FAS

US Army: Hand and Arm Signals

03.21.17 | 1 min read | Text by Steven Aftergood

Under ordinary circumstances, the U.S. Army relies on high-speed digital communications. But sometimes that is not an option, and soldiers must revert to more primitive methods.

“When electrical and/or digital means of communication are inadequate, or not available,” a new Army publication explains, messages may be transmitted “through the use of hand-and-arm signals, flags, pyrotechnics, and other visual aids.” Many of those alternate communication methods are described in Visual Signals, U.S. Army Training Circular TC 3-21.60, March 2017.

So, for example, “To signal ‘chemical, biological, radiological and nuclear attack,’ extend the arms and fists. Bend the arms to the shoulders. Repeat. (See figure 1-16.)”


Of course, hand and arm signals have limitations. For one thing, they may be misunderstood.

“Visual signals are generally contextual in nature. For example, the hand-and-arm signal for ‘take cover’ and ‘slow down’ are similar in their perspective movements, however the situation in which each is given is completely different.”

Also, “The range and reliability of visual communications are significantly reduced during periods of poor visibility and when terrain restricts observation.”

Finally, visual or gestural communications “are vulnerable to enemy interception and may be used for deception purposes,” the new Army publication said.

publications
See all publications
FAS
FAS Statement on Michael Kratsios’ OSTP Hearing

With so much at stake, we cannot afford to cede science and technological leadership or its underpinnings: foundational federal R&D investments, growing STEM talent pipelines, and the best scientific and technical expertise to support policymakers.

02.26.25 | 1 min read
read more
Global Risk
Report
Reawakening a Nuclear Legacy: The Potential Return of the US Nuclear Mission to RAF Lakenheath

Even without weapons present, the addition of a large nuclear air base in northern Europe is a significant new development that would have been inconceivable just a decade-and-a-half ago.

02.26.25 | 2 min read
read more
Government Capacity
day one project
Policy Memo
Reforming the Federal Advisory Committee Landscape for Improved Evidence-based Decision Making and Increasing Public Trust

Protecting the health and safety of the American public and ensuring that the public has the opportunity to participate in the federal decision-making process is crucial. As currently organized, FACs are not equipped to provide the best evidence-based advice.

02.18.25 | 11 min read
read more
Emerging Technology
day one project
Policy Memo
A Federal Center of Excellence to Expand State and Local Government Capacity for AI Procurement and Use

As new waves of AI technologies continue to enter the public sector, touching a breadth of services critical to the welfare of the American people, this center of excellence will help maintain high standards for responsible public sector AI for decades to come.

02.14.25 | 9 min read
read more