Northrop Grumman and the U.S. Air Force put the B-21 Raider on public display in December 2022, but as of today the program remains in test preparation and production phases rather than routine flight operations. The Raider is being presented as a digital, open‑architecture stealth bomber intended to be the backbone of a modernized bomber force, and planners have talked about multiple test articles moving through Plant 42 and a flight test program led out of Edwards Air Force Base.

From an operational pilot perspective the single, unavoidable truth about any new low observable platform is that stealth is a capability and a constraint at the same time. Low observability reduces the range at which conventional radar will spot the airframe, which is great for survivability in contested airspace. It also complicates domestic airspace management when military test flights cross paths with civil traffic or transit through shared training corridors. Stealth lowers radar cross section but it does not erase the aircraft from the sky. Detection varies by radar band, aspect, altitude, and background clutter. Advances in passive and low frequency sensing can reduce stealth advantages against detection, but those systems bring their own coverage and accuracy tradeoffs.

The practical implications for shared airspace come down to three pieces: surveillance, procedures, and communications. Surveillance in the National Airspace System is now an ADS‑B centric network in many environments. The ADS‑B mandate requires equipped aircraft to broadcast position data in designated airspace, and the FAA has established where ADS‑B Out is mandatory for safety and traffic management. Military test missions, however, often operate with different requirements for operational security. That mismatch creates a potential gap: ATC surveillance tools expect cooperative broadcasts, while some military test sorties may intentionally limit emissions. Pilots and dispatchers on both sides should treat that gap as an operational hazard to be managed, not an abstract security problem.

Second, procedures. The FAA and the services already use a toolbox of special use airspace, military operating areas, temporary flight restrictions and NOTAMs to protect test activities and to warn civil operators. When a new class of aircraft like the B-21 enters testing those tools are the first line of risk control. FAA scheduling systems and the SUA/TFR processes allow the range and ATC to publish active time windows and lateral limits so civilian pilots can plan around them. There are also formal provisions for MARSA, which assign responsibility for separation within a defined military operation when properly coordinated. In short, the regulatory framework exists. The work is in execution and training.

Third, communications. For safety we should assume a simple operational baseline: if a test sortie must operate in or through airspace with civilian traffic there must be predictable coordination points. That can mean scheduled windows in restricted areas, an escort or chase aircraft that maintains a cooperative transponder and radio profile, or explicit ATC routing that keeps high speed or low observable testing inside protected corridors. Chase and safety aircraft are not a new idea. They are a blunt and effective mitigator because they provide a reliable cooperative target for ATC to use for separation and they can visually acquire and monitor the test platform if necessary. Those tactics are low cost and immediately implementable without compromising sensitive mission details. (If OPSEC really requires transponder silence for short segments those segments must be bounded by strict procedures and notified to FAA range and terminal facilities ahead of time.)

There are also technology options that civil authorities and the services should jointly invest in. Multilateration and passive surveillance techniques can fill gaps where traditional primary radar underperforms against low observable shapes. Passive bistatic and multistatic systems exploit existing transmissions or use distributed receive sites to detect disturbances that a stealthy planform might not reflect back to a monostatic radar. Those systems do not magically return a full track and identify solution everywhere, but they can provide a cue that lets ATC and range controllers apply procedural mitigations. Expect tradeoffs: passive systems can suffer from localization accuracy and clutter. Combining multiple sensing modalities, including electro‑optical trackers on range assets and dedicated ground sensors inside test complexes, will be the pragmatic path forward.

From the pilot lane here are concrete, low‑friction recommendations I would give to flight operations and local ATC where B-21 test activity will increase:

  • Treat NOTAMs and SUA schedules as living mission briefs. Check the FAA SUA/TFR listings and file with the expectation that Plant 42 and Edwards complex activity could change on short notice. Planning beats improvising.

  • Use chase assets proactively. Designate and equip chase aircraft or safety ships to carry continuous transponder and ADS‑B broadcasts during any test profile that could intersect civil flight paths. That provides ATC with a cooperative surrogate target for separation.

  • Standardize interoperability checklists. Before any sortie that will transit near populated corridors have prebriefed points of contact at the TRACON, the range scheduling office, and the FAA service area. Keep one phone line and one frequency for immediate coordination.

  • Expand training and simulations. Terminal controllers and local GA operators should see table top scenarios that include stealthy profiles, transponder off segments, and emergent contingency plans. Practicing the edge cases makes the real events manageable.

  • Invest in layered sensing on ranges. Multilateration, passive sensors, and optical trackers are complementary to ATC radar. Do not expect a single silver bullet. Instead plan for a sensor mosaic that supports controllers during test windows.

Finally a reality check. Test programs like the B-21 will change the rhythm of local aviation when they move from factory to flight test. Northrop and the Air Force have signaled the Raider will be a digitally engineered, networked platform that will enter a multi‑aircraft test flow. That means predictable spikes in test activity around Plant 42 and Edwards, not a continuous, covert presence. Civil operators and controllers get time to prepare if the parties treat safety as a shared responsibility rather than a secondary concern to security. The sooner range managers, FAA service units and local operators align on clear, practiced procedures and invest in modest sensing upgrades, the lower the risk will be when the Raiders start to fly.

Stealth technology gives military planners options. It should not create surprises for the pilots who share the same sky. Practicality wins in the end: robust NOTAMing, cooperative surrogate targets, trained controllers, and a layered sensor approach will let civil and military flights coexist safely as the next generation of low observable aircraft enters testing and, later, service.