UNITED24 - Make a charitable donation in support of Ukraine!

Weapons of Mass Destruction (WMD)

Chapter 3


Reconnaissance is a mission undertaken to obtain information by visual observation, or other detection methods, about the activities and resources of an enemy, or about the meteorologic, hydrographic, or geographic characteristics of a particular area. NBC recon is a specific type of reconnaissance. The purpose of NBC recon is the detection and identification of NBC hazards. This includes finding gaps and detours around NBC contaminated areas.


The goal of NBC reconnaissance is to produce combat information to allow friendly forces to avoid contaminated areas. NBC reconnaissance also can produce technical intelligence concerning the enemy's offensive NBC capability. NBC recon is part of the overall intelligence collection effort. It is performed in advance of other combat operations, as well as during them, to provide information used by the commander to confirm or modify his concept. NBC recon also is conducted throughout the framework of the battlefield from the forward combat area to deep in the theater's rear area. NBC recon missions are conducted wherever the enemy has the capability of employing NBC weapons.


NBC recon operations are planned and performed with six fundamentals in mind:

  • Retain freedom of maneuver.
  • Orient on the threat.
  • Report all information rapidly and accurately.
  • Develop the situation rapidly.
  • Avoid contact with enemy forces.
  • Maximize the capability of NBC recon units.

Retain Freedom of Maneuver

By avoiding contaminated areas, the commander maintains freedom of maneuver. Knowing the location of contaminated areas allows all units to practice the first principle of NBC defense--contamination avoidance. This limits the effects of degradation on soldiers operating in high MOPP levels.

Orient on the Threat

NBC recon operations are limited to those areas where the enemy can employ NBC weapons. The use of persistent chemical agents is the major threat that the majority of NBC operations will be directed against. The intelligence preparation of the battlefield (IPB) will identify where, when, how, and why the enemy will employ his NBC weapons. It is impossible to conduct NBC recon continuously at all points on the battlefield. The IPB assists in focusing the NBC recon effort at the most critical places and times on the battlefield.

Report All Information Rapidly and Accurately

NBC recon is performed to obtain information. Higher commanders need this information to confirm or make decisions. Combat information loses value quickly. Negative reports tell as much as positive reports. Accurate reporting of locations is essential to avoiding NBC hazards.

Develop the Situation Rapidly

Once contamination is encountered, the unit performing the mission must rapidly identify the type and intensity. Possible bypass routes or gaps must be quickly identified.

Avoid Contact with Enemy Forces

Detecting and identifying NBC agents is extremely difficult on the battlefield. Many of the detection procedures are time consuming. Contact with enemy forces has a degrading effect on NBC recon operations. It is seldom possible to accurately detect and identify NBC agents while in close combat. The loss of a single M93 NBCRS to enemy direct fire severely degrades the ability of the entire force to conduct future NBC recon operations.

Maximize the Capability of NBC Recon Units

When selecting an NBC recon unit to perform a task, the commander must consider the various capabilities and limitations of the unit. The mobility, survivability, and detection capabilities of each type of unit is considered when assigning tasks and missions.

Actions on NBC Contact

When the unit performing NBC recon encounters NBC contamination, the unit uses a series of actions to develop the situation:

  • Stop and report.
  • Determine agent type and intensity.
  • Choose a course of action for the recon unit.
  • Recommend a course of action to the supported unit.
  • Commander's decisions.

Stop and Report

Upon encountering contamination, the recon unit halts and reports the presence of contamination. A simple contact or spot report can be used or an NBC 4 report. If enemy contact is likely or expected, the unit must not remain in an area of limited cover and concealment. Also, the unit must minimize its exposure to the contamination.

Determine Agent Type and Intensity

The unit develops the situation by determining the exact type and intensity of the contamination if possible. Depending on the unit's detection and identification capability, the time required can be rather short, or take up to 20 minutes. If the unit has limited detection and identification capability, one element should remain at the contaminated area to determine the agent type. Other elements should move to covered and concealed positions to provide overwatch.

Choose a Course of Action

Once the leader has gathered enough information to make a decision, he selects a course of action. The course of action should adhere to the intent of the commander, be within the capability of the unit, and allow the unit to resume its mission as soon as possible. Courses of action include--

  • Survey. An NBC survey determines the exact boundaries of the contaminated area. This provides the maximum information concerning the contaminated area.
  • Bypass. Routes around the contaminated area are located and marked. This allows follow-on forces to avoid the contaminated area.
  • Cross. Bypassing the contaminated area may not be possible. The shortest, safest route across the contaminated area is located. This allows follow-on forces to minimize their exposure while crossing the contaminated area.

Recommend a Course of Action

Once the recon leader has selected a course of action, he reports it to his commander. The commander approves or disapproves the course of action based upon its impact on the overall mission. The SOP or OPORD may provide automatic approval of certain actions to avoid unnecessary delay.

Once the recon unit has reported the presence of NBC contamination, the commander acts on this information. The impact of the reported contamination must be analyzed against current and future operations. The commander may decide to alter the scheme of maneuver to avoid the contamination area or to increase the protective posture.

Recon Techniques

Units performing NBC recon use NBC recon techniques to accomplish their missions. These techniques fall into the two categories of search and survey. Search techniques are used initially to find the contamination. Once contamination is detected, survey techniques determine the size of the contamination. These techniques can be used while mounted or dismounted or in combination to meet the needs of the situation. Various NBC recon techniques are discussed in detail in Chapter 8 and apply to any unit needing to perform an NBC recon mission.

It may be necessary to dismount to conduct a detailed survey of an area or to obtain readings in areas not accessible to vehicles. The majority of dismounted operations will be performed by units not equipped with the M93 NBCRS.

Aerial radiological survey techniques are discussed in FM 3-3-1. Aerial operations normally are conducted to locate radiologically contaminated areas because of the large area typically contaminated after nuclear events.

NBC Route Recon

An NBC route reconnaissance is a directed effort to obtain information of a specific route. (A route is the prescribed course to be traveled from a specific point of origin to a specific destination). A route may encompass a single road or could be an axis of advance. Units performing a route recon typically conduct an NBC route recon as part of the overall operation.

A unit, particularly an NBC recon unit, could be given the specific mission of conducting an NBC route reconnaissance. This mission is appropriate when the commander feels there is a high likelihood of contamination along the route. An NBC route recon proceeds faster than an NBC zone recon. The size of the route and the time available dictate the size of the recon element. Once contamination is detected, the recon element has the following options:

  • Conduct an NBC survey to define the boundaries of the contamination.
  • Locate and mark clear bypass routes.
  • Terminate the mission and move to the coordinated decon point.
  • Continue the mission.

Critical Tasks

Certain tasks must be accomplished during a route recon. The IPB will indicate possible locations for contamination along with previous NBC reports. The critical tasks are--

  • Reconnoiter the route, and determine the location of any contamination.
  • Locate and mark bypass routes if contamination is encountered.
  • Report and mark all NBC hazards along the route.

NBC Zone Recon

An NBC zone reconnaissance is a directed effort to obtain detailed information on NBC hazards within a specified zone. An NBC zone recon is appropriate when previous knowledge of the area is limited and there are indications or reports of NBC hazards. Typically, a zone NBC recon is performed to determine the suitability for large unit (brigade or higher) assembly areas or logistic bases (such as BSAs, DSAs, and CSAs). Previous reports or intelligence indicate a high probability of past NBC attacks within the zone. A zone recon is a deliberate, time-consuming process that requires a large expenditure of resources. Once contamination is detected, the recon element has the following options:

  • Conduct an NBC survey to define the boundaries of the contamination.
  • Terminate the mission and move to the coordinated decon point.
  • Continue the mission.

Critical Tasks

Certain tasks must be accomplished during a zone recon unless specifically directed otherwise by the commander. Based on time and the commander's intent, the commander may direct the reconnaissance towards specific information only. The critical tasks are--

  • Reconnoiter all terrain within the zone for contamination.
  • Locate all previously reported NBC attack areas and determine if there is still a hazard.
  • Locate all possible contamination within the zone.
  • Check all water sources for contamination.
  • Locate all commercial chemical or nuclear facilities.
  • Report all information.
  • Mark contaminated areas.
  • Locate routes to bypass contamination.

NBC Area Recon

An NBC area reconnaissance is a directed effort to obtain detailed information concerning a specific area. An area recon is a specialized form of zone recon which proceeds faster since the effort is focused on a specific piece of terrain. This mission typically is assigned when employing a unit to reconnoiter a reported NBC attack area. Once contamination is detected, the recon element usually performs a survey to define the boundaries of the contamination.

Critical Tasks

During an NBC area reconnaissance, the critical tasks are--

  • Reconnoiter all terrain within the area.
  • Locate and mark all NBC hazards within the hazard.
  • Locate bypass routes around identified contaminated areas.
  • Report all information.

NBC Survey

An NBC survey is a directed effort to obtain detailed information concerning a contaminated area. The extent of the contamination is determined and marked. This is a resource intensive operation typically conducted in rear areas to prevent units from unknowingly entering the contaminated area.

Critical Tasks

    During an NBC survey, the critical tasks are--
  • Locate the general boundaries of the contaminated area.
  • Place warning markers at specified intervals around the contaminated area and at all entry points.
  • Determine the intensity of the contamination.
  • Report information via NBC5 report.

NBC Surveillance

NBC surveillance is the systematic observation of surface areas to detect NBC attacks and hazards. All units perform a type of NBC surveillance-monitoring. Units monitor their areas to provide early warning by using the automatic chemical agent alarm. Units can be given the mission to perform NBC surveillance by observing specified areas for indications of a chemical attack. After observing the indications of an NBC attack, the recon element has the following options--

  • Conduct an NBC survey to define the boundaries of the contamination.
  • Locate and mark clear bypass routes.
  • Terminate the mission and move to the coordinated decon point.
  • Continue the mission.

Critical Tasks

    The critical tasks are--
  • Occupy observation posts to overwatch the designated area.
  • Report all indications of an NBC attack.

Join the GlobalSecurity.org mailing list