# Accident 20170905015899A: Cobalt Aircraft Ind, Inc CO50, Atwater, CA, September 5, 2017 - Type: FAA accident report (Accident/Incident Data System), as reported - Date: September 5, 2017, 14:05 local time - Place: Atwater, CA - Airport: Castle Airport - Damage: Substantial damage - Phase of flight: Landing: Touchdown - Operating rules: General operating rules (Part 91) - Location: 37.3758° N, 120.5731° W: From the FAA - Nearby events: https://openairdocs.org/map.md?lat=37.3758&lon=-120.5731&mi=10 - Aircraft: N523CA, a cancelled registration (https://openairdocs.org/deregistered/N523CA-2020-02-03) (OpenAirDocs) - Registry model: Cobalt Aircraft Industries VALKYRIE (registry code 05635N6, https://openairdocs.org/model/cobalt-aircraft-industries-valkyrie) (OpenAirDocs) - Registry engine: Continental TSIOF550-D (registry code 17415, https://openairdocs.org/engine/continental-tsiof550-d) (OpenAirDocs) - Reported make and model: COBALT AIRCRAFT IND, INC CO50 - Reported engine: TCM TSIOF550-D - People aboard: 1 - Fatal injuries: 0 - Other injuries: 0 - Pilot certificates: Airline transport, flight instructor - Pilot flight hours: 9,455 total, 2 in this make and model, 5 in the last 90 days - NTSB investigation: [NTSB WPR17LA201](https://openairdocs.org/ntsb/WPR17LA201) (OpenAirDocs) - FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/) - Page: https://openairdocs.org/incident/20170905015899A ## Narrative As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^. THIS HARD LANDING ACCIDENT OCCURRED DURING AN UNDECLARED EMERGENCY LANDING THAT OCCURED AT THE CONCLUSION OF THE FIRST FLIGHT OF THIS SECOND PROTOTYPE COBALT CO50 VALKYRIE CARBON FIBER AIRCRAFT S/N PE04, AND ON THE FIRST FLIGHT IN THIS AIRCRAFT BY THIS PILOT. UPON INITIAL LIFTOFF, DIRECTLY INTO A 7 KT HEADWIND FROM RW 31, A 300 FT X 12000 RUNWAY, THE HIGHLY EXPERIENCED TEST PILOT OF THIS EXPERIMENTAL R&D AIRCRAFT EXPERIENCED UN COMMANDED ROLL, PITCH AND YAW; BUFFETING OF THE AIRFRAME, AND SUBSTANTIAL UN RESPONSIVENESS OF THE FLIGHT CONTROLS. THE PILOT ELECTED TO CONTINUE THE FLIGHT, DESPITE THE AVAILABILITY OF NEARLY 10,000 FEET OF RUNWAY AVAILABLE AHEAD OF THE AIRCRAFT, AND FLEW IN THE VICINITY OF THE AIRPORT FOR A SHORT WHILE, ASSESSING THE FLIGHT CONTROL UNRESPONSIVENESS AND UN COMMANDED ROLL, PITCH AND YAW. THE PIC LET THE ATC TOWER KNOW HE HAD SUCH CONTROLABILITY ISSUES. ATC QUERIED THE PILOT IF HE WANTED TO DECLARE AN EMERGENCY AND WANTED THE EMERGENCY EQUIPMENT, WHICH THE PILOT DECLINED. THE PILOT FOUND THAT THESE FLIGHT CONTROL AND HANDLING ISSUES DID NOT IMPROVE, AND ONLY WORSENED, AS SPEED WAS REDUCED. IT IS ALSO NOTED THAT THE AIRCRAFT WAS EQUIPPED WITH A BALLISTIC RECOVERY PARACHUTE SYSTEM, WHICH THE PILOT ELECTED TO NOT USE. HE ELECTED TO RETURN FOR LANDING ON THE SAME RW 31, CARRYING EXCESS SPEED IN AN EFFORT TO MINIMIZE THE DEFICIENCIES IN THE FLIGHT CONTROL EFFECTIVENESS. THE AIRCRAFT CONTINUED TO EXPERIENCE THE UN COMMANDED MOVEMENTS AND REDUCED FLIGHT CONTROL RESPONSIVENESS ALL THE WAY TO TOUCHDOWN, RESULTING IN A HIGH FLARE, RESULTANT HIGH SINK RATE, AND HARD LANDING ON THE LEFT GEAR FOLLOWED BY THE RIGHT GEAR, THEN NOSE GEAR. THE RIGHT WHEEL, BRAKE AND LOWER STRUT BROKE AWAY UPON CONTACT WITH THE RUNWAY, RESULTING IN A SEVERE RIGHT YAW FROM THE UPPER STRUT HOUSING GRINDING ON THE PAVEMENT. THE LEFT WHEEL, BRAKE AND LOWER STRUT ASSEMBLY THEN SEPARATED DUE TO THE SIDE LOADING, RESULTING IN THE AIRCRAFT SLIDING BACKWARD TO A STOP WITH BOTH UPPER STRUTS GRINDING ON THE RUNWAY SURFACE, FACING 180 DEGREES TO THE LANDING DIRECTION. THE PROPELLER, LEFT WING TIP AND LOWER STRAKE CONTACTED THE PAVEMENT. THE PILOT WAS NOT INJURED, AND EXITED THE AIRCRAFT AFTER SECURING THE COCKPIT. EMERGENCY EQUIPMENT ARRIVED SOMETIME LATER. -EXAMINATION OF THE AIRCRAFT AFTER THE ACCIDENT REVEALED INDICATIONS OF MAIN SPAR CRACKING AND DELAMINATION OF THE CARBON FIBER PLIES INBOARD OF THE RIGHT AFT LANDING GEAR TRUNNION ATTACHMENT TO THE RIGHT WING SPAR. -BOTH MAIN UPPER STRUTS, THE AFT LOWER VERTICAL STRAKE WERE DAMAGES BADLY BY CONTACT WITH THEW RUNWAY SURFACE. THE LEFT WINGLET AND LEFT AILERON LOWER SKINS WERE SLIGHTLY ABRADED BY RUNWAY CONTACT, AND THE PROPELLER TIPS WERE BENT FROM CONTACT AS WELL. -THE RIGHT GEAR WELL'S TEMPORARY SHEET METAL AND ALUMINUM TAPE CLOSEOUT PANEL WAS SLIGHTLY DISLODGED, AND THE ADJACENT LOWER WING SKINS HAD SMALL PUNCTURES FROM IMPACTS OF THE SEPARATED RIGHT MAIM WHEEL AND BRAKE ASSEMBLY. -ALL FLIGHT PUSH PULL CONTROLS WERE FOUND CONNECTED, AND RUDDER CABLES ADEQUATELY TENSIONED. ## The NTSB's investigation of this event (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB WPR17LA201](https://openairdocs.org/ntsb/WPR17LA201), Sep 5, 2017: Cobalt Aircraft Industries Co50 Valkyrie (N523CA), Atwater, CA, substantial damage. Probable cause: A loss of aileron effectiveness due to the airplane's design configuration, which resulted in the pilot's inability to control the roll axis and led to a hard landing. From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.