Thermawing System May Short-Circuit

The Federal Aviation Administration (FAA) and Australia's Civil Aviation Safety Authority (CASA) have issued airworthiness directives calling for the immediate deactivation of anti-icing systems installed on some Lancair Columbia (shown below) and Columbia Aircraft Manufacturing 400-series aircraft.

The AD's state the Kelly Aerospace Thermal Systems Thermawing Deice System installed on those aircraft could short-circuit where the deice heater connects to the copper lightning protection mesh embedded in the aircraft's composite structure.

CASA states incidents have occurred in the field where such electrical shorts have caused burning of the wings and horizontal stabilizer. The agency says those burns could damage the structural integrity of those surfaces.

The short circuit is caused by insufficient removal of copper mesh when the deice heater connectors were installed.

Both directives call for the system to be deactivated, and a placard placed in the cockpit labeled "DEICE SYSTEM INOPERABLE" to discourage pilots from entering conditions where they would use the system.

Columbia markets the anti-icing system as E-Vade.

Aero-News has been in touch with Columbia Aircraft, who is working on the issue in concert with Kelly Aerospace, the vendor who builds the Therma Wing system. Columbia notes that they are referenced in the title of the AD only because the Therma Wing kits are not serialized as the FAA requires for tracking purposes and to date, they have only been installed on Columbia Aircraft (which thereby become the serialized tracking element). Columbia also notes that, "naturally we regret the inconvenience to our customers but we feel confident that Kelly Aerospace will have a solution published quickly."

ANN will update the progress of this matter as details develop.

FMI: Read The FAA AD, Read The CASA AD