Be aware of DCPC structural damage and electrical arcing risks
Effectivity: Challenger 3XX aircraft
ATA: 24
By: Abderrahman Karra Aircraft operators are increasingly aware of the challenges associated with handling and maintaining direct current power center (DCPC) units. Despite this awareness, incidents of structural damage during removal, installation or transportation, as well as electrical arcing during maintenance, continue to be a significant concern. These issues not only affect turnaround time (TAT) but also inflate repair costs.
This article aims to highlight these risks and provide practical suggestions to mitigate them.
Structural damage during handling and transportation
DCPC units are susceptible to damage if not handled correctly during removal and installation. Improper use of tools, excessive force and incorrect alignment can cause structural issues. Damage often occurs during transportation due to insufficient packaging. Vibration, impact and environmental factors can compromise the unit's integrity.
Distorted bracket
Damage to the DCPC structure can require significant repair time, delaying the aircraft's return to service. Structural repairs are often costly, especially if specialized parts or labor are required.
Distorted cover and casing
Ensure that all personnel involved in handling DCPC units are adequately trained in proper procedures and handling techniques. Use the correct tools and follow manufacturer guidelines during removal and installation to prevent unnecessary damage. Implement robust packaging standards for transportation and re-use original packaging whenever possible. Use shock-absorbing materials and secure the DCPC units to prevent movement and impact. Conduct thorough inspections before and after transportation to identify and address any potential damage early.
Electrical arcing during maintenance
One of the most critical issues occurs when maintenance personnel open the circuit breaker (CB) panel while the DCPC is still powered. This can lead to electrical arcing between the CBs and the casing, posing significant risks.
Arcing during maintenance
Establish and enforce strict protocols to ensure that the DCPC is completely powered down before opening the cover and the CB panel. Regularly train and certify maintenance personnel on the correct procedures for handling electrical components, emphasizing the dangers of electrical arcing. Use clear visual warnings and lockout/tagout procedures to prevent accidental powering of the DCPC during maintenance. Conduct routine safety audits to ensure compliance with safety protocols and confirm technicians are following setup procedures according to the AMM:
Electrical/electronic safety precautions (TASK 24−00−00−910−801)
Electrostatic−discharge safety precautions (TASK 24−00−00−910−802)
Disconnect the batteries (TASK 24−32−00−040−801)
Remove the external DC power from the aircraft (TASK 24−41−00−861−802)
Conclusion
Proper handling, transportation and maintenance of DCPC units are crucial to ensuring aircraft safety and operational efficiency. By adhering to recommended practices and protocols, aircraft operators can minimize structural damage and electrical arcing incidents, thereby reducing TAT and repair costs. Continuous training, proper tool usage, stringent packaging standards and strict adherence to safety procedures will help in achieving these objectives.
Ensuring the safety and longevity of DCPC units not only enhances operational reliability, but also contributes to overall cost efficiency in aircraft operations.