PACE stands for Primary, Alternate, Contingency, Emergency. A PACE plan orders a primary method and three fallback roles for a particular task. For a person isolated during military operations, a communications PACE plan sets out which actually available methods can carry a report or establish contact with an agreed recipient when the preferred method fails. The roles describe what each method does and the consequences of switching.
A personal plan for isolation
In US preparations for isolation, communications PACE is linked to personal equipment, reporting one's status and the intended actions after separation from the unit. It starts with the devices and signalling aids the individual actually carries: their power supply, transmission paths and the receiving stations able to receive and pass on a report. If a device assigned to the plan is left behind when a vehicle is lost, the person has to skip the contact methods that depend on it.
The receiving side also needs to know the plan. This includes the intended contact method, the conditions for switching and the expected report format. These details are coordinated with recovery capabilities and the evasion plan of action. The EPA records intended actions after isolation and is made available to the responsible organizations beforehand. They therefore retain a description of those intentions even when they receive no new message.
What the four roles mean
| Role | Function in the plan |
|---|---|
| Primary | The normally most effective principal method. It performs the required task under the anticipated conditions. |
| Alternate | A replacement that performs the task with little or no additional impact. It may already be used alongside the primary method to remain available and practiced. |
| Contingency | A further fallback that still performs the task within an acceptable time, but involves greater delay, effort or risk. |
| Emergency | The last usable method, often with substantial disadvantages or risks. Using it requires assessing those consequences in the current situation. |
The minimum information required is established before selecting methods. If the immediate task is to make the isolation and location known, a dialogue path and an alert path can perform that limited task in different ways. If a new movement intention needs to be conveyed and coordinated, a locating signal alone is insufficient. A fallback is assessed against the information the receiving side actually needs for the next step.
Shared failures and clear switching conditions
A phone call, a text message and an email on the same mobile phone depend on the same device and battery; depending on the connection, they may also depend on the same mobile network. Losing the phone makes all three methods unavailable. A second phone with its own battery can replace the lost device, but failure of the shared network still affects both. A fallback must therefore avoid the particular cause of failure: another device for device loss, another functioning transmission path for network failure.
The plan establishes beforehand how a contact attempt is recognized as successful or unsuccessful and which event triggers a switch. This might be a clearly damaged device, unsuccessful completion of the agreed contact procedure or a threat that prevents the intended use. Both sides need to know the same conditions so that the recipient accounts for the fallback. After losing the phone, the person selects the next planned method using another available means of communication and skips all applications that depended on the lost device.
For a connection that permits replies, the expected response forms part of contact planning. Sending a message and receiving a reply are separate events. An agreed acknowledgement shows that the other side has established contact; the content of the exchange then determines which further actions have been coordinated. A one-way alert path requires a plan that works without that dialogue.
Which information goes by which method
Recovery planning depends on the person's current location, condition, threat and next intentions. A short situation report can therefore combine position and the time associated with that position, injury or ability to move, observed threats and the intended next action. If the person has moved since the last position report, an older position needs to remain identifiable as such. Otherwise, the receiving side may plan around a location already left behind.
The selected means determines how much of this can be conveyed. A prepared voice or data contact can carry questions and changes in the situation. A distress beacon using the Cospas-Sarsat system sends an alert with identification and location information through a satellite, ground station and mission control centre to the responsible search and rescue authority. This alert follows the Cospas-Sarsat reporting chain rather than the agreed military dialogue path; it does not carry the same freely worded report about injuries, adversaries and movement intentions. A visual signal, in turn, has to be seen and understood by the intended recipient.
Information protection also affects the choice. The content of an open voice contact can reach unwanted listeners; a visible signal can attract observers beyond the forces being addressed. The person therefore assesses what information and visibility the remaining method requires. Personal authentication information is used within the prepared procedure rather than added to a distress signal that can be widely perceived.
Radio, distress beacon and visual signal in a fallback plan
For the limited task of reporting isolation and making one's location apparent, Primary could be an agreed two-way radio or telephone contact. The person must be carrying the appropriate device, and the receiving side must be prepared for the contact. Alternate would be a separate device using another usable transmission path. A carried distress beacon could serve as Contingency if its alert chain is suitable for the mission and the threat permits its use. Emergency could be an agreed visual signal once the intended friendly forces are actually in sight and able to recognize it. For that last method, the person needs to weigh the opportunity to establish contact against the additional risk of detection.
The example can be checked against failures: loss of the primary device leads to the separate replacement; failure of both dialogue methods leaves only the limited alert function. If no usable beacon remains, the agreed visual signal becomes the last method provided for in this example. The intended friendly forces must be in sight and able to recognise the signal. If the person has lost all devices and no such contact opportunity exists, they assess their present ability to move and the threat to decide which of the alternatives prepared in the EPA remains possible.
Movement PACE as a separate task
A personal PR plan can include a separate PACE block for movement after isolation alongside its communications plan. This concerns intended actions and destinations: which route is intended, which alternative is considered if it is blocked and which intention applies if an injury changes mobility? Failure of a communications device and inability to use a planned route are different triggers. Each requires a decision for the affected task.
The EPA therefore also prepares injury-dependent intentions and alternatives for contact or recovery locations. The isolated person selects the option that can be carried out with the remaining means under the actual conditions. If the destination or movement intention changes, that change is passed on at a later suitable contact so that the recipient can adjust planning to the new area.