Alexandria, MN, USA
N8417A
Piper PA-34-220T
During landing rollout, the airplane veered off the snow-covered runway and impacted runway lights and a sign. The airplane's windshield had an 1/8-1/4 inch of ice accumulation. The pilot was issued a Center Weather Advisory (CWA) while en route to the destination airport. The CWA reported patchy severe mixed icing in clouds and precipitation with a chance of severe clear icing. The left and right side pilot windshields of a standard PA-34 were found to have rectangular areas of approximately 23 inches by 32 inches. The heated windshield plate area was approximately 3-1/2 inches by 7-1/2 inches.
On December 23, 1999, at 1210 central standard time, a PA-34-220T, N8417A, owned and piloted by an instrument rated private pilot, was substantially damaged during landing rollout on runway 31 (5,100 feet by 100 feet, asphalt/snow) at Chandler Field (AXN), Alexandria, Minnesota. Instrument meteorological conditions prevailed at the time of the accident. The pilot and two passengers reported no injuries. The 14 CFR Part 91 personal flight was operating on a instrument rules flight (IFR) plan. The flight originated from Fort Collins, Colorado, at 0710 mountain standard time, en route to AXN. In a written statement, the pilot reported the following. "At approx. 13Z I obtained a wx briefing from Den FSS and filed an IFR flight plan. The current conditions at AXN were snow and limited visibility. The forecast was for improving conditions. Area forecast included tops to 15K MSL and a chance of icing in the clouds. No reports of ice. I departed VFR and requested "flight following". At Valentine, NE I radioed in a pirep. Conditions had been much better than forecasted. With some clouds ahead, I activated my IFR flight plan. Given the "chance of ice in clouds", I climbed to 11,000' to stay clear. Turned out to be unnecessary. The clouds were thin and scattered. At Huron, SD I sent in another pirep. "Still VMC conditions." I was informed that conditions at AXN had improved substantially. Was also informed of a SIGMET for potential severe icing "eastern Dakota / most of Minnesota". Back on frequency, I requested 13,000 at Watertown, SD to avoid the cloud bank ahead. Assumed that must be the ice. Was cleared for descent and elected to maintain VMC on top until last opportunity to arrive at the IAF at approach altitude with a 1000 fpm descent. The ASOS report varied but, visibility ranged from 1 to 2 miles; ceiling 1000 to 2000 feet. Wind: 250 at 7. Started down from 12,000' and had "ground in sight" at 6000' MSL. Continued descent to 3500'. Picked up light ice on the descent; about 1/8" on the wing's leading edge. Under the clouds, I was getting little drops of liquid precip sticking to the windshield. OAT 20-25F Visibility was 1 to 2 miles. The DME ARC to the NDB 31 approach is a bit lengthy, but from my present position, the full approach was about the shortest route to the airport. The dots continued to accumulate. I stuck my hand over the defroster outlet to see that it was blowing warm air. It was. I also cycled the power on the windshield hot plate observing the ammeters to ascertain that it was drawing power. An substantial deflection on both ammeters verified the plate was drawing power. The dots on the hot plate were sliding up the plate, but jamming at the top edge. When I arrived at the airport, that jam had backed down two thirds of the way leaving me with an obscured view out the plexiglass and the bottom 1/3 of the hot plate clear. At first I couldn't identify the airport. It was completely buried in a very smooth even layer of snow. Too late to land, I identified rwy 31 as "that space between the two rows of dots" (runway lights) in the snow. I announced a go around and circled over to see it rwy 4-22 might be a better option. It was the same. My pattern brought me back to the threshold of 31 too high to land, so I announced another go around. This time I flew a standard left down wind, base, 1/2 mile final and lined up on the sequenced flasher and VASI through the bottom quarter of the hot plate. I touched down on the runway between the VASI lights and rolled out aiming for the far end runway lights through that clear spot at the bottom of the hot plate. However, when the nose settled down, my view to the side window to try to identify the runway edge. Nothing, but white. I saw one runway light go by, but could not determine my direction from that single point. Looking forward again, I saw the intersection marker 50 feet ahead. I pulled back on the yoke and pressed on the right rudder pedal. Too late. I watched the nose wheel knock the sign from its mount and into the right prop. The prop kicked it back under the plane where it rolled and did considerable damage to the right wing spar, fuselage bottom and right stabilator edge. The thump of hitting the sign bounced the hot plate and most of the ice departed. I could now steer back on to the runway and taxied to the tiedown area." A witness reported that at the time of the accident, there was light freezing drizzle and ice pellets. The ice pellets were more predominant than the freezing drizzle. Cloud conditions were 700 agl overcast with 2-1/2 mi visibility in snow. The runway was in good shape and had a covering of snow. The black surface of the runway was visible through the snow layer covering the runway. The witness added that during landing, the accident aircraft was coming in "hot". It had touched down nearly on the centerline of the runway and then veered off approximately 1/3 down the runway and then returned back to the runway. After the aircraft's first approach, the witness noticed the pilot had not turned the runway lights on, so the witness turned the runway lights on "high". The witness stated that the runway lights were working. The witness described the accident aircraft as having 1/4-3/8 inch of mixed ice on the nose cone and 1/8-1/4 inch of ice on the windshield with ice accumulation around the lip of the ice plate. The witness stated that the hot plate was pretty much cleared of ice except along the edge lip of the hot plate. The spinner was full of ice along with the antennas which appeared to be intact. The witness also reported that a Beech King Air landed after the accident aircraft, at approximately 1230-1300, and had accumulated about 1/2 inch of ice. Center Weather Advisory (CWA) 101 stated the following: "ZMP1 CWA 231620 ZMP CWA 101 VALID UNTIL 231820 FROM 50W INL TO ODI TO FOD TO 75NW GFK WDSPRD LGT TO MOD RIME/MXD ICG 090-170 WITH PTCHY SVR MXD ICGIC PATCHY FRZG RAIN WITH CHC SVR CLR ICG BLO 040 WEST END OF AREA CONDS XPCD TO CONT BYND 18Z" A plot of CWA 101 area is attached to this report. Advisory Circular 00-45D, Aviation Weather Services, lists in Table 15-1, Icing intensities, airframe ice accumulation, and pilot report. "Light" intensity, next to the column "Airframe ice accumulation" states, "The rate of accumulation may create a problem if flight is prolonged in this environment (over one hour). Occasional use of deicing/anti-icing equipment removes/prevents accumulation. It does not present a problem if the deicing/antiicing equipment is used". "Moderate" intensity "Airframe ice accumulation" states, "The rate of accumulation is such that even short encounters become potentially hazardous and use of deicing/antiicing equipment or diversion is necessary". "Severe" intensity "Airframe ice accumulation" states, The rate of accumulation is such that deicing/anti-icing equipment fails to reduce or control the hazard. Immediate diversion is necessary". The aircraft departed off to the side of runway 31 during its rollout and damaged two runway lights and the runway 4-22 hold short sign. The left and right side pilot windshields of a standard PA-34 were found to have rectangular areas of approximately 23 inches by 32 inches. The heated windshield plate area was approximately 3-1/2 inches by 7-1/2 inches.
The pilot's inadequate inflight decision to continue flight into icing conditions. An additional cause was the directional control not maintained by the pilot. Contributing factors were the viewable area of the aircraft's heated windshield panel, in-flight icing conditions, the snow covered runway, haze, runway edge lights and the runway sign.
Source: NTSB Aviation Accident Database
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