Sikorsky flew its CH-53K King Stallion 100ft above the ground with a 12,250kg (27,000lb) payload, meeting a key requirement for the US Marine Corps helicopter, the company announced on 23 June.

In May, Marine Corps officials expressed an interest in expanding the aircraft’s payload capacity to about 13,600kg, though early analysis indicated the helicopter would not meet that threshold, Flightglobal previously reported.

The CH-53K will replace the aging CH-53E Super Stallion, which the Marines first introduced in 1980. The past three decades have degraded the heavy-lift platform’s performance and led to operational concerns. The new helicopter promises better range and triple the E model’s payload in hot weather conditions, as well as flight-by-wire flight controls designed to reduce pilot workload in degraded visual environments, according to Sikorsky.

During recent flight tests, the CH-53K lifted the payload to a height greater than the helicopter’s 24.1m (79ft) rotor diameter. The demanding lift condition requires increased power from the aircraft and marked the most strenuous tests on the aircraft before entering production, Col Hank Vanderborght, Marine Corps programme manager for the Naval Air Systems Command's heavy lift helicopters, said in a Sikorsky press release.

Michael Torok, Sikorsky’s vice-president of CH-54K programmes, says the successful test indicates the programme is on track to complete an initial operational assessment this year, according to a company press release.

Although Torok offered an optimistic assessment of the program, Sikorsky has faced previous stumbling blocks that have drawn out the helicopter’s fielding time. Last October, the CH-53K achieved first flight, following a yearlong delay attributed to gearbox issues.

The Marines are planning to decide whether to launch low-rate initial production by January 2017 and achieve initial operational capability by fall of 2019, according to budget documents. Sikorsky is contracted for 200 aircraft and will deliver the first four helicopters to the Marines next year.