A brand new photograph of the second B-21’s first flight presents a brand new have a look at the engine exhaust, which seems similar to the B-2’s one.
Final week, the second B-21 Raider stealth bomber took to the skies for the primary time, flying from Palmdale’s Air Pressure Plant 42 to Edwards Air Pressure Base, California. A brand new photograph, captured shortly after takeoff, presents a brand new have a look at the engine exhaust of the brand new bomber.
B-21’s Rear Finish
Official photographs launched because the rollout of the B-21 all the time averted exhibiting the rear finish of the bomber. Nevertheless, a photograph of it already emerged in October 2023, captured throughout floor testing exterior of the bomber’s Palmdale hangar, as we reported on that event right here at The Aviationist.
On that first event, the photograph was captured from a distance and fairly blurry due to haze and warmth distortion. This time, the picture is kind of clear, and the form of the nozzle is clearly seen.
B-21 Raider early morning departure pic.twitter.com/WjqFhKCfNj
— jmh.creates (@JarodMHamilton) September 19, 2025
Opposite to many observers’ impressions after the primary photograph, it now seems that the B-21 adopted an exhaust system similar to the one already seen on the B-2 Spirit. These are designed to cut back as a lot as doable the infrared signature of the engines, contributing to the low observability of the plane.
It’s extremely possible that, similar to the B-2, air from the secondary air intakes can be combined with the recent exhaust gases to additional lower the temperature. Essentially the most notable distinction is the absence of the saw-tooth trailing edge discovered instantly behind the B-2’s exhaust, which on the B-21 has been changed by a straight edge.
The B-2 Spirit’s Flat Exhaust System
One of many B-2 Spirit’s most distinctive low-observable options is its uncommon (on the time) exhaust association. In contrast to typical fight plane, the B-2’s 4 Common Electrical F118-GE-100 non-afterburning turbofans (a variant of the well-known F110) are utterly buried inside the airframe, with no uncovered spherical nozzles seen.
As a substitute, the recent exhaust gases are routed by way of lengthy inner ducts earlier than being expelled by way of broad, shallow slot-like retailers on the higher floor on the trailing fringe of the wing. This configuration serves a number of functions.
First, it shields the most well liked components of the engines -combustors and generators – and the exhaust plume from direct line of sight, particularly from under, the place most infrared (IR) sensors and surface-to-air threats would try and detect the bomber. Second, the flat exhaust spreads the circulation over a wider space, rising the blending with cooler ambient air and bypass air, accelerating plume dissipation.
Lastly, the B-2’s aft deck construction partially masks the exhaust circulation, lowering the infrared output with the assistance of specialised heat-resistant supplies – like titanium and ceramic tiles – to assist diffuse residual thermal emissions. The absence of afterburners additional limits exhaust temperature.
Such a design introduces engineering challenges, resulting in tradeoffs that are nevertheless important to the B-2’s mission. The bomber was designed to penetrate dense air protection programs, thus minimizing its detectability throughout radar and infrared spectrums was prioritized over uncooked engine efficiency.
Exhaust Designs in Stealth Plane
The B-2 isn’t the one stealth plane to make use of unconventional exhaust options. Earlier, the F-117 Nighthawk was one other notable case, because it used a pair of flat, huge exhausts positioned above the rear fuselage.
Very similar to the B-2, these nozzles combined sizzling exhaust with ambient air and directed the plume throughout the plane’s higher floor to defend it from sensors under, utilizing a mixture of small channels, bypass air and “heat-reflecting” supplies. Nevertheless, the Nighthawk’s smaller measurement and fewer superior supplies know-how at the moment restricted its effectivity, with the plane nonetheless producing a noticeable infrared signature in comparison with extra fashionable designs.
Later stealth plane adopted totally different approaches. The F-22 Raptor, as an example, employs rectangular thrust-vectoring nozzles. These keep a level of infrared suppression by spreading the plume whereas additionally offering distinctive maneuverability. Nevertheless, they continue to be extra uncovered than the deeply buried exhausts of the B-2 or F-117, reflecting the Raptor’s design stability between low observability and high-performance air fight functionality.
The F-35 Lightning II returns to a extra typical, spherical nozzle structure, albeit closely optimized with serrated edges, signature-reducing supplies, and thermal administration measures. Its stealth depends extra closely on radar-cross-section discount, with infrared signature administration thought of much less crucial given its totally different mission set in comparison with the B-2 or F-117.
Stealthy unmanned fight air automobile (UCAV) demonstrators such because the Northrop Grumman X-47B additionally undertake flattened, shielded exhaust programs that echo classes from the B-2 and F-117. The X-47B routes its engine exhaust by way of an extended, shallow rectangular nozzle recessed into the higher rear fuselage.
As might be seen, stealth plane exhaust designs range relying on operational necessities, requiring totally different tradeoffs to realize the objective. Devoted strike platforms just like the B-2 prioritize infrared masking over effectivity, whereas multirole fighters such because the F-22 and F-35 undertake compromises between stealth, agility, and thrust efficiency.
The Second B-21 Raider
On Sept. 11, 2025, the U.S. Air Pressure’s second flight-worthy B-21 Raider, referred to as T-2, efficiently accomplished its maiden flight. The stealth bomber departed from Air Pressure Plant 42 in Palmdale, California, accompanied by an F-16 chase plane, earlier than touchdown at Edwards Air Pressure Base.
There the Raider joined the primary B-21, T-1, which has been flying since November 2023. As we reported right here at The Aviationist, the second Raider marks a big step ahead in this system, bringing extra capability to the continued check marketing campaign.
Alongside the 2 flying prototypes, two extra plane, G-1 and G-2, are devoted to floor testing. This combine permits the check marketing campaign to run in parallel, accelerating the tempo of analysis and lowering danger as this system strikes nearer to manufacturing.
With T-2 now flying, the Air Pressure can divide duties between the 2 airborne Raiders and progress into the following part of testing. The service will in truth use this second B-21, which is production-representative, to increase testing into weapons integration and sustainment assessments.
Thanks to Jarod Hamilton for permitting us to make use of his photograph. You should definitely take a look at and observe him on X and Instagram.
