Jeremy Dwyer-Lindgren

Special for USA TODAY

EVERETT, Wash. — Air China became the second airline Monday to take delivery of the Boeing 747-8 Intercontinental passenger jet, the U.S. jetmaker's newest and biggest version of its iconic jumbo jet. Air China's delivery of the jet comes as sagging sales have led industry analysts to doubt the economic viability of the model only a few years after its birth.

The Beijing-based carrier received its first of seven 747-8s at a ceremony at the Future of Flight museum that's adjacent to Boeing's 747 assembly line north of Seattle.

Starting Oct. 11, Air China plans to debut the jet between its Beijing hub and domestic destinations such as Chengdu, Guangzhou, and Shanghai. The airline says long-haul flights from Beijing to Frankfurt are expected to begin later this year, with Los Angeles and New York coming at a later date.

Passengers on the new jumbo will find 366 seats. Taking advantage of the airplane's size, Air China has installed a full, three-class cabin, with 12 seats in first class, 52 in business, 36 in premium economy, and 266 in economy.

Air China says it chose the airplane because of its operating economics and positive experience with the -8's older cousin, the 747-400 that preceded the "dash-8." By configuring its 747s with a seating layout that's heavy on first- and business-class seats, Air China hopes the aircraft will help it attract more business fliers. The jets will be used to replace Air China's aging fleet of 747-400s, which the carrier says will be retired by the end of 2015.

The Boeing 747, characterized by the famous "hump" in the design of the upper deck, is considered by many industry observers to be the most iconic jet in aviation history. The jets are widely credited with making long-haul travel readily accessible to budget-minded vacationers. The extensive range of the 747-400, virtually unmatched for decades, provided fast, non-stop service on routes such as Los Angeles-Sydney and Minneapolis-Honolulu. Since 1968, Boeing has produced more than 1,500 747s, the most of any jumbo-jet program to date. There have been six variants of the 747 since its introduction.

The 747-8i, as it is more casually known, is the latest model, launched in 2005. Boeing unveiled the first model of the 747-8i passenger jet in 2011.

Envisioned as a natural replacement to the exceptionally popular 747-400 series as well as a competitor to the Airbus' "superjumbo" A380, Boeing substantially rebuilt the jet in a bid to propel the 747 program well into the 21st century. New wings, new engines, and new interior design points are among the changes that help make it 16% more fuel-efficient than its predecessor, according to Boeing.

Despite the renovations and additions, however, the 747-8i sales have been less than robust, leading to speculation that the aircraft may be teetering on the brink of retirement just three years into its production schedule.

"The 747-8 program is on its last legs," says Scott Hamilton, an industry analyst with Leeham Co., a Seattle-based aviation consulting group.

So far, just 40 Intercontinentals have been ordered across only four carriers, creating a shrinking backlog that could soon force Boeing's hand.

Boeing "will either have to announce a rate cut this year or face terminating the program soon," Hamilton predicts.

The airplane has faced stiff competition from Airbus' larger A380, which itself continues to struggle. Fuel efficient twin engine jets seem to have become far more popular with airlines than both the four-engine 747 and A380. That's been particularly true as seat counts on airplanes such as the 777 have risen into the general range of the 747-8. And sales show it. Boeing's 777X, a revamp of its wildly popular 777 classic, are double that of the new 747 despite the jet still being three years away from first flight.

Despite the ongoing dearth of sales, Boeing isn't losing hope.

"We're just getting going with this program," Bruce Dickinson, vice-president for the 747 program, said during the Air China delivery ceremony Monday night.

Dickinson says the company is engaged in a number of campaigns to sell the jet, though he declined to share who the talks are with, citing company policy.

"We remain very optimistic that we'll see activity of the -8i in the near future," he says, adding Boeing "is even more optimistic now that this airplane is going to penetrate the Asian market and show what it can do."

With the aircraft set to fly away to Beijing on Tuesday (Sept. 30), Air China now joins the German flag carrier Lufthansa as the only operators of the airplane. Lufthansa has 19 of the jets on order, 15 of which have already been delivered.

Korean Air will be the next of the four airlines that have ordered the jet to take delivery of the 747-8. That's expected to come in early 2015. Russian carrier Transaero has also ordered the plane.

Jeremy Dwyer-Lindgren is a Seattle-based photojournalist and aviation writer and an occasional contributor to Today in the Sky.