Is a Boeing 777 easy to fly?

Boeing 777 or: When engines disintegrate

The long blades are made of titanium, the hardest metal available. They are in the shape of swords in order to direct as much air as possible into the turbines as efficiently as possible, which is then heated and generates propulsion. Some types have hollow titanium blades on the inside to save weight. The tips of the engine blades, depending on the engine type and aircraft class, there are around 22 to 38 on an engine, rotate at the inlet at more than supersonic speed.

Especially when taking off, the huge high-tech units of modern wide-body aircraft run to the limit in order to get a takeoff weight of 250 tons and more into the air with maximum performance. In this most critical phase of the flight, there were two significant incidents on Saturday, one in Europe and the other in the USA. First, a 30-year-old Boeing 747-400 in the cargo version took off in Maastricht, the Netherlands, for a flight to New York.

The Boeing 747 Cargo taking off from Maastricht Airport. Shortly thereafter, the left outer engine explodes.

Popular engine family from Pratt & Whitney

As soon as it was in the air, there was an explosion on the far left of the four engines. At the rear, broken turbine blades flew out of the turbine and easily injured an elderly woman and a child on the ground. That was luck in misfortune, because the sharp-edged metal parts pierced like knives vertically into some of the cars parked in the suburb of Meerssen. The crew explained the emergency, turned holding loops and let the fuel off before they could safely make an emergency landing in neighboring Liège, Belgium, after about an hour. The Dutch Aircraft Accident Investigation Authority DSB is currently investigating the cause and the exact circumstances of the incident.

A torn off metal part from the turbine of a Boeing 747 is stuck in a car roof near Maastricht

The affected PW4056 engine comes from the manufacturer Pratt & Whitney in the USA, one of the world market leaders for aircraft engines, and was developed in the mid-1980s. The PW4000 family is one of the most important basic types for the propulsion of commercial aircraft, to date well over 2500 have been produced. Certain airlines have PW4000 engines on the wings of such different types as the Airbus A330 (but not the ones flying at Lufthansa) or the Boeing variants 777, 767 and 747-400.

Not a Boeing problem at first sight

The engine and not the aircraft manufacturers are responsible for the development and above all for the extensive tests up to the traffic approval. Turning the current incidents into a problem for Boeing is therefore not enough, even if such events always damage the image of the aircraft manufacturer.

The destroyed and burning engine of United's Boeing 777

Especially when two normally rare incidents occur on Boeing aircraft in one day - and dramatic videos and photos spread worldwide via social media. On Saturday afternoon local time, United Airlines flight UA328 took off with 229 passengers and ten crew members on board for the flight from Denver to Honolulu, Hawaii. Shortly after take-off, there was an explosive engine failure of the right of both engines, also of the type PW4077 from Pratt & Whitney. First of all, the huge, ring-shaped air inlet of the engine cowling, a good three meters in diameter, fell into a front yard, fortunately nobody was injured. Videos also show other metal parts of the engine cowling staggering ominously from the sky, which hit a soccer field without causing any damage.

Meanwhile, the passengers on flight UA328 were faced with a dramatic sight: the badly plucked turbine without cladding, which was clearly missing two blades at the front, was turning in the wind, while flames licked at the outlet at the rear, and the whole aircraft vibrated at the same time. Here, too, the crew explained Mayday, an emergency. However, the redundancy and extreme shielding of engines built into all aircraft systems seemed to have worked perfectly in this case. Just as the crew dealt with the emergency often practiced in the simulator in a textbook manner.

Such engine explosions can lead to dangerous debris escaping if broken blades and debris such as projectiles hit the fuselage and wings and, in the worst case, paralyze vital aircraft functions. Like with Qantas flight QF32 in November 2010, when an engine explosion damaged an Airbus A380 so badly that the later successful emergency landing was at times on the knife's edge.

Blessing in disguise

At UA328 on Saturday it appeared that the high-strength Kevlar protective cover had held around the engine and prevented the dreaded escape of debris. The aircraft was still fully maneuverable and was able to make an emergency landing in Denver 23 minutes after take-off, no one on board or on the ground was damaged.

However, an examination of the fuselage revealed that the occupants were probably more lucky than initially assumed: A piece of debris from the engine had torn a large hole below the wing root. And only a few centimeters from the full main tanks in the wing. The American transport safety authority NTSB has meanwhile announced its first investigation results.

Accordingly, one of the blades on the suspension has broken off, apparently due to material fatigue that has already occurred in earlier cases in the case of internally hollow titanium blades. The neighboring one broke in the middle, and the investigators found a part of the scoop embedded in the outer Kevlar shell. The PW4077 engine type is found on early aircraft of the 777 series from the mid-1990s, the 777 now affected has been flying since 1995. It was only in December 2020 that a similar incident occurred on a 777-200 operated by Japan Airlines, almost exactly three ago Years also on a sister machine of the now damaged 777 from United Airlines.

The US aviation authority FAA has now a factual grounding for the type by ordering stricter inspections on Sunday: "These should be reinforced for the hollow engine blades that only fly in this engine variant and only in the Boeing 777," explained FAA- Chef Steve Dickson. In addition to United in the USA, only Japan Airlines (JAL) and ANA in Japan and Korean Air in South Korea operate the 777 model concerned. A total of 69 were last still in active operation, another 59 were already shut down due to the pandemic. All of them are currently no longer allowed to fly, and it is to be expected that many of them will no longer return to regular service because of the corona-related collapse in traffic.

  • The end of the giant aviators

    Farewell to Sydney

    Qantas CEO Alan Joyce has retired the last Boeing 747 in his fleet. The last trip leads to the California Mojave Desert. Qantas was once the only airline in the world with a 747 fleet. A total of 30 Jumbos are currently still in use around the world, most of them as freighters.

  • The end of the giant aviators

    Bye Bye Jumbo in London too

    At the end of last week, British Airways announced that it would shut down its entire 747 fleet early and with immediate effect. "With the decline in travel caused by the COVID-19 pandemic, it is unlikely that our 'queen of the skies' will ever again offer commercial services to British Airways," the airline said.

  • The end of the giant aviators

    Crowds on the first flight

    The first commercial flight of the Boeing 747 with PanAm was on January 21, 1970 from New York to London. Around 9,000 people had registered for the premiere, in the end only 360 could fly with them and only with obstacles. After one engine overheated, everyone had to transfer to a replacement machine, which then started almost seven hours late.

  • The end of the giant aviators

    Glamor of the queen of the skies

    Until the end of the 1960s, flying was something for the wealthy. Now, thanks to cheaper tickets, normal wage earners could also afford flights. Still, the 747 was not easy to fill. Since air prices were still set by the state at that time, the airlines lured people with luxury such as cocktail lounges with sofas and kidney-shaped tables in the rear. To date, the 747 has carried almost six billion people.

  • The end of the giant aviators

    The oil crisis also slowed the Boeing 747

    A few years after the glamorous start, the 1973 oil crisis stifled enthusiasm for the Jumbo. Many airlines have had to leave their 747s on the ground because it was simply too expensive to get in the air. Aircraft orders have been canceled. It was not until the mid-1970s that the jumbo jet became the dominant long-haul aircraft.

  • The end of the giant aviators

    Long-haul icon revolutionized aviation

    Over the past five decades, the 747 has helped transform global air travel. Airports were expanded into huge hubs, because with the huge jumbo jet many passengers could be transported over long distances at the same time, in order to be flown on to regional airports in smaller planes.

  • The end of the giant aviators

    Assassinations, technical problems, human error

    There were also tragic events in the jumbo jet era, such as the Lockerbie bombing in 1988 (picture) or the collision of two 747s on the runway of Tenerife Airport in 1977, in which more than 500 people were killed. Several Boeing 747s lost a complete engine in flight. As a result, a freight version fell on a house in Amsterdam.

  • The end of the giant aviators

    747 hardly asked for in the end

    The industry is now relying on smaller machines with two engines that use less fuel. Boeing ordered the last parts for the 747 from its suppliers at least a year ago, according to industry circles. With a construction rate of half an aircraft per month, the program still has more than two years ahead of it, according to a company spokesman.

  • The end of the giant aviators

    The US President continues to fly 747

    According to Bloomberg, the dozen or so aircraft ordered from Boeing are all freight versions of the 747, and in the passenger area no new jumbos have been ordered for years. The last order came from 2017, according to the Reuters news agency. The US government ordered two 747-8s as Air Force One for the president.

  • The end of the giant aviators

    Airbus no longer produces either

    In total, more than 1550 model 747 machines have been delivered in over 50 years. The European competitor Airbus gave up its prestige A380 project at the beginning of 2019. Production of the giant aircraft will only run until 2021, Airbus announced in February. In total, only around 250 aircraft of the A380 were sold.

    Author: Insa Wrede, Henrik Böhme