Boeing AH-64E Block 2 Compound
Twin-Seat, Twin-Engine Attack Helicopter Proposal
The AH-64E Block 2 Compound is being proposed by Boeing as a potential replacement for the in-service AH-64E attack models.
Authored By: Staff Writer | Last Edited:
The AH-64 "Apache" dedicated twin-seat, twin-engine attack helicopter has been an American Army mainstay since 1986, proving its worth in the tank-killing / support / escort roles during the Persian Gulf War of 1991 and extending its usefulness in the hunt for enemy forces during the invasions of Afghanistan (2001) and Iraq (2003). The series has been exported to a select group of U.S.-friendly countries that includes Egypt, India, Israel, Japan, Saudi Arabia, South Korea, and the United Kingdom. Originally developed under the Hughes brand label in the 1970s, the product then moved to McDonnell Douglas in the 1980s-1990s and is currently (2019) owned by Boeing.
Despite its continued excellence, the helicopter's design does have its roots in a 1970s Army requirement which saw the Soviet Union, and its mass collection of tanks and related heavy armor, as the "enemy-of-the-day". This makes the series decades-old and efforts have been undertaken to ensure the aircraft's viability over the changing battlescape - resulting in such entries as the B and B+ model upgrades, the AH-64D "Apache Longbow", and the AH-64E (D-model Block III). The AH-64F was proposed in 2014 towards the Army's Future Vertical Lift (FVL) program which intends a successor for the AH-64 line before 2040.
To head off complete abandonment by the Army of the Apache line altogether, Boeing has moved on developing the conceptual "Advanced AH-64E Block 2 Compound", or "Advanced Apache", to fill the potential void. It is intended as an evolutionary successor to the in-service AH-64E Apache attack helicopter models relied on so heavily by the United States Army. The design was revealed in scale model form during the latter part of 2018 (HELicopter Military Operations Technology = HELMOT) and, as of this writing (May 2019), a scale model of the Advanced Apache has been successfully tested to prove the overall design sound.
At its core, the proposed "compound helicopter" retains the stepped, tandem seating cockpit arrangement of the original Apache to house its two crewmen, a pilot in the rear cockpit and a weapons specialist in the forward cockpit (the cockpit is also assumed to be heavily armored). Optics are also retained at the nose in a limited-traversing mount. The main rotor system appears to be of a rigid four-bladed design while a six-bladed propeller unit is seated in a "pusher" arrangement at the extreme rear of the aircraft (this quality is what gives the helicopter its "compound" classification as well as enhanced speed capabilities). Additionally, there is a port side-mounted 2 x Two-bladed tail rotor unit (featuring contra-rotating blades) used to cancel out the torque effects of the main rotor unit.
The engines straddle the boxy, slab-sided fuselage and each unit sports oval intakes with modified, slim exhaust ports, the latter most likely intended to reduce heat signatures. The engines are held high and mounted close to the fuselage sides. In terms of performance, estimates include a sustained 212 mile-per-hour speed limit out to a range of 530 miles.
Comparatively, the AH-64E production model can reach speeds of 165 mph (cruising) and 182 mph (maximum) while traveling out to ranges of 300 miles (ferry range of 1,180 miles).
Of note in the new design is that the wingstubs having been lengthened to allow for three underwing hardpoints per wing member (an increase from the original's two). The vertical tail fin is not only of a larger-area shape but it has also been positioned ventrally so as to better clear the tail unit for the pusher prop system as well as engine wash. The tail unit also includes the usual horizontal planes, one member to each side of the tail stem with the port side member holding the contra-rotating tail-rotor component.
Unlike the current-generation Apache, the Advanced Apache does not figure to have a fixed, wheeled, "tail-dragger" undercarriage. Instead it showcases a fully-retractable undercarriage to promote better aerodynamic efficiency - considering the increased speeds expected of this helicopter, this design quality makes sense (a tailwheel is retained at the ventral tail fin however).
In terms of armament, a chin-mounted (largely enclosed) turret structure remains under the nose. With each wing sporting three hardpoints, tactical usefulness of the helicopter is considerably broadened as the system would now be able to carry more ordnance in the way of rocket pods, Anti-Tank Guided Missiles (ATGMs), fuel tanks, and special-missile pods - in pairs or in mixed sets. This means as many as 16 x Hellfire ATGMs alongside 2 x 19-shot rocket pods giving the platform inherently strong capabilities to undertake multiple mission sets with one loadout.
For instance, the current-generation Apaches are typically armed for the "Anti-Armor" (tank-killing), "Covering Force" (support), or "Escort" roles dictating a heavy reliance on either missiles or rockets or a limited mix of the two. In the new approach, a single Advanced Apache would be outfitted with a heavy load out of both missiles and rockets (as well as its chin-mounted gun) to better respond to mulitple battlefield threats related to any role it was needed to fulfill.
It remains to be seen if the Advanced Apache design comes to any sort of fruition as these sorts of grand evolutionary steps to existing products rarely materialize - the service almost always proceeding with clean-sheet designs for future growth.
NOTE: Some values presented on this page have been estimated on the part of the author based on contemporary helicopter designs. The article will be updated as new information allows.