All Gippsland GA8 Airvan aircraft.
This Continued Airworthiness Notice (CAN) alerts operators and maintenance providers of possible safety concerns related to incorrect assembly of the throttle cable to the Fuel Control Unit (FCU) on Gippsland GA8 Airvan aircraft.
This CAN is revised following an in-flight loss of engine control due to the throttle cable disconnection on a GA8 Airvan.
During a routine flight the pilot noticed a 10kt uncommanded reduction in airspeed with an associated 3 inHg reduction in engine manifold pressure.
The pilot determined that the engine was unresponsive to throttle movement, with some engine control maintained via the mixture control. A subsequent inspection by a maintenance engineer found that the throttle linkage had disconnected from the engine FCU.
Operators and maintenance providers should ensure that Gippsland GA8 Airvan aircraft conform to the appropriate throttle attachment configuration as detailed in the manufacturer’s instructions for continuing airworthiness.
Incorrect assembly of the throttle cable and associated linkages can cause fouling of the throttle cable, or loosening of the attachment hardware.
Engineers connecting the throttle cable on Gippsland GA8 Airvan aircraft should familiarise themselves with the specific requirements for the installation. As an example, the throttle body lever arm specific to GA8 aircraft is 12mm shorter than the ‘typical’ configuration for an engine when installed on other aircraft types.
Gippsland SB-GA8-2011-64 specifies repeat inspections of the spring-loaded throttle and mixture levers to ensure movement to a position for safe flight if the control cables become disconnected.
Operators and maintenance providers are advised to review the SB to ensure that the repetitive inspection requirements for correct spring function are incorporated into the aircraft maintenance schedule.
If any defects are found accomplish appropriate corrective actions before further flight. CAA requests that operators and maintenance providers report any defects found via the occurrence reporting process:
https://occurrencereporting.services.aviation.govt.nz(external link)
Gippsland SB-GA8-2011-64 Issue 2 dated 3 August 2012 provides the initial and repetitive inspection requirements for the spring tension on servo regulators.
The Gippsland SB is available at: SB-GA8-2011-64(external link)
