique challenges for MRO.

Kirk Thornburg, Spirit Airlines vice president for technical operations, discusses the ultra-low-cost carrier’s maintenance strategy, its vendors and why it’s buying aircraft coming off lease. Thornburg spoke with Lee Ann Shay shortly after winning A4A’s Nuts and Bolts award in April.

Given that Spirit is an ultra-low-cost carrier, what is your maintenance strategy?

We do as much as we can to level out our maintenance cost structure. Leveraging long-term partnerships is a good way to try to take costs out of our business. We try to sign up for partnerships for as long a term as we can, as long as the economics are right. Flight-hour agreements (FHA) are prevalent here. The second thing is trying to optimize our maintenance programs for the Airbus fleet and the engine—it’s about doing the right task at the right time. The last strategy is trying to replace some of the non-competitive products on the fleet. One example is some of our seats that are either difficult to maintain or the seat weight is too high. Another is that one of our APUs isn’t as reliable as we’d like, so we’re investing in a different one. We’re also leveraging our talent to see where the reliability improvements should come from. We have an external partnership with Lufthansa Technik (LHT) to evaluate our reliability data. They make recommendations based on their knowledge of the aircraft—from what they have from their airline and their customers throughout the world—so it was a nice reach for us, as a smaller airline, to be able to tap their worldwide expertise. We have two reliability analysts on staff and a strong partnership with Lufthansa Technik.

You mentioned seats and APU reliability problems. Can you elaborate?

Spirit Airlines

Kirk Thornburg, Spirit Airlines vice president for technical operations

We’re flying three seat types that have joined the fleet over the years. We’re currently putting an Acro seat on the aircraft as the new standard for Spirit. We’re looking to rotate out one our other seat types, a Weber, that has proven more costly to maintain and is a little heavier than the new standard.

For APUs, we operate both a Honeywell and a Pratt & Whitney Canada (an old Hamilton Sundstrand design) product, and the Honeywell one is proving more reliable, so we are standardizing where we can on that. We don’t have a fleet-wide approval process, but every year we’re trying to change two to three installations. We do it ourselves on an overnight check under an Airbus service bulletin.

Spirit opened a maintenance hangar in Detroit last May. How has this impacted the airline’s maintenance? Are you planning to open any other facilities?

We are very proud of that state-of-the-art facility. We can get three Airbus aircraft in comfortably, and if we ever have bad weather, we could probably squeeze two more in there. It’s a deep hangar with a long, clear span, which gives us a lot of flexibility. We are routing some things to that facility that we previously had to outsource, such as landing gear changes and some modification work. Internally, where we used to change engines outside, we’ve consolidated that activity there. We also used to induct new aircraft in Fort Lauderdale [Florida]. We’re kind of consolidating a lot of things in Detroit that just didn’t make sense to have distributed around the network—from parts availability to being exposed to the weather.

We just completed a five-year plan for the tech ops department, and on our list, probably in three years, is to bring on a second internal facility. It’s debatable about the timeline and the value of a second one, but essentially, I’d like the option, given that our network goes from Lima, Peru to the upper East Coast—and from Seattle to Cabo San Lucas in Mexico. I’d like to find a second hangar location that would balance Detroit, so I’ll be looking south and west. If you have an aircraft that needs a repair, it’s nice to have a couple of options indoors, for something like a window or engine change. We’re still working on the internal approval process—and just started looking at potential locations.

What MRO does Spirit Airlines perform in-house and what does it outsource? Do you plan to change any of that in the near-term?

The work we do in-house is typically line-level work, so we go up through A checks. Our heavy checks (C checks and higher) are outsourced to Lufthansa Technik in Puerto Rico. We’re in the third year of a five-year deal with LHT to do all of our heavy maintenance. Pratt & Whitney maintains the engines. Lufthansa Technik maintains one of the APUs, and Honeywell does the other. Components are a mix—but Lufthansa Technik and Honeywell are the two main ones.

Are you thinking about bringing any of that work in-house?

We’re pretty happy with what’s outsourced. But with our Detroit facility coming online, there are intermediate-level maintenance tasks that require a facility and some planning for down time, such as structural inspections. If the tasks don’t align with the heavy- check interval, they become a fall-out package so that intermediate maintenance could be a reduced C check-level that might take 1-2 days of down time. We’re considering doing that internally, as we finalize the maintenance optimization package.

When will you finish the maintenance optimization package?

We’re targeting the end of the year.

Spirit will be purchasing 14 Airbus A319s in the second quarter that it operated under lease. Given that there were maintenance reserves for these aircraft, how will operations and maintenance be affected? Who was the lessor?

It takes a lot of energy to return an aircraft off lease. We returned two last year. As you are going through return conditions with a lessor, ensuring you have met all of the age requirements and standards for parts that have been changed, it takes a lot of energy for an operation like ours. Buying them off lease makes that process a lot simpler for us, so we are managing them to our own internal standard. There is a lot of cost pressure from the lessor (AerCap) to meet those return conditions. Overall, it takes the end-of-lease cost risk and puts it into maintaining the airplane going forward on your own program. It didn’t help us much on maintenance reserves because the reserves were trued out as the airplanes transitioned. What engine and APU work was already done, we’ve pulled those reserves from the lessor, so the reserves were pretty much a wash from our perspective. The main thing was getting out from under all the energy required for the lease return.

Is Spirit considering purchasing other aircraft as they come off lease?

I think the answer is unknown as this point. We’re in the process of evaluating the fleet types and the period for which they’ll be in service.

 Spirit is introducing quite a few new routes in the first and second quarters, including to Ecuador, Haiti and the Virgin Islands. How do you cover line maintenance, spare parts and other contingencies at new destinations?

We’re not too different than other airlines: we contract locally with a certified contract maintenance organization that takes care of the typical service needs and MELs (minimum equipment list). The question does become complicated when you’re at a destination like that and you need a part that is back in one of your facilities—for us it would probably be Fort Lauderdale or Dallas, the closest warehouse locations to our international network. So we do it with a combination of sending parts on our own aircraft fairly quickly or the partnership with Lufthansa Technik that I mentioned, which gives us access to their worldwide inventory. There are times when we’ll charter an aircraft to get the part to a location to get the aircraft and our customers back to their destination quickly. It is a challenge, but I think the partnership helps us extend our reach.

You’ve had a diverse career—from Express Airlines to Northwest, AirTran and Delta Air Lines. What attracted you to Spirit Airlines?

I look back at my time with AirTran, and there’s a lot of satisfaction about an airline of this size. When I look back at what was done and I see the potential here, it’s exciting to be part of building something. The business model works. I’m as well-resourced here and as anywhere I’ve been in terms of budget, from parts to tooling. It’s exciting to see the airline build and offer the product that we do. That’s what gets me excited. There’s a lot of satisfaction building an organization and optimizing the maintenance program and driving the reliability that’s needed for this type of operation. We’re a very high-utilization operation, so there is a lot of demand on the aircraft and we need to have a first-rate response system and maintenance program to support that.

What is the daily utilization average for aircraft?

We’re at 11.0-11.5 flying hours and trying to get to 13-13.5 hours. There’s not a stake in ground for when we’ll get there, it’s just an objective. The airline is trying to grow ASMs (available seat- miles) this year by 27%. We’re also taking on 16 new aircraft this year, so it’s a matter of adding the airplanes but also getting the routes defined that are profitable for us.

You just won A4A’s coveted Nuts and Bolts award for “an extensive career in airline engineering and maintenance, rising from OEM systems engineering to leading technical operations for airline category leaders in worldwide operations as well as safe, efficient low-cost airlines.” Given your broad experience, how do you see the airline aftermarket evolving in the next five years?

The first thing that comes to mind: we’ve been talking about the technician shortage for a long time, and I’m seeing signs of that now, in the last year. At MRO Americas in April, a number of discussions led me to believe that technician labor costs are going to increase because of the shortage. Will it force additional MRO consolidation? I see structures and avionics talent especially being in demand in the next five years. Those of us who figure out how to do it efficiently and competitively will be the ones leading the development and expansion of the business in the next five years. I also think you’ll see some PMA growth, especially in the single-source supplier markets because the pricing has gone so far that it’s inviting competition, particularly for engine accessories and cabin interiors. The start of drone inspections should be interesting over the next five years—to see what they can do more efficiently. But I’m a little skeptical about predictive maintenance. I may be one of the few in the business who is. While the technology is there, I don’t know whether the indicators that we’re going to look at are reliable in a lot of cases. I’m also worried about the business model I see coming forward to develop that. While I’m skeptical, I think it will be proven out in the next five years, but the business model has to evolve and the indicators really have to be scrutinized to make that successful. 

Spirit Airlines Fact File

Fleet Size: 118 (as of April 2018)

Fleet Composition: A319 (31), A320 (52), A320neo (5), A321ceo (30)

Average Fleet Age: 5.2 years

Number of destinations: 65

2017 Fleet Completion Factor: 99.92%

2017 Fleet Maintenance Dispatch Performance: 99.06%

Launched scheduled passenger service: 1990 (As Charter One)

Moved headquarters to Miramar, Florida: 1999


TAGS: Operations
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