18.3 Preparedness and Protection (AFH-1 Section 17C)

Key Takeaways

  • Preparedness actions are mission critical and get high priority when the threat of enemy attack is high; every installation must have a rapid warning and notification system, and personnel should enroll in mobile alerts.
  • A three-to-five minute steady tone means a disaster or incident is imminent or in progress; a wavering tone means an attack or hostile act is imminent or in progress.
  • Alarm green is attack not probable at MOPP 0; yellow is attack probable in less than 30 minutes at MOPP 2; red or blue is air or ground attack imminent or in progress at MOPP 4; black is attack over with CBRN or UXO suspected at MOPP 4.
  • The installation commander sets the initial MOPP level; Table 17.1 is cumulative from overgarment through footwear, mask/hood, and handwear; Split MOPP divides the installation into CBRN zones rather than declaring the whole base contaminated.
  • The ground crew ensemble is the best immediate protection against chemical agents; collective protection uses overpressure; critical resources get cover — one layer of barrier minimum, two layers on tops when possible.
Last updated: August 2026

18.3 Preparedness and Protection (AFH-1 Section 17C)

Quick Answer: Know the installation's preparedness actions before an attack. Steady tone = disaster/incident; wavering tone = hostile attack. Alarm yellow = attack probable in less than 30 minutes at MOPP 2; red/blue and black = MOPP 4. The installation commander sets MOPP. Wear gear in order: overgarment, footwear, mask/hood, handwear. The ground crew ensemble is the best immediate protection against chemical agents — not against TIM. Cover aircraft and equipment before the attack.

Preparedness Actions

DAF installations must take actions to protect, prepare for, respond to, recover from, and mitigate the effects of an attack or incident so the force can conduct prompt, sustained, and decisive operations in a contested environment. Countering WMD and CBRN requires extraordinary preparedness and increases protection of mission-critical resources and force survivability.

Actions should be considered mission critical and given a high priority when the threat of an enemy attack is high. Installations set counter-actions using intelligence, threat probabilities, and subject-matter-expert recommendations. Learn the local actions before the siren.

Warning and Notification

Every DAF installation must have a rapid and effective system for watches, warnings, evacuation routes, and protective actions. Personnel must respond to mass warning systems or other visual or audible channels and are highly encouraged to enroll in mobile device notifications.

Attack warning signals notify personnel of warnings or impending attacks via mass notification systems, alarm condition flags, or other channels. They posture installations for attacks, warn of attacks in progress, initiate post-attack recovery actions, and return the installation to a normal state of readiness. Variations may be used in some geographical regions; personnel are notified before departure of home station and/or upon arrival.

Tones and Voice Announcements

SignalWhat it meansIndividual actions
Three-to-five minute steady toneA disaster or incident is imminent or in progressBe alert, take cover or evacuate to safety, follow instructions, and account for personnel
Three-to-five minute wavering toneAn attack or hostile act is imminent or in progressBe alert, execute security measures, follow instructions, and account for personnel
"Lockdown, lockdown, lockdown"An active shooter incident is in progressRemain calm and implement lockdown procedures
"Shelter-in-place"A natural disaster warning or a technological disaster warning requiring personnel to take shelter indoors per the Emergency Action PlanNatural: take refuge in an interior room without windows and doors and take cover. Technological: take refuge in a pre-designated room, shut off heating, ventilation, and air conditioning, and cover vents and doors with plastic
"All clear"The immediate disaster or threat has endedRemain alert, account for personnel, and report hazards, injuries, and damages

Steady versus wavering is the highest-frequency 17C item. A steady tone is a non-hostile disaster or incident; a wavering tone is a hostile act. Shelter-in-place is not one procedure: interior room for natural hazards; sealed pre-designated room with HVAC off for technological hazards.

Alarm Conditions

AlarmConditionMOPPActions
GreenAttack is not probableMOPP 0 (or as directed)Normal wartime conditions; resume operations; continue recovery actions
YellowAttack is probable in less than 30 minutesMOPP 2 (or as directed)Protect and cover assets; go to protective shelter or seek best protection with overhead cover
Red / BlueAir or ground attack is imminent or in progress. The "Blue" variation may be used at some installations within the PacificMOPP 4 (or as directed)Seek immediate protection with overhead cover; report observed activity or attacks
BlackAttack is over and CBRN contamination and/or UXO hazards are suspected or presentMOPP 4 (or as directed)Perform self-aid/buddy care; remain under overhead cover or within shelter unless directed otherwise

Alarm black has three release variations: Initial, Limited, and General Release. Initial Release applies to CBRN and specialized teams. Limited Release applies to Post Attack Reconnaissance teams. General Release applies to mission-essential personnel only.

Lock the pairings: green = MOPP 0, yellow = MOPP 2 and less than 30 minutes, red/blue and black = MOPP 4.

MOPP Levels

MOPP levels quickly communicate required IPE for CBRN operations or attack conditions. The installation commander determines the initial level from MOPP condition analysis and adjusts as mission priorities and intelligence change. MOPP is used with the alarm conditions in paragraph 17.6.

AFH 1 Table 17.1, MOPP Levels and Individual Protection:

MOPP levelWearCarry
ReadyField gear (as directed)Overgarment, footwear, mask/hood, handwear
0Field gearOvergarment, footwear, mask/hood, handwear
1Field gear, overgarmentFootwear, mask/hood, handwear
2Field gear, overgarment, footwearMask/hood, handwear
3Field gear, overgarment, footwear, mask/hoodHandwear
4Field gear, overgarment, footwear, mask/hood, handwearN/A

The pattern is cumulative: each level moves one item from carry to wear in the order overgarment → footwear → mask/hood → handwear. MOPP 4 wears the gloves and carries nothing additional — maximum individual protection.

Split MOPP is "a tactic used to divide an installation or operating location into two or more CBRN zones, rather than having to declare the entire installation contaminated." Where movement between zones is necessary, zone transition points contain contamination while allowing people, equipment, and supplies to move.

Individual Protection

Individual protection is IPE, vaccinations and prophylaxes, protective shelters, evacuation, relocation, exposure control, contamination control, and warning and notification systems, taken in stages matching the threat. Command and theater-specific instructions direct the postures.

Regardless of the type of agent, concentration, or method of attack, the best immediate protective equipment against chemical agents is the ground crew ensemble — a whole-body system that protects against chemical-biological warfare agents, toxins, and radiological particulates. It includes a protective mask with filters, overgarment, protective gloves, and footwear covers or overboots, plus M8 and M9 detector paper, reactive skin decontamination lotion, and M295 decontamination kits.

The ensemble is not designed to protect against toxic industrial materials. For TIM, evacuate.

Personnel Sheltering and Collective Protection

All installations conduct threat-based shelter planning. The installation commander establishes a shelter management plan and designates who prepares and operates each shelter. Shelters protect personnel from CBRN or hazardous material release over extended periods. Selection is based on structural and personnel housing capabilities versus the disaster type. Further guidance is in AFMAN 10-2502 and DAFI 10-2503.

Shelter-in-place applies when the hazard is unknown or evacuation would be dangerous. Occupants close all windows and doors and turn off ventilation so interiors stay uncontaminated.

Collective Protection Systems (COLPRO) may be fixed-site or expeditionary. They use overpressure to keep threat agents outside, so occupants can work or rest without protective gear. Many have contaminated control areas for entry after decontamination and outer-garment removal. Overpressure is the defining feature.

Critical Resource Protection

Prior to a CBRN attack, every installation must determine which equipment and assets can be stored, protected, or covered. Doing so minimizes or removes the requirement to decontaminate them after an attack.

  • Aircraft, support vehicles, aerospace ground equipment, and munitions — move inside or cover to the maximum extent possible
  • Bulk supplies — shelters or overhead cover
  • No overhead cover — at least one layer of barrier material
  • When possible, two layers on the tops of vehicles and equipment so contamination can be removed and replaced
  • Train personnel to remove barriers without transferring contamination

One layer minimum, two layers on tops when possible. Cover before the attack. Attack actions and recovery decontamination are Section 17D.

Test Your Knowledge

An installation announces alarm yellow. What does that condition indicate, and what MOPP level does it direct?

A
B
C
D
Test Your Knowledge

An Airman hears a three-to-five minute wavering tone. What does it signal, and what are the individual actions?

A
B
C
D
Test Your Knowledge

At MOPP level 2, which items are worn and which are carried?

A
B
C
D
Test Your Knowledge

What is Split MOPP, and what is its advantage?

A
B
C
D