Accident Overview
On January 8, 2016, about 0900 central standard time, a Cessna 441, registration N779CC, sustained substantial damage during a hard landing at Hector International Airport (FAR) in Fargo, North Dakota. The airline transport rated pilot, who was the sole occupant, was not injured. The airplane was owned and operated by Northern Meridian LLC under 14 Code of Federal Regulations Part 91 as a positioning flight. Instrument meteorological conditions prevailed, and an instrument flight rules flight plan was filed. The flight departed from Detroit Lakes Airport (DTL) in Detroit Lakes, Minnesota, about 0830 and was destined for FAR.
Flight History
The pilot reported that this was the first flight after a phase maintenance check and that he was positioning the airplane to FAR, about 40 nautical miles from DTL. After departure, he climbed to 4,000 feet above mean sea level (msl) and engaged the autopilot in preparation for landing at FAR. He stated that he heard a "thumping" in the left rudder pedal and noted a 20-degree angle of bank to the left on the attitude indicator. He disengaged the autopilot, rolled wings level, and started troubleshooting. Then the left fuel pressure low light illuminated. Thinking it was an indication problem, he switched to the left AUX pump and then back to the main pump, and the light went out.
The air traffic controller (ATC) cleared the flight to descend to 2,800 ft msl, but the pilot requested a climb to 5,000 ft msl to get out of icing conditions and "sort out the problems." During the climb, the pilot noticed a discontinuity message between the headings on the Avidyne Entegra flight displays. Once at 5,000 ft msl, the pilot engaged the autopilot, and the airplane made a 180-degree turn to the right. The pilot disengaged the autopilot again and turned back towards FAR. The left fuel pressure low light and the left X-FER pump fail light illuminated. The pilot declared an emergency, and ATC cleared the flight to descend to 2,800 ft msl and provided vectors for the ILS Runway 36 approach to FAR.
Approach and Landing
The pilot stated that as the airplane was descending through 4,000 ft msl, the left engine started to surge. He reported that the engine never failed during the flight, but he thought an engine failure was imminent. He programmed his flight instruments for the approach and activated the vectors to final, but the discontinuity message light illuminated again. He flew through the localizer of the ILS Runway 36 approach, and subsequently requested ATC to fly the RNAV (GPS) 32 approach instead. The pilot reported that about this time, the airplane was picking up ice accumulation and he cycled the deice boots. ATC vectored the airplane back to the southeast for the RNAV (GPS) 32 approach.
The airplane intercepted the final approach course for the RNAV (GPS) 32 approach and was cleared by ATC for the approach. The airplane broke out of the clouds about 600–700 ft above ground level (agl) at 120 knots and less than a mile from the runway, and the pilot lowered the landing gear. The pilot reported that before starting the flare, he closed the throttle, selected the last notch of flaps, and flared at 110 knots. He stated there was shaking and shuddering, but no stall warning horn, and then the "bottom fell out." The airplane landed hard, and the left propeller blades struck the runway. While taxiing to the ramp, the pilot noted that it was necessary to forcefully kick in the right rudder pedal to turn right.
Post-Accident Examination
The pilot conducted a post-accident examination of the airplane and stated that there was about 1/2 to 1 inch of rime ice accumulated on the leading edge surfaces of both wings. Photographs of the airplane on the ramp after the accident indicated that there was ice accumulated on the leading edge surfaces of the horizontal stabilizer and vertical stabilizer as well. The examination revealed substantial damage to the wing spar and damage to the left propeller blades from the propeller strike. The stall warning horn was tested on the ground and it operated.
Aircraft Information
The pilot stated that he normally enters the flare at 95 knots between 5–10 ft agl, holds the nose off, and the airplane typically floats onto the runway. The Cessna 441 Pilot Operating Handbook (POH) states that the stall speed for the airplane in the landing configuration at 9,360 lbs is 74 knots indicated airspeed. The POH also includes details about the deice boot system, which consists of pneumatic air operated boots on the leading edges of the wings and stabilizers. The system should be cycled when ice accumulates to between 1/4 to 1/2 inch. A note in the POH states: "Prestall buffet and stall speeds can increase when deice boots are actuated."
At 0853, the surface weather observation at FAR was: wind 340 degrees at 19 knots, 5 miles visibility, mist, overcast at 700 ft, temperature -7 degrees C, dew point -9 degrees C, altimeter 29.98 inches of mercury.