ISO 22072:2011

Overview

ISO 22072:2011 specifies the characteristics, requirements and design data to be included in procurement technical specifications for electrohydrostatic actuators (EHA) used in aerospace applications. An EHA is an integrated, electrically powered hydraulic actuator (motor + pump + hydraulic ram + reservoir + electronic module) that serves as an alternative to conventional hydraulically powered servo-control actuators. ISO 22072:2011 focuses on the unique requirements of EHAs so they can be procured, installed and certified consistently across aircraft programs.

Key Topics

This standard defines the technical content that purchasers and suppliers should include in EHA procurement documentation. Major topics covered:

• System description & interfaces
  • Mechanical, electrical and hydraulic interface definitions (envelope, connectors, filling/bleeding points)
  • Line‑replaceable units, access and attachment features
• Electronic module hardware & software
  • Role of motor drive electronics (MDE) or full Electronics Control Unit (ECU)
  • Requirements for software/firmware criticality referencing DO‑178B and DO‑254
• Performance requirements
  • Output force (maximum, continuous), rate, run‑up times and dynamic sizing cases
  • Static and dynamic servo‑loop characteristics: accuracy, hysteresis, bandwidth, stability margins, overshoot
  • Regenerative power and electrical power consumption limits
• Hydraulic, thermal and electrical considerations
  • Hydraulic consumption, internal filtration, anti‑cavitation, anti‑back‑driving features
  • Thermal behaviour and heat dissipation tied to mechanical/operational limits
  • Bonding, lightning protection and electromagnetic compatibility (EMC)
• Reliability, safety and maintainability
  • Failure modes, redundancy/segregation, built‑in test (BIT), fatigue/wear life and maintainability data
• Installation & operating conditions
  • Environmental, duty‑cycle, mechanical and electrical supply data required for procurement

Applications and Who Uses It

ISO 22072:2011 is used by:

• Aerospace OEMs and systems engineers specifying actuators for flight controls and control surfaces
• Supplier/manufacturer design teams producing EHAs or Electrohydrostatic Modules (EHM)
• Procurement and integration engineers preparing interface control documents and procurement specifications
• Certification and safety authorities evaluating EHA installation requirements and failure modes

Practical applications include primary/secondary flight control actuation, flap/slat actuation and actuation of other moving aerospace surfaces where electric-hydraulic integration, redundancy and local power/energy regeneration are important.

Related Standards

• ISO 7137 - Environmental conditions and test procedures for airborne equipment
• DO‑178B - Software considerations in airborne systems (referenced for software criticality)
• DO‑254 - Design assurance guidance for airborne electronic hardware
• SAE ARP1383B - Impulse testing of aerospace hydraulic components

Keywords: ISO 22072, electrohydrostatic actuator, EHA, aerospace actuator procurement, EHM, servo-loop, electronic module, DO‑178B, DO‑254.