MIAMI— It may not come as much of a surprise that the world’s largest airline operates the world’s largest commercial airplane maintenance facility – an enormous operation that encompasses 22 buildings on the main base, including 3.3 million square feet of hangar and shop space sprawled across 33 acres. What may be a surprise is that American Airlines’ Maintenance and Engineering Center isn’t located at its Dallas-Ft Worth hub, or even the carrier’s other hubs at Miami or Chicago. AA’s behemoth M&E Center is 250 miles to the north of DFW at an airport where American operates only a relatively paltry 12 flights a day – Tulsa International Airport (TUL).

Though it seems counter-intuitive perhaps that a city once known as “The Oil Capital of the World”, Tulsa made all the sense in the world to American executives when the M&E Center relocated to here from New York City’s LaGuardia Airport in 1946. Tulsa was a prime contributor to the war effort during WWII – manufacturing famed Boeing B-24 Bombers. Over the years, this under-recognized but vry live-able mid-sized Midwestern city has punched way above its weight in the aviation world. Rockwell, McDonnell Douglas, Spirit AeroSystems, and the renowned Spartan College of Aviation and Technology have called Tulsa home over the years. The city’s active aviation scene was where the cargo doors for the Space Shuttle Enterprise were built.

Though American was still headquartered in New York (until 1979) the airline had outgrown its LGA base. The airline had already set its sights beyond the Big Apple with much of the airline’s flight training at the time located in nearby Ardmore, Oklahoma and AA’s expanding operations at Dallas. Tulsa city officials seized at the opportunity and lured the Eagle to T-Town. With a skilled workforce and 4 recently moth-balled hangars, Tulsa became AA’s maintenance and aviation hub – a title it still holds today. Virtually every AA mainline fleet type up to the present has been maintained and overhauled here with the exception of a few such as the 777. Storied models like the Convair 990, Boeing 727, 707, and 747, McDonnell Douglas DC-10 and MD-11, Fokker 100, Lockheed Electra L-1088, even the 747s AA leased to NASA to ferry the Space Shuttle Orbiters were given tech “TLC” here.

The M&E Center is a major driver of the region’s economy. 5,400 people, about 5% of the merged American’s 100,000 workforce are employed here at the base – a round-the-clock machine that works 3 shifts, 24 hours per days, 7 days per week. The benefits and stakes to the airline and to the region can’t be overstated. In 2013, TUL M&E spent over $48 million with over 110 Oklahoma vendors. In 2014, it provided $418.9 million in wages and benefits to the region.

Don’t Call It MRO: AA’s TUL M&E Has Only One Customer

Unlike more high profile industry counterparts and competitors, American doesn’t consider its M&E operations an MRO. While Lufthansa Technik, Haeco, and Delta Tech Ops perform service for other airline and private customers, AA’s M&E Center only services American’s fleet. This vast operation is obsessed with providing a safe, efficient, world class operation that contributes to the airline’s bottom line and operations – a theme continuously emphasized during our recent visit there. The base is on a quest to continuously push itself toward productivity and quality improvements that reveal themselves on the flight line and the P&L – examples of which we’ll touch on later in this piece. American employees and management from around the system point to the Tulsa base with a lot of pride – a point and responsibility not lost on the team there.

American’s entire fleet of MD80s, 737s, 757s, and 767s are maintained and overhauled here. The 777s are currently maintained in Asia following the shutdown of the short-lived of the Ft. Worth Alliance Airport base in 2013.The DFW maintenance hangars are utilized for new aircraft ingestion (except the 737) and line maintenance. The new American Airbus A320 family aircraft and Boeing 787 maintenance bases have yet to be announced, though Tulsa has to compete on cost, capacity, and quality for every aircraft program as if it were a separate business from the airline.

The USAirways legacy fleet continues to be maintained and overhauled in Pittsburgh and Charlotte. The merging of the 2 fleets from a maintenance and overhaul perspective is not expected to be completed until 2018, thus no plans have been announced for those bases. Even though there were up to 2,000 jobs lost beginning during the airline’s bankruptcy filing in 2011, Tulsa’s employment fortunes have been improving thanks to the industry’s recovery and the AA/US merger. In February 2014, 400 jobs earmarked for elimination were avoided as the carrier announced that it would bring its MD-80s to Tulsa for structural inspections and would also use the site to accept deliveries of its new 737s, though there was still attrition from buyouts. American also has its dedicated cadre of customer C-1 test pilots based here who are also responsible for delivering aircraft from the manufacturer to the airline.

Everything (But the Paint) Including the Lavatory Sink

With Tulsa’s M&E Center squarely focused only on its mainline customer, AA endeavors to keep as much work in house as possible. There are support shops for cabin related items, avionics, wheels, engine test cells, and brakes – just for starters. From light maintenance to heavy C checks, teardowns, overhauls and engine rebuilds, the Tulsa base is its own highly integrated eco-system. The numbers are staggering: In 2014, American reported that the Tulsa base “accomplished 756 aircraft visits and worked on 94,632 components, 52,311 parts were manufactured, 322 engines visited for overhaul and maintenance, 146 full heavy overhauls, and 64 landing gear overhauls.” They accomplished this with a 45% reduction in the OSHA injury rate from 2009. About the only thing the base doesn’t under-take is painting. That function is out-sourced to vendors out of state.

During our briefing, American officials went to great pains to demonstrate their commitment to reducing costs and timelines without sacrificing quality. The CFM-56 engine shop was held up as an example to illustrate the point with American determined to beat the world standard. The CFM-56 engines that American uses on its 737-800 fleet need overhauls every 5-7 years depending on their age. From tear down to overhaul to test cell to re-hanging a CFM-56 an aircraft has been reduced from 70 days to 53 days.

American’s entire program of fuel efficiency and range increasing winglets conversion to its 737, 757, and 767 fleet all occurred in house, on-site at Tulsa. The Aviation Partners 737-800 kit, that adds a total of 1,400 pounds per airplane between the winglets and spar strengthening took 10 days per airplane. Boeing 757 conversions began in 2005, occupied 16-18 days a piece, and were all completed in 2012. The Boeing 767 conversions occurred over the course of 24-25 days per aircraft with the last one completed in February of 2014. American has also chosen to do all GoGo inflight connectivity conversions here as well.

Heavy C checks and teardowns of the company’s 737s, 757s, 767s, and MD-80s, are the most obvious sign of the activity at TUL. The base can accommodate 23 aircraft at a time in its 7 cavernous hangars. The time and man hours involved in an overhaul vary substantially by aircraft type and age. A Boeing 737’s heavy C check can happens every 5-6 years. An early 737-800 delivered from 1998, when they first joined the fleet, to the early 2000s can consume 25 calendar days in three shifts and 14,000 man hours of round-the-clock work. A newer 737-800 can occupy 15 calendar days in 3 shifts and up to 10,000 man hours.

The next stop is Hangar 6. Built in 1991, this newest of the hangars at TUL M&E can accommodate 3 767s at once. On a wide-body aircraft which often fly fewer cycles, the full overhaul heavy C check happens at intervals of 72 months with checks taking from 22-30 days and 17,000 to 22,000 man hours. We encountered 2 different 767s undergoing different scenarios. One aircraft, the newest 767-300ER at 11 years old, in AA’s fleet has only 46,000 hours on it. Remarkably it is still flying with 1 of its original engines. This aircraft was 14 days into a 24-day check. This jet was receiving the new Business Cabin seating AA has ordered to tide the 767s until their retirement. Meanwhile, its stable-mate, a 767-300ER delivered in 1987 was on a light C check, that occur ever 18 months. The light C check lasts around 10 calendar days and 7,200 man hours. Why not a heavy C? Simply, that in around 18 months time this aircraft will be retired.

Overhauling the Operation with New Aircraft Entering the Fleet

The airline industry as a whole is experiencing tailwinds with record profits and rapid growth, reaping the benefits of lower oil prices. However, there are headwinds on the horizon: Year on year revenues and yields are dipping in some of American’s key markets while capacity is increasing. While new aircraft are a positive for airlines, aircraft manufacturers, and customers, they can have a potentially negative affect on MRO’s and in house maintenance shops such as AA’s Tulsa M&E. While the Tulsa base seems primed for growth post the AA/US merger, there are flashing yellow lights of caution. In its mission to have the youngest fleet of any US airline, American is now adding up to 2 new aircraft to the fleet each week. The new build planes are replacing older retiring aircraft. Hence, there is less of a demand for heavy checks and overhauls particularly of the retiring 757s, 767s, and MD80s that are the base’s staple. American’s Tulsa maintenance base workers are mindful of the fact that no new and for that matter, existing programs are guaranteed unless they can compete to provide a better priced and better produced product then lower-cost out-sourced competitors. Though Tulsa would seemingly be the logical candidate for the new A320 and 787 fleets, and the coming A350 fleet, this decision hasn’t been publicly announced nor will these new aircraft need heavy maintenance for years. The take-away to TUL’s future seems to be staying ahead of the cost and quality curve, and competing to host new programs and aircraft – a theme echoed in every shop we visited.