ASTM F1591-95(2019)

Standard Practice for Visual Signals Between Persons on the Ground and in Aircraft During Ground Emergencies

SIGNIFICANCE AND USE
3.1 While many of the reasons for needing the signals contained in this practice have been overcome by technology development, situations still arise where voice communications cannot be established between aircraft and persons on the ground during emergencies. This is particularly true of persons in distress, who typically have no communications equipment. These signals continue to meet the need for communications.  
3.2 Most of these signals have been adopted by international convention, the others by civilian and military agencies of the United States Government. The signals described in this practice are intended for use on land and can be made without special equipment such as flares or colored panels. Other signaling systems are described in the National Search and Rescue (SAR) Manual.3  
3.3 The signals are also useful in situations where either complete or partial voice communications exist. Where only partial capabilities exist, for example, a ground unit with receive-only capability, the aircrew can transmit voice and the ground crew can respond with the appropriate signal.  
3.3.1 The signals described in Section 4, by their nature, are not intended for real-time communications with aircraft. They can be left unattended as messages for aircrews. Persons on the ground (SAR or otherwise) can make a signal and continue on without contact with the aircraft. The SAR personnel should keep this in mind when encountering the signals of Fig. 1.
FIG. 1 Ground-to-Air Signals  
3.4 Search and rescue agencies utilizing this practice should disseminate these signals to the public as part of their preventative search and rescue (PSAR) efforts. The signals have changed over the years and a number of publications contain obsolete signals.
SCOPE
1.1 This practice covers the signals to be used between persons on the ground and in aircraft when two-way voice communications cannot be established during ground emergencies. Ground signals are limited to land-based ones that do not require special equipment. Flare, light, panel, and maritime signals are specifically excluded.  
1.2 The signals are divided into two categories: those used by persons on the ground and those used by aircraft.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Mar-2019
• ICS: 03.220.50 - Air transport
• Technical Committee: F32 - Search and Rescue
• Drafting Committee: F32.02 - Management and Operations

Relations

• Replaces: ASTM F1591-95(2012) - Standard Practice for Visual Signals Between Persons on the Ground and in Aircraft During Ground Emergencies
• Effective Date: 01-Apr-2019
• Referred By: ASTM F2958-14(2019) - Standard Guide for Helicopter Inland Search and Rescue (SAR) Technician
• Effective Date: 01-Apr-2019
• Referred By: ASTM F3026-14(2019) - Standard Guide for Helicopter Inland Search and Rescue (SAR) Crew Chief
• Effective Date: 01-Apr-2019
• Referred By: ASTM F3193-16 - Standard Guide for Training of a Land Search and Rescue Team Leader
• Effective Date: 01-Apr-2019

Overview

ASTM F1591-95(2019), titled Standard Practice for Visual Signals Between Persons on the Ground and in Aircraft During Ground Emergencies, is an international standard developed by ASTM to facilitate reliable communication in situations where two-way voice communications cannot be established between aircraft and ground personnel during emergencies. The standard outlines a system of simple, recognizable visual ground-to-air and air-to-ground signals, specifically for land-based situations, which do not require specialized equipment such as flares, lights, or colored panels.

This standard fulfills a crucial role in supporting emergency response, search and rescue (SAR) operations, and training by providing a set of internationally recognized visual signals that can be used when conventional communication tools are unavailable or impractical.

Key Topics

• Visual Communication for Emergencies: The standard provides an effective method for transmitting essential information when radio or verbal communication is unavailable, particularly aiding distressed individuals and SAR personnel.
• Land-based Visual Signals: Signals described in ASTM F1591 are specifically for use on land and must be constructed using materials readily available in the environment (e.g., brush, stones, surface material).
• Signal Categories: The visual signals are divided into:
  • Those used by persons on the ground to convey messages to aircraft,
  • Those used by aircraft to respond or direct ground parties.
• Signal Construction and Visibility: Emphasis is placed on making signals as large and as high-contrast as possible, placed in the open, and away from potential obstructions. This enhances signal visibility for overflying aircraft.
• Air-to-Ground Response Signals: Aircraft may indicate acknowledgment or non-understanding through maneuvers such as rocking wings or circling.
• Body Signals: For real-time communication when an aircraft is overhead, standardized human body signals are prescribed.
• International Adoption: Many of these signals are incorporated into international agreements, such as the International Civil Aviation Organization (ICAO) standards.

Applications

ASTM F1591-95(2019) is vital for a variety of aviation and emergency response scenarios, including:

• Search and Rescue (SAR) Operations: Ensures effective communication between aircrews and ground teams or individuals without radio backup, increasing the chance of successful rescues.
• Aviation Emergency Preparedness: Integrates into training programs for pilots, ground personnel, and emergency responders to recognize and use standard visual signals.
• Public Education: Recommended for dissemination to outdoor enthusiasts, hikers, or remote workers as part of preventative SAR efforts.
• Military and Civil Aviation: Serves both government and civilian agencies in establishing clear and consistent ground-to-air communication protocols.

Related Standards

Adherence to ASTM F1591-95(2019) supports alignment with other key international standards, including:

• ICAO Annex 12, International Standards and Recommended Practices: Search and Rescue - Recognizes many of the same visual signals for ground-to-air communication.
• National Search and Rescue (SAR) Manual - Provides supplementary signaling systems for search and rescue missions, especially in the United States.
• Other ASTM Search and Rescue Standards - For example, standards addressing operations and safety in SAR missions.

Practical Value

Implementing ASTM F1591-95(2019) increases safety and communication effectiveness in emergency aviation scenarios where technology may fail or be unavailable. By requiring no special equipment, the visual signals are universally accessible, adaptable for a wide range of environments, and are recognized internationally-crucial for cross-border or multinational operations. Accurate application and public awareness of these standards have direct, positive impacts on search-and-rescue outcomes and overall emergency response protocols.

Keywords: aircraft, ground-to-air signals, visual communication, emergencies, aviation safety, search and rescue, SAR, ground signals, ASTM F1591, international aviation standards.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F1591 − 95 (Reapproved 2019)
Standard Practice for
Visual Signals Between Persons on the Ground and in
Aircraft During Ground Emergencies
This standard is issued under the fixed designation F1591; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope in distress, who typically have no communications equipment.
These signals continue to meet the need for communications.
1.1 This practice covers the signals to be used between
persons on the ground and in aircraft when two-way voice 3.2 Mostofthesesignalshavebeenadoptedbyinternational
communicationscannotbeestablishedduringgroundemergen- convention, the others by civilian and military agencies of the
cies. Ground signals are limited to land-based ones that do not United States Government. The signals described in this
require special equipment. Flare, light, panel, and maritime practice are intended for use on land and can be made without
signals are specifically excluded. special equipment such as flares or colored panels. Other
signaling systems are described in the National Search and
1.2 The signals are divided into two categories: those used
Rescue (SAR) Manual.
by persons on the ground and those used by aircraft.
3.3 The signals are also useful in situations where either
1.3 This standard does not purport to address all of the
complete or partial voice communications exist. Where only
safety concerns, if any, associated with its use. It is the
partial capabilities exist, for example, a ground unit with
responsibility of the user of this standard to establish appro-
receive-only capability, the aircrew can transmit voice and the
priate safety, health, and environmental practices and deter-
ground crew can respond with the appropriate signal.
mine the applicability of regulatory limitations prior to use.
3.3.1 The signals described in Section 4, by their nature, are
1.4 This international standard was developed in accor-
not intended for real-time communications with aircraft. They
dance with internationally recognized principles on standard-
can be left unattended as messages for aircrews. Persons on the
ization established in the Decision on Principles for the
ground (SAR or otherwise) can make a signal and continue on
Development of International Standards, Guides and Recom-
without contact with the aircraft. The SAR personnel should
mendations issued by the World Trade Organization Technical
keep this in mind when encountering the signals of Fig. 1.
Barriers to Trade (TBT) Committee.
3.4 Search and rescue agencies utilizing this practice should
2. Referenced Document
disseminate these signals to the public as part of their preven-
tative search and rescue (PSAR) efforts. The signals have
2.1 International Civil Aviation Organization Standard:
changed over the years and a number of publications contain
International Standards and Recommended Practices,
obsolete signals.
Search and Rescue, Annex 12 to the Convention on
International Civil Aviation
4. Ground-to-Air Signals
3. Significance and Use 4.1 Signals for use by either SAR personnel or persons in
distress on the ground are shown in Fig. 1.
3.1 While many of the reasons for needing the signals
4.1.1 The signals in Fig. 1 have been adopted by the
contained in this practice have been overcome by technology
Convention on International Civil Aviation. As defined in
development,situationsstillarisewherevoicecommunications
Annex 12 to the Convention (see 2.1), these signals are divided
cannot be established between aircraft and persons on the
into those for use by SAR personnel and those for use by
ground during emergencies. This is particularly true of persons
persons in distress. Several of the signals have only been
adopted by certain countries.
1 4.1.2 Since the signals are useful regardless of the user’s
This practice is under the jurisdiction ofASTM Committee F32 on Search and
Rescue and is the direct responsibility of Subcommittee F32.02 on Management and
situation or location, this practice includes all of them without
Operations.
limitation. While there may be potential for this to cause
Current edition approved April 1, 2019. Published April 2019. Originally
approved in 1995. Last previous edition approved in 2012 as F1591 – 95 (2012).
DOI: 10.1520/F1591-95R19.
2 3
Available from the International Civil Aviation Organization; Document Sales National Search and Rescue (SAR) Manual, Vol I, Joint Publication 3-50, Feb.
Unit; 1000 Sherbrooke St. West, Suite 400; Montreal, Quebec, Canada H3A 2R2. 1, 1991. Available from United States Coast Guard; Washington, DC 20953-0001.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1591 − 95 (2019)
FIG. 2 Minimum Signal Dimensions and Proportions
4.7 Once a signal has served its intended purpose, it shall be
destroyed if at all possible, to prevent confusion and additional
search effort later.
5. Ground-to-Air Body Signals
5.1 The signals of Fig. 1 are “messages,” in that they take
considerable time to prepare, and so are not suitable for direct
communications when an aircraft is overhead. For real-time or
spontaneous communications, the body signals of Fig. 3 shall
be used.
5.1.1 The signals in Fig. 3 shall have the meanings indi-
FIG. 1 Ground-to-Air Signals
cated.They shall be used only for the purpose indicated and no
other signals likely to be confused with them shall be used.
5.1.2 The person making the signal shall be in the open and
as conspicuous as possible. Clothing worn should contrast with
confusion for aircrews seeing the signals, this would be a
the background. Attraction techniques such as flares, signal
temporary condition and the aircrew’s response should not be
mirrors, and smoke can be used to draw the aircrew’s attention.
dependent on the user’s status.The benefits of unlimited use of
These devices should not be used once contact has been made,
the signals outweighs any confusion caused by their us
...