This week has seen the aviation industry focus on United's massive order for 270 new narrowbodies. While these planes will replace the 757-200 fleet and others, there is one aircraft United still does not have a replacement for yet: the 757-300. So which planes could fill the role of the 'Flying Pencil'? Let's find out.

Boeing 757
The 753 often visits Los Angeles, although Chicago is the best place to see them. Photo: Getty Images

Unique place

United currently operates a fleet of 21 Boeing 757-300s (753s), all of which came from its merger with Continental. The aircraft are routinely deployed on short- and medium-haul services in the United States, flying routes such as Chicago to Los Angeles, Honolulu to Los Angeles, Denver to Houston, Orlando to Washington Dulles, and many more.

What makes the aircraft unique (and popular) is its high seating capacity packed into a narrowbody (thanks to its length). The 757-300 seats 234 passengers for United, split into 24 in first, 54 in economy plus, and 156 in standard economy. This allows the plane to be deployed on high-density business and leisure routes, such as the ones listed above, and still fit at narrowbody airport gates with no issues.

United Airlines Boeing 757-300
The 753s play a special role in United's fleet, connecting high-demand locations across the country. Photo: Vincenzo Pace | Simple Flying

However, these planes are aging quickly. The fleet averages an age of 18.9-years-old, giving it another eight to 10 years before retirement comes around. Despite this, United does not have a clear successor to the plane. Even the carrier's massive 270 aircraft order for the 737 MAX and A321neo couldn't solve this conundrum.

In a statement this week, seen in FlightGlobal, CEO Scott Kirby said,

"This order is not intended to replace our 757-300 aircraft, which is larger...We will make a decision as to what the optimum replacement for that jet will be in the future.”

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Possible replacements

While Scott Kirby insists the A321neo and MAX 10 won't replace the 757-300s, they are fairly close in specifications. Airbus' option can seat 180-220 passengers in a two-class layout, while Boeing's offering seats 188-204 in a two-class configuration.

Despite these two planes being close to the 753s in their seating, they fall short of being natural replacements for United. Indeed, increasing the gauge of the fleet is central to United's future plans, and replacing the Flying Pencil with a smaller aircraft would be a step backward for the carrier.

United Getty
Currently, no natural successor exists for the 753s, with the 737 MAX and A321neo both falling short (737 MAX 9 pictured above). Photo: Getty Images

However, there could be one plane United is holding out hope for: Boeing's NMA (new midsize airplane). This aircraft has long been touted as the upcoming middle-of-market aircraft, meant to replace the aging 757 and 767 fleets. This new aircraft could seat 225-275 passengers, depending on the variant and layout, easily solving United's 753 woes.

Notably, Boeing has not formally announced plans for the NMA/797 project. While it is reportedly back on the table, the exact timeline for delivery remains elusive and could easily slip into the late 2020s and beyond.

Time to go

For now, United has ample time to make a decision regarding its 753s. The carrier likely won't have to worry about announcing a replacement until 2025, hopefully by which time Boeing has firmed up plans for its new mid-market offering. However, if no new plane is available by then, the A321neo and 737 MAX 10 both stand at the ready.

What do you think about United's choices for the 757-300's replacement? Let us know in the comments!