The world of aviation and aerospace engineering is one of the most interesting with the latest technologies coming to the fore. One such example is the Defiant X advanced assault helicopter from Boeing and Lockheed Martin set to replace the stalwart UH-60 Black Hawk.

Building The Most Advanced Assault Helicopter

Developed for the US Army’s Future Long-Range Assault Aircraft (FLRAA), this advanced assault helicopter is the fastest, most agile and survivable helicopter ever built.

The Defiant X is based on the SB>1 Defiant prototype, which we also covered in a previous article. That concept actually took inspiration from the Sikorsky’s X2 Technology Demonstrator project which ended in 2011.

Much has happened since then as Lockheed Martin and Boeing reveals with the newly unwrapped Defiant X. So what makes this advanced assault helicopter extra special?

Related: ‘Future Military Aircraft’ 

What Is The FLRAA?

The United States Army initiated the Future Long-Range Assault Aircraft (FLRAA) programme in 2019. They wanted to develop a successor to the Sikorsky UH-60 Black Hawk utility helicopter as part of the Future Vertical Lift programme.

Under the Joint Multi-Role Technology Demonstrator (JMR-TD) programme, the US Army has been gathering data from flying prototype designs that could fill the role of the FLRAA.

They posted a request for information (RFI) in April 2019 to identify any interested manufacturers. The objective of the FLRAA competition is to produce a medium-class multi-role assault helicopter with twice the speed and range of existing designs.

The US Army plans to bring the FLRAA into service in 2030, in anticipation of retiring the UH-60 after 50 years of stellar service. The UH-60 Black Hawk was developed in the early 1970s and has been in service since June 1979.

Defiant X Assault Helicopter Design Shows Exceptional Control

The Defiant X advanced assault helicopter uses coaxial main rotors and a rear-mounted pusher propellor. This layout helps eliminate the risk of retreating blade stall and uneven lift forces when travelling at high speeds, which is common in single rotor designs. It will also enable the craft to retain exceptional handling capabilities when travelling at lower speeds.

Overall, the design is similar to the SB>1 Defiant prototype showing the same basic layout. However, the airframe is more aerodynamic, the nose is sharper and the engine nacelle has been specially refined to minimise the craft’s thermal signature.

Specifications Of The New Defiant X Assault Helicopter

Boeing and Lockheed Martin aren’t giving anything away as there’s no confirmation yet whether they will replace the T55 engine with a more advanced turbine.

Assuming they do, he Defiant X could be able to fly 100-knots (115 mph or 185 km/h) faster than conventional rotorcraft. At the same time, it will have 60% more range and 50% better performance in hot-hover manoeuvres.

Although it’s a new design, the Defiant X keeps close in the footsteps of the Black Hawk. This includes elements such as close-formation flying, tactics, techniques, procedures, training, and infrastructure.

The Defiant X has big boots to fill as the Black Hawk has been a stalwart in the military sector. But, with the next-gen capabilities of this advanced assault helicopter, it will be an incredibly powerful addition to the defence force.


If the idea behind the Defiant X is to create a stealthier, faster, well-armed assault helicopter with exceptional manoeuvring capabilities, it appears to check all the right boxes. The new design enables it to fly at high speeds and enter hostile territory at low altitude to deliver or extract troops and equipment.

This advanced assault helicopter is currently being tested in a virtual combat environment. We can expect to see contracts from the FLRAA competition to be awarded in 2022 and if the US Army approves, it will enter service around 2035.

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