MIL-STD-704 Training | Aircraft Electrical Power Characteristics, MIL-STD-704F Version

MIL-STD-704 establishes the requirements and characteristics of aircraft electric power provided at the input terminals of electric utilization equipment.

MIL-STD-704 is a Department of Defense standard that describes a standardized power interface between a military aircraft and its equipment and carriage stores.

The purpose of the MIL-STD-702 interface standard is to ensure compatibility between the aircraft electric system, external power, and airborne utilization equipment and establishes the requirements and characteristics of aircraft electric power provided at the input terminals of electric utilization equipment.

One of the more important things to keep in mind about MIL-STD-704 is that compliance is not exactly simple. Products must prove they can function effectively under extreme conditions, and customers may subject them to a variety of different tests to see how well they hold up and how those conditions affect them.

MIL-STD-704 covers the power generation system by citing the requirements that the power system is to provide at the utilization equipment power terminals. The testing evaluates the utilization equipment for compatibility with the cited performance of the power system.

Among topics the MIL-STD-704 standard covers include abnormal operation, emergency operation, and load characteristics for both AC and DC power systems.

MIL-STD-704 was issued in October 1959, as a standard superseding the engineering document MIL-E-7894 dealing with aircraft electrical power. The initial MIL-STD-704 considered only 28 Vdc and 115/200 Vac at 400 Hz from a three-phase, four-wire, “y” source.

The requirements were based on the available technology for power generation and distribution without undue weight and volume demands within the airframe capacity.

Revisions have been made over the years to implement new requirements, add voltage ranges, clarify and correct errors, update limits and establish more standardized test methods.

In addition to new revisions, change notices were released to make corrections between revision releases.

MIL-STD-704 Training Course by Tonex

MIL-STD-704 Training, Aircraft Electrical Power Characteristics, covers details of standardized power interface between a military aircraft and its equipment and carriage stores covering interfaces such as: voltage, frequency, phase, power factor, ripple, maximum current, electrical noise and abnormal conditions (overvoltage and undervoltage), for both AC and DC systems.

Learn about  MIL-STD-704 requirements, testing and measurements to ensure compatibility between the aircraft electric system, external power, and airborne utilization equipment.

MIl-STD-704 training course covers requirements and characteristics of AC and DC power for aircraft provided at the input terminals of electric utilization equipment including test methods and procedures for determining airborne utilization equipment compliance with the electric power characteristics requirements defined herein. Electromagnetic interference and voltage spikes are not covered by this standard.

To ensure that aircraft electronics and other electrically-powered equipment will operate reliably, tests under extreme power conditions are required: Guidance for Test Procedures for Demonstration of Utilization Equipment Compliance to Aircraft Electrical Power Characteristics are covered including:

• Demonstration of Utilization Equipment Compliance to Aircraft Electrical Power Characteristics
• Single Phase, 400 Hz, 115 Volt
• Three Phase, 400 Hz, 115 Volt
• Single Phase, Variable Frequency, 115 Volt
• Three Phase, Variable Frequency, 115 Volt
• Single Phase, 60 Hz, 115 Volt
• 270 VDC
• 28 VDC

Power testing is required to demonstrate compatibility of avionics with aircraft electrical power under operating conditions and power groups of MIL-STD-704.