HACM (Hypersonic Attack Cruise Missile) by RTX (Raytheon): status and timeline

HACM (Hypersonic Attack Cruise Missile)

Give US fighters a weapon fast enough to reach well-defended targets before air defences can react, using an air-breathing engine for longer range than rocket-only hypersonic weapons.

ProtoStage 2 of 5

First flight-test release over Australia confirmed Oct 2026; fielding decision due in fiscal 2027.

Updated 6d agoChecked 11 Oct1 update this week

Milestones

Next · First three flight tests completed

HAWC prototype flies above Mach 5 on a scramjetSep 2021Complete.
Raytheon wins $985M HACM development contract22 Sep 2022Complete.
First flight-test release over Australia2026+24 mo~~originally 2024~~Complete.
First three flight tests completedNowCurrent milestone.
Rapid fielding and production decisionTarget 2027Not yet reached.

Most important updates

Upcoming

2027Rapid fielding and production decision (next)

Current obstacles

Two years late to first flightThe first flight test was due in 2024 and slipped twice. Whether the 2026 release flew under its own power has not been disclosed.
Fewer tests, zero slackCutting from seven to five tests saves time but leaves less data, and auditors warn one major failure could derail the 2027 decision.

Physics limits

Lighting a match in a hurricaneAir rushes through a scramjet so fast that fuel has a tiny fraction of a second to mix and burn. Keeping the flame stable across speeds and altitudes is the core difficulty.
Heat soaks the whole airframeAbove Mach 5, compressing and rubbing against the air heats the skin and engine intensely for the whole flight. Materials, cooling and electronics must survive it, adding weight and cost.
Testing is only possible in flightGround wind tunnels can hold hypersonic conditions only briefly and not at full scale, so the real test is an expensive flight, which makes progress slow.

How it works

3 parts

Boost

A rocket gets it up to speed

Dropped from a fighter, the missile fires a solid rocket motor that accelerates it to the very high speed a scramjet needs before it can start.

Scramjet

Burning fuel in supersonic air

The engine has no moving parts: its shape squeezes incoming air, fuel is sprayed in and burns while the air still moves faster than sound, giving thrust.

Cruise

Air-breathing means longer reach

Taking oxygen from the air saves weight a rocket would spend on oxidiser, so HACM can keep powered flight longer and change course en route.

Spec sheet

vs HAWC (DARPA prototype)

Spec	HACM (Hypersonic Attack Cruise Missile)	HAWC (DARPA prototype)	Change
Speed	Above Mach 5^R (reported)	—	—no comparable change
Propulsion	Solid booster + scramjet^R (reported)	—	—no comparable change
Development contract (2022)	$985M^R (reported)	—	—no comparable change
Missiles in prototyping phase	13^R (reported)	—	—no comparable change
Planned flight tests	5^R (reported)	7 (before 2026 cut)	▼ 2
FY2027 production request	$404M^R (reported)	—	—no comparable change
Designation	AHM-4A^R (reported)	—	—no comparable change

^R reported by the company

Papers & demos

1 item

Sep 2021demo
HAWC scramjet missile free-flight test above Mach 5 (opens darpa.mil)Raytheon's air-breathing prototype, the design HACM was developed from.

Update log

3 updates

About RTX (Raytheon)

The team behind HACM (Hypersonic Attack Cruise Missile)

RTX (Raytheon)

Missiles, jet engines, avionics

RTX is a US aerospace and defence group formed in 2020 from the merger of United Technologies and Raytheon. Its three businesses are Raytheon (missiles and defence systems), Pratt & Whitney (jet engines) and Collins Aerospace (aircraft systems).

Raytheon builds HACM, the US Air Force's first scramjet-powered hypersonic cruise missile, with a Northrop Grumman engine.
HACM's first flight-test release happened over Australia, confirmed 5 Oct 2026, two years after the original target.
The Air Force wants a decision to field HACM in fiscal 2027 and has asked $404M to start production.

Company profile →

Founded: 20206 yrs
Headquarters: United States
Status: Public
Listed: RTX (opens google.com)NYSE
Valuation: public
Staff: ~180,000Jan 2025
Works in: AviationSupersonic & hypersonic
Coverage: 1 program · 3 updateslatest 6d agochecked 11 Oct
Customers: US Air Force (opens defensenews.com)
Partners: Royal Australian Air Force (opens twz.com)
Suppliers: Northrop Grumman
People: Christopher T. Calio (opens en.wikipedia.org)Chairman and CEO

Spec

HACM (Hypersonic Attack Cruise Missile)

HAWC (DARPA prototype)

Change

Speed

Above Mach 5^R (reported)

—

—no comparable change

Propulsion

Solid booster + scramjet^R (reported)

—

—no comparable change

Development contract (2022)

$985M^R (reported)

—

—no comparable change

Missiles in prototyping phase

13^R (reported)

—

—no comparable change

Planned flight tests

5^R (reported)

7 (before 2026 cut)

▼ 2

FY2027 production request

$404M^R (reported)

—

—no comparable change

Designation

AHM-4A^R (reported)

—

—no comparable change

HACM (Hypersonic Attack Cruise Missile)

Milestones

Most important updates

Upcoming

Current obstacles

Physics limits

How it works

A rocket gets it up to speed

Burning fuel in supersonic air

Air-breathing means longer reach

Spec sheet

Papers & demos

Update log

Mon 5 Oct

Thu 22 Sep 2022

Mon 27 Sep 2021

About RTX (Raytheon)

Current obstacles

Physics limits

How it works

A rocket gets it up to speed

Burning fuel in supersonic air

Air-breathing means longer reach

Spec sheet

Papers & demos

Update log

Mon 5 Oct

Thu 22 Sep 2022

Mon 27 Sep 2021

About RTX (Raytheon)