ISO 46:1973

Overview

ISO 46:1973 is an international standard established by the International Organization for Standardization (ISO) that defines the specifications for fuel nozzle grounding plugs and sockets used in aircraft refuelling systems. This standard ensures that grounding plugs attached to the nozzles of aircraft refuelling tankers and the corresponding sockets on the aircraft provide a secure and reliable electrical grounding connection to prevent static electricity hazards during refuelling operations. The document specifies exact dimensions, cable length, diameter, and material requirements for grounding cables, promoting safety and uniformity across the aerospace industry.

Key Topics

• Plug Dimensions: The standard details precise measurements for the grounding plugs to ensure compatibility and secure fit into aircraft sockets.
• Socket Specifications: The grounding sockets installed on aircraft must accommodate plugs as specified, with a bore diameter ensuring proper insertion and electrical contact.
• Grounding Cable Requirements:
  • Minimum Length: 1.4 meters (4.5 feet) to provide sufficient flexibility.
  • Maximum Diameter: 1.6 mm (0.062 inches) to maintain compatibility with connectors.
  • Material: Steel wire coated with zinc or tin to ensure durability and reliable conductivity.
• Electrical Contact Assurance: The plug design incorporates a mechanism to guarantee good electrical contact when fully engaged, reducing risks associated with static discharge.

Applications

ISO 46:1973 plays a crucial role in aerospace safety and refuelling operations by standardizing components essential for maintaining proper static grounding during aircraft refuelling. Common applications include:

• Grounding systems for aircraft refuelling tankers and refuelling nozzles.
• Installation of grounding sockets on various types of aircraft to ensure compatibility with tanker plugs.
• Enhancing static electricity mitigation to prevent sparks that could cause fires or explosions.
• Use in airport fuel handling infrastructure to maintain standardized safety protocols internationally.

This standard is especially relevant for aerospace engineers, safety officers, refuelling personnel, and manufacturers of aircraft refuelling equipment.

Related Standards

• ISO/TC 20: The Technical Committee responsible for standards related to aircraft and space vehicles, including accessories and safety equipment.
• ANSI/ISA Standards: Related to electrical grounding and bonding in industrial applications, providing complementary guidance.
• ASTM Aircraft Fueling Standards: Provide additional guidelines on safe fuel handling and equipment compatibility.
• International Civil Aviation Organization (ICAO) Regulations: Cover broader fuel safety and operational guidelines that complement grounding standards.

Conclusion

ISO 46:1973 is a foundational standard in the aerospace industry that enhances safety by specifying the precise requirements for aircraft fuel nozzle grounding plugs and sockets. By ensuring consistent dimensions, material quality, and electrical contact performance, this standard helps mitigate the risk of static-related incidents during aircraft refuelling worldwide. Compliance with ISO 46 supports international interoperability and safe refuelling practices crucial for aircraft maintenance and operation safety.