Factual Report: Caravan encountered wind shear

 - December 14, 2007, 6:11 AM

CESSNA CARAVAN 208B, ROCKFORD, ILL., DEC. 17, 2002–At 10:51 p.m., Caravan N277PM crashed while on the ILS approach to Runway 7 at the Greater Rockford Airport (RFD). The pilot was killed and the airplane was destroyed. The Part 135 nonscheduled flight, operated by Planemasters as Flight 1627, was transporting cargo for UPS and was operating in IMC on an IFR flight plan, from Decatur Airport (DEC), Ill.

At 10:30:47 p.m., the pilot contacted RFD approach and was given the ILS Runway 7 approach. After PMS1627 contacted the tower, the local controller gave the wind as 140 degrees at 18 knots and cleared the turboprop single to land. The pilot’s acknowledgment of this transmission was his last contact.

At 10:57 p.m., the Winnebago County Sheriff’s department received a report of the airplane crash. The witness lives approximately a half mile north of the accident site. He heard the airplane fly over at a “mid-throttle” power setting, then a sound like an airplane “falling” before the engine sound increased “when the pilot throttled it.” At the time of impact, the witness reported “severe winds, mostly from the south, shifting volatile directly from the east,” with “extremely poor” visibility.

The weather at RFD was wind 110 degrees at 17 knots, gusting to 20 knots; visibility 1.25 miles in light rain and mist; and 300 feet overcast. Temperature was 2 degrees C and dew point was -1 degree C. A band of southerly low-level wind of 40 knots was in the vicinity of the accident site and nearby station models indicated wind from the south at 30 to 40 knots, which resulted in an approximate 90-degree shift from the surface winds north of the warm front. The National Weather Service radar chart showed very strong (VIP 3 to 4) echoes of thunderstorms and rainshowers, with several embedded areas of intense to extreme-intensity (VIP 5 to 6) echoes in the vicinity.

Other flight crews who landed around the time of the accident did not report icing conditions, but they noted a strong crosswind while on the glideslope and airspeed fluctuations of up to ±10 knots, a low ceiling, turbulence and visibility less than one mile.