US Marine Corps officials are seeking clarity from their army counterparts over the latter's priorities for the Future Vertical Lift helicopter programme, as the service eyes the long-term replacement of its Bell UH-1Y fleet.

FVL is meant to fulfil the future requirements of all four US services, but negotiations will be necessary to align each operator's replacement timelines.

The USMC is most interested in a medium-class FVL rotorcraft to replace its fleet of Bell UH-1Y Venoms in the 2040s, said Col David Walsh, the service's H-1 programme manager, speaking at SMI's Helicopter Technology Eastern and Central Europe conference.

Although the initial focus of the FVL effort was thought to be on the medium-weight category, there have been suggestions from the US Army that it could prioritise a lighter helicopter, meeting its Capability Set 1 requirements, as a replacement for its now retired fleet of OH-58D/F Kiowa Warrior armed scouts.

Col Chad Chasteen, commander of the US Army's 110th aviation brigade, says that while a smaller rotorcraft would "fill a gap created by the divestment of the OH-58", no decision has yet been taken; more clarity is expected "in the next couple of months".

Walsh says the USMC will need an aircraft able to escort its fleet of Bell Boeing MV-22 Ospreys: "The H-1 in its current form can't keep up," he says.

"There is an analysis of alternatives going on between the marines and the army to see if we can come to some common solution," he says.

The USMC recently took delivery of the last of 160 UH-1Ys, with outstanding deliveries from a 189-unit order for the related AH-1Z attack helicopter continuing until 2022.

In the coming years, it plans to upgrade the Venoms, adding new weapons, including the future joint air-to-ground missile (JAGM) and Raytheon AIM-9X guided missiles, as well as an improved datalink and navigation systems to cope with degraded visual conditions.

In addition, the service intends to perform a structural upgrade of the UH-1Ys, adding an extra weapons or fuel store on either side of the helicopter. This process is currently in the design phase, says Walsh.

Bell has secured export orders for the AH-1Z from Bahrain and Pakistan via the US Foreign Military Sales process, but has yet to replicate that success with the UH-1Y.

Although production of the Venom has now ended, Steve Mathias, vice-president global military business development at Bell, says there would be no issue restarting the assembly line should another customer appear, noting the high commonality with the AH-1Z.

The Czech Republic previously expressed an interest in the utility type, with the USA last year approving a possible FMS sale.

However, the procurement was halted following a change of government in Prague and there is currently no indication over when that process might resume.

The Leonardo Helicopters AW139M was also a contender for the Czech requirement.