United Airlines is taking an aggressive approach to removing ageing Boeing 757-200s from its fleet, with its domestic fleet of the type targeted to be all but gone by the end of 2015.
The Chicago-based carrier plans to remove 73 of the type and replace them with Boeing 737-900ERs over the next two and a half years, says John Rainey, chief financial officer of United, during an earnings call on 25 July.
However, United only has 48 737-900ER deliveries scheduled over the same period - 25 less than its planned retirements of 757s - Flightglobal's Ascend Online database shows.
It is unclear how the airline plans to fill this gap. It also has deliveries of Boeing 787 and Embraer 175 aircraft scheduled during the same period but neither could be considered a replacement for domestic 757s.
Leasing additional aircraft could be an option. However, this would be a break from United's typical fleet renewal strategy that involves ordering new aircraft and financing them with secured debt.
In addition, Rainey reiterates management's plan to keep the carrier's "overall fleet count roughly flat over our planning horizon over the next five years", during the call.
United declines to comment.
The airline has 129 757-200s in its fleet and firm orders for 88 737-900ERs, according to Ascend. It has 88 757s powered by the Pratt & Whitney PW2000 turbofan engine, and 29 use Rolls-Royce RB211s.
Most of the domestic 757-200s were made before 1995, with those made after largely concentrated in United's international fleet. Ascend shows that 90 of the aircraft in its fleet were delivered before 1995.
United will sell up to 30 of the outgoing domestic 757s to FedEx, under a deal that was announced in March.
International 757s will remain in United's fleet for the time being. Ron Baur, vice-president of fleet at United, told Flightglobal in May that it had "no plan to replace the international [757s] other than to upgauge".