The key finding of the exhaustive investigation into the aircraft-weaponized mass murder of Americans on Sept. 11, 2001 was that our government had suffered from a “failure of imagination.” I know. I was there — as a CIA Officer before 9/11, as a White House national security lawyer after the attacks, as a principal liaison to the 9/11 Commission itself, and living about a mile from the Pentagon.

A Failure of Imagination

We re-organized our entire government after these attacks, including the creation of the Transportation Security Administration (TSA) and the broader Department of Homeland Security (DHS), to prevent future such failures. These efforts have protected Americans from a myriad of threats far better than most thought possible in late 2001. But we cannot rest on these successes in the face of constantly evolving threats.

In 2023, TSA issued a directive requiring larger airports to conduct randomized physical screening of aviation workers and their physical property for explosives and prohibited items by April 2025 (later extended for a year of “Informed Compliance” to April 2026) (the “TSA Mandate”). These new Aviation Worker Security (AWS) requirements address potential “insider threats” to aviation safety, with TSA commendably improving all Americans’ future safety by imagining types of security threats that have not materialized — yet.

Although the exact requirements of the TSA Mandate are classified as security sensitive information and therefore, are not public, they require larger airports to implement Explosive Detection Screening Equipment (EDSE), both for aviation workers themselves and for any bags they carry. To comply with this requirement by the April 2026 deadline, a number of major airports, including JFK’s new “Terminal One”, have already chosen AI-enabled millimeter-wave employee screening technology (“MM-Wave Screening”), which both “future proofs” airports’ threat detection and will enhance not only safety, but employee convenience and efficiency. Some airports are selecting, at least initially and as part of an overall solution, randomized employee screening via Explosive Trace Detection boxes (ETDs).

So, the compliance question is: MM-Wave or ETDs or both? Bearing in mind that, in almost all security challenges, a layered defense is better than any single technology, let’s look at the evolving threat environment and take a deeper dive into these two separate, but potentially complementary, technologies.

Americans will continue to face myriad, constantly metastasizing threats, from international terrorism and foreign nation-state adversaries (such as active sabotage operations being conducted in Europe by Russia and Chinese agents attempting to smuggle deadly fusarium into the U.S.) to disgruntled, ill-motivated, and/or mentally disturbed aviation workers (such as the 2009 Philadelphia incident in which an aviation worker reportedly concealed a handgun in a passenger’s bag).

This reality was brought home tragically in November 2025 as an apparently disgruntled and/or blackmailed former CIA asset murdered and grievously injured National Guard service members in Washington, DC. I have worked on all aspects of such threats, at all levels of government and in the private sector, and the stark reality is this: Whatever the threat, including some we have not yet imagined, two of our last lines of defense are passenger and aviation worker screening.

ETDs for Explosives Detection and Identification

One approach to TSA Mandate compliance is randomized employee screening via Explosive Trace Detection boxes (ETDs). We’ve all been pulled from an airport security line and swabbed for microscopic explosive residue. This solution may be cost effective and can not only detect explosive residue but, in some circumstances, identify the precise explosive substance found.

There are, however, some downsides of using ETDs as your only AWS solution. First, ETDs are labor-intensive for airport security personnel: each ETD check requires manual sampling, taking 10-30 seconds per person and, for the average covered airport, requiring 5-10 security operators, leading to significant employee hiring, retention, and training burdens. Secondly, false positives from environmental contaminants (20-30% rate) lead to more delays and frustration, as highlighted in GAO reports on TSA bottlenecks.

Most importantly, ETDs will never be able to detect a whole range of potentially deadly threats beyond explosives including:

• Non-metallic explosives that do not leave traces
• All metallic and non-metallic weapons, including 3D-printed and other “ghost guns,” such as the one reportedly used to murder a healthcare CEO in New York City in 2024
• Ceramic knives
• Ceramic and other hard-to-detect ammunition
• Fusarium and other deadly biological and chemical weapons
• Narcotics and other dangerous drugs and alcohol and other prohibited liquids

MM-Wave Screening

AI-powered and “future-proofed” MM-Wave Screening, in which aviation workers walk through a portal without stopping unless a threat is detected also complies with the TSA Mandate, while also detecting myriad other threats ETDs are not intended to detect. This solution also excels in terms of convenience, labor and training costs, and portability. Importantly, MM-Wave Screening will be able to detect new threats as they evolve thanks to advanced, and constantly updated, AI capabilities. This is “future proofing".

Contactless, MM-Wave Screening portals use advanced 3D imaging and AI to detect a broad spectrum of threats — metallic and non-metallic weapons, liquids, powders, plastics, 3D-printed guns, bio-agents, explosives, and narcotics in seconds. Such systems protect privacy by not storing scan images and/or making images available to security operators. MM-Wave Screening’s high throughput also will minimize queues, reducing the need for additional checkpoints and staff. Some MM-Wave solutions also are portable: a single person can relocate and recalibrate the scanning equipment in under 30 minutes, avoiding costly permanent installations. Such solutions also are highly adaptable, enabling each airport to tailor the deployment to its own physical infrastructure, the AWS randomization requirement, employee work patterns, budget, and other specific needs.

In other words, MM-Wave screening is adaptable to many different Concepts-of-Operations (CONOPS). ETDs also can be used under different CONOPS. For example, upon detection of potential explosives or other powdered or liquid threats, a nearby ETD would be useful to identify whether the substance is an explosive and, if so, what type. However, the threat is neutralized once the substance is detected and seized, with identifying the type important but not necessary.

In some cases, ETDs might also be initially cheaper than some MM-Wave solutions. However, such initial capital outlays may be offset by a 50-70% labor savings over 1-2 years, as well as significantly lower maintenance and consumables costs compared with ETDs.

Aviation Worker Security threats are real and constantly evolving. Thankfully, multiple options are available. Whatever an airport’s particular CONOPS is, the clock is ticking, both due to the April 2026 TSA compliance deadline, and also to do all we can to protect American flyers and airport employees from another tragic failure of imagination.