Denver-Centennial

The pilot reported to Denver Air Route Traffic Control Center (ZDV) that his left engine had an oil leak and he requested to land at the nearest airport. ZDV informed the pilot that Akron (AKO) was the closest airport and subsequently cleared the pilot to AKO. On reporting having the airport in sight ZDV terminated radar service, told the pilot to change to the advisory frequency, and reminded him to close his flight plan. Approximately 17 minutes later, ZDV contacted Denver FSS to inquire if the airplane had landed at AKO. Flight Service had not heard from the pilot, and began a search. Approximately 13 minutes later, the local sheriff found the airplane off of the airport. Witnesses on the ground reported seeing the airplane flying westbound. They then saw the airplane suddenly pitch nose down, "spiral two times, and crash." The airplane exploded on impact and was consumed by fire. An examination of the airplane's left engine showed the number 2 and 3 rods were fractured at the journals. The number 2 and 3 pistons were heavily spalded. The engine case halves were fretted at the seam and through bolts. All 6 cylinders showed fretting between the bases and the case at the connecting bolts. The outside of the engine case showed heat and oil discoloration. The airplane's right engine showed similar fretting at the case halves and cylinder bases, and evidence of oil seepage around the seals. It also showed heat and oil discoloration. An examination of the propellers showed that both propellers were at or near low pitch at the time of the accident. The examination also showed evidence the right propeller was being operated under power at impact, and the left propeller was operating under conditions of low or no power at impact. According to the propeller manufacturer, in a sudden engine seizure event, the propeller is below the propeller lock latch rpm. In this situation, the propeller cannot be feathered. Repair station records showed the airplane had been brought in several times for left engine oil leaks. One record showed a 3/4 inch crack found at one of the case half bolts beneath the induction manifold, was repaired by retorquing the case halves and sealing the seam with an unapproved resin. Records also showed the station washed the engine and cowling as the repair action for another oil leak.

The pilot was flying a three leg IFR cross-country, and was on an ILS approach in IMC weather conditions for his final stop. Radar data indicated that the pilot had crossed the final approach fix inbound and was approximately 3 nm from the runway threshold when he transmitted that he had "lost an engine." Radar data indicates that the airplane turned left approximately 180 degrees, and radar contact was lost. A witness said "the airplane appeared to gain a slight amount of altitude before banking sharply to the left and nose diving into the ground just over the crest of the hill." Postimpact fuel consumption calculations suggest that there should have been 50 to 60 gallons of fuel onboard at the time of the accident. Displaced rubber O-ring seals on two Rulon seals in the left fuel valve and hydraulic pressure/deflection tests performed on an exemplar fuel valve suggest that the fuel selector valve was in the auxiliary position at the time of impact. The airplane's Owner's Manual states: "The fuel selector valve handles should be turned to LEFT MAIN for the left engine and RIGHT MAIN for the right engine, during takeoff, landing, and all emergency operations." No preimpact engine or airframe anomalies, which might have affected the airplane's performance, were identified.

The airplane was fueled to capacity and placed in a heated hangar about one hour before departure. The instrument rated pilot obtained a weather briefing, filed an IFR flight plan, and obtained an IFR clearance. Low ceiling, reduced visibility, and ice fog prevented control tower personnel from observing the takeoff. Radar (NTAP) and on-board GPS data indicated the airplane began drifting to the left of runway centerline almost immediately after takeoff. The airplane made a climbing left turn, achieving a maximum altitude of 7,072 feet and completing 217 degrees of turn, before beginning a descending left turn. The airplane impacted terrain on airport property. Autopsy/toxicology protocols were unremarkable. There was no evidence of preimpact failure/malfunction of the airframe, powerplant, propeller, or flight controls. The autopilot and servos, pitot-static system, and flight instruments were tested and all functioned satisfactorily. The pilot's shoulder harness was found attached to the seatbelt, but the male end of the seatbelt buckle was broken.

The purpose of the flight was for the instructor pilot to administer second-in-command (SIC) flight training to the commercial pilot in the twin-engine aircraft. According to the training manual, SIC training encompassed 4 hours of normal and emergency flight maneuvers to include stalls in the landing and takeoff configuration and while turning at a 15-30 degree bank. A witness heard the airplane's engines and observed the airplane from her driveway. The witness stated that as "the [engine] noise was getting louder and louder, I spotted it spiraling downward." The witness thought that the airplane was performing aerobatics; however, the airplane was getting too close to the ground. The witness heard a loud thud, and approximately 3 seconds later, she heard a loud boom and saw black smoke billow up. Another witness stated that she observed the airplane "going nose first straight down and spinning...counterclockwise." She thought the airplane was performing aerobatic maneuvers; however, the airplane did not stop descending. The airplane disappeared behind trees and the witness heard a loud explosion and saw smoke. She added that she did not observe what the airplane was doing prior to seeing it in a "downward spiral." Radar data depicted the airplane at 8,400 feet msl for the last 2 minutes and 26 seconds of the flight. The recorded aircraft ground speed during that time period fluctuated between 75 and 59 knots. The final radar returns depicted the airplane as making a 180 degree turn before radar contact was lost. No mayday calls were received from the airplane. The airplane impacted the ground in a near wings level attitude and was consumed by a post-crash fire. No anomalies were noted with the airplane or its engines during a post-accident examination. It is unknown which of the pilots was flying the airplane at the time of the accident.

The aircraft crashed on the side of a mountain during visual meteorological conditions. The pilot had been in voice and radar contact with air traffic control until the aircraft disappeared from radar. The pilot reported severe turbulence and a rough running engine to ATC as he was nearing a mountain pass. The pilot stated that he thought the rough running engine was due to fuel contamination. A witness reported that the pilot had said the fuel had contained a lot of water. The pilot reported to ATC that he had just lost the engine and he was attempting to make it through a saddle. A sigmet had been issued for that region and the severe turbulence was confirmed by another pilot. Engine teardown revealed no evidence of preimpact mechanical failure/malfunction.

The pilot had been flying approximately 7 hours and was completing the flight at night when the accident occurred. He was using visual cues (the airport environment) to position the aircraft at a proper altitude for a visual approach and landing. The terrain south of the airport rises several hundred feet above the airport elevation. The terrain is sparsely lit. The aircraft touched down two miles short of runway 34R in an open pasture at an elevation of approximately 400 feet higher than the airport. The pilot had flown approximately one hour of night time in the last 90 days, according to his logbook. All three occupants were injured, two seriously.

During weather briefings the pilot was advised of icing conditions in the Denver area. While approaching the Denver area the pilot radioed 'can you get me down, it's a little bit icy up here.' The pilot was subsequently asked and was given a close turn onto the outer marker. The aircraft was observed to overfly the airport at about 500 feet agl. The pilot then acknowledge the missed approach instructions, and 1 minute later reported ...'lots of ice...' and '...i'm stalling out...' The pilot reportedly did not like to fly approaches to minimums and set the altitude alerter to an altitude above minimums as a safety margin. The pilot had logged 3.5 hours actual and 4.1 hours simulated instrument time, and 3 instrument approaches in the last 6 months. The aircraft's cg was 6 inches aft of the aft cg limit.

During arrival, the pilot checked the lighted windsock and estimated that the wind was from 020° at 10 knots. He elected not to land on runway 31 since there were obstacles near the approach end. He stated that when the aircraft was about to touch down on runway 13, there was a big gust of wind which made the aircraft land long. As the aircraft landed, the pilot selected max reverse, but got no response. He decide he could not make a successful go-around so he applied max braking, but was unable to stop on the remaining runway. Subsequently, the aircraft departed the runway, went thru a fence, crossed a road, hit a pole and then the gear collapsed as it went over railroad tracks. A witness estimated that at about the time the aircraft was landing, the wind shifted to the north and increased to about 35 to 40 mph. Reportedly, the final approach speed was about 13 knots too fast. Skid marks were found on the runway, starting about 2,000 feet from the approach end. With a 35 knots tailwind, landing roll without reverse thrust would have been 3,015 feet. No malfunctions found, but it was noted that reverse system was inoperative above 90 knots. All three occupants escaped uninjured.

About 9 1/2 minutes after departure from Denver-Arapahoe County Airport, while climbing, the crew declared an emergency, reporting airframe icing. The crew was vectored to Denver-Stapleton International Airport when the aircraft entered a controlled descent until it crashed in a prairie located about 13 miles east of Arapahoe Airport, northeast of Parker. The aircraft was totally destroyed upon impact and all 10 occupants were killed.