TSA Computer-Based Test (TSA CBT) Prohibited Items and Threat Recognition Syllabus

Prohibited Items and Threat Recognition syllabus — full chapter and topic list

Expand any chapter to see its topics and sub-topics. This is the whole examinable outline for Prohibited Items and Threat Recognition in TSA Computer-Based Test (TSA CBT), not a summary of it.

1. 1

   Firearms and Firearm Components

   4 topics

   • Recognizing assembled handguns and long guns on X-ray
     • Barrel, slide, trigger guard, and grip silhouettes
     • Revolver cylinder profiles
   • Disassembled and concealed firearm parts
     • Receivers, magazines, and barrels separated across a bag
     • 3D-printed and polymer firearm indicators
   • Ammunition and loose rounds
     • Clustered dense metallic shapes
     • Magazines vs. loose cartridges
   • Replica and toy firearms
2. 2

   Improvised Explosive Devices (IEDs)

   4 topics

   • The five components of an IED
     • Power source (batteries)
     • Initiator/detonator
     • Explosive main charge
     • Switch/trigger
     • Container and wiring connections
   • Recognizing wire bundles and circuitry
     • Suspicious wiring vs. legitimate electronics
     • Connections bridging multiple components
   • Sheet, bulk, and molded explosives
     • Uniform orange masses without internal structure
     • Concealment in linings and false bottoms
   • Time and command initiation devices
3. 3

   Sharps, Blades, and Blunt Weapons

   4 topics

   • Knives, box cutters, and razor blades
   • Concealed blades in everyday objects
     • Comb knives, belt-buckle blades, pen knives
   • Martial arts and self-defense weapons
   • Blunt instruments and clubs
4. 4

   Dangerous Goods and Hazardous Materials

   4 topics

   • Flammable liquids and gases
     • Aerosol cans and pressurized cylinders
     • Lighter fluid and fuel containers
   • Corrosives, oxidizers, and reactive chemicals
   • Lithium batteries and fire risks
   • Liquids, aerosols, and gels (LAGs) rules
5. 5

   Concealment Techniques

   4 topics

   • False compartments and modified luggage
   • Shielding to block X-ray penetration
   • Artful concealment within electronics and shoes
   • Bulk concealment of contraband and currency

Prohibited Items and Threat Recognition flashcards for TSA Computer-Based Test (TSA CBT)

25 of 50 cards from the Prohibited Items and Threat Recognition deck — real questions with worked answers.

1. On a dual-energy X-ray image, what color are most firearms displayed as, and why?

   Orange/blue color depends on density, but the metal of a firearm typically appears dark blue or black because metals are highly X-ray absorbent (dense, high atomic number) and block penetration.

2. What distinctive shape silhouette should an operator look for to identify an assembled handgun on X-ray?

   The characteristic L-shape or right-angle profile formed by the barrel/slide meeting the grip, often with a visible trigger guard loop.

3. How does a long gun (rifle/shotgun) typically present on an X-ray image compared to a handgun?

   As a long, straight, dense barrel with a stock at one end; its length often means it is laid diagonally or broken down to fit in a bag, so look for elongated dense metal shapes.

4. Why might a firearm be disassembled before being placed in luggage by a threat actor?

   To break the recognizable gun silhouette into separate, less identifiable components that are harder for an operator to mentally reassemble on X-ray.

5. What individual firearm components should a screener be trained to recognize separately on X-ray?

   The barrel, slide/receiver, frame/grip, magazine, trigger group, and firing pin/bolt assembly.

6. What is the single most regulated and critical firearm part legally, and why does it matter in screening?

   The receiver (frame) - it is legally 'the firearm' and bears the serial number; recognizing a lone receiver is essential because the rest can be commercial parts.

7. How does ammunition typically appear on an X-ray image?

   As small, dense, uniform cylindrical/bullet-shaped objects, often grouped together in a box pattern or loose as repeated identical opaque shapes.

8. What clue helps distinguish loose rounds of ammunition from other small dense items?

   Their consistent, repeated shape and size (tapered cartridge profile) and high density appearing as identical dark objects, frequently in linear or clustered arrangements.

9. Why are replica and toy firearms a screening concern even though they cannot fire?

   They can be used to threaten/intimidate, may be indistinguishable from real weapons on X-ray, and many jurisdictions prohibit them in the cabin; they require a bag search to differentiate.

10. On X-ray, how can a screener attempt to tell a real firearm from a plastic toy replica?

    Real firearms show dense metallic (dark blue/black) components like barrel and slide, while plastic toys appear orange (organic/low density) with little or no dense metal.

11. What are the five components of an Improvised Explosive Device (IED)?

    Power source, initiator (detonator), explosive (main charge), switch (trigger), and container. (Mnemonic: PIES + switch, often taught as Power, Switch, Initiator, Explosive, Container.)

12. In an IED, what is the function of the initiator?

    It is the detonator that provides the initial energy/shock to set off the main explosive charge when the switch completes the circuit.

13. In an IED, what role does the switch (trigger) play?

    It completes or breaks the electrical circuit to activate the initiator - it is the firing mechanism (e.g., timer, command, victim-operated).

14. Why is the power source of an IED a key X-ray indicator?

    Batteries are dense and appear as distinct dark cylindrical or rectangular blocks; an out-of-place battery wired to other components is a classic IED signature.

15. What does a wire bundle connecting separate components in a bag suggest to a screener?

    A potential IED - wires linking a power source, switch, and a mass (charge) form a circuit; unexplained wiring between components is a primary threat indicator.

16. On X-ray, how do wires and circuitry typically appear and why are they suspicious?

    As thin, dense (dark) lines/strands often coiled or running between components; suspicious when they bridge a battery, switch, and bulk mass with no legitimate device purpose.

17. What is sheet explosive and why is it difficult to detect on X-ray?

    A thin, flexible explosive (e.g., Detasheet/PETN-based) that can be molded flat and hidden in linings, walls, or laptops; its thin organic profile blends into the bag and lacks a distinctive shape.

18. How do bulk and molded explosives appear on X-ray, and why are they hard to identify?

    As amorphous orange (organic) masses with no clear shape; molded explosives can be shaped to mimic ordinary items, so operators must look for associated IED components (wires, detonator, power source).

19. What X-ray color family do most explosives fall into, and what does that indicate?

    Orange, indicating organic/low-atomic-number material; explosives are organic compounds, so a dense orange mass with wiring is a red flag.

20. What is a time initiation device in an IED context?

    A switch that detonates after a preset delay using a timer (digital clock, mechanical timer, or electronic circuit), allowing the bomber to be elsewhere when it fires.

21. What is a command initiation device and how does it differ from a time device?

    It is detonated on demand by an operator via a remote signal (cell phone, radio, wire) rather than a preset delay, giving the attacker control over timing.

22. Name three common types of IED initiation (triggering) methods.

    Time/timer initiation, command/remote initiation, and victim-operated (e.g., trip-wire, pressure, or movement-activated) initiation.

23. What is the key visual difference between a knife and a box cutter on X-ray?

    A knife shows a single solid dense blade with a handle; a box cutter/utility knife shows a small dense blade often within a slim rectangular metal/plastic housing with a slide mechanism.

24. Why are razor blades especially challenging to detect on X-ray?

    They are very thin and flat, so when laid edge-on to the beam they present minimal density and may nearly disappear; orientation can hide them in paper, cardboard, or clothing.

25. What everyday objects are commonly used to conceal blades?

    Belt buckles, combs, pens, lipstick tubes, credit-card knives, hairbrushes, canes, and the soles or heels of shoes.

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