Broomfield-Rocky Mountain Metropolitan

The commercial pilot was relocating the multiengine airplane following the completion of an extensive avionics upgrade, which also included the installation of new fuel flow transducers. As the pilot neared the destination airport, he reported over the common traffic advisory frequency that he had "an engine out [and] smoke in the cockpit." Witnesses observed and airport surveillance video showed fire emanating from the airplane's right wing. As the airplane turned towards the runway, it entered a rightrolling descent and impacted the ground near the airport's perimeter fence. The right propeller was found feathered. Examination of the right engine revealed evidence of a fire aft of the engine-driven fuel pump. The fuel pump was discolored by the fire. The fire sleeves on both the fuel pump inlet and outlet hoses were burned away. The fuel outlet hose from the fuel pump to the flow transducer was found loose. The reason the hose was loose was not determined. It is likely that pressurized fuel sprayed from the fuel pump outlet hose and was ignited by the hot turbocharger, which resulted in the inflight fire.

The pilot stated that, during the preflight inspection of the airplane, he checked the fuel gauge, and it indicated 65 gallons. Due to the design of the fuel system, it is not possible to visually check the fuel level to confirm that the fuel gauge indication is accurate. During takeoff and as he reduced power for enroute climb, the left engine began to surge and lose power. He immediately turned left back toward the airport and contacted the control tower to advise that he was making a single-engine, straight-in approach to land. When he lowered the landing gear, the right engine began to surge and lose power. Subsequently, the pilot declared an emergency, and, realizing he had insufficient engine power and altitude to return to the airport, he retracted the landing gear and made a no-flap, gear-up landing on a nearby golf course. Postaccident application of battery power to the airplane confirmed that the fuel gauge indicated 65 gallons; however, when the airplane's fuel system was drained, only about 1/2 gallon of fuel was recovered. Thus, the engines lost power due to fuel exhaustion.

The visibility at the time of the accident was 1/2 mile with fog and the vertical visibility was 100 feet. A witness stated that the pilot checked the weather, but that he appeared to be in a hurry and took off without performing a preflight inspection of the aircraft. After takeoff, air traffic control instructed the pilot to turn left to a heading of 270 degrees. The pilot reported to the controller that he was at 1,300 feet climbing to 3,000 feet and the controller cleared the pilot to climb to 4,000 feet; the pilot acknowledged the clearance. Witnesses on the ground noted that the airplane was loud; one witness located about 1.5 miles from the departure airport reported that the airplane flew overhead at treetop height. The airplane impacted trees and a residence about 2.3 miles north-northeast of the departure airport. The airplane's turning ground track and the challenging visibility conditions were conducive to the onset of pilot spatial disorientation. Post accident inspection failed to reveal any mechanical failure that would have resulted in the accident. The pilot purchased the airplane about three months prior to the accident; at that time he reported having 72.6 hours of instrument flight experience and 25 hours of multi-engine experience, with none in the accident airplane make and model. After purchasing the airplane, the pilot received 52 hours of flight instruction in the accident airplane in 7 days. Logbook records were not located to establish subsequent flight experience.

A Piper PA-31T "Cheyenne" and a Cessna 172P "Skyhawk" collided in midair during cruise flight at dusk and in visual meteorological conditions. The Cheyenne departed under visual flight rules (VFR) from a local airport northwest of Denver, and was proceeding direct at 7,800 feet to another local airport south of Denver. Radar indicated its ground speed was 230 knots. Its altitude encoder was transmitting intermittently. The Skyhawk departed VFR from the south airport and was en route to Cheyenne, Wyoming, at 7,300 feet. The pilot requested and was cleared to climb to 8,500 feet and penetrate class B airspace. Radar indicated its ground speed was 110 knots. The Skyhawk was flying in the suggested "VFR flyway"; the Cheyenne was not. When the controller observed the two airplanes converging, he asked the pilot of the Cheyenne for his altitude. He replied he was at 7,600 feet. The controller immediately issued a traffic advisory, but the pilot did not acknowledge. Both airplanes departed controlled flight: the Skyhawk struck a house, and the Cheyenne fell inverted into the backyard of a residence. Wreckage was scattered over a 24 square block area in west Denver. At the time of the accident, the controller was handling low altitude en route, arrival and departure traffic for both airports. Wreckage examination disclosed four slashes, consistent with propeller strikes, on top of the Cheyenne's right engine nacelle, the cabin above the right wing trailing edge, the empennage at the root of the dorsal fin, and at the tail cone. The Cheyenne was on a similar flight three days before the collision when the pilot was informed by air traffic control that the transponder was operating intermittently. According to recorded radar and voice communications from that flight, the transponder/encoder operated intermittently and the pilot was so advised. Examination of the Cheyenne's altimeter/encoder revealed a cold solder connection on pin 8 of the 15-pin altimeter connector. When the wire was resoldered to the pin, the information from the altimeters, encoder, and altitude serializer was normal.

The airplane was maneuvering to deliver fire retardant when its left wing separated. Aircraft control was lost and the airplane crashed into mountainous terrain. A witness on the ground took a series of photographs that showed the air tanker's left wing separating at the wing root and the remaining airplane entering a 45-degree dive to the ground in a counterclockwise roll. An examination of the airplane wreckage revealed extensive areas of preexisting fatigue in the left wing's forward spar lower spar cap, the adjacent spar web, and the adjacent area of the lower wing skin. The portion of the wing containing the fatigue crack was obscured by the retardant tanks and would not have been detectable by an exterior visual inspection. An examination of two other air tankers of the same make and model revealed the area where the failure occurred on the accident airplane was in a location masked by the airplane's fuselage construction. The airplane was manufactured in 1945 and was in military service until 1956. It was not designed with the intention of operating as a firefighting airplane. In 1958, the airplane was converted to civilian use as an airtanker and served in that capacity until the time of the accident. The investigation revealed that the owner developed service and inspection procedures for the airtanker; however, the information contained in the procedures did not adequately describe where and how to inspect for critical fatigue cracks. The procedures were based on U.S Navy PB4Y-2 airplane structural repair manuals that had not been revised since 1948.

The pilot said he was on the glide slope for an ILS approach. The pilot said, "The autopilot was coupled on to the approach. The autopilot also coupled on to the Glide slope. Approximately 2-1/2 to 3 miles out, we visually had approach lights and runway lights. I then disconnected the autopilot and yaw damper, and hand flew a visual approach using the glide slope indicator as a cross check for a correct glide path to the airport. Continuing visually on the approach, I checked the GS (glide slope) and it indicated we were slightly above glide path, but was corrected, and seconds later hit a pole going through electrical wires, coming to rest short of the approach lights and to the right." An examination of the airplane revealed no anomalies. An examination of the ILS approach to the runway showed the facility operated satisfactorily.

While receiving radar vectors for an approach to land, the airplane (a Cessna 421C) departed controlled flight and impacted the terrain. Witnesses reported that they heard the engines operating before the plane crashed. During an investigation, no mechanical anomalies of the airplane were found. The pilot of a Boeing 727 reported that his airplane accumulated a 'quick load' of ice during his descent to land at the same airport within an hour of the accident.

In preparation for a cross country flight with takeoff occurring during a snow storm, the aircraft was loaded in the hangar and towed out by fbo personnel. Following the tow, the torque link was not properly connected and separated during the takeoff run. Due to a loss of nose wheel steering, the takeoff was aborted. The aircraft departed the side of the runway during the abort and the nose wheel was sheared off causing damage to both engines, wings, the fuselage, and landing gear. All four occupants escaped uninjured.

The pilot and two mechanics were on a maintenance test flight. As the aircraft was on a straight-in approach to runway 11 from the west, the pilot was advised of traffic ahead and told to slow his speed as much as possible. The pilot acknowledged. About 15 seconds later, the controller told the pilot (of N63XL) to make a 360° turn to the left for spacing. Shortly hereafter, witnesses observed the aircraft enter a steep bank (turn), then go into a steep spiraling, nose down, descent and crash. No preimpact mechanical malfunction or failure of the aircraft or engines was found. All three occupants were killed.