NTSB Finds “No Flight Control Anomalies”

On Thursday, 30 March 2023, a Cessna 525B CitationJet/M2 equipped with Tamarack Aerospace Group’s proprietary SMARTWING technology made a successful emergency landing at Tampa International Airport (TPA) after the aircraft’s left wing-tip—to include the SMARTWING winglet—separated in flight.

The National Transportation Safety Board’s preliminary report on the incident sets forth that the CitationJet was "substantially damaged" when the left winglet—along with the Tamarack active control surface designed to automatically limit airframe loads attributable to subject winglet—departed the aircraft during cruise descent into Fort Myers, Florida’s Page Field (FMY).

The 525B’s pilot—the aircraft’s sole occupant at the time of the incident—informed NTSB investigators that following a routine departure from Arkansas’s Walnut Ridge Regional Airport (ARG) and an uneventful cruise segment, he’d perceived two “big jolts” while descending through FL300 over the Gulf of Mexico. A subsequent uncommanded yawing of the aircraft compelled the pilot to check the cockpit instruments, which read normally. Visual inspection of the CitationJet’s wings proved less encouraging, however, as the pilot observed the aircraft’s left wingtip to be missing. Acting admirably in accordance with checklist procedures, the aviator promptly disengaged the CitationJet’s autopilot, declared an emergency, and commenced diverting to TPA, where he executed a successful emergency landing.

The pilot later stated the aircraft had handled remarkably well and remained readily controllable throughout the unscheduled descent, approach, and landing. However, when later interviewed by NTSB investigators, the pilot reported experiencing some “binding” of the aircraft’s ailerons on final approach.

Released on 05 April, the NTSB’s Preliminary Report on the incident reads in part: "The pilot performed an emergency landing at Tampa International Airport (TPA) Tampa, Florida, without issue. Furthermore, he (the pilot) stated that there were no flight control anomalies."

The final minutes of the damaged aircraft’s flight were recorded by an airborne news helicopter. The video depicts the CitationJet, sans left winglet, in a controlled, normal descent attitude. The aircraft’s landing gear is lowered and its flaps deployed. After an unremarkable landing within the touchdown-zone of TPA Runway 10 and a smooth roll-out, the CitationJet is seen to exit the runway via a high-speed taxiway and come to a controlled stop. Neither fire nor leakage of fuel or hydraulic-fluid is observable in the video. A TPA emergency vehicle comes into frame and attends the stopped aircraft—largely as a matter of protocol.

Post-flight examination of the CitationJet revealed the aircraft’s left wing extension and the left aileron had been substantially damaged in the event. The entirety of the 525B’s Tamarack winglet and Tamarack Active Camber Surfaces (TACS) were missing. The remaining components of the Tamarack system were documented and examined on the aircraft; no system anomalies were noted.

The aircraft has since been released to be repaired and returned to service. Repairs will be conducted by a Florida maintenance (MRO) facility.

Initial investigation of the incident indicated the winglet had functioned normally throughout the flight and likely separated from the CitationJet’s wing after being acted upon by an external cause—e.g., bird or lightning strike.

The NTSB’s investigation of the incident remains underway.

Tamarack Aerospace Group president Jacob Klinginsmith remarked: “We are obviously grateful that nobody was injured in this strange incident. We’re still investigating, but it appears that external factors caused the winglet to be ripped from the aircraft. Our certification and engineering process served this pilot very well because he was obviously able to control the airplane and make a very smooth approach and landing. During certification, we successfully flight tested a one winglet removed scenario simulating a bird-strike, lightning strike, or any other abnormal event to the winglet, so we would expect the plane to handle as well as the pilot described.”

Differing from conventional, passive winglets, Tamarack’s Performance SMARTWING technology automatically controls wing bending during turbulence and other inflight events by effectively “turning off the winglets”—thereby alleviating wing-loading. This is accomplished via load-sensors and a camber surface capable of responding to system inputs in fractions of a second. The Active Winglet/load-alleviation system is fully automatic, requires no pilot action, and functions independently of other aircraft systems. What’s more, installation of Tamarack’s Performance SMARTWING requires no aircraft structural reinforcement.

FMI: www.tamarackaero.com