Boeing's iconic 747 will leave the assembly line for the last time this year. See one of last jumbo jets the planemaker will ever build.

Boeing's iconic 747 double-decker jet is soon leaving the assembly line forever.

By the end of 2022, the last three 747 aircraft to ever be produced will roll out of Boeing's factory in Everett, Washington.

All three planes, which are 747-8 freighters, are scheduled to go to US cargo carrier Atlas Air. The deliveries will mark the end of an era and a close to one of the most incredible aviation programs in history.

Production of Boeing's famous Queen of the Skies started after Pan American World Airways founder Juan Trippe asked the planemaker to create a huge, high-capacity passenger jet that could fly long-haul.

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The demand for air travel was booming in the 1950s and 1960s, so the industry needed bigger jets that could carry more customers while also driving down airfare.

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After 16 months of design and assembly, the first 747 flew in February 1969. Some 50,000 employees, dubbed "Incredibles," worked to bring the mammoth plane to life, which featured four engines and a second level above the nose.

Source: Boeing

With twice the capacity of the Boeing 707 narrowbody jet and the lowest seat-mile cost in the industry at the time, the 747 revolutionized the aviation industry.

Source: Boeing

The jet's low costs made international travel more affordable for the first time, meaning long-haul flying was no longer a privilege reserved only for the rich and famous.

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The first 747, which was fit to carry 347 passengers, flew with Pan Am in 1970 from New York to London.

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Other airlines were quick to buy the game-changing jet, like British Overseas Airways Corporation…

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…KLM…

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…Delta Air Lines…

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…and Qantas.

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Boeing took media on a tour of its Everett factory to see one of the last 747s to be built and learn more about its history. Take a look.

Insider saw the third-to-last 747-8 freighter being built. The variant first flew in 2010 and has served several airlines, like European carriers Cargolux and Lufthansa.

The 747-8F model is the successor to Boeing's 747-400F variant, stretching about 18 feet longer and holding 16% more revenue payload volume.

A dedicated group of employees are producing the final 747s, many of which have been working on the jumbo jet their entire career, Boeing's head of communication for the 747, Brianna Jackson, told media.

"I can't emphasize how big of a sense of employee pride there is with this airplane," she said. "There are people here who have worked on this plane for 40 years — their entire career on the 747. They love this airplane and want to see it to the end."

It takes about a month to build half of a 747, according to Jackson, and the planemaker can produce one full jumbo jet about every two months.

She explained the workforce will not be impacted when the Queen of the Skies leaves Everett for the final time, but some staff are planning to retire after the last one is built.

The plane was not fully complete when media visited, but its full body was already assembled, including the wings and tail.

To connect the pieces, Boeing uses giant cranes connected to the factory ceiling to move parts around.

However, the jet still lacked its landing gear and engines, which will be General Electric's GEnx-2B engines that have lower fuel burn.

Employees were working on the nose cargo door during our visit.

The nose opens on the 747 freighters, allowing carriers to load and unload oversized cargo that cannot fit through a traditional side door. It's a unique feature of the jet, and one cargo carriers will not easily find a replacement for when the program ends.

The 747 still had its green exterior but will be painted in the Atlas Air livery before delivery. The cargo carrier has four 747-8Fs on order and took the first in May.

When the last 747 is complete, it will be the 1,574th jumbo jet Boeing has made in the over 54 years of the program, according to Jackson.

“We’re incredibly proud of the legacy of the 747, and we’re proud of the incredible 747 team,” she said.