Chino

Shortly after takeoff from Chino Airport runway 21, while climbing, the twin engine airplane rolled to the left, descended to the ground and crashed in a grassy area, bursting into flames. Both occupants were fatally injured. The airplane was operated on behalf of the Yanks Air Museum.

The pilot departed Stockton Airport on a solo flight to Chino. On a standard approach in rainy conditions, the airplane suffered two altitude deviations which the pilot attributed to a problem with the autopilot. Towards the end of the flight, the airplane descended past the Minimum Vectoring Altitude (MVA) of 7,400 feet and was issued an altitude alert by the controller, but there was no response from the pilot. The airplane entered an uncontrolled descent with a rate of about 10'000 feet per minute until it crashed in mountainous terrain. The airplane was destroyed by impact forces and the pilot was killed.

The airplane was removed from a heated hangar and refueled, at which time water droplets were visible on both wings. The airplane remained outside for about 40 minutes, with no deice or anti-ice treatment, until takeoff was initiated. Multiple witnesses near the accident site reported observing the airplane take off and enter a nose-high attitude, after which it immediately rolled left and impacted the terrain. Wreckage and impact signatures at the accident site were consistent with the left wing impacting the runway surface before the nose of the airplane impacted terrain just to the left of the runway. Witnesses characterized the precipitation at the time of the accident as snow and misty rain, varying in intensity between light and medium. The airplane was equipped with a Wing and Horizontal Stabilizer Anti-Icing System to prevent and remove any ice formation on the leading edges of the wing and the horizontal stabilizer; the system is activated by a “Wing Stab” switch. Based upon both witness statements and flight data from the Cockpit Voice Data Recorder (CVDR) and Flight Data Recorder (FDR), the Wing Stab ice switch was turned on about 9 minutes after engine start, while the pilot was performing his checklist; however, it was turned off shortly thereafter. The recorded position of the Wing Stab system switch remained off through the remainder of the recorded data. The airplane pilot’s operating handbook (POH) stated that airplane surfaces contaminated by ice, frozen precipitation, or frost must be deiced before departure. The POH also stated that the airplane must be anti-iced when the risk of freezing precipitation exists or is actually taking place. While deicing removes ice, anti-icing protects against additional icing for a certain period of time. The POH further states that the entire wing should be inspected during the pre-takeoff contamination check, not just the leading edge of the wing or wingtips, and that “when inspecting the wing, during the pre-takeoff contamination check, look at the entire upper surface and not only at the leading edge or wing tip. Although the wing tips can be seen from the cockpit, almost the entire wing is visible from a cabin window. Therefore, it is strongly advised that the visual inspection be done by a crew member from the cabin. Additionally, the crew should ask for the assistance of trained and qualified personnel outside the airplane to assist in the pre-takeoff and check to make sure that the tail and fuselage, which are not visible from the cockpit or cabin, are free of any ice contamination.” Furthermore, the before-takeoff checklist included an ice accumulation check, and included guidance that, “aerodynamic surfaces must be confirmed free of all forms of frost, ice, snow and slush prior to entering the takeoff runway or initiating takeoff.” No evidence of the pilot requesting a passenger or vocalizing that he was checking the wings for ice accumulation was heard on the CVR audio. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. Although the Wing Stab ice protection switch was found in the on position, recorded data indicated that, after the initial system check, the wing stab ice protection system remained off through the remainder of the recorded data. The panel the switch was mounted to had separated from the instrument panel and had an area of dirt/mud directly below the switch itself. The anti-ice system valves and controller were tested at the respective manufacturers and functioned normally. Accordingly, based on the evidence, the switch was likely moved to the on position during the accident sequence. It could not be determined why the Wing Stab ice protection switch was turned off. At the accident time, and in the 3 hours before the accident, light snow, mist, IFR ceilings, and a temperature of -1°C were reported at the departure airport. Witnesses reported that around the time of the accident light snowfall with freezing mist existed, which would have allowed for accumulation of ice to form on the upper surfaces of the wings, fuselage, and tail surfaces in the 40 minutes between when the airplane exited the hangar and when it took off. Given that the pilot did not obtain any deice or anti-ice services before departure, and the immediate roll to the left as the weight on wheels transitioned from ground to air, the airplane likely had some degree of ice contamination on the upper surfaces of the wings, fuselage, and tail that affected the flight characteristics of the airplane.

Two technicians were performing engine tests on apron at Chino Airport. While facing a hangar, the aircraft jumped over the chocks and collided with the metallic door of the hangar before coming to rest half inside. Both occupants escaped uninjured and the aircraft was damaged beyond repair.

The pilot departed the airport mid-morning to fly to his home airport, 63 miles to the northwest. Weather conditions at the departureb airport were visual flight rules (VFR), the weather at the destination airport was not reported, and the weather conditions en-route were marginal VFR. The global positioning system (GPS) track for the flight indicated that the airplane departed from the airport and headed west along a highway corridor flying approximately 1,000 feet above ground level (agl) through a mountain pass. For the majority of the flight, the airplane maintained altitudes between 900 feet and 1,200 feet agl. Twenty-nine minutes after takeoff, the airplane’s GPS track turned southwest away from an area of concentrated precipitation and directly towards an isolated mountain peak that rose approximately 1,000 feet above the surrounding terrain. The pilot contacted the local air traffic control facility, reported his position and requested traffic advisories through the local airspace to his destination airport. About 6 minutes later, the pilot stated that he was having difficulty maintaining VFR and asked for an instrument flight rules (IFR)clearance. At the same time, the GPS track showed that the airplane came within 50 feet of the mountainous terrain. No further transmissions from the pilot were received. The final GPS position was recorded 1 minute later, at 500 feet agl and approximately half a mile from the crash site. The terrain rapidly ascended in this area and intersected the airplane's flight path over the remaining 1/2 mile. An airport located about 4 miles from the accident site and in an area of flat terrain 1,000 feet below the isolated mountain top, recorded weather at the time of the accident as few clouds at 900 feet agl, overcast clouds at 1,500 feet agl, and a variable ceiling between 1,200 and 1,800 feet agl, in drizzle. Weather radar images at the time of the accident depicted precipitation at the elevation and location of the accident site, indicating probable mountain obscuration.

The pilot had filed an instrument flight rules flight plan with a planned departure time of 0700 in order to arrive at his intended destination in time for a planned engagement. He and his passenger arrived at the airport approximately 0800 and requested that the airplane be fueled. The airplane was pulled from its heated hangar into heavy snowfall and fueled at 0917. As the airplane sat outside in the heavy snowfall, a measurable amount of wet slushy snow accumulated on the airplane. The Fixed Base Operator manager suggested to the pilot that the airplane be deiced, but he declined. The airplane was then pulled out to the taxiway in an effort to prevent it from becoming stuck in the snow. At 0939, approximately 22 minutes after the airplane was pulled out if its hangar, the pilot departed with a visibility of 3/4 of a mile in snow and with a 4-knot direct tailwind. The pilot then made a right turn and announced that he was heading to his first waypoint. The airplane continued into an ever tightening right turn until it impacted the ground while in an inverted position about one mile north-northwest of the runway. An examination of the airplane’s wreckage revealed no anomalies with either the engine or airframe that would have contributed to the loss of control. The airplane’s Pilot Operating Handbook and Airplane Flight Manual contained the following limitation: "The aircraft must be clear of all deposits of snow, ice and frost adhering to the lifting surfaces immediately prior to takeoff."

The airplane departed under daytime visual meteorological conditions on a cross-country flight from an airport on the east side of a mountain range to a destination on the west side of the mountains. The airplane, which had been receiving flight following, then collided with upsloping mountainous terrain in a mountain pass while in controlled flight after encountering instrument meteorological conditions. The controller terminated radar services due to anticipation of losing radar coverage within the mountainous pass area, and notified the pilot to contact the next sector once through the pass while staying northwest of an interstate highway due to opposing traffic on the south side of the highway. The pilot later contacted the controller asking if he still needed to remain on a northwesterly heading. The controller replied that he never assigned a northwesterly heading. No further radio communications were received from the accident airplane. Radar data revealed that while proceeding on a northeasterly course, the airplane climbed to an altitude of 6,400 feet mean sea level (msl). A few minutes later, the radar data showed the airplane turning to an easterly heading and initiating a climb to an altitude of 6,900 feet msl. The airplane then started descending in a right turn from 6,900 feet to 5,800 feet msl prior to it being lost from radar contact about 0.65 miles southeast of the accident site. A weather observation station located at the departure airport reported a scattered cloud layer at 10,000 feet above ground level (agl). A weather observation system located about 29 miles southwest of the accident site reported a broken cloud layer at 4,000 feet agl. A pilot, who was flying west bound at 8,500 feet through the same pass around the time of the accident, reported overcast cloud coverage in the area of the accident site that extended west of the mountains. The pilot stated that the ceiling was around 4,000 feet msl and the tops of the clouds were 7,000 feet msl or higher throughout the area. Postaccident examination of the airframe and both engines revealed no anomalies that would have precluded normal operation.

The reported weather at the time of the accident was calm winds, a 1/4-mile visibility in fog and a vertical visibility of 100 feet. Shortly after takeoff for the instrument-flight-rules flight, the airplane made a slight turn to the left and impacted the tops of 25-foot trees about a 1/2 mile from the runway. An enhanced ground proximity warning system was installed on the airplane and data extraction from the system indicated that the airplane achieved an initial positive climb profile with a slight turn to the left and then a descent. A witness reported hearing the crash and observed the right wing impact the ground and burst into flames. The airplane then cartwheeled for several hundred feet before coming to rest inverted. The airframe, engines, and propeller assemblies were inspected with no mechanical anomalies noted that would have precluded normal flight.