The Stakes

On January 29, 2025, PSA Airlines Flight 5342 — a Bombardier CRJ700 regional jet operating as American Eagle — collided with a U.S. Army Sikorsky UH-60 Black Hawk helicopter on approach to Runway 33 at Ronald Reagan Washington National Airport. All 67 people aboard both aircraft were killed. The National Transportation Safety Board's (NTSB) final report, released February 17, 2026, concluded without qualification that this accident was preventable — and that the technology capable of preventing it already existed and was mandated, in part, by the very regulatory system that failed to deploy it fully. ^[1]

The NTSB found that, had the crew of Flight 5342 been equipped with an airborne surveillance system using Automatic Dependent Surveillance-Broadcast In (ADS-B In) information configured to show directional traffic symbols and provide audible alerting, they would have received a collision warning approximately 59 seconds before impact. The traffic alert and collision avoidance system (TCAS) they had gave them 19 seconds. One minute versus 19 seconds — and the NTSB is unambiguous that the difference was a matter of life and death for 67 people. ^[1]

The NTSB also noted that its predecessor bodies and the Board itself had recommended, over the course of more than two decades, that the Federal Aviation Administration (FAA) require aircraft to both broadcast and receive real-time location signals, a recommendation made and ignored 18 times. The history of inaction is not simply a regulatory failure; it is a structural one, and it demands a response equal to the scale of its consequences. The purpose of this article is to make the case for why ADS-B In display in the airline cockpit is not optional, not aspirational, and not a matter for further study. It is a safety obligation that we must fulfill now. ^[2]

What ADS-B Does — And the Distinction That Matters

Automatic Dependent Surveillance-Broadcast is a surveillance technology in which an aircraft determines its own position via a Global Navigation Satellite System and periodically broadcasts that information via International Civil Aviation Organization (ICAO)-endorsed global standard. It is 'automatic' because no pilot or external input is required to trigger its transmissions; 'dependent' because it relies on the aircraft's own redundant navigation systems for position data; and 'broadcast' because the signal is transmitted omni-directionally, available to any receiver within range without interrogation. ^[3]

There are two distinct ADS-B functions, and the distinction between them is the central issue here. ADS-B Out is the transmit function: the aircraft broadcasts its own position, altitude, velocity, and identification to ground stations, satellite receivers, and other aircraft. ADS-B In is the receive function: the aircraft captures the broadcasts of surrounding traffic and displays that information to the flight crew on a Cockpit Display of Traffic Information (CDTI). A CDTI integrates data from ADS-B, TCAS, and Traffic Information Service-Broadcast (TIS-B) into a unified traffic picture — showing the crew where surrounding aircraft are, at what altitude, and on what vector, with audible alerting when conflict thresholds are crossed. ^[4]

ADS-B was conceived and deployed primarily as a ground surveillance tool — a cost-effective replacement and supplement for radar, capable of providing surveillance coverage in areas where radar is technically infeasible or commercially unviable. In that function, it has succeeded enormously. Now is the time to complete the system: extending the same data that ground controllers, satellite receivers, and operations centers already use into the one environment where it is most critically needed — the airline cockpit.

The Global Mandate Landscape: Out Without In

The FAA's own ADS-B Out mandate took effect January 1, 2020, requiring ADS-B Out in most controlled U.S. airspace and is codified in 14 CFR §§ 91.225 and 91.227. Europe's mandate followed under Commission Regulation (EU) No 1207/2011 (the SPI IR), with a final compliance deadline of December 7, 2020, for aircraft over 5,700 kilograms or capable of more than 250 knots. ICAO's Aviation System Block Upgrades (ASBU) framework — endorsed at the 12th Air Navigation Conference in 2012 — positions ADS-B as the primary global surveillance modernization tool, with supporting Standards and Recommended Practices in Annex 10 (Volume IV), Annex 11, and the suite of documents that includes Doc 9871, Doc 9924, and Doc 9994. ^[3]

None of these instruments mandate ADS-B In. Every commercial airliner operating in controlled airspace is now required to broadcast its position continuously; not one of those aircraft is required to receive the positions of surrounding traffic in the cockpit. This asymmetry was not accidental — it reflected a phased approach to surveillance modernization in which the ground infrastructure and aircraft transmit capability would be established first, and the cockpit receive capability would follow in a subsequent rulemaking. That subsequent rulemaking has not come. More than five years after the FAA's ADS-B Out mandate, and more than 15 years after the standard was established, the cockpit half of the system remains entirely voluntary for airline operators. ^[5]

The ICAO APAC Surveillance Implementation Coordination Group's implementation guidance (the AIGD) makes explicit that ADS-B deployment should not be undertaken without proper contingency planning, and that states should not decommission radar until sufficient risk analysis confirms ADS-B can safely assume the surveillance role. That counsel was sound. However, it addressed the ground side of the system — the infrastructure question. The airborne application question, addressed in ICAO Doc 9994, the Manual on Airborne Surveillance Applications, has not been met with comparable regulatory urgency. We have built the broadcast side of a two-way system and left the receive side to the market. ^[6]

The Information Asymmetry: Who Can See the Traffic

This information asymmetry is impossible to defend. Air traffic controllers on the ground receive a fused picture of radar data, ADS-B, and TIS-B in near-real time, giving them continuous situational awareness of the traffic in their sectors. Since 2019, the space-based ADS-B network using low-Earth-orbit satellites has extended that surveillance picture globally, covering oceanic, polar, and remote regions where ground-based radar cannot reach. Air navigation service providers over the North Atlantic, including NAV CANADA and NATS, now receive aircraft position updates within seconds, compared to the prior standard of several minutes between voice position reports. ^[7]

The benefits of that system are documented and substantial: 45,000 tons of CO₂ saved annually in North Atlantic airspace alone, £19 million in annual fuel-burn savings for airlines, and reduced separation standards that allow more aircraft to fly at optimum altitudes. An independent analysis by the British consultancy Steer found that the space-based ADS-B investment returns roughly £2 in value for every £1 spent. ^[8] Airlines themselves now access ADS-B data through their operations centers, integrated with fleet analytics platforms such as GE Aerospace's EMS solutions, providing real-time global tracking of their own aircraft. Even members of the public tracking flights on commercial platforms such as Flightradar24 receive near-real-time ADS-B position data on their personal devices.

The airline flight crew, the people legally responsible for the aircraft and for every life aboard it, often has access to none of this. Their traffic awareness rests on TCAS, a system whose Traffic Advisory indicates only that a threat is nearby without specifying where to maneuver, and whose more precise Resolution Advisory is automatically suppressed below 1,000 feet AGL — the exact altitude band where this accident occurred. ^[1] The pilot is the last person in the ADS-B information chain, and in most airline cockpits today, the pilot is not in that chain at all. This is simply unacceptable.

The Safety Case: What DCA Proved

The NTSB's final report on the DCA collision runs 378 pages plus supplemental material, and its probable cause determination is precise and unsparing. The Board determined that the collision resulted from the FAA's placement of Helicopter Route 4 in close proximity to the Runway 33 approach path; the FAA's failure to regularly review and evaluate that route or to act on prior recommendations to mitigate the collision risk at DCA; the air traffic system's overreliance on visual separation without adequate consideration of the limitations of the see-and-avoid concept; and the Army helicopter crew's failure to apply effective visual separation, which resulted in the collision. Contributing factors included the limitations of the collision alerting systems on both aircraft, the unsustainable arrival rate and controller workload at DCA, and the Army's failure to implement a safety management system that would have identified known altitude exceedances. ^[1]

One contributing factor is named with clarity: the FAA's failure across multiple organizations to implement previous NTSB recommendations, including Automatic Dependent Surveillance-Broadcast In. The Board does not suggest that ADS-B In was a remedy the FAA was unaware of; the agency had been counseled to require it 18 times over more than two decades. The Army Black Hawk had ADS-B In installed — but it was not connected to the crew's audio system, so no alert was received. The Black Hawk's ADS-B Out was not functioning at the time of the collision. PSA Airlines Flight 5342 had ADS-B Out but no ADS-B In. ^[1]

NTSB Chairwoman Jennifer Homendy testified before the Senate Committee on Commerce, Science, and Transportation that had the Black Hawk crew been able to hear ADS-B In alerts, they would have received a warning 48 seconds before impact — at a point when the aircraft were still far enough apart to maneuver clear. Had Flight 5342 been equipped with ADS-B In, the crew would have received an alert 59 seconds before impact. Nineteen seconds was not enough time to identify the threat, confirm it, and execute a maneuver at low altitude on approach. Fifty-nine seconds is. The technology that could have saved 67 lives was available. It was not required. It was not there. ^[9]

NTSB Chairwoman Homendy said plainly: 'This was 100% preventable.' ^[2] The Board issued 33 safety recommendations to the FAA, 8 to the U.S. Army, and additional recommendations to the Department of Transportation and the RTCA. The primary recommendation is unambiguous: the FAA must require all commercial aircraft to carry ADS-B In with a CDTI configured to provide audible alerting to the pilot or flight crew. That recommendation does not call for a study. It does not call for a rulemaking notice. It calls for a mandate. The same kind of regulatory authority the FAA used without hesitation when it required ADS-B Out.

The Technology Is Ready: The Barrier Is Regulatory Will

The argument that ADS-B In cockpit integration requires further development does not withstand scrutiny. The FAA's ADS-B In Retrofit Spacing Initiative (AIRS) evaluated three advanced cockpit applications in operational conditions: CDTI-Assisted Visual Separation (CAVS), which allows flight crews to maintain visual-like separation from traffic using an electronic display even when that traffic has moved out of direct sight; CDTI-Assisted Separation on Approach (CAS-A), which permits pilots to acquire traffic on the CDTI without first sighting it through the window; and Initial Interval Management (I-IM), a spacing precision tool for high-density arrivals. Standards for CAVS are complete and ready for manufacturers to produce the necessary avionics. ^[10]

American Airlines, working with ACSS, equipped a fleet of Airbus A321 aircraft with ADS-B In avionics in 2022, enabling I-IM operational evaluations in Albuquerque enroute airspace. ^[11] MITRE Corporation's research has produced a multi-purpose CDTI integrating 13 distinct functional capabilities within a single cockpit interface, designed to manage the full range of ADS-B In applications without creating new crew workload burdens. ^[12] The Radio Technical Commission for Aeronautics (RTCA) has developed the technical standards. The FAA has evaluated the applications. Airlines have demonstrated operational feasibility. In addition, the ICAO Assembly's 42nd Session identified the cybersecurity dimensions of ADS-B — spoofing, jamming, data integrity — as requiring systematic remediation, a fact that argues not against cockpit ADS-B In but for rigorous certification standards for the systems that deliver it. ^[13] A properly certified CDTI using validated data is a safety tool; the alternative — no display at all — is demonstrably more dangerous, as the DCA tragedy proved.

We must be in the mandate phase, and the mandate has not come. The question before regulators, legislators, and the aviation community is not whether this technology works. It does. The question is whether we will require it — before the next preventable collision, or after.

The Legislative Moment: Two Gaps, One Obligation

The DCA collision exposed two structural gaps in the ADS-B regulatory framework, and both must be closed. The first is the absence of an ADS-B In mandate for commercial aircraft — the gap that denied Flight 5342's crew the 59-second warning that could have saved their lives and the lives of the 60 passengers in their care. The second is the military loophole: the Army Black Hawk helicopter was operating in high-density civilian airspace without a functioning ADS-B Out broadcast, a condition that denied both the flight crew and the air traffic controller a complete picture of the traffic environment. These two gaps are related. An ADS-B In cockpit display is only as effective as the completeness of the ADS-B Out environment it receives. A military or government operator not broadcasting renders that display incomplete when it matters most. ^[1]

The legislative response to the DCA accident produced a clear vehicle for correcting both gaps. The Rotorcraft Operations Transparency and Oversight Reform (ROTOR) Act, sponsored by Senators Ted Cruz and Tammy Duckworth, passed the United States Senate unanimously on December 17, 2025. It would require all aircraft equipped with ADS-B Out to carry ADS-B In with an integrated CDTI providing audible alerting by December 31, 2031, and would require military and government operators to broadcast ADS-B Out when operating in high-volume or high-risk airspace. The Senate acted with unanimity because the evidence was conclusive and the obligation was clear. ^[14]

The House of Representatives has not acted with the same clarity. The ROTOR Act failed in the House under a process requiring a two-thirds majority on February 24, 2026. The House alternative, the Airspace Location and Enhanced Risk Transparency (ALERT) Act, was identified by Air Line Pilots Association (ALPA), the Allied Pilots Association, the Association of Flight Attendants-CWA, the NTSB, and the families of those killed in the accident as falling short — specifically because it does not mandate ADS-B In with an integrated CDTI, instead relying on a rulemaking process that would delay meaningful action by years. ALPA President Captain Jason Ambrosi stated the pilot community's position clearly: any aircraft required to broadcast ADS-B Out must also have ADS-B In integrated into the flight deck for pilot use. That position is not a union preference. It is a safety requirement, grounded in the NTSB's findings and in two decades of deferred recommendations. ^[15]

Our window of opportunity to effect change is open now, but it will not remain open indefinitely. The families of 67 people, the entire pilot community, the air traffic control workforce, the NTSB, and the unanimous membership of the United States Senate have spoken. The House must amend the ALERT Act to include a specific, time-bound mandate for ADS-B In with CDTI, and it must close the military loophole that allowed a non-broadcasting government helicopter to converge unseen on a commercial airliner in the airspace of the nation's capital. These are not complex demands. They are the minimum that the evidence requires.

The International Dimension: A Role for ICAO

The United States does not bear this obligation alone, and the current legislative moment in Washington, while urgent, is not the entire picture. ICAO has not yet moved to mandate ADS-B In for airline cockpits within its Standards and Recommended Practices, and the U.S. failure to lead forfeits the opportunity to shape the global standard at a moment when that standard is being written. ICAO's Doc 9994, the Manual on Airborne Surveillance Applications, provides the technical framework for airborne ADS-B use cases; what it does not yet provide is a mandate. ICAO's 42nd Assembly, convened in 2025, identified ADS-B cybersecurity as a growing concern requiring systematic attention. This is a recognition that the system's integrity must be actively managed, not assumed. That work is necessary and deserves our complete support. However, it must not become a reason for delaying the airborne display mandate that the safety record demands. ^[13]

Looking back at the trajectory of ADS-B deployment, one can trace a clear arc: the technology was standardized, the ground infrastructure was built, the mandate for ADS-B Out was issued, and space-based ADS-B completed the global surveillance picture in 2019. Each of those steps represented genuine progress, and we all must affirm that progress. The arc is not complete until bringing ADS-B data into the cockpit with a certified, integrated display and audible alerting is mandated globally. ICAO member states and their pilot representative organizations, including IFALPA, must add their voices to the call that ALPA and the allied pilot community in the United States have already raised. ^[16]

Closing: The Obligation We Cannot Defer

On January 29, 2025, 67 people died in an accident that the National Transportation Safety Board determined was 100% preventable. The crew of Flight 5342 had 19 seconds of warning at a critical phase of flight. The technology that would have given them 59 seconds was mature, standardized, and available. The regulatory mandate for ADS-B In had been recommended 18 times and ignored. It is impossible to characterize what followed as an accident of fate. We must characterize it as the consequence of a decision, or of a series of decisions not made, and all of us must resolve that the next such decision will be made differently. ^[1]

The case for mandating ADS-B In display in airline cockpits is complete. We have the technology. We have the standards. We have the operational experience. We have the NTSB's unambiguous findings and recommendations. We have the legislative vehicle in the ROTOR Act. We have the unanimous endorsement of the United States Senate and the unified voice of the global professional pilot community. What we must now secure is the political and regulatory will to finish what the ADS-B Out mandate began — to close both the receive gap and the military loophole, and to do so on a timeline measured in months, not years.

Every aircraft required to broadcast ADS-B Out must also carry ADS-B In, integrated into the flight deck with an audible alert capability. Every operator — military, government, commercial, and general aviation — that enters high-density or high-risk airspace must broadcast. These are not technically difficult requirements. They are simple, enforceable, and long overdue. The 67 people who died over the Potomac River on a January night deserve nothing less than complete action. The pilots who fly every day into complex and demanding airspace deserve the information they need to protect their passengers. We all must ensure they have it.

I am proud to stand with ALPA, IFALPA, the Allied Pilots Association, the Association of Flight Attendants-CWA, the families who have advocated with courage and clarity throughout this legislative process, and every organization that has called on Congress to fulfill the NTSB's recommendations without exception or delay. The work of building a safer aviation system is collective work, and it has never been more urgent.