MCWP 3-17.4 governs engineer reconnaissance tasks, support, route classification, and technical assessments and surveys.
View MCWP 3-17.4 on armypubs.army.mil
MCWP 3-17.4 describes reconnaissance before, during, and after missions, including mobility, countermobility, survivability, and other environments. It states that engineer reconnaissance is prescribed and task-organized in orders and covers technical information collection for routes, bridges, infrastructure, resources, and airfields.
Engineer reconnaissance consists of tasks that are undertaken to obtain (by visual observation or other detection methods) information about the activities and resources of an enemy or adversary or to secure data concerning the meteorological, hydrographical, or geographical characteristics of a particular area. (paragraph 1-1)
Reconnaissance is performed before, during, and after missions to provide information used in the intelligence preparation of the battlefield/battlespace process and by the commander to format, confirm, or modify a course of action. (paragraph 1-1)
The assessment requires less time, but it provides less technical detail. (paragraph 1-28)
The primary focus of the ERT is collecting technical information in support of mobility. (paragraph 3-2)
Tunnel reconnaissance is reported on DD Form 3012. (paragraph 4-42)