DC-10 Flown - History

DC-10 Flown - History

On August 29th the DC 10 made its first flight. The DC 10 as designed to carry 270 passengers. It encountered stiff competition from the Lockehhed L-1011 a very similar plane.

What Happened To Varig’s McDonnell Douglas DC-10s?

In 1927, Varig became the first airline to be founded in Brazil. For decades, it dominated Brazilian commercial aviation, particularly its international market. Among its aircraft were 15 examples of the striking wide-bodied McDonnell Douglas DC-10-30 trijet. By the time the airline folded in 2006, most of its DC-10s had already left for other carriers. But where did these aircraft end up?

From Cargo Door Failures To One Of The Most Reliable Aircraft – The DC-10

Throughout history, aviation authorities grounded 8 aircraft. Many of them were true pioneers and brought something new the first time they lifted off the ground.

For example, the Lockheed Constellation was the first pressurized aircraft that saw commercial usage. The de Havilland Comet was the first commercial jet, bringing the world close together with an engine type that initially nobody believed in. But while it proved to everyone that commercial jet travel was the future, it also brought several disasters related to a design issue.

And of course, the one aircraft that changed everything. The jet that shortened the distance between London and New York to 3 hours on a flight – Concorde. While it certainly brought a revolution with it, the type was grounded for a year following a crash in Paris.

Most recently, following two deadly incidents, aviation’s regulators grounded the Boeing 737 MAX in March, sparking the debate whether the type will be canceled. However, with Boeing’s persistence, the aircraft seems to be on track to fly again in 2019.

But the 737 MAX was not the only grounded Boeing aircraft. The Boeing 787 Dreamliner was told to stay put in 2013 after several 787’s operated by ANA and Japan Airlines showcased a design flaw with the battery design. The aircraft has also recently shown up in headlines, showcasing Boeing’s negligence when building the 787.

Nevertheless, there was one more aircraft. Sure, it was not revolutionary like the Concorde or the Comet, but it certainly has brought something to the table and reliably serves airlines to this day, even after 48 years after its first test flight.

It's name? The McDonnell Douglas DC-10 or just DC-10 for short.

The history of the DC-10

The now-defunct and operating under Boeing‘s name manufacturer, McDonnell Douglas had built the DC-10.

At the time, in the late 60‘s-early 70s, Boeing did not compete with Airbus. Airbus had just launched it‘s first commercial jetliner in 1972, but it struggled early on to make sales in the United States.

Boeing competed with Douglas, which was later merged with McDonnell and subsequently was renamed to McDonnell Douglas.

For a short period of time, Lockheed also provided some competition with the L-1011, but the aircraft had its fair share of issues, which prevented it from dominating the United States aviation market.

Anyways, Boeing went head-to-head with Douglas. After the Second World War, aircraft named DC captured a huge portion of the civil aviation market.

However, as soon as the jet age began in commercial aviation, Boeing started out very strong with the Boeing 707 in 1958. Slowly, but surely Boeing started to take over the skies above the US and even around the world.

Initially, Douglas was not fascinated by the Comet or jet-powered aircraft, as they thought it was just a fad that would go away. Plus the groundings certainly did not help, as everybody still believed the Comet’s problems were related to its jet engine.

But, as Douglas realized how far ahead Boeing was, the company started playing catch up. Convincing airlines to order a commercial jetliner was difficult enough, Boeing made the job that much more difficult when they successfully showcased the 707 to airline executives.

However, Douglas had just recently released their DC-7, a piston-powered aircraft, and thus it was difficult to come up with a new jetliner quickly.

Nonetheless, in 1958, Douglas began testing their first jet-liner – the DC-8. Three years prior, Boeing already showcased a flight-capable 707 prototype called the 367-80.

Maneuvering around Boeing

While the article is focused mostly on the Douglas DC-10, you’re probably asking why I am telling you the story of the DC-8 and the Boeing 707.

It’s important to understand the current situation at hand, as Douglas essentially was late to the jet-engine party. They had to make moves around Boeing’s decisions. That’s how the DC-9 started – by undercutting Boeing with the intent to dominate the regional airline market.

But the DC-10 had a different backstory. At first, it started out as a military aircraft for the Air Force. The USAF approached Douglas, Boeing, and Lockheed for an aircraft capable of transporting lots of equipment. Lockheed won the contract.

So, Douglas and Boeing questioned themselves on what to do.

After the very successful debut of the 707 and rising passenger numbers, airlines wished for more. More range, more passenger room and more aircraft generally. Thus, widebodies were born. Boeing was first and announced the Boeing 747, an icon that still flies today. The aircraft could fit from 374 to 490 passengers, depending on the airline configuration.

Airlines were ecstatic, especially the now-bankrupt Pan American. The airline immediately ordered 25 Boeing 747s and heavily influenced how Boeing designed the aircraft.

However, some were cautious. So, McDonnell Douglas had an open market with no competition to work in and a customer – American Airlines (A1G) (AAL) had decided not to take a risk with the 747, as they did not think they would fill the seats on a 747 to justify a purchase of such a jet. While eventually, they did purchase some, they were definitely not as excited as Pan American. Maybe they were right, as American Airlines (A1G) (AAL) is still alive to tell the tale.

However, before coming to McDonnell Douglas, American Airlines (A1G) (AAL) had approached Lockheed for the same reason – they wanted a smaller wide-body jet than the Queen of the Skies.

DC-10 vs L-1011

Suddenly, there was competition, as Lockheed had begun designing and building their own tri-jet.

Nevertheless, Lockheed had not built a commercial airliner since the Electra, which was last produced in 1961. Even then, the Electra was powered by a turboprop engine. They had a big task on their hands to develop a jet-powered commercial airliner.

On the other hand, Douglas had plenty of experience in building passenger jets. The DC-8 and DC-9 programs had provided them with enough background information to move quickly in the development process.

They did not go overboard, unlike Lockheed. McDonnell Douglas focused on providing a simple, reliable and easy to understand aircraft design based on the previous jets.

While Lockheed‘s design was arguably much more advanced, as the L-1011 had such features as an autoland system, it also required more time and resources. And when competing, sometimes you don‘t have the luxury to tell your customers that you‘ll have to wait or pay more to justify Lockheed‘s massive spending bill when developing the L-1011.

Interested in the story of the Lockheed L-1011? Read our article about it right here!

That‘s where the DC-10 had gained an advantage. Finally, McDonnell Douglas releases a jet before their competitors do. While their prices were identical according to an old Flight International magazine edition from 1972, the DC-10 had just developed quicker.

Thus, American Airlines (A1G) (AAL) in 1968 announced they would order 25 new DC-10‘s. The announcement shocked Lockheed. But in doing so, Douglas had to offer AA a significant discount, which they happily did, as they wanted to make sure their jet is the number one priority for airlines.

In addition, Douglas offered more versions of the DC-10. In total, there were 9 different DC-10 variants.

First issues

Douglas offered more flexibility with their airliner fitting a variety of domestic and international markets, while Lockheed could not do so at first.

With American Airlines (A1G) (AAL) and United Airlines securing the future of the DC-10 with their orders, Douglas started the DC-10 production in January of 1970. After adjusting their manufacturing process, the company showcased the first DC-10 to the world in July of the same year. More customers lined up for the newest jet and Douglas now were certain that the aircraft is a success amongst airlines.

The previous year the company also announced the DC-10-30, which became the most popular variant of the tri-jet. Out of the 386 DC-10s that McDonnell Douglas had built, 206 of them were the -30.

But when testing the DC-10 in 1970, engineers have discovered that their cargo door design was faulty. As they pressurized the cabin, the cargo door went flying and the floor, separating the passenger cabin and the cargo hold failed.

But why did the DC-10 cargo doors fail?

In order to save weight, the cargo door locking mechanism was changed from a hydraulic actuator to an electrical one. This was new for Douglas, as they operated a hydraulic actuator on their older DC-8s and DC-9s. As a result, it was less reliable.

It also pointed to corner cutting on Douglas’ part, as they wanted to secure the order of American Airlines (A1G) (AAL) – the decision to switch to an electric actuator was due to their influence.

However, there were a lot of fundamental design flaws in the DC-10, especially with the cargo doors.

Failure of the aircraft doors

Every single passenger jet is split into two. Passengers are seated on the upper section, while cargo is loaded into the lower part.

But what differs is the position of the wires, cables and hydraulic lines. For example, on the Boeing 747, they are placed above the passenger cabin, in the ceiling. In contrast, the DC-10’s control cables are located under the floor. Which means that any damage to the floor that separates the passenger compartment and the cargo area will hinder the pilot‘s ability to control the aircraft, which can potentially lead to a fatal crash.

It all comes back to the DC-10’s cargo door. As passenger aircraft fly in really high altitudes to achieve the best efficiency possible, the cabin needs to be pressurized, so that the passengers could breathe. But the cargo area also needs to be pressurized, as the pressurization process adds excess loads to the cabin floor. However, because the cargo bay is also pressurized, the forces are equal, thus the floor doesn’t collapse.

If suddenly a door on either the passenger cabin or the cargo area blows open, the floor will fall apart. While the chance of such a thing happening is very rare, the result of one of the doors saying goodbye to the aircraft can be fatal.

Especially if the aircraft’s main controls are located under the floor, which would collapse in such case.

A cargo door on a passenger is larger than the door opening itself, so it’s impossible to open the door while mid-air, as the pressurization, prevents you from doing so. Even though some have attempted to open the doors while in the air, you’d have to have the force of Hulk to do so.

DC-10 Cargo doors faulty design

But the cargo latches present a different story, as different manufacturers have used different cargo door designs in the past.

Lockheed, the competitor to McDonnell Douglas at that time, designed the door similarly to the passenger one. It was bigger than the opening itself and the door was heavier than on the DC-10.

The DC-10 had used a very similar system to car boot or trunk. When you open your car boot, you can see on the boot that there is a latch. When you close it, the latch attaches to a metal loop in the car frame, thus making it impossible to open while the car is locked or you are driving it.

The DC-10 used a similar system, except of course it had several loops to shut the door securely.

So why did the DC-10 cargo doors would explode?

Firstly, the electric actuator, which controlled a shaft that moved and thus the latches are hooked onto the metal loop and the door would stay closed. As the mechanism reaches the center, the latches stay put because of the forces of pressurization. But if it does not reach the center for some reason automatically, the design of the electrical actuator prevents any manual movement of the shaft to properly lock the door.

Secondly, the lock mechanism was not strong enough. If the mechanism was not properly adjusted, the locking handle, which completely shuts the door, would be able to close. However, the door would not be fully latched, thus at certain altitudes, it would blow out.

And as a result, the cargo area would lose pressure, then the floor would collapse and then the pilots would lose control of the plane, as the aircraft‘s controls are in the floor between the two compartments.

First incidents

While Douglas did make changes after the 1970 test, where the doors blew out, they were not enough. Simply put, the system was still faulty.

The DC-10 made its debut flight on the 5th of August, 1971 with American Airlines (A1G) (AAL) . 10 months later, on the 12th of June, 1972, the first cargo door accident happened.

On American Airlines Flight 96, shortly after the American Airlines DC-10 had taken off from Detroit‘s Airport, a cargo door at the back of the aircraft blew open.

Luckily, the aircraft was only partly occupied – only 67 people were on board. So the floor collapsed only partially, thus the pilots had retained some of the control and landed back at Detroit safely.

After the incident, the NTSB told McDonnell Douglas to implement two changes to the DC-10:

First of all, to strengthen the locking mechanism. Secondly, to install a vent at the back of the aircraft.

The NTSB designated the FAA to force Douglas to make these changes. The aircraft manufacturer changed the locking mechanism, but behind closed doors, the two parties agreed that a vent installation would complicate things.

That decision was fatal to 346 people two years later.

In 1974, a Turkish Airlines DC-10 had just landed in Paris after stopping on the journey from Istanbul to London. As personnel on the ground refueled the aircraft, they also loaded and unloaded some cargo.

As the aircraft took off for its second leg of the scheduled service to London, the very same thing happened – the cargo door burst open, the air pressure inside the cabin dropped, the floor collapsed and subsequently, pilots lost the control of the aircraft.

Outcome of the Turkish Airlines Flight 981

McDonnell Douglas eventually lost a lawsuit worth over $18 million to the victims’ families. The aircraft manufacturer tried to direct the blame elsewhere – blaming the FAA for not issuing an airworthiness directive, blaming Turkish Airlines of improperly implementing the locking mechanism modifications and blaming General Dynamics for the poor design of the cargo doors.

Nevertheless, none of this had worked and McDonnell Douglas had to pay the $18 million.

On the technical side of things, a complete redesign of the locking mechanism followed. The FAA finally held its ground, issued an airworthiness directive and ordered a vent to be installed in the cabin floor, in order to prevent the loss of pressure destroying the cabin floor.

After the Turkish Airlines Flight 981 crash and the subsequent changes, the DC-10 never experienced another cargo door blowout.

But its reputation was shaken, as people were nervous when getting on board a DC-10. Nevertheless, the aircraft continued to fly successfully.

Yet that was about to change.

5 years later after the Turkish Airlines flight, an American Airlines DC-10 on Flight 191 crashes just outside Chicago.

DC-10 Engine separation

The crash occurred on the 25th of May, 1979. On June 6th, the FAA grounded the aircraft. The cargo door did not explode this time.

What happened was, that the left side engine separated from the aircraft, punctured critical hydraulic lines and the aircraft subsequently stalled, as it began rolling to the left. The DC-10 slammed to the ground, killing 271 people on board and two people on the ground.

However, the FAA‘s actions were swift and harsh, as no ferry flights would be able to take place during the grounding. In contrast, the Boeing 737 MAX was still able to conduct ferry flights around the United States.

After the NTSB concluded the investigation, the board acquited the DC-10, as the fault lied at the hands of American Airlines (A1G) (AAL) ‘ maintenance procedures. Improper engine maintenance caused structural damage to the pylon, which holds the engine together with the wing.

At this point, the DC-10‘s reputation was shattered. The media had released many pictures of the aircraft flying without an engine and photographs depicting the fireball resulting from the crash.

If people were already double-questioning themselves about getting on a DC-10, after the American Airlines Flight 191, the message was clear – people refused to get onto a DC-10.

Lessons for the future

Looking back at the DC-10 misfortunes and loss of lives, there are a lot of similarities with the current situation of the Boeing 737 MAX.

Corner cutting, the manufacturer‘s and FAA‘s negligence played a big part in the accidents.

Even then, after several deadly accidents, the DC-10 became one of the statistically safest aircraft in the air. Even now, after almost 50 years from the first test flights, you can still see a DC-10 in the sky. But they only fly cargo, as the last passenger flight landed in 2014.

What the story of the DC-10 showcases, that even after initial tribulations and difficulties, an airliner can still serve the passengers safely.

And that‘s what you have to remember when people discuss a crash – that these very freak accidents that happen very rarely. Thousands upon thousands of flights leave daily and the aviation industry is regarded as the safest way to travel from point A to point B.

A Tale of Two DC-10s

On June 12, 1972, American Airlines Flight 96, a DC-10, broke through a spotty cloud layer over the Canadian industrial city of Windsor, Ontario. Almost five minutes had passed since the wide-body jet had lifted off the runway at Michigan’s Detroit Metropolitan–Wayne County Airport at 7:20 p.m. Captain Bryce McCormick took a moment to appreciate the 180-degree view through the curved window of the cockpit, and leaned back and took a sip of coffee. Flight 96 was on its way to La Guardia Airport in New  York City that evening, with a stopover in Buffalo. That morning, McCormick had flown the first leg of the flight, out of Los Angeles, so he let First Officer Peter Paige Whitney, 34, fly the takeoff from Detroit. All the gauges on the instrument panel registered normal. The autopilot was on, but Whitney kept his hands on the yoke out of habit.

Both pilots were well aware that their new DC-10 was only the fifth manufactured by McDonnell Douglas. The first had made its maiden flight in August 1970 and entered commercial service with American Airlines one year later, on August 5, 1971, on a round-trip flight between Los Angeles and Chicago.

McCormick was a veteran pilot who had accumulated 24,000 hours of flying time, while Whitney had almost 8,000 hours to his credit. The airplane was carrying just 56 passengers (the wide-body had the capacity for 206), plus 11 crew members, which included eight flight attendants and the three-man cockpit crew. (At the time, the DC-10 required a flight engineer.) Along with the passengers’ luggage, a casket carrying a corpse bound for Buffalo was stored in the cargo hold.

McCormick checked the radar and confirmed that no bad weather lay between Detroit and Buffalo. McCormick was an exceptional pilot. His presence in the cockpit inspired confidence. “He was the epitome of the perfect captain,” said Cydya Smith, the chief flight attendant on Flight 96. “He was very professional, yet he was warm and friendly and very respected, and respectful of the flight attendants.”

Captain Bryce McCormick (from an American Airlines newsletter) has been frequently praised for his performance during Flight 96, when the aft cargo door blew out during the flight. (Courtesy American Airlines CR Smith Museum) On June 12, 1972, a powerful explosion ripped through American Airlines Flight 96 (a similar aircraft). (Andrew Thomas) When the DC-10 finally landed, the crew could see the aft cargo door was gone. What remained was a jagged piece of metal curling upward. (NTSB)

Both the “Fasten Seat Belt” and “No Smoking” signs had been turned off in the cabin. Passenger Alan Kaminsky and his friend Hyman Scheff unbuckled their seat belts and left their wives in the first class section to go play gin rummy in the forward lounge. They wanted to get in a few quick hands before the airplane touched down in Buffalo. Smith was out of her jump seat in the front of the plane before the “Fasten Seat Belt” sign blinked off. Following her usual routine, she walked to the galley and began to make coffee. “That’s when it happened,” she recalled. Exactly five minutes after takeoff, Smith was lifted off her feet by a powerful explosion. As the galley doors burst open, she could see entire sections of laminated ceiling panels falling into the passenger compartment, which was filling with a dense grayish-white fog. She could not hear the screams of the passengers. Instead, she felt as if she were enveloped in a gauzy silence.

As both pilots were jolted violently backward, a noxious cloud of charcoal-gray dust filled the cockpit, blinding McCormick, who feared the airplane had been damaged in a midair collision.

The actual cause of the unfolding calamity was something more insidious but just as devastating. A cargo door blowout in the hull had torn a gaping rectangular hole in the side of the aircraft, large enough to disgorge the six-foot-long casket, which tumbled two miles to earth, along with dozens of suitcases. Far worse, the explosive release of pressurized air had ripped out a large section of flooring in the passenger cabin directly above the gash in the hull. A hurricane-like wind was blasting through the length of the airplane. Flight attendant Beatrice Copeland had been knocked unconscious and lay trapped in the debris of the collapsed floor. Another flight attendant, Sandi McConnell, had barely escaped being sucked out of the airplane when the floor gave way beneath her acting purely on instinct, she fought against the rushing air that threatened to pull her out into the sky. Without looking, she knew the lavatory door was directly behind her. It was her best chance for survival. Once inside, she closed and locked the metal door. She was safe for the time being, but cut off from rescue.

Alan Kaminsky remembers a “huge crunch” as his playing cards flew out of his hands and up into the air. Passengers shrieked as the DC-10 lurched to the right and fell several thousand feet.

The two pilots knew nothing about the gaping hole in the back of the airplane but were trying to contend with the stricken DC-10. As his vision cleared, McCormick took over the controls from his first officer. He had only seconds to regain control using a technique that had never been put to the test in an actual emergency.

Earlier that year, McCormick had been chosen by American to fly one of the new McDonnell Douglas airplanes. He had not been fazed by the jet’s size and engine power. What concerned him was one particular feature of the DC-10 that made it radically different from all the other big jets he had flown: its lack of a backup system to operate the airplane’s flaps, elevators, and rudder by hand in case the hydraulic system failed. In this regard, the DC-10 was very different from the DC-6 and -7 and the Boeing 707 and 727—all aircraft that McCormick had flown for more than two decades. All the older aircraft were equipped with reversion systems that gave pilots manual command of control surfaces if the hydraulic systems were knocked out. What would happen, he wondered, if all of the airplane’s systems were damaged?

He found the answer on a DC-10 flight deck simulator at the American Airlines training school in Fort Worth, Texas. Using the computerized simulator, McCormick spent hours repeatedly testing his alarming hypothesis of total hydraulic system failure and learned how to exploit the DC-10’s exceptional ability to fly on its engines without assistance from the rudder or ailerons, the surfaces that make the aircraft turn and bank. He also learned how to manipulate the engines to push the nose of the DC-10 up or down. Most jets have this ability to some degree, but McCormick discovered that the DC-10 was especially responsive.

The day his worst fears were realized, McCormick knew exactly what to do: He shoved two of the idle throttles fully forward, delivering a burst of enormous power to the aircraft’s wing engines, and felt them surge back to life. In response, the DC-10’s nose pitched up. McCormick had reversed the DC-10’s fatal descent. The returned engine power also bought him precious minutes to figure out how to steer the aircraft, which continued to yaw stubbornly to the right. He immediately flipped a switch to cut power to the fuel pump that fed the idle tail engine, taking it out of play and lightening the load on the elevators adjacent to the tail, making them slightly more responsive. Two of the four cables to the tail elevators had snapped. The ailerons were responding but sluggish. Without full hydraulic control, the DC-10 could not be banked in either direction by more than a gentle 15 degrees. Anything more would put it into a spin. McCormick decided that his best bet was to rely on the differential engine technique—boosting the thrust on one wing engine or decreasing it on the other—to slowly turn the DC-10 around and return to Detroit.

McCormick knew he would need ground controllers to give his crippled aircraft priority to land, and he contacted the control tower in Detroit: “Ah, Center, this is American Airlines Flight 96. We got an emergency.”

The response from Detroit control was equally terse. “American 96, Roger. Returning back to Metro?”

He hesitated. Where should they attempt to land? He briefly considered Wright-Patterson Air Force Base in Ohio, where the runways are especially long and equipped with protective barriers in the event of a crash. But Detroit was closer. Better yet, the approach was clear. Detroit it was.

McCormick quickly reviewed their situation. “I’ve got no rudder control whatsoever, so our turns are gonna have to be very slow and cautious,” McCormick told Detroit control. All he could do was pray that the slats and flaps he needed to give the airplane lift at lower speeds would work when he began his descent.

The announcement had the desired effect. Whatever had happened, the pilot was not alarmed, and that inspired confidence.

McCormick’s biggest challenge would be to slow the aircraft enough to land safely. The DC-10 was approaching the runway at 184 mph, and McCormick needed to bring its speed down. However, without command of the rudder to keep the jet pointed straight ahead, McCormick might have to fly faster to ensure control.

At 7:40 p.m., 20 minutes after flying out of Detroit, Flight 96 was once again visible on the radar screen in the control tower. As the jet began its descent, it was Whitney’s job to monitor the aircraft’s critical sink rate, or rate of descent. As the ground rose up to meet them, the first officer began calling out the sink rate numbers with a sense of urgency that bordered on alarm. The rate was too steep and too fast. At the start of the descent, the jet was descending at a manageable 300 feet per minute. But as their speed slowed, the sink rate shot up to 500, 600, 700, 800, and finally 1,500 feet a minute. The aircraft wasn’t descending—it was falling. The only way to prevent a crash was to push the throttles forward and increase the speed. McCormick eased the throttles forward to deliver more power. And in a matter of seconds, the sink rate fell back to 800 feet per minute and the jet’s speed shot back up to 184 mph.

When its tires hit the concrete runway, the DC-10 was speeding like a race car the jet veered off the runway to the right, where it bumped across taxiways and grass medians on a collision course with the main terminal. McCormick reacted by throwing the number 1 and 3 engines into reverse thrust, but even that could not counteract the airplane’s momentum.

Whitney reached over and took control of both throttles, simultaneously pushing the right wing-engine throttle full forward and the left wing-engine throttle into full-reverse thrust, delivering 10 percent more power and forcing the jet to swing to the left, on a return course to the runway. It hurtled along, with two sets of wheels on the runway and the other two off. When it finally stopped, half the wheels were on concrete and half on grass, with more than 980 feet of runway to spare.

When the cargo door failed on Turkish Airlines Flight 981, all aboard perished in the crash, the fourth deadliest in history. (Beutter/SIPA)

A vastly relieved McCormick gave the order to shut down the two engines. Smith and the other flight attendants helped the passengers at the emergency exits. After the six chutes had inflated and the first passenger slid down to safety, it took only 30 seconds to get all 56 passengers off the airplane. McCormick gave his final order to evacuate the cockpit he and Whitney were the last to exit.

As emergency vehicles came rolling up, red lights flashing, the crew members all wanted to get a good look at the mysterious hole in the fuselage. There it was, easy to see even in the deepening twilight: The large aft cargo door was gone. Above the opening, a jagged piece of metal curled upward, as if it had been peeled back by a giant can opener.

The entire episode on Flight 96, from its explosive onset to the perilous landing, had taken place in less than 30 minutes. The jet’s aft cargo door had separated from the aircraft with explosive force at 11,750 feet above sea level. How and why the door had blown out in midair was a mystery that needed to be solved as quickly as possible.

The accident investigators were in luck: The same day as the accident, Ontario police contacted airport officials about an airplane door—and coffin—that had landed in a cornfield outside Windsor. After going over every inch of the door, the investigators made a shocking discovery: The airplane had taken off with the door closed but not secured. As the airliner ascended and internal air pressure increased to a critical level, it was only a matter of time before the large cargo door would give way and blow out.

And there was another design flaw: The section of the cabin floor above the cargo hold lacked pressure relief vents that would have permitted the air from the cabin to flow through without ripping the floor apart. When the National Transportation Safety Board issued its final report, it implicated both the door and the floor.

The Federal Aviation Administration agreed not to issue an airworthiness directive, but quietly told McDonnell Douglas to fix the problem. NTSB investigators recommended modifying the DC-10’s cargo door and cabin floor McDonnell Douglas claimed that what happened to Flight 96 was an isolated incident. (The problem was actually intermittent and ongoing.) Less than two years later, a sudden blowout tore through Turkish Airlines Flight 981 from Paris to London. That DC-10 crashed in France none of the 346 people on board survived.

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This story is a selection from the December/January issue of Air & Space magazine

The alliance pressed on

Northwest Airlines merged with Delta in 2008, with a single air operator’s certificate coming in late 2009, at which point the former ceased to exist. The full brand, however, was retired in January of 2010.

Delta and KLM continue to have an extensive partnership. As members of the SkyTeam alliance, the two also have a joint venture that includes KLM’s sister, Air France, and Virgin Atlantic in the United Kingdom.

Delta’s KLM and Air France alliance is one of the most important transatlantic alliances. The Northwest-KLM tie-up paved the way for Delta to pursue the strong relationship it has with these airlines.

While Delta and KLM no longer have any planes painted in a hybrid livery, the two carriers still have deep ties, all thanks to Northwest Airlines.

Have you flown on the hybrid livery DC-10? Let us know in the comments!

A Historical Look at the DC-10 Before its Final Passenger Flight

Starting tomorrow, the last Douglas DC-10 will start its farewell tour as the last passenger DC-10. Biman Bangladesh Airlines will fly to Birmingham, UK, by way of Kuwait and then offer scenic tours before it is finally ferried to a final “resting” location in the US. Our own Bernie Leighton will be covering these events from Bangladesh and beyond, but before we tell the last chapter of this majestic aircraft’s life, we wanted to start at the beginning with this historical look at the DC-10.

The birth of the wide-body airliner as we know it today can be traced back to one event in the early 1960’s: The United States Air Force’s request for proposals for the CX-HLS, the program that would ultimately become the C-5 Galaxy. Lockheed won the CX-HLS competition, and as legend would have it, Boeing would strike gold when they converted their design into what we know today as the 747. However, that is not quite 100% true, and Boeing was not the only company to transfer design philosophies from the CX-HLS to the commercial market.

A United Airlines DC-10 in Friend Ship livery – Photo: Bob Garrard

U pon losing the USAF contract, the powers that be at Douglas aircraft immediately started altering their ideas to fit the commercial market, and a race was starting to see who would bring the first wide-body aircraft to market. Like Boeing, Douglas also studied the possibility of a double deck design, capable of seating upwards of 500 passengers, and also like the Boeing airliner concept, Douglas moved from a high, shoulder-mounted wing to a low-wing design.

Douglas studied several different designs, including the D-950 and D-952 concepts, which would have carried 525 and 454 passengers, respectively. However, as further studies at the time decided, there was really no market for a large number of large-sized aircraft, and after Douglas shopped around their proposal for a large, four-engine aircraft to various airlines, including Pan Am (who at the time had just signed an order with Boeing for 25 747s), Douglas management wisely decided to take a step back and consider a detailed look at what the market predicted.

Around this same time, Douglas Aircraft merged with McDonnell Aircraft to form the McDonnell Douglas Company, and the new management team decided to make the DC-10 airliner program a priority. The project team aired for criteria spelled out by American Airlines a twin-engine airliner that could carry at least 250 passengers and 5,000 lbs of cargo 1,850 miles, cruise at Mach 0.80, and could meet this criteria from the short runways at New York’s LaGuardia Airport. After deciding to tackle this request, Douglas engineers, on their own merit, decided to pitch the idea of a three-engine aircraft, arguing that it would be no more costly than a twin, and would offer better performance in hot weather.

DC-10 in factory colors – Photo: Bob Garrard

Douglas convinced American of the three-engine layout after seeking the advice of other airlines, and the revelation that Lockheed was developing a similar aircraft: the Lockheed L1011. As a result, in July 1967, American issued a refined set of requirements: A tri-jet capable of transcontinental flight, with full payload and a trip time within minutes of the 747, comparable economics to the 747 between New York and San Francisco, and a Mach 0.85 cruise speed at 35,000 feet.

With this revised criteria from an airline, the McDonnell Douglas board gave its permission to launch the DC-10 in November, 1967. This was officially realized in February 1968, when American Airlines placed an order for 25 aircraft, with 25 options. Two months later, the program was launched when United Airlines placed an order for 30 aircraft, and 30 options. With orders in the books, the process of fine-tuning the design and moving towards production could begin.

Douglas chose the GE CF-6 high bypass turbofan, since Pratt & Whitney was heavily involved in producing engines for the war effort in Vietnam, and the JT9D was the sole engine choice at the time on the 747. Rolls Royce was in an awkward position, since they had a sole source contract with Lockheed for the powerplant on the L1011. Douglas engineers studied various options for locating the third engine. Looking at everything from an S-duct in the tail (Lockheed chose this for the L1011), to having the engine buried in the tail cone with a bifurcated duct that wrapped around the base of the vertical fin. The design that the engineers finally chose was to have a straight pass through duct mounted on top of the tail cone, creating a so-called “banjo”.

Wind tunnel tests proved that this arrangement would yield better performance results, and would also ease maintenance and spares issues. By placing the engine on top of the tail cone, and having all engine attach fittings in the top of the banjo, one engine could be used in any of the three engine locations, with only 45 minutes worth of work needed to reconfigure an engine off a wing for mounting in the tail.

This DC-10-30 was the last ever produced – Photo: Ken Fielding

Douglas had originally planned on having three models of the DC-10 the DC-10-10, 10-20, and the 10-30. The base model (the 10-10) was a transcontinental aircraft, and was not optimized for intercontinental routes. The 10-20 was to be the first of the intercontinental DC-10s, powered by the Pratt & Whitney JT9D. Lastly, the DC-10-30 was to be the same as the -20, however it was to be powered by up-rated versions of the CF-6. The main distinguishing features of the -20 and the -30 were the addition of a third main landing gear leg, mounted directly on the centerline of the aircraft.

Northwest Orient was the first airline to order the intercontinental model in October 1968, and they chose the JT9D engines for fleet commonality with their 747s already on order. Only one other carrier would order the -20, and that was Japan Airlines. Now, I am sure that many aviation fans here are thinking that no DC-10-20 ever saw service, and you would be technically correct. Prior to delivery of the first -20 to Northwest, according to popular legend, Northwest and Japan Airlines both approached Douglas saying that they did not want their aircraft to seem inferior to the -30 model, and wanted their aircraft to appear to be the best and latest model of the DC-10. Douglas gave in and designated the DC-10-20 as the DC-10-40.

The first DC-10, a -10 model, made the type’s first flight on August 29 th , 1970 from Long Beach, California, just one month after the official rollout on July 23 rd . A year later, after a flight test program that spanned 1,500 flight hours over 929 flights, using 5 aircraft, the DC-10 received its FAA Type Certificate on July 29 th , 1971. That same day, the first two aircraft were officially delivered to two inaugural customers: American Airlines and United Airlines. The first passenger flight of the type occurred just a week after the first delivery, when American flew a round trip flight from Los Angeles to Chicago on August 5 th , using N103AA, the 5 th DC-10 built. United followed suit on August 16 th , with a round trip from San Francisco to Los Angeles using N1802U. Deliveries quickly followed to other airlines, and soon the DC-10 could be seen on routes all over the United States and, for that matter, the world. Entry into service was smooth however, the aircraft soon gained a reputation that no one wants for any aircraft.

A Caribbean Airways DC-10 with a Lockheed L1011 and Boeing 707 in the background – Photo: Bob Garrard

On June 12 th , 1972, the DC-10 experienced its first major incident, and a serious design flaw was uncovered. N103AA, the same aircraft that just less than a year before completed the type’s first passenger flight, was operating American Airlines Flight 96 between Detroit and Buffalo. Just after departure, as the aircraft was passing through 11,750 ft, the aft cargo door explosively departed the aircraft. The resulting decompression caused the floor over the cargo compartment to cave in, damaging the flight control cables that passed through the area. Parts of the door also impacted the horizontal stabilizer of the aircraft.

Upon a safe landing back in Detroit, investigators found that the door on this particular aircraft had been difficult to latch prior to departure. The ground crew member stated that he had to use more force than normal to latch the door. He also noted that the pressure relief vent door, a smaller door to relieve any aircraft pressurization prior to normal opening of the door, was not fully seated closed. Upon investigation of the door, which was recovered intact from Windsor, Ontario, it was discovered that the door latch never engaged, and moved just enough to cause the “Door Open” warning light to extinguish in the flight deck – the door appeared to be closed. Following this incident, McDonnell Douglas immediately issued a service bulletin to modify the doors, but airlines were not mandated to make the repair. The FAA also failed to issue an Airworthiness Directive, which would have made the Douglas modifications required before the airplane could fly again.

The type soldiered on for two more years before the cargo door issue came back to haunt McDonnell Douglas, this time with disastrous results. On March 3 rd , 1974, Turkish Airlines Flight 981, operated by TC-JAV, departed Paris Orly Airport bound for London with a full load of 346 passengers and crew. As the aircraft was climbing out of Paris, muffled, panic-filled calls came over the ATC frequency. Turkish Flight 981 had been lost with no survivors over the Ermenonville Forest outside of Paris. Investigators soon discovered that the cause of the crash was the rear cargo door opening in flight. Pieces of wreckage were found that included the intact door, still attached to parts of the aircraft skin and cabin floor structure. The investigation soon revealed that a similar scenario to the American Airlines incident nearly two years prior had occurred, and this time, the FAA acted. McDonnell Douglas immediately redesigned the door, and added small windows that would allow the ground crew to visually verify that the latch pins were engaged. The DC-10’s reputation was already tarnished and the aircraft was in the public eye for the wrong reasons.

Pan Am DC-10 – Photo: Bob Garrard

The next major incident would come on May 25 th , when American Airlines Flight 191, operated by N110AA, departed Chicago bound for Los Angeles. Moments after takeoff, the aircraft’s #1 engine separated from the left wing and flipped up over the top of the aircraft. The ensuing crash killed all 271 passengers and crew onboard, and two on the ground. In the investigation into what remains the deadliest single plane crash on US soil, it was discovered that American Airlines was using a method to change engines on the aircraft that was not approved by McDonnell Douglas, and it was soon discovered that two other US carriers, United and Continental, used similar methods.

This method was to remove the engine and support pylon at the same time, instead of removing the engine first, and then the pylon like Douglas called for. In the case of United, they used a series of hoists to accomplish this task. However, American and Continental used a large forklift to support the engine/pylon assembly during the removal process. It was discovered that eight weeks prior to the crash, the #1 engine on N110AA was changed using this method, and that undue stress was placed on the pylon to wing attach fittings during the process. At a critical time in flight, when full thrust of the engine was applied to these fittings, they finally failed, causing the results witnessed.

Upon investigation, it was revealed that many other American and Continental DC-10s had damage to their mounts, while aircraft from United did not. Since this crash was caught on film, and the footage was shown on TV news broadcasts across the nation, many refused to fly on the DC-10, labeling it an unsafe aircraft and a death trap. It was so bad that American, who had labeled all of the DC-10s with “DC-10 Luxury Liner” monikers on the nose, removed the DC-10 markings, and just called them “Luxury Liners”.

Aeromexico DC-10 – Photo: Bob Garrard

Throughout the next ten years, there would be many more accidents involving the DC-10, however most of them would be the result of crew error, such as the November 28, 1979 sightseeing flight over Antartica by an Air New Zealand DC-10, ZK-NZP. This crash was the result of controlled flight into terrain when the aircraft flew into the side of Mount Erebus, killing all 257 passengers and crew. The next major technical malfunction would bring the DC-10 into the spotlight again, but this time in a positive light.

On July 19 th , 1989, United Airlines Flight 232, operated by N1819U, was en route from Denver to Chicago when the #2 engine, located in the tail, suffered a catastrophic uncontained failure over Iowa farmland. I will not go into too much detail about this crash, since it is one of the best known and documented aviation incidents, but a brief synopsis follows: As a result of engine fragments severing all three hydraulic systems, the pilots lost all control of the aircraft, and it was only through the application of differential thrust that they were able to rudimentaly control the aircraft and attempt a landing in Sioux City Iowa.

It was the efforts of Captain Al Haynes, First Officer William Records, Second Officer Dudley Dvorak, and Captain Dennis Finch, that there were any survivors. When one looks at the footage of the crash, it is hard to believe that anyone could have survived, but 185 of the passengers and crew lived.

A veritable cornucopia of tri-jets in Amsterdam – Photo: Ken Fielding

After the Sioux City crash, the DC-10 has led a relatively quiet life, serving many airlines and cargo haulers safely for decades. After Northwest Airlines retired their last DC-10 in 2007, the type left mainstream commercial service in North America and Europe. However, the type continued to soldier on in southern Asia with Biman Bangladesh. In the following days, over 42 years after the type’s entry into full passenger service, its days will be nearly over, as Biman retires their last DC-10, the second to last airframe built. The type will live on for many more years, however, just not carrying passengers anymore: it will still make money as a freight hauler, mainly with FedEx.

The History of the DC-10, Part One: Taking Shape and Taking Off

MIAMI — By this time next week, the last passenger DC-10 flight will be completed, and a 43-year reign will be over. As our co-editor-in-chief travels to Bangladesh for the last set of flights, we take a look back at the extensive history of the airplane in a two part series.

The story of the DC-10 starts not with commercial aviation but with the US Air Force. In the early 1960s the USAF was seeking an enormous airplane capable of carrying lots of equipment and troops, known as the CX-HLS. All of the big names got involved, including Boeing, Lockheed, and Douglas. The three all submitted ambitious proposals, looking to snag what was sure to be a lucrative contract. Despite a strong bid from all three, Lockheed wound up winning the contract, leaving Boeing to go on to produce the 747, while Douglas pondered what was to be next.

With the CX-HLS contract now officially lost, Douglas attempted to salvage the work already done by creating a combo passenger/freight version of the same airplane. Later dubbed the D-918, the fully double-decked, high-wing airplane would have been able to fit up to 900 passengers. The project was scaled down into the D-950 and D-952. Neither was to be. Expecting supersonic (SST) passenger jets to crowd out subsonic passenger travel in the near future, the company predicted demand would be minimal for such an airplane. As a result both were scrapped.

Belief that a market existed for a subsonic, transcontinental freighter—Douglas opted out of the SST race—spurred the creation of the D-956 in 1966. The double-decked, low-wing airplane had a swinging nose for main deck cargo loading and could accommodate up to 400 passengers. But it too was left languishing on the drawing board of history, however, after American Airlines (AA) put out a request that was too good for Douglas to pass up.

In April 1966 American’s senior vice president of engineering Frank Kolk put out a request for a 727-style replacement. The request was largely centered on being able to operate in and out of New York LaGuardia’s congested ramp space, short runways, and increasingly restrictive noise levels. Ideally it would seat 250 passengers at a cruise speed of Mach .82 with an 1850 nautical mile range.

Once Douglas made the decision to chase the challenge, a flurry of designs for the new airplane came and went through the remainder of the year. The airplane began as a twin engine with a raised cockpit—the D-966. As Douglas began to work with other airlines, including United, the D-966 morphed first into the three-engine D-967, and then the four-engine D-968.

Douglas became McDonnell Douglas in 1967, after Douglas put itself up for merger while facing insolvency. After the merger, the design work continued to go back and forth between other two-, three-, and four-engine concepts (J2/J3/DC-10-3DC-10-4) before settling on a version of the D-967, which eventually became known as the DC-10A. The bubble-style upper deck cockpit and swing-nose that was original to the D-967 design was ultimately abandoned in mid-1967 as potential customers backed down on cross-over freighter potential, leading to the single deck version we know today.

As the airplane settled into its present form, the last major design decision involved the now iconic tail engine. Several options, including a Tristar-like S inlet, long tail pipe option, and long inlet version were considered. At first, the design incorporated a weird looking tail engine assembly with a bifurcated inlet. It was dropped after wind-tunnel testing proved it was not viable, leading to the long pipe-style inlet we have today.

Final design in place, McDonnell Douglas began to offer the airplane for sale in the first weeks of 1968. First stop, American Airlines. While the airplane may not have fit the original proposal, it still fit the majority of the carrier’s requirements. AA was also seriously considering the DC-10s direct competitor, the Lockheed L-1011 Tristar, which had been put up for sale several months ahead of the DC-10. Still, the DC-10 proved victorious, and AA placed an order on February 19, 1968 for 25 airplanes and 25 options on the condition that two other carriers also placed orders.

The jubilation would not last long. Only six weeks later the Tristar began a banner month. Eastern and TWA jointly announced their respective orders for a total of 94 airplanes, while a British holding company picked up 30. Delta wound up deciding to pick up 24 of the L-1011s, fearing that the DC-10 would not make it past paper. These decisions left the company chasing down the remaining big two airlines: Continental and United.

To make the DC-10 more appealing the company made several design changes, incorporating requests from American and recommendations from United. These included wing changes, modifications to the tail engine, altered dimensions, and, crucially, acceptance of the General Electric CF6-34 engines at 39,500 pounds of thrust each. The modifications and solidified design was enough to hook United, which ordered 30 jet plus 30 options on April 25, 1968.

Despite only having two of the needed three customers, the jet began production shortly following United’s order. Iron Birds, which are basically full-scale, fully equipped non-flying models were built to test fit the sections and systems. Sub-assembly production began not long after, and incorporated a vast system of suppliers and subcontractors. Wings were built in Ontario, Canada, fuselage barrels were made in San Diego, California, and horizontal tail parts were produced in Italy, just to name a few. Final production, along with production of parts too large to transport, took place in the company’s mammoth Long Beach, California facility. Several hangars were built specifically for the purpose of producing the jet on site.

Final production began on January 9, 1970 in Long Beach. Unlike previous airplanes, the DC-10 was in some ways a snap-together aircraft. Major subsections arrived largely completed with piping and wiring, requiring connections rather than extensive onsite assembly. The company planned five aircraft for the test program, with the first four airplanes structurally complete by the time the plane was formally rolled out.

The very first DC-10 was rolled out, or rather, in, on July 23, 1970. Then vice president Spiro T Agnew and California governor Ronald Reagan were among the VIPs in attendance as the airplane taxied under its own power to a crowd of over one thousand. McDonnel Douglas received a spate of sales shortly thereafter, booking orders, or firming options with Continental, Finnair, Lufthansa, Sabena, and UTA.

The first DC-10 rolled down a runway and into the skies over Southern California for the first time on Saturday, August 19, 1970. The airplane stayed aloft for three hours and 26 minutes before landing at Edwards Air Force Base. The life of the DC-10 had now officially begun.

The test fleet began its second flight only two days later, and by October 6 th had logged 100 hours of airtime. By the end of the year, four of the five aircraft had joined the test fleet, with ships three and four in American and United liveries, respectively.

Deliveries were first made to American and United on June 29 th , 1971, in a joint ceremony. Following the ceremony, both airplanes taxied out to the runway and took off. As the airplane had received a provisional FAA approval, the carrier’s could begin crew and flight training, but were unable to start service. Four weeks later the airplane received its FAA Type and Production Certificates, allowing the carriers to begin scheduled service.

With these regulatory obstacles cleared, American and United raced to be the first to begin scheduled DC-10 service. Initially American was to run the airplane between Chicago and Washington, DC but then switched to Chicago and LA on August 17 th . United then planned to begin service on August 14 th between San Francisco and Washington, DC. But American slid up the entry into service by two weeks, running flight AA184 from Los Angeles to Chicago on August 5 th .

As the airplane entered service, both airlines struggled to fill cabins due to the recession, and came up with a creative way to solve this problem: lounges. American added a first-class lounge in the very forward of the airplane, and a coach lounge in the rear. United added a lounge for each cabin as well, adding them fore and aft the galley, respectively. The lounges were incorporated on a number of other carriers, though as the global economy ramped back up carriers quickly ditched them again in favor of paying seats.

By the end of 1971 a total of 136 aircraft were on firm order, with 80 options. New carriers included Air New Zealand, KLM, National, Swissair, and Western. The orders also now included the derivativeSeries-30. This new variation, which was technically launched in the summer of 1969, featured GE CF6-50A engines at 49k pounds of thrust each, a new payload to 104k pounds, and a range of 4,750 miles. It also featured the now well-known center main wheel bogie to support the increase in weight. It would go on to be the most popular of the nearly one dozen variations introduced before the type was retired.


On the days between, more than a thousand passengers were treated to one-hour scenic flights on the craft, travelling towards Scotland before looping back towards England's second city.

Biman Bangladesh Airlines was the last airline to use the craft. It said it would now be retired and replaced with newer models.

The model, which first took to the air in 1971, will still be used in the military - for the U.S. Air Force for refuelling purposes, for instance - and freight services.

Biman Bangladesh Airlines was the last airline to fly the DC10, which it has now retired so it can begin using more modern aircraft

This was the scene on the very last scenic flight of the aircraft, which took off from Birmingham Airport at 3pm on Monday, February 24

One of the 35 passengers on-board the final flight into the UK was Gordon Stretch, who had travelled to Bangladesh from Solihull a few days before to be a part of the journey.

'The reason I did this is because I'm an aircraft enthusiast,' he said.

'When the opportunity came and I heard that the last DC10 flight was coming to Birmingham, I thought "wow".

'I decided to go out to Bangladesh and fly back on the plane.'

One of the 35 passengers on-board the final flight was Gordon Stretch, who had travelled to Bangladesh from Solihull a few days before to be a part of the journey

'When the opportunity came and I heard that the last DC10 flight was coming to Birmingham, I thought "wow". I decided to go out to Bangladesh and fly back on the plane'

He said Bangladesh is not a country he'd choose to visit ordinarily, but he was happy to spend two and a half days there - after flying from Heathrow - in order to be on the flight.

If a 14-hour journey doesn't sound difficult enough, Biman Bangladesh Airlines is a non-alcohol airline.

Mr Stretch said: 'It was completely dry. We were only on the Diet Cokes, as they say.'

But he flatly refused to say he regretted the decision to go on the flight. 'It was definitely worth it,' he said.

The flight even gave passengers - all aircraft enthusiasts - the opportunity to venture into the plane's cockpit and speak to the pilots.

Mr Stretch spent 14 hours on the flight, had to travel to Bangladesh to board the flight and was not allowed to drink alcohol on the plane, but said: 'It was definitely worth it'

The final DC10 was initially supposed to be flown from Birmingham to New York to go to a museum in Seattle, before the airline was told there was no room for it

Then, until a week before it landed in Birmingham, the plane to scheduled to be housed at the Bruntingthorpe Aviation Museum in Leicestershire

The aircraft's final flight - which did not carry any passengers - took off from Birmingham and flew back to Dhaka for its parts to be sold.

It was originally intended that the plane be flown to New York from Birmingham, to be positioned in a museum.

But, when the Seattle museum said it could not accommodate for it, plans were changed so it would be exhibited at the Bruntingthorpe Aviation Museum, Leicestershire, instead.

Then, with days to go before its landing at Birmingham, the airline announced it had found a buyer for the craft's three jet engines, and it would be taken back to Bangladesh to be taken apart.

The last flight took off from Birmingham at 3pm on February 24.


Prided on its comfort, reliability and efficiency, the DC10 was designed and built by the Douglas Aircraft Company in Long Beach, California.

With six models designed – the first running from 1971 – the crafts accommodate for between 250 and 380 passengers.

The first time a DC10 is believed to have visited Birmingham - the destination of its final commercial passenger flight - was on November 30 1972, when Laker Airways operated a demonstration flight.

This photograph shows a Laker Airways DC10 aircraft, which was first operated in 1971, taking off from Gatwick Airport in 1979

This photograph shows the inside of a DC10 in 1980, showing passengers on a flight from London Gatwick to New York

The aircraft was first used by American Airlines, with its first commercial flight operated on August 5 1971 for a round-trip between Los Angeles and Chicago.

United Airlines began using the airliner in the same month.

It had 222 seats to American Airlines’ 206.

This photograph shows Sir Freddie Laker, standing in the engine of the DC10. The first time a DC10 is believed to have visited Birmingham was on November 30 1972, when Laker Airways operated a demonstration flight

At the time, the first class area of the cabin had six seats across, while in standard class there were eight seats across.

The 446th and final DC10 was delivered to Nigeria Airways in 1989.

A number of airlines used the DC10 model in its history, including British Caledonian, Northwest Airlines, Japan Airlines and Iberia.

The model was a successor to the Douglas DC-8 for long-range operations, and competed in the same markets as the Airbus A300, Boeing 747 "jumbo jet", and the physically similar Lockheed L-1011 TriStar. Some were built for the United States Air Force as air-to-air refueling tankers, designated the KC-10 extender.

The DC-10 was McDonnell Douglas's first wide-bodied commercial airliner, built to a specification from American Airlines for a widebody aircraft smaller than the Boeing 747 but capable of flying similar long-range routes. It first flew on August 29, 1970 and entered commercial service in 1971, nearly a year before the Lockheed Tristar (which was built to the same specification).

Although the DC-10's lifetime safety record is comparable to that of other heavy passenger jet aircraft, the DC-10 suffered a trying time during the 1970s when a string of highly publicized crashes resulted in a brief grounding by the United States Federal Aviation Administration.

Unlike most other aircraft, the DC-10 was designed with cargo doors that opened outward instead of inward. This required a heavy locking mechanism to secure the door against the outward force caused by pressurization of the fuselage. In the event that the door lock malfunctioned, there was potential for catastrophic blow-out of the whole door.

This problem was first identified in 1972 , when American Airlines Flight 96 lost its aft cargo door after takeoff from Detroit fortunately the crew were able to perform an emergency landing with no further incident. On Flight 96, an airport employee had violently forced the door shut, weakening the locking pin and causing the door to subsequently blow-out as it reached altitude. McDonnell Douglas attempted to place the blame on the employee, who they described as "illiterate", and deflected criticism of the aircraft design itself.

Although many carriers voluntarily modified the cargo doors and re-trained their ground crews, there was no mandatory redesign of the system. Severe design problems persisted with the aircraft's cargo doors. Indeed, two years after the American Airlines incident an almost identical cargo door blow-out befell Turkish Airlines Flight 981, which crashed into a forest shortly after leaving Orly Airport in Paris. 346 people were killed in one of the worst aviation disasters of the twentieth century. The circumstances surrounding this crash were similar to those surrounding the previous crash however, a modified seating configuration on the Turkish aircraft exacerbated the effects of decompression and caused the aircraft control cables to be severed, rendering the aircraft uncontrollable. In the aftermath of this crash, all DC-10s underwent a mandatory door redesign. The DC-10 was starting to get a reputation as a dangerous aircraft.

In 1979, with the cargo door issues resolved, DC-10s around the world were grounded following the crash of American Airlines Flight 191, which killed 273 people. Flight 191 lost one of its underwing engines after taking off from O'Hare International Airport in Chicago, USA, and the engine loss damaged the aircraft's hydraulic systems, causing it to lose control. The United States National Transportation Safety Board officials discovered that a maintenance procedure was the culprit: American Airlines mechanics had removed the engine and its pylon at the same time using a forklift, and the forklift operator had inadvertently cracked the pylon in the process. The procedure was not approved by Douglas, but most major airlines used it. Although Douglas was not at fault for the pylon separation, it redesigned the DC-10 to allow more redundancies in the hydraulic systems. (It is rumored, although not confirmed, that the crash was a factor in a deal several years later where AA purchased a large order of McDonnell Douglas MD-80 's at a discount.)

Also in 1979, Air New Zealand Flight 901 crashed into Mount Erebus in Antarctica during a sight-seeing trip, killing all 257 on board. (This DC-10 accident was caused by complex factors not relating to the airworthiness of the aircraft.)

Perhaps the most infamous instance of a DC-10 crash was the Flight 232 disaster at Sioux City, USA, in 1989. After an emergency landing with no hydraulic controls available to the crew, the aircraft was completely destroyed. The crash ironically pointed out one of the DC-10's unique safety features: it is one of the only aircraft in the world that can be flown solely by throttle, without using rudder, elevators, or ailerons. After the hydraulics failed on Flight 232, the pilots were able to crash-land the plane although many died, over half of the passengers walked away without major injury.

The 446th and final DC-10 rolled off the production line in December 1988 and was delivered to Nigeria Airways in early 1989.

Despite its troubled beginning, the DC-10 ultimately proved &mdash and continues to be &mdash a reliable aircraft, much loved by engineers and pilots. The aircraft's safety record continually improved as design flaws were ironed out and fleet hours increased. In fact, the DC-10's lifetime safety record as of 2003 is comparable to similar second generation passenger jets.

19 July 1989

United Airlines’ DC-10 N1819U, Flight 232, on final approach to Sioux City Gateway Airport, 19 July 1989. In this image, damage to the right horizontal stabilizer is visible, and the aircraft tail cone is missing. (Wikipedia)

19 July 1989: United Airlines Flight 232 was a McDonnell Douglas DC-10-10, registration N1819U, enroute from Stapleton International Airport, Denver, Colorado to O’Hare International Airport, Chicago, Illinois. There were 296 persons aboard the airliner: 285 passengers and 11 crew members. The flight crew consisted of Captain Alfred C. Haynes, First Officer William Record, and Second Officer Dudley Dvorak. Also aboard, riding in the passenger cabin, was an off-duty United Airlines DC-10 Check Airman, Captain Dennis E. Fitch.

At 3:16:10 p.m., the fan disk of the airliner’s tail-mounted General Electric CF6-6 turbofan engine (Number Two) failed catastrophically. Shrapnel from the exploding engine chopped through the DC-10’s tail section and severed the three independent hydraulic systems that powered the flight control surfaces. The crew immediately lost their ability to control the airliner with rudder, elevators and ailerons. Flaps and wing leading edge slats were inoperative. Controls to the damaged engine also failed and only by cutting off fuel flow were they able to shut if down and prevention further damage or a fire. Landing gear could only be lowered by use of an emergency procedure.

The uncontrolled airliner immediately started to roll and dive. The pilots’ cockpit flight controls were completely useless to stop the roll. Only by varying the thrust on the two remaining wing mounted engines could some degree of control be maintained. Realizing there was a problem with the DC-10, Captain Fitch told a flight attendant to inform Captain Haynes that he was aboard and ask if he could assist. Haynes immediately asked Fitch to come forward, and once there to take over the throttle controls while the crew dealt with all the other problems that were occurring.

Flight 232 radar track. (NTSB)

The simultaneous loss of all three hydraulic systems was considered to be “impossible” and there were no emergency procedures to deal with the problem. The crew did the best they could by varying power on the two remaining engines to turn the airplane and to descend. They were heading for an emergency landing at Sioux City Gateway Airport, Iowa (SUX).

United Airlines Flight 232 on final approach to Sioux Gateway Airport, 19 July 1989. (Gary Anderson/Sioux City Journal)

At 4:00:16 p.m., the DC-10 touched down on Runway 22 at an estimated at 215 knots (247.4 miles per hour, 398.2 kilometers per hour) and a rate of descent of 1,620 feet per minute (8.23 meters per second). At about 100 feet (30.5 meters) above the ground, the airliner’s nose began to pitch downward and the airliner started to roll to the right. Touchdown was at the runway threshold, just left of the centerline.

The DC-10 touched down at the threshold of Runway 22, just left of the centerline. Captain Alfred C. Haynes

The force of the impact caused the airframe break apart and the wreck rolled over to the right side of the runway. Fuel exploded and fire spread. 110 passengers and 1 flight attendant were killed in the crash and fire. There were 185 survivors of the crash, including the four pilots who were trapped in the crushed nose section of the airplane which had broken away from the main wreckage.

The National Transportation Safety Board (NTSB) investigation determined that the the center engine fan disk failed due to a crack which had formed when the original titanium ingot from which it was made had been cast 18 years before.

The official report said that a landing under these conditions was stated to be “a highly random event“. The NTSB further noted that “. . . under the circumstances the UAL flight crew performance was highly commendable and greatly exceeded reasonable expectations.”

This was one of the finest displays of airmanship during an inflight emergency since the beginning of aviation.

An Iowa National Guard UH-1 medevac helicopter hovers over the wreckage of the United Airlines DC-10, 19 July 1989.