As Boeing announced delivering the 100th AH-64E Apache helicopter on 30 March, the US Army is already planning a new round of upgrades.

A decision on whether to replace the AH-64E with a high-speed rotorcraft – the Future Vertical Lift – or perhaps re-engine the existing gunship remains at least a decade away.

In the meantime, the AH-64E will regain the ability to fire the Raytheon Stinger missile as a self-defense weapon if attacked by other aircraft. The US Army removed the Stinger from the wingtip of the AH-64E to install self-defence equipment. The South Korean government, however, is paying to re-integrate the missile for its army's AH-64E fleet.

The US Army has no requirement to install the Stinger missile on the AH-64E, but the capability will be available, says Col Jeff Hager, Apache programme manager.

The army will soon begin soliciting contractors for a new self-protection system against small arms. The ground fire acquisition system, which senses incoming fire by bullets and rocket-propelled grenades and alerts the flightcrew, will be acquired with money added to this year’s budget by Congress.

Boeing is expected to deliver a new version of the AH-64E software this year called Version 6 (V6). That will add a cognitive decision aid in the cockpit that will automatically adjust the flight plan if sensors detect the presence of unexpected threats along the original route, Hager says. The new software also will improve the fire control radar and introduce the soldier networking radio waveform.