Flight History
On February 19, 2012, at 1525 mountain standard time, a Cessna 414A airplane, N4772A, impacted terrain at the Yampa Valley Airport (KHDN), Hayden, Colorado. The commercial pilot and one passenger were fatally injured, and four passengers were seriously injured. The airplane was substantially damaged. The flight was operated under 14 Code of Federal Regulations Part 91 as a personal flight, departing Dalhart Municipal Airport (KDHT), Dalhart, Texas, at approximately 1415 central standard time. Instrument meteorological conditions developed during the flight, which operated on an instrument flight rules flight plan.
Air traffic control communications indicated the pilot was cleared for the instrument landing system (ILS) approach to runway 10 via the initial approach fix REVME. Airfield personnel, who provided enhanced UNICOM service, heard the pilot report final approach. The pilot acknowledged the airport lights being set to high. No distress call was reported. A passenger (the airplane owner) stated that the pilot made two left turning circles and began a third when the airplane "just stalled" and fell straight down. He later recalled hearing a loud "pop" or "bang" from the right side just before the crash, and the pilot looked to the right and reached toward the throttle console.
Pilot Information
The 75-year-old pilot held a commercial pilot certificate with ratings for single-engine land, multi-engine land, single-engine sea, instrument airplane, and gliders, as well as a flight instructor certificate for several categories. He was also an airframe and power-plant mechanic who performed some maintenance on the accident airplane. His most recent second-class medical certificate, issued March 31, 2011, required corrective lenses. His previous flight review was on October 27, 2011, in the same make and model.
Aircraft Information
The Cessna 414A, serial number 414A005, manufactured in 1978, was a two-engine, low-wing, eight-seat airplane powered by two 310-horsepower Continental Motors TSIO-520-NB engines driving three-bladed, variable-pitch McCauley propellers. The most recent annual inspection was completed December 8, 2011, at a total airframe time of 8,245 hours. The left engine had 2,028.9 hours since major overhaul; the right engine had 901.6 hours. The tachometer at the accident site read 2,833.9 hours. The published stall speed is 70 knots.
Meteorological Conditions
At 1515, an automated weather reporting facility at KHDN reported wind from 310° at 8 knots, 5 miles visibility, few clouds at 800 feet, scattered clouds at 1,700 feet, broken ceiling at 2,900 feet, temperature -1°C, dew point -3°C, and barometric pressure 29.62 inches of mercury. By 1535, conditions deteriorated to wind from 290° at 10 knots gusting to 14 knots, visibility 1/4 mile, overcast ceiling at 400 feet, temperature -2°C, dew point -3°C. Conditions were favorable for heavy snow. A front passed over the airfield between 1430 and 1445, shifting wind from east to west and lowering ceiling and visibility. Several AIRMETs were active for IFR conditions, mountain obscuration, moderate turbulence, and moderate icing.
Navigation and Communications
The pilot flew the ILS approach to runway 10, with an inbound course of 104°, initial approach fix REVME at 15 nautical miles, final approach fix INEDE at 8.1 nautical miles, and a decision height of 7,371 feet msl (weather requirement: 800-foot ceiling, 2 3/4 miles visibility). Radar audio showed the pilot requested a visual approach if ceiling exceeded 1,000 feet, but accepted an IFR clearance after being told a previous aircraft broke out at minimum altitude. The airport is non-towered; UNICOM advisories were provided by ARFF.
Wreckage and Impact Information
The accident site was 95 yards south-southwest of runway 10, with a debris path aligned on a 090° heading. The main wreckage came to rest facing 320°. The fuselage showed buckling and crushing. Left and right wing damage was nearly symmetric. Elevator counterweights separated downward. All major components were present. Flight control continuity was established. Flaps and landing gear were retracted. Electric anti-ice and propeller anti-ice were off. No preimpact airframe anomalies were found. Both engines were test run and operated normally throughout their power ranges without preimpact anomalies.
Medical and Pathological Information
An autopsy noted the pilot had severe coronary artery narrowing (>90% in the right coronary artery with recanalization), severe cardiomegaly (570 grams), and myocardial fibrosis of the left ventricle. Forensic toxicology was negative for carbon monoxide, cyanide, ethanol, and drugs.
Additional Information
A Garmin GPSmap 295 recovered from the cockpit showed the airplane turned inside the initial approach fix, crossed through the approach course several times, crossed INEDE 260 feet below the published altitude, and was consistently below glide slope. At 1523:25, the airplane reached decision height (7,331 feet msl) while below glide slope and drifting right of the localizer course, three miles from the airport. It continued descending to 6,591 feet msl, then climbed to 6,824 feet with groundspeed decreasing to 78 knots before descending toward terrain.