What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
On the morning of 03/02/2016, BE-99, N198WA, was enroute on flight #WIG1090 from mht to rkd with only the pilot onboard. She was in the clouds, on descent for the ILS approach into rkd and she was encountering continuous light to moderate turbulence. At slightly below 2000 feet altitude, airspeed 130 knots, she experienced severe turbulence which made her momentarily lose control of the aircraft. She regained control and executed a missed approach while still encountering moderate turbulence. She decided not to attempt another approach and diverted to bgr. She continued to have light to moderate turbulence enroute to bgr. She made a safe landing at bgr and entered the severe turbulence encounter in the aircraft log book. She also contacted wiggins flight control and maintenance control. The Maine aero repair station was contacted by maintenance control and asked to do a severe turbulence inspection. The mechanic immediately noted and reported the fuselage side skins and top skin on the wings were obviously deformed. Wiggins grounded the aircraft.
Subsequent inspection revealed the following:
1. Significant top skin deformation, right wing root between fuselage and nacelle just aft of main spar.
2. Right wing root to fuselage fillet fairing was also damaged just aft of main spar.
3. Significant skin deformation right side of fuselage just above right wing root.
4. Moderate skin deformation on top of right horizontal stabilizer.
5. Moderate top skin deformation, left wing root between fuselage and nacelle just aft of main spar.
6. Moderate to light skin deformation left side of fuselage above left wing root.
7. Light top skin deformation on outboard right wing just forward of right aileron.
8. Slight evidence of light top skin deformation on outboard left wing.
Note: some of the lighter skin deformation may be the result of normal wear and tear (aging) and not directly related to this turbulence encounter.
Aircraft manufactured in 1970 / total time 13,350+ hours / total cycles 16194+.
We were initially advised that immediately after the missed approach, the pilot had to use full left aileron trim to maintain control. When we interviewed the pilot over the phone we asked about the left aileron trim. The pilot said she was going back and forth, using both left and right aileron trim to find the ?happy place?. She did say that the aircraft seemed to fly differently than it did prior to the severe turbulence.
As the FAA filed it
ON THE MORNING OF 03/02/2016, BE-99, N198WA, WAS ENROUTE ON FLIGHT #WIG1090 FROM MHT TO RKD WITH ONLY THE PILOT ONBOARD. SHE WAS IN THE CLOUDS, ON DESCENT FOR THE ILS APPROACH INTO RKD AND SHE WAS ENCOUNTERING CONTINUOUS LIGHT TO MODERATE TURBULENCE. AT SLIGHTLY BELOW 2000 FEET ALTITUDE, AIRSPEED 130 KNOTS, SHE EXPERIENCED SEVERE TURBULENCE WHICH MADE HER MOMENTARILY LOSE CONTROL OF THE AIRCRAFT. SHE REGAINED CONTROL AND EXECUTED A MISSED APPROACH WHILE STILL ENCOUNTERING MODERATE TURBULENCE. SHE DECIDED NOT TO ATTEMPT ANOTHER APPROACH AND DIVERTED TO BGR. SHE CONTINUED TO HAVE LIGHT TO MODERATE TURBULENCE ENROUTE TO BGR. SHE MADE A SAFE LANDING AT BGR AND ENTERED THE SEVERE TURBULENCE ENCOUNTER IN THE AIRCRAFT LOG BOOK. SHE ALSO CONTACTED WIGGINS FLIGHT CONTROL AND MAINTENANCE CONTROL. THE MAINE AERO REPAIR STATION WAS CONTACTED BY MAINTENANCE CONTROL AND ASKED TO DO A SEVERE TURBULENCE INSPECTION. THE MECHANIC IMMEDIATELY NOTED AND REPORTED THE FUSELAGE SIDE SKINS AND TOP SKIN ON THE WINGS WERE OBVIOUSLY DEFORMED. WIGGINS GROUNDED THE AIRCRAFT.
SUBSEQUENT INSPECTION REVEALED THE FOLLOWING:
1. SIGNIFICANT TOP SKIN DEFORMATION, RIGHT WING ROOT BETWEEN FUSELAGE AND NACELLE JUST AFT OF MAIN SPAR.
2. RIGHT WING ROOT TO FUSELAGE FILLET FAIRING WAS ALSO DAMAGED JUST AFT OF MAIN SPAR.
3. SIGNIFICANT SKIN DEFORMATION RIGHT SIDE OF FUSELAGE JUST ABOVE RIGHT WING ROOT.
4. MODERATE SKIN DEFORMATION ON TOP OF RIGHT HORIZONTAL STABILIZER.
5. MODERATE TOP SKIN DEFORMATION, LEFT WING ROOT BETWEEN FUSELAGE AND NACELLE JUST AFT OF MAIN SPAR.
6. MODERATE TO LIGHT SKIN DEFORMATION LEFT SIDE OF FUSELAGE ABOVE LEFT WING ROOT.
7. LIGHT TOP SKIN DEFORMATION ON OUTBOARD RIGHT WING JUST FORWARD OF RIGHT AILERON.
8. SLIGHT EVIDENCE OF LIGHT TOP SKIN DEFORMATION ON OUTBOARD LEFT WING.
NOTE: SOME OF THE LIGHTER SKIN DEFORMATION MAY BE THE RESULT OF NORMAL WEAR AND TEAR (AGING) AND NOT DIRECTLY RELATED TO THIS TURBULENCE ENCOUNTER.
AIRCRAFT MANUFACTURED IN 1970 / TOTAL TIME 13,350+ HOURS / TOTAL CYCLES 16194+.
WE WERE INITIALLY ADVISED THAT IMMEDIATELY AFTER THE MISSED APPROACH, THE PILOT HAD TO USE FULL LEFT AILERON TRIM TO MAINTAIN CONTROL. WHEN WE INTERVIEWED THE PILOT OVER THE PHONE WE ASKED ABOUT THE LEFT AILERON TRIM. THE PILOT SAID SHE WAS GOING BACK AND FORTH, USING BOTH LEFT AND RIGHT AILERON TRIM TO FIND THE ?HAPPY PLACE?. SHE DID SAY THAT THE AIRCRAFT SEEMED TO FLY DIFFERENTLY THAN IT DID PRIOR TO THE SEVERE TURBULENCE.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.