APPLICATION NOTE: LINE REPLACEABLE UNIT (LRU) TESTING FOR REPAIRS AND REBUILDS

LRU TESTING - APPLICATION SUMMARY

HEICO Component Repair Group is an FAA-approved repair station based in Miami, FL. They hold various FAA Parts Manufacturing Approvals (PMAs) authorizing them to repair and rebuild a wide range of electro-mechanical devices called Line Replaceable Units (LRUs) for transport aircraft operators.

 

LRU maintenance manuals specify various electrical QC tests such as resistance, capacitance, bond strength, continuity, dielectric strength (HiPot), etc.

Fuel Metering Valve (LRU testing)
Fuel Metering Valve (LRU testing)

PREVIOUS TEST METHOD

Traditionally, HEICO technicians use a variety of manual instruments like multimeters, ohm meters, micro ohm meters, hi-pot testers, bond testers, etc.

Often these tools are located at different work stations around the shop. The test technician must move the LRU under test to several different work stations and manually record test results.

Each tool requires annual calibration and the technicians have to be trained how to operate them.

MK SOLUTION & BENEFITS

HEICO now uses MK’s Automeg D2500 which features 128 test points, 2500VDC and 1500VAC programmable power supplies and an EEM (External Excitation Module) option that enables them to stimulate active components such as solenoids, switches, relays, motors, lights, etc.

Automated test procedures
To date HEICO have created automated test procedures for over 25
different LRUs including:

  • Engine FMU (fuel monitoring unit)
  • HMU (hydro-mechanical unit)
  • Fuel controls
  • Trim stabilizers
  • Motorized valves
  • Servo actuators
  • Autopilot controllers, etc.

Time-saving
Time-saving is a clear and huge benefit. Testing time for just one LRU was reduced from 50 minutes to 8 minutes - an 85% reduction.

Other benefits
Automeg eliminates specialized operator training, reduces labor cost, minimizes shop travel time by replacing 4-5 different manual tools.

HEICO LRU testing Automeg D2500

More information

This application note is available as a PDF download.  Choose your preferred language format from the list on the right to start your download.

 

To learn more about Automeg, visit the product page.

 

For more information about our work in the aerospace sector, visit our industry page.

AN-2022-2 - LRU testing for repair - D2500 (1)