After more than 50 years in production, the final Boeing 747 (BA  ) was shipped out of the company's Seattle factory on December 6, marking the end of an era for the iconic hump-backed jumbo jet.

"It's a very surreal time, obviously," said the vice president and general manager of Boeing's 747 and 767s programs in Seattle, Kim Smith. "For the first time in well over 50 years we will not have a 747 in this facility."

In 1990, 747s made up 28% of wide-body passenger jets and 71% of wide-body cargo jets worldwide, but those percentages slumped to just 2% and 21%, respectively, as of 2021, according to data from the Centre for Aviation.

In total, Boeing has manufactured 1,574 of the 63-foot-tall 250-foot-long jet, but only 109 of the 747 aircraft are currently used in passenger fleets.

"It was a great plane. It served us brilliantly," Sean Doyle, British Airways (ICAGY  ) CEO, told reporters. "There's a lot of nostalgia and love for it but when we look to the future it's about modern aircraft, more efficiency, more sustainable solutions as well."

When it was introduced in 1970, the 747's four engines were on the cutting edge of efficiency for mass travel. 747s continue to be used by carriers, but in recent years, the market has become dominated by cheaper, more sustainable two-engine jets, including Boeing's own 737 Max.

"The biggest enemy of Boeing quads was Boeing twins," said the managing director at consulting firm AeroDynamic Advisory, Richard Aboulafia.

During its initial rollout, the 737 Max was involved in two crashes, killing a total of 346 people. Due to alleged misconduct during the jet's design and production process, the plane's software forced the craft into a nosedive soon after takeoff. The 737 was pulled from the market and has since been adjusted and re-introduced.

In addition to the 737, airlines have also begun placing major orders for Boeing's next twin-engine wide-body jet, the 787 Dreamliner, but production has faced delays.