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Upset incidents lead EASA to issue emergency AD on CitationJets with active winglets
23 April 2019

The European Union Aviation Safety Agency (EASA) issued an emergency airworthiness directive (2019-0086-E) in the wake of recent in-flight upset incidents involving Cessna CitationJets, modified to have Tamarack ATLAS winglets.

The active load alleviation system (ATLAS), when operational, deflects the Tamarack active control surfaces (TACS) on the outboard wings. This system can aerodynamically “turn off” the winglet in specific conditions, thus dumping additional loads. Load alleviation enables a substantial increase in aspect ratio without the need for wing reinforcement and added weight, according to Tamarack. The modification is available for Cessna CitationJet models.

Recently, occurrences have been reported in which ATLAS appears to have malfunctioned, causing upset events where, in some cases, the pilots had difficulty to recover the aircraft to safe flight. Investigation continues to determine the cause(s) for the reported events. This condition, if not corrected, could lead to loss of control of the aircraft, EASA states.

The AD issued by EASA requires the Tamarack ATLAS to be deactivated and the TACS to be fixed in place. It also requires implementation of operational limitations and repetitive pre-flight inspections by amending the applicable flight manual.

Within 100 flight hours, owners must contact the ATLAS-manufacturer for modification instructions.

Update 11 July 2019
Both EASA and the FAA approved fixes incorporated in two Tamarack Aerospace service bulletins to resolve the emergency airworthiness directive that required deactivating Tamarack’s active load-alleviation system (ATLAS) on Cessna CitationJets.