How retired aircraft find a second act

Dec 19th 2024 | MUMBAI AND TUCSON

On a clear Monday morning in April 2024 an Air India 747-400 named Agra lined up on runway 27 at Mumbai airport and commenced its take-off roll. As the aircraft left the ground and started its ascent over the densely packed metropolis it looked for a brief, scary moment as though something might be wrong. Grounded in the pandemic, for three long years it had sat exposed to humidity and monsoons. Its enormous wings, nearly as wide as its body is long, tipped alarmingly to the left, and then to the right, before it stabilised and soared over the Arabian Sea.

For observers in the know it was an enthralling moment, tinged with sadness. The manoeuvre, called a wing wave, is an aviation tradition commemorating an aircraft’s last journey. For a quarter of a century Agra had carried families to loved ones, students to new lives and executives to fresh markets. It had flown prime ministers to summits, taken pilgrims to Mecca and repatriated stranded citizens during the pandemic. All told, it made more than 13,000 trips and spent 63,120 hours—over seven years—in the sky. Now it was en route to its final destination: Roswell, New Mexico, in the deserts of the American south-west. That is where it sits today, among the cactus and the odd lost extraterrestrial. But Agra will have an afterlife—one that is crucial to keeping global aviation aloft.

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A Boeing 747 has 6m parts, many of which can be reused. Parts need to be certified and have a comprehensive maintenance history, or else their provenance becomes suspect and value plummets.

The robust-looking outer covering is in fact a millimetre-thin “skin” of aluminium alloy covering a metal frame, insulated with foam. That skin is harvested by firms such as Planetags, which turns it into keychains and other keepsakes.

The most valuable part is the engine, usually the first thing to be harvested. “As you start to retire a fleet out you can mix-and-match parts to extend the life of an engine,” says Mike McBride of Delta Air Lines.

Cockpit instruments can be removed and reused in other aircraft of the same type. Sometimes the entire cockpit is repurposed as a simulator for pilot training.

Seats and carpets are changed every eight to ten years. Higher-class seats may be sold to other airlines or hobbyists but economy seats are, on the ground as in the air, the least desirable things on a plane.

Airlines are constantly disposing of old aircraft and acquiring new ones. The reasons rarely have much—if anything—to do with airworthiness. A Boeing 747-400 can fly at least twice as many hours and nearly three times as many trips as Agra did before its structure starts to reach its limits. For an industry that operates on razor-thin margins and frequently stands accused of being environmentally unsustainable, it might seem extravagant not to wring every last mile out of a pricey asset. The case is in fact the opposite. The life and death of aircraft are determined by hard-nosed business calculations.

The biggest factors in deciding to stop operating a particular type of aircraft are customer expectations, costs and accounting. The first may come as a surprise to flyers accustomed to shrinking legroom and vanishing baggage allowances—the well-being of its passengers can seem like the last thing on an airline’s list of priorities. Yet flying has become more pleasant in subtle but important ways.

The latest generation of long-haul planes—Boeing’s 787 “Dreamliner” and the Airbus A350—is less noisy and more stable in turbulence. The new jets can manage higher humidity levels, lowering the chances of dehydration for travellers, and maintain higher cabin pressures that feel closer to conditions on the ground. An economy-class passenger on Air India’s new flagship A350s will not enjoy the 747’s menu of suprême de poulet à la imperiale served with pommes à la savoyarde and haricots verts au beurre, but she will feel fresher when she arrives at her destination.

New planes are also more efficient. Fuel is the single largest cost for any airline. Engines and weight are major factors in determining consumption. The biggest modern aircraft have just two engines compared with four on the 747 or the enormous Airbus A380 double-decker, and much of the airframe is made of light composite materials, such as carbon fibre, instead of heavier aluminium alloys. Airbus boasts that the A350 consumes 25% less fuel per seat than its predecessors, producing comparably fewer emissions.

Then there are the mysterious workings of an airline’s accountants, who unlike its pilots are not bound by the laws of physics. Guidance from the International Air Transport Association, an industry body, states that the accounting for aircraft acquisition and depreciation is “complex” and “requires judgment by airlines”. The oversimplified version is that an aircraft’s individual parts may eventually be worth more than their sum. Or the cost of the most extensive mandatory maintenance checks can exceed a plane’s book value. Better to sell it off.

External factors also affect in the life cycle of aircraft. Commercial aviation is in the middle of a demand boom. But manufacturers are struggling to produce enough new planes to fill orders and many aircraft are stuck on the ground because of engine troubles. Some airlines are flying older jets for longer than planned or bringing others back from retirement. Conversely, the pandemic hastened the departure of planes a step away from retirement, including most passenger 747s. British Airways had planned to fly its 31-strong fleet of 747s until this year but in July 2020 it announced the “heartbreaking decision” to retire them immediately. Agra operated the last scheduled flight of any Air India 747, from Delhi to Mumbai, in March 2021.

Final approach

Estimated jet retirements by 2030*

*Between November 20th 2024-December 31st 2029

The post-retirement careers of aircraft are diverse. Some transition to different forms of hospitality. The Jumbo Stay Hotel is a 747 parked outside Arlanda airport near Stockholm; guests can sleep in a cockpit room equipped with a shower and minibar. One retired British Airways 747 has been turned into a party venue in the Cotswolds.

Others serve society in different ways. A 747 that flew passengers for two decades was converted in 1997 into a flying space observatory for America’s National Aeronautics and Space Administration (nasa). In Iztapalapa, a poor corner of Mexico City, a retired 737—the workhorse of short hops—is now a library. In 2012 America’s Discovery Channel and Britain’s Channel 4 deliberately crashed a 727 in the Sonoran Desert to see which seats offered the best odds of survival (the cheap ones). A lucky few end up as exhibits in aviation museums, continuing to evoke wonder in future generations of pilots, engineers and frequent flyers.

But the majority of retirees make their way, like Agra, to somewhere like the American south-west. This remote corner of the world is the exact opposite of Mumbai. Land is cheap and there are barely any people. The sun shines for some 300 days a year. Humidity levels hover in the low double digits. It is so dry that the soil, known as caliche, hardens to a cement-like consistency—ideal conditions for storing planes, heavy things whose enemy is corrosion-causing moisture. (Interior Spain offers a similar climate and some European planes end up there.)

Doors to manual and re-sell

Commercial aircraft head to a facility like Pinal County Airpark, about 50km north of Tucson, where private companies store, maintain, convert and disassemble planes of all sorts. As you turn off the interstate and head west through the desert, you are greeted by the incongruous sight of dozens of tail fins rising in the middle of the desert. Pinal is home to some 200-300 aircraft at any given time. Unless a plane is simply there for storage (about $5,000 a month for a single-aisle jet, twice that for a big one), it usually has a new owner by the time it gets here. What happens to it next depends on the owner’s business, what kind of plane it is and market conditions. But each path allows it to keep flying, in whole or in part.

One route back into the skies is acquisition. Airlines in rich countries prefer factory-fresh aircraft because of fuel efficiency and customer expectations. But smaller carriers in poorer places are willing to settle for older models. A 15-year-old Boeing 737 or Airbus A320 may well find a post-retirement gig ferrying passengers around Africa. An aircraft can also be converted to carry cargo, which can add ten to 20 years to its flying life. Despite higher operating costs, second-hand planes offer better value to logistics firms than more-efficient but pricey new ones because freighters clock fewer hours in the air than passenger services.

The other route back into the skies is more convoluted, but more common. Every aircraft at every airline undergoes routine checks of increasing degrees of intensity. These range from monthly “A checks”, inspecting parts that see the heaviest usage, to multi-year “D checks”, at which point “You’re really taking apart nearly the entire aircraft” to identify problems and fix them, says Scott Butler of Ascent Aviation Services, a major aircraft maintenance and teardown company based at Pinal.

An airline with hundreds of planes will be running checks every day. Worn-out or damaged components are replaced. “With the amount of maintenance that goes into it, you’re basically rebuilding that airplane two to three times over the course of its life,” says Mike McBride, a vice-president of maintenance operations at Delta Air Lines, which has nearly 1,000 aircraft.

An Air India Boeing 747, with a “jharokha”-style window livery to resemble traditional architecture

Image: Alamy

The view from an interior of a retired TWA 747 looking out on to Pinal Airbase. Pinal Airpark is sometimes called a graveyard or boneyard for planes. — The view out of a partially stripped 747 at Pinal County Airpark, from what would have once been a sought-after window seat
Image: Dustin Chambers/zReportage.com/eyevine

For a sense of the scale of the operation, consider the Boeing 777. It has 132,500 unique parts and some 3m in total, including bolts and rivets. Beneath the soft, rounded surfaces of the passenger cabin is a bewildering tangle of sensors, radars, pumps, pistons, cylinders and drums. Miles of wires connect avionics to the cockpit. Hydraulic systems move the rudder or wing flaps or brakes. Airlines need a reliable supply of all these bits and pieces. The global aviation industry would grind to a halt without them. (Sanctions-hit Russian airlines have resorted to smuggling in components in passenger luggage.)

The industry’s insatiable appetite for parts is fed by retired planes. Some aircraft parked at Pinal sit atop Jenga assemblies of wooden railway sleepers, their landing gears long since wheeled away. Others are missing flight decks or chunks of the fuselage, exposing the innards of the aircraft like a grotesque real-life version of a cutaway diagram. Clamber into one—watching for rattlesnakes—and half the instruments in the cockpit may be gone. Many of those parts are either inside other aircraft or in storage waiting to be used. There are warehouses in nearby Phoenix, pleasingly named after the mythological bird that regenerates from the ashes, that look like Amazon fulfilment centres if Amazon only did aircraft spares.

The first things to come off when a plane arrives in Arizona are the engines. Next to go is the landing gear. Avionics, instruments, hydraulics and other components are either harvested and stored or removed gradually on the basis of need. Cockpits are sometimes removed to be converted into flight simulators for pilot training. Luxurious seats at the front of the plane find new homes with second- or third-tier airlines or in the basements and garages of aviation aficionados.

The least desirable parts of a plane, in the desert as in the sky, are the economy-class seats. Nobody wants them. Nor are they easily recyclable. An airplane seat contains 20 or 30 different materials, says David Butler of the University of Birmingham. They end up being shredded or in a landfill or both. Some airlines have tried to reduce the waste. When Southwest, an American carrier, undertook a rebranding exercise in 2014 it eventually replaced coverings on 71,786 seats, resulting in 43 acres of leather weighing 635 tonnes. It has since been donating the leather to non-profits which turn it into footballs, shoes and bags.

Emirates, a big carrier based in Dubai, is likewise in the process of overhauling the interiors of its planes. An A380 carries around 800-900kg of soft furnishings, says Ahmed Safa, the airline’s head of engineering. Emirates employs 14 tailors who repurpose materials from its cabins into bags, wallets and suitcases, with proceeds from sales going to charity. The airline is thinking about expanding its range to things like umbrellas made from escape slides. “This actually costs us money,” says Mr Safa. The returns for such efforts come in the form of good corporate citizenship.

Upcycling bits of planes is a fun idea, and some aviation nuts may be willing to spend, for example, €7,000 on a chair made from the nose of an A350 (this actually exists). But for the most part it is neither economic nor scalable, except for the odd product. One example is made by PlaneTags, a California-based firm, which harvests the metal sheet, or “skin”, that covers a plane’s airframe and turns it into engraved keyrings that sell for a handsomely marked-up $40.

Partly the same, and partly not the same

More commonly, the skin of the plane meets the same fate as the rest of the airframe. Once everything—engines, components, interiors—has been stripped out, the metal structure is all that remains. Made of high-quality aluminium alloy, it commands premium prices in scrap. Airbus and Boeing both estimate that around 90% of their aircraft by weight is recycled or reused in some form. The use of composites in new aircraft poses challenges—it is not as easily recyclable as metal—but the industry has about a decade to work it out before the retirements start.

This is the end that probably awaits Agra. Even after its corporeal form has vanished from this Earth, it will continue to roam the skies as a small part of other jets. Five airlines—Air China, Korean Air, Lufthansa, Mahan Air and Rossiya Airlines—still use the 747 for passenger services. And the model is still hugely popular as a freighter. Of the 1,574 produced from the first in 1969 until production ceased in 2023, as many as a quarter remain in service, the majority carrying cargo.

Agra and its counterparts from Air India, British Airways and every airline that operated the 747 will live on in another way too. Despite the great advances in technology and cabin comfort, no aircraft has ever been as beloved (or beautiful) as the 747. It ushered the world into the jet age. It formed the backbone of the global fleet at a time when international travel was broadening out beyond the wealthy. It is the aircraft on which many readers of this piece will have taken their first foreign trips. It will live on in legend. ■

Sources:

ch-aviation.com; The Economist

How retired aircraft find a second act

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Doors to manual and re-sell

Partly the same, and partly not the same

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