New approach to control cable replacement
Aircraft owners, operators and maintainers need to be aware of a new approach being taken by CASA to the mandatory replacement of a range of primary flight control cable assemblies.
The new approach will offer an inspection regime instead of the mandatory replacement of all affected flight control assemblies at 15 years time in service.
This will provide relief from the cost and time needed to replace all affected flight control assemblies.
An airworthiness directive issued in early 2015 - AD/GENERAL/87 Primary Flight Control Cable Assembly Retirement – put in place the mandatory replacement regime.
The directive covered primary flight control cable assemblies with terminals constructed of SAE-AISI 303 Se or SAE-AISI 304 stainless steel with a total time in service of 15 years or more.
The requirements of this airworthiness directive take effect from 1 January 2018.
As the airworthiness directive currently stands this means flight control cable assemblies on affected aircraft that have already reached or exceeded 15 years time in service must be replaced before 1 January 2018.
However, CASA will soon be issuing a proposed airworthiness directive which will put forward amendments to the current airworthiness directive, AD/GENERAL/87.
The aviation community will be asked to comment on the proposed amendments before CASA finalises the new control cable assembly airworthiness requirements.
CASA has now agreed that inspections - if performed in a particular and thorough manner - can satisfactorily address the risks of cracking and failure of control cable assemblies.
The repeating inspection regime will require detailed inspection for evidence of corrosion and fraying, which if found, will require cable replacement.
CASA understands many aircraft owners, operators and maintainers will currently be planning to replace control cables to meet the deadline of 1 January 2018.
This information is being released by CASA ahead of the proposed airworthiness directive to allow these people and organisations to consider whether to proceed with cable assembly replacement at this time.
CASA estimates the control cable assembly requirements will affect about 10,000 Australian aircraft.
The proposed airworthiness directive will be issued for comment in May 2017.