EASA SIB CASA-2021-06
Electrical Connector Corrosion
Summary
The document titled Electrical Connector Corrosion is a Transport Canada Civil Aviation Safety Alert (CASA 2021-06) addressing corrosion issues on electrical connectors and backshells of De Havilland Canada Limited Dash-8-401 and -402 series aeroplanes. It highlights the occurrence of corrosion in harsh operating environments, particularly in landing gear bays and wing trailing edges, which can affect electrical bonding and shielding integrity. The alert provides information and recommendations to operators and maintainers to mitigate these risks.
What Changed
This CASA introduces awareness of the corrosion trend affecting electrical connectors and backshells on Dash-8-401 and -402 aircraft and updates maintenance guidance. De Havilland Aircraft of Canada Ltd. has revised the Aircraft Maintenance Manual and Maintenance Task Card Manual to include corrosion prevention and inspection procedures. A service letter (DH8-400-SL-20-006B) has also been published to inform operators of these updated procedures.
Why It Matters
Corrosion on electrical connectors can increase electrical bonding resistance and transfer impedance, leading to higher electromagnetic interference during lightning or high-intensity radiated fields events. This can cause damage or malfunction of electrical and electronic systems, impacting aircraft safety and reliability. Proper maintenance and corrosion prevention are essential to reduce nuisance warnings and ensure continued airworthiness of affected aircraft.
What To Do
Operators and maintainers of Dash-8-401 and -402 series aeroplanes should incorporate comprehensive connector and backshell inspection and rectification instructions into their maintenance programs. They should follow the updated procedures in the revised Aircraft Maintenance Manual and Maintenance Task Card Manual, as well as the guidance in Service Letter DH8-400-SL-20-006B. For further information, stakeholders can contact Transport Canada or the designated continuing airworthiness office.