History of Flight
On November 30, 2018, about 1353 central standard time, a Cessna 550, N941JM, departed controlled flight and impacted terrain while on approach at the Hector International Airport (FAR), Fargo, North Dakota. The pilot and one passenger were not injured, and nine passengers received minor injuries. The airplane sustained substantial damage. The airplane was registered to Slice of the 406 LLC and operated by the pilot under 14 CFR Part 91 as a business flight. Instrument meteorological conditions prevailed, and the flight operated on an instrument flight plan. The flight departed from Sloulin Field International Airport (ISN), Williston, North Dakota, about 1250 with FAR as the destination.
The pilot reported that after departure, the flight was cleared direct as filed. He obtained destination weather when 100 nautical miles (nm) and 30 nm from FAR. Air traffic control provided radar vectors to the inbound course for the FAR ILS RWY 18 approach and cleared the flight for the approach. He completed the approach checklist, activated the deicing equipment, and started a descent to 2,500 ft mean sea level (msl). The airplane was about 10 nm from FAR when it entered clouds at 3,100 ft msl at 160 kts. Ice started accumulating on the wings, so he activated the de-ice boots. While inbound from the final approach fix, he switched to tower frequency, maintained 140 kts, completed the landing checklist, and was cleared to land. He activated de-ice boots several times and slowed to 120 kts for final approach. The airplane exited clouds at 400 ft above ground level (agl), right of centerline with the airport and runway in sight. He turned off the autopilot and yaw damper, corrected left, and maintained 120 kts over the airport fence. At about 100 ft agl, the airplane pulled to the right. He applied left controls, but the airplane continued right. He applied power for a go-around, but the airplane landed in the grass just right of runway 18. He shut down engines, turned off the battery, and conducted an emergency evacuation through the main cabin door.
A witness observed from an office window facing the approach threshold for runway 18. He reported watching the airplane fall out of the sky, with wings slowly fluttering back and forth, recognizing an impending stall from 130 to 140 ft agl. The nose pitched up, then the right wing went down; he estimated the bank angle at possibly 80°.
Another witness saw the airplane on final approach over the runway threshold, looking odd. The airplane was 30–50 ft high, too high for flare. The nose rose and then leveled off, then rose again and wings started waffling, about to stall. The right wing dropped and hit the ground about 2 seconds later; estimated bank angle about 40°.
The passenger in the right cockpit seat reported ice on the windshield and the deicing boot on the right wing during approach in clouds. The approach was normal until near the ground when the tail started fish tailing. He saw the pilot push throttles forward, but the left wing climbed and the airplane pulled hard to the right, impacting on its right wing and then its belly.
The passenger on the couch behind the copilot's seat reported the airplane was in clouds for about 15 minutes, with ice forming on the windshield. When about to land, she saw the pilot holding the control wheel all the way toward him, arms shaking from pulling back so hard. The pilot said an expletive, and the airplane crashed seconds later.
Personnel Information
The 41-year-old pilot held a commercial pilot certificate with single-engine land, multi-engine land, and airplane instrument ratings. He held a second-class medical certificate issued July 12, 2018, with no limitations. He reported 1,513 total flight hours, 263 hours in a Cessna 550, and 432.9 total turbine hours. His logbook indicated he passed his commercial multi-engine check ride on July 31, 2016, with 479.1 hours. On May 11, 2017, he passed a check ride in a Cessna 550 with 1,071.8 hours, 69.6 turbojet, and 85.1 turboprop. On June 28, 2018, he passed the Pilot Proficiency Check (14 CFR 61.58) for single-pilot operation in a Cessna 550 with 1,420.5 hours, 257.5 turbojet, and 85.1 turboprop.
Single-pilot Exemption: The logbook entry for single-pilot exemption #9917 stated the pilot met requirements for FAA exemption No. 9917, received training, and completed the FAA Approved Training Course by VUE, Inc. The exemption allowed single-pilot operation of certain Cessna Citation airplanes. One requirement was at least 1,000 hours total flight time, including 50 hours night, 75 hours instrument (40 actual), and 500 hours PIC or SIC in turbine-powered airplanes. The pilot's logbook indicated less than 500 hours PIC or SIC in turbine aircraft, required to exercise the exemption.
Aircraft Information
The Cessna 550 is a low-wing airplane powered by two Pratt & Whitney Canada JT-15B-4 turbofan engines producing 2,500 lbs thrust each. It has straight wings with integral wet-wing fuel tanks, a conventional tail, and retractable tricycle landing gear. The accident airplane was manufactured in 1980, with seating capacity for seven passengers and two pilots, and a maximum gross weight of 13,500 lbs.
According to the Cessna Citation Model 500 Airplane Flight Manual (AFM), the airplane was originally certificated under 14 CFR Part 25, requiring a two-pilot crew. FAA later allowed exemptions, including VUE, Inc. No. 9917, for single-pilot operation.
A FAA inspector reported that in 1986, two regular forward-facing passenger seats were removed and replaced with a 3-person couch, installed without approved data. During the accident, the seat belt attachment cable for the mid and aft passenger failed during ground impact. The factory-installed toilet seat (and bench covering it) was a non-belted seat, not designed for use during takeoffs and landings. Its seat belt installation was not approved and did not meet Part 25 requirements.
During the accident flight, one passenger sat in the copilot's seat, five in originally installed cabin seats, three on the side-facing couch (right, front side of cabin), and one on the bench over the toilet seat in the rear. All passengers wore the provided seatbelts.
The AFM described stall warning: aerodynamic, aided by stall strips on each wing's inboard section, disrupting airflow and causing prestall buffet. The optional Teledyne Angle-of-Attack System supplement stated it could be used as a reference for approach speed (1.3 VS1).
Flaps: Three settings – UP, Takeoff and Approach (T.O. & APPR), and LAND. The Before Landing checklist required flaps extended to T.O. & APPR below 202 KIAS, and LAND below 176 KIAS. LAND position was required for all normal landings. The manual stated flaps could be extended to T.O. & APPR below 202 KIAS and LAND below 176 KIAS, and should be in LAND for all normal landings. After passing the instrument approach fix outbound or nearing the airport traffic area, airspeed should be reduced below 202 KIAS and flaps extended to APPR (15°). Approaching the final fix inbound (or downwind abeam), extend landing gear below 176 KIAS. At final descent, extend FULL flaps, establish vertical rate, and adjust power to maintain VREF to VREF + 10 KIAS. At a gross weight of 12,100 lbs, VREF was about 106 KIAS.
Ice Protection: The Cessna 550 had an anti-ice system for the windshield and a separate de-ice system using pneumatically expanding boots on wing and tail leading edges.
Meteorological Information
At 1353, FAR reported wind from 200° at 10 knots, visibility 5 statute miles, mist, ceiling overcast at 400 feet agl, temperature -1°C, dew point -1°C, altimeter 29.91 inches of mercury. Remarks: station with precipitation discriminator, sea level pressure 1014.2 hPa, temperature -1.1°C, dew point -1.1°C.
The Terminal Aerodrome Forecast (TAF) issued at 1133 CST for FAR forecasted for the accident time: variable wind at 6 knots, visibility 5 statute miles, mist, ceiling overcast at 300 feet agl.
At 0845 CST, an AIRMET ZULU was issued for moderate icing below 10,000 feet. Images from the National Center for Atmospheric Research showed the Current Icing Potential (CIP) and Forecast Icing Potential (FIP) valid between 1300 and 1400 CST, indicating a 60% to 70% chance of light icing below 3,000 ft msl in the vicinity. About 30 minutes after the accident, a pilot of a Citation Excel at 3,000 ft and close to FAR reported overcast skies and moderate rime ice with a temperature of -2°C.
Flight Recorders
Multiple Electronic Devices: The NTSB Vehicle Recorders Division examined a Sandel ST3400 Terrain Awareness Warning System, Honeywell KLM 900, and Garmin AT MX20 Chart View. Data downloaded did not have pertinent data concerning the accident airplane while flying the ILS RWY 18 approach.
Cockpit Voice Recorder (CVR): The airplane was equipped with a Fairchild GA-100 CVR recording 30 minutes of analog audio on continuous loop tape. The magnetic tape was successfully read out. A summary indicated the pilot did not verbalize approach and landing checklist responses. About 45 seconds after ATC instructed switching to tower frequency and cleared landing on runway 18, the CVR recorded a sound consistent with landing gear extension and a voice stating "all green." The pilot responded "check, check, check," followed by "outer marker, four miles." No other indication of verbalized checklist items or audible comments about activating de-ice boots or windshield anti-ice.
Flight Data Recorder: The airplane was not equipped, nor required to be, with a flight data recorder.
Wreckage and Impact Information
The accident site examination revealed the right wingtip impacted the right edge of runway 18. After initial impact, the airplane bounced and skidded on the grass infield for about 635 ft before stopping on its belly. No ground fire. Immediately after accident, about ½ to 1 inch of mixed ice was found on the leading edge of the right wing, vertical stabilizer, horizontal stabilizer, and angle-of-attack (AOA) probe. Ice was also observed on the windshield. Ice accretion on the vertical stabilizer leading edge was the same size and shape on de-icing boots as on unprotected surfaces.
Initial examination showed the right wing's outboard section pushed up and aft. The nose wheel landing gear assembly bent right, trunnion broken in two pieces; nose wheel separated from fuselage with part of trunnion attached. Left main landing gear folded into the wheel well, components pushed upwards through upper wing surface. Left and right pitot tubes on the nose broken. The AOA probe on the right side of fuselage was intact, but its heat element operation could not be verified. Wing flaps were found in the up (0.0 degrees) position. Limited damage to bottom surface or trailing edge of flaps consistent with UP position. Cockpit flap handle was in LAND (down) position, but flap indicator was in UP position.
FAA inspectors verified flap position via cable and drive chain; number of chain links confirmed flaps were full up at time of accident. Both primary and secondary cables for left and right flaps were in same position, with no signs of damage. Flap indicator cable continuity was confirmed.
Tests and Research Information
NTSB Radar Performance Study: The NTSB Vehicle Performance Division conducted a radar performance study. Radar track data indicated the airplane approached FAR from the west, receiving vectors to capture ILS signal for runway 18. The airplane encountered icing conditions for about 9–10 minutes while flying the ILS approach. During the last 2 minutes on final approach, indicated airspeed was as low as 99 kts. The last radar return recorded 104 kts at 900 ft msl, same as touchdown zone elevation for runway 18.
The study included a simulation matching altitude and position data from radar. The simulation indicated that during the last 2 minutes, angle-of-attack (AOA) approached angles very close to stall AOA, and momentarily exceeded the linear portion of the Cessna 550 "no-ice" lift curve with flaps retracted. When lift coefficient was reduced by 5% to model ice accretions, the AOA with lift reduction was consistently into the non-linear portion of the no-ice lift curve for the last 30 seconds.
Additional Information
Operational Control: FAA inspectors interviewed passengers to determine operational control. The passenger who made flight arrangements reported contacting the pilot via text and making all arrangements. The pilot was responsible for operation, including fuel, maintenance, pilot qualifications, and weather. The pilot was the single source provider for the flight. The passenger was not informed it was a charter flight or that there was a separate lease for airplane and pilot services. The passenger stated he would be billed for the flight and then sub-bill the cost to other parties.