Northrop Grumman's F/A-XX Contender?

[Signal Witch]

Did Northrop Just Tease Its F/A-XX Contender?
 



In Northrop Grumman’s third-quarter 2025 recap video, there’s a brief shot showing a sleek, unfinished fuselage section that has people talking. It’s metallic, smooth, and shaped like something meant to fly fast and clean through the air. Most noticeably, it has a pair of deeply curved S-shaped air intakes along the sides. That kind of design is used to hide an engine’s compressor face from radar, which is one of the trademarks of stealth aircraft.

 Because Northrop Grumman is still competing in the Navy’s F/A-XX program to replace the F/A-18 Super Hornet, many think the fuselage could belong to a prototype or technology demonstrator for that effort. The F/A-XX is expected to share a lot of the same design philosophy as the Air Force’s F-47 under the NGAD program: a much longer combat radius, lower radar signature from all angles, and the ability to work directly with unmanned wingmen in combat.
 
Right now Boeing and Northrop are both in that race, and Congress has already set aside about seventy-six million dollars for the next phase in the 2026 defense budget. The contract award is expected soon. Whether the fuselage in the video was a hint or just background footage, it was enough to make people think Northrop is quietly further along than they’ve let on.

[Zaphod58]

I was thinking either F/A-XX or a new F-35 Center fuselage. I was leaning towards F/A-XX though.

[Blackfingers]

Green is zinc chromate primed metal (probably CNCed aluminium like 7075 T6),black is carbon fibre weave either moulded or laid down by a CNC robot.
Dual engine ducting by the look of the centre piece.

[Signal Witch]

Green is zinc chromate primed metal (probably CNCed aluminium like 7075 T6),black is carbon fibre weave either moulded or laid down by a CNC robot.
Dual engine ducting by the look of the centre piece.

 Yeah, I’d say you’re right on that.

The yellow-green is classic zinc chromate primer used on aluminum for corrosion control, mostly along frames and joint lines. The black is definitely carbon fiber panels laid over a metal frame, which is pretty typical for newer stealth builds where theyre trying to keep strength up and weight down.
 
My guess would be the subframe is aluminum-lithium alloy, probably one of the newer 2000-series Al-Li mixes, with the chromate primer over it. That setup keeps things light but stiff and helps cut down on corosion between the metal and composite. As for titanium, that only shows up near the inlets or engine mounts where the heat gets high enough to be an issue.

[Blackfingers]

My guess would be the subframe is aluminum-lithium alloy, probably one of the newer 2000-series Al-Li mixes

Oohh nice one.Thats a new one for me :) im used to the traditional 2024 series for most structural stuff.Will have to check out its sheer and torque specs and see how bendy it is!
One thing under the Zinc Chromate it should be bathed and rinsed in a solution of Alodine and clean water. The centre section is a high stress area as a lot of the plane attaches to it so it would be most likely third generation 2297 or 2397.

[EXETER]

 Yeah, I’d say you’re right on that.

The yellow-green is classic zinc chromate primer used on aluminum for corrosion control, mostly along frames and joint lines. The black is definitely carbon fiber panels laid over a metal frame, which is pretty typical for newer stealth builds where theyre trying to keep strength up and weight down.
 
My guess would be the subframe is aluminum-lithium alloy, probably one of the newer 2000-series Al-Li mixes, with the chromate primer over it. That setup keeps things light but stiff and helps cut down on corosion between the metal and composite. As for titanium, that only shows up near the inlets or engine mounts where the heat gets high enough to be an issue.

Agree.  Some design studies show that structures made from some of the Al-Li alloys can have a higher strength to weight ratio than carbon fiber in some applications.

[Blackfingers]

Think the third gen Al-Li alloys are better in compression than Carbon fibre.

[NoCorruptionAllowed]

 Yeah, I’d say you’re right on that.

The yellow-green is classic zinc chromate primer used on aluminum for corrosion control, mostly along frames and joint lines. The black is definitely carbon fiber panels laid over a metal frame, which is pretty typical for newer stealth builds where theyre trying to keep strength up and weight down.
 
My guess would be the subframe is aluminum-lithium alloy, probably one of the newer 2000-series Al-Li mixes, with the chromate primer over it. That setup keeps things light but stiff and helps cut down on corosion between the metal and composite. As for titanium, that only shows up near the inlets or engine mounts where the heat gets high enough to be an issue.

Good old Fuel resistant aerospace primer. Had to spray a lot of this at Boeing, Boeing material specification 10-20 type II.. All the big aerospace companies use it. The spec is cross company, and other companies use it since it conforms to their specs as well as Boeing's.
I still use it at a smaller supply chain company for some F-35 parts we make and other company parts
Aerospace Fuel resistant primer
It has a few heavy metals in it, also Strontium Chromate. 
The yellow that is. 
The green comes in a few flavors, one contains hexavalent chrome, nasty.   :)

[Blackfingers]

Good old Fuel resistant aerospace primer. Had to spray a lot of this at Boeing, Boeing material specification 10-20 type II.. All the big aerospace companies use it. The spec is cross company, and other companies use it since it conforms to their specs as well as Boeing's.
I still use it at a smaller supply chain company for some F-35 parts we make and other company parts
Aerospace Fuel resistant primer
It has a few heavy metals in it, also Strontium Chromate. 
The yellow that is. 
The green comes in a few flavors, one contains hexavalent chrome, nasty.   :)

Otherwise known in Australian aviation circles as "Green Death"..MEK is just as bad.

[Avicula]

Otherwise known in Australian aviation circles as "Green Death"..MEK is just as bad.

That’s a fact. Every HazMat qualification and certification never had to sit through in 20+ years as a firefighter, we always joked (?) about the MEK “Rule of Thumb”: If you couldn’t cover the ENTIRE scene with your thumb on an outstretched hand, you weren’t far enough away and needed to fall back until you could. That stuff is nasty.