Boise

The pilot and passenger departed on a cross-country flight. Automatic dependent surveillance – broadcast (ADS-B) data indicated that the airplane flew at a cruise altitude between 11,000 ft and 13,000 ft mean sea level (msl) on a north to northeast heading consistent with its planned destination for most of the flight. About 30 minutes before the end of the flight, the airplane began a descent and then turned east. Shortly thereafter, the pilot of the airplane declared minimum fuel with air traffic control (ATC). A few minutes later the pilot declared critical fuel due to a fuel leak. The pilot stated in his last communication that he would attempt to make a nearby airport. Subsequently, the airplane impacted hilly, desert terrain at an elevation of about 5,780 ft and on a heading of about 034°. An acquaintance of the pilot who was a flight instructor stated that, on the two previous flights he had flown with the pilot, the left wing of the airplane felt heavy. The accident pilot thought it was because of a fuel imbalance. The postaccident examination revealed that the left tank fuel valve was positioned ON and the right tank valve was positioned OFF, consistent with the pilot balancing the fuel by feeding from the left-wing fuel tank. It is possible that when the pilot noticed the minimum fuel status, he failed to recall that he had previously selected the rightside fuel tank OFF, and thus did not have this fuel available. Given that the cruise altitudes on the accident flight were similar to what the previous owner used to make his fuel range and duration estimates, even with about a 20% reduction in fuel due to the pilot allowing 2 inches from the top of the fuel tanks during refueling, the airplane should have had adequate fuel to make its destination. A strong smell of fuel and fuel staining were also observed at the accident site. Page 2 of 11 WPR22FA173 A review of radar imagery from Boise, Idaho, revealed that the airplane flew through several areas of light to moderate intensity echoes as it proceeded northward, and then after turning eastward, the airplane’s fight track was through an area of moderate to heavy intensity echoes. The accident site was located on the southeast edge of the echo. Light-to-moderate icing conditions in the clouds with clear to mixed type icing below 12,000 ft msl were expected. Thus, it is likely that the airplane, which was not certified for flight in icing, encountered icing in the final portion of the flight. The pilot was flying with insulin-dependent diabetes, having type 1 diabetes mellitus. Given the urine glucose level of 29mg/dL, no detectable glucose in vitreous fluid, and ongoing verbal communication, it is unlikely that the pilot was experiencing significant metabolic disturbance from high blood glucose. Whether he was experiencing less severe effects of high blood sugar could not be determined. Whether he had symptoms of low blood glucose, such as diminished concentration or increased nervousness, is unknown. The pilot’s use of diphenhydramine (Benadryl), which can cause sleepiness, was likely not a factor due to fact that it was detected only in the urine and not in the blood. Thus, it is unlikely that effects of the pilot’s diphenhydramine use contributed to the accident. Accident site signatures and a review of the weather were consistent with a loss of control of the airplane. In addition, an examination of the airframe and engine revealed no evidence of any preimpact mechanical failures or malfunctions that would have precluded normal operation. It is likely that, while maneuvering to an alternate airport due to a critical fuel situation, in icing conditions, the pilot failed to maintain the proper airspeed, which resulted in the exceedance of the airplane’s critical angle of attack and the airplane experiencing an aerodynamic stall.

During the first 15 minutes of the flight, the pilot of the complex, high performance, jet airplane appeared to have difficulty maintaining the headings and altitudes assigned by air traffic controllers, and throughout the flight, responded intermittently to controller instructions. After reaching an altitude of 27,000 ft, the airplane began to deviate about 30° right of course while continuing to climb. The controller alerted the pilot, who did not respond, and the airplane continued to climb. Two minutes later, the airplane entered a tight, spiraling descent that lasted 8 minutes until the airplane impacted the ground at high speed in a rightwing-low attitude. The airplane was highly fragmented on impact; however, examination did not reveal any evidence of structural failure, in-flight fire, a bird strike, or a cabin depressurization event, and both engines appeared to be producing power at impact. Although the 72-year-old private pilot had extensive flight experience in multiple types of aircraft, including jets, he did not hold a type rating in the accident airplane, and the accident flight was likely the first time he had flown it solo. He had received training in the airplane about two months before the accident but was not issued a type rating and left before the training was complete. During the training, he struggled significantly in high workload environments and had difficulty operating the airplane’s avionics suite, which had recently been installed. He revealed to a fellow pilot that he preferred to “hand fly” the airplane rather than use the autopilot. The airplane’s heading and flight path before the spiraling descent were consistent with the pilot not using the autopilot; however, review of the flight path during the spiraling descent indicated that the speed variations appeared to closely match the airplane’s open loop phugoid response as documented during manufacturer flight tests; therefore, it is likely that the pilot was not manipulating the controls during that time.

The twin engine aircraft performed a technical stop in Boise, Idaho, enroute from Arizona to Kelowna. While flying at an altitude of 8,500 feet, both engines failed simultaneously. The pilot reduced his altitude and attempted an emergency landing in a flat area located near Beaverdell, about 37 miles south of Kelowna. By night, the airplane crash landed in a Christmas tree plantation, hit several trees and a fence and eventually came to rest. All six occupants evacuated safely while the aircraft was damaged beyond repair. According to preliminary information, there was still enough fuel in the tanks, and investigations will have to determine the cause of the double engine failure.

After takeoff from Palm Springs Airport, while on a positioning flight to Boise, the crew encountered technical problems with the undercarriage. Following a holding circuit, the crew decided to return to Palm Springs and to complete a gear up landing. Upon touchdown, the aircraft slid on its belly for few dozen metres before coming to rest. Both pilots evacuated safely and the aircraft was damaged beyond repair.

The commercial pilot was conducting a personal flight. He reported that he did not recall what happened the day of the accident. One witness, who was former pilot, reported that he saw the airplane fly over his house and that the engines sounded as if they were "out of sync." A second witness, who lived about 5 miles away from the airport, reported that she saw the airplane flying unusually low. She added that the engines sounded terrible and that they were "popping and banging." A third witness, who was holding short of the runway waiting to take off, reported that he saw the airplane approaching the runway about 75 ft above ground level (agl). He then saw the airplane descend to about 50 ft agl and then climb back to about 75 ft agl, at which point the airplane made a hard, right turn and then impacted terrain. Although a postaccident examination of both engines revealed no evidence of a mechanical failure or malfunction that would have precluded normal operation, the witnesses' described what appeared to be an engine problem. It is likely that one or both of the engines was experiencing some kind of problem and that the pilot subsequently lost airplane control. The pilot reported in a written statement several months after the accident that, when he moved the left rudder pedal back and forth multiple times after the accident, neither the torque tubes nor the rudder would move, that he found several of the rivets sheared from the left pedal, and that he believed the rudder had failed. However, postaccident examination of the fractured rivets showed that they exhibited deformation patterns consistent with overstress shearing that occurred during the accident sequence. No preimpact anomalies with the rudder were found.

The airplane was equipped with two main fuel tanks (132 usable gallons each) and two nacelle fuel tanks (60 usable gallons each). In normal operation, fuel from each nacelle tank is supplied to its respective engine, and fuel is automatically transferred from each main tank to its respective nacelle tank. While at the airplane's home airport, the pilot noted that the cockpit fuel quantity gauges indicated that the nacelle tanks were full, and he believed that the main tanks had fuel sufficient for 30 minutes of flight. The pilot did not verify by any other means the actual fuel quantity in any of the tanks. Thirty gallons of fuel were added to each main tank; they were not topped off. The airplane, with two passengers, then flew to an interim stop about 45 miles away, where a third passenger boarded. The airplane then flew to its destination, another 165 miles away. The pilot reported that, at the destination airport, he noted that the cockpit fuel quantity gauges indicated that the nacelle tanks were full; he surmised that the main fuel tanks were not empty but did not note the actual quantity of fuel. Forty gallons of fuel were added to each main tank. Again, the main tanks were not topped off, and the pilot did not verify by any other means the actual fuel quantity in any of the tanks. The return flight to the interim stop was uneventful. The third passenger deplaned there, and the airplane departed for its home airport. While on final approach to the home airport, both engines stopped developing power, and the pilot conducted a forced landing to a field about 1.2 miles short of the runway. The pilot later reported that, at the time of the power loss, the fuel quantity gauges indicated that there was still fuel remaining in the airplane. Postaccident examination of the airplane revealed that all four fuel tanks were devoid of fuel. The examination did not reveal any preimpact mechanical anomalies, including fuel leaks, that would have precluded continued flight. The airplane manufacturer conducted fuel-consumption calculations for each of the two city pairs. Because the pilot did not provide any information regarding flight routes, altitudes, speeds, or times for any of the flight segments, the manufacturer's calculations were based on direct routing in zero-wind conditions, nominal airplane and engine performance, and assumed cruise altitudes and speeds. Although the results are valid for these input parameters, variations in any of the input parameters can significantly affect the calculated fuel requirements. As a result, although the manufacturer's calculations indicated that the round trip would have burned less fuel than the total available fuel quantity that was derived from the pilot-provided information, the lack of any definitive information regarding the actual flight parameters limited the utility of the calculated value and the comparison. The manufacturer's calculations indicated that the accident flight leg (from the interim airport to the home airport) would have consumed about 28.5 gallons total. Given that the airplane was devoid of fuel at the accident site, the pilot likely departed the interim airport with significantly less than the manufacturer's minimum allowable departure fuel quantity of about 39.5 gallons per side. The lack of any observed preimpact mechanical problems with the airplane, combined with the lack of objective or independently substantiated fuel quantity information, indicates that the airplane's fuel exhaustion was due to the pilot's inadequate and improper pre- and inflight fuel planning and procedures.

The airplane was flying a VOR/DME-C approach that was on an oblique course about 40 degrees to the runway 30 centerline; the wind conditions produced an 8-knot tailwind for landing on runway 30. Despite the tailwind, the captain elected to land on the 6,600-foot-long runway instead of circling to land with a headwind. Moderate to heavy rain had been falling for the past hour, and the runway was wet. The crew said that the airplane was flown at the prescribed airspeed (Vref) for its weight with the wing flaps fully extended on final approach, and that they touched down just beyond the touchdown zone. The captain said that he extended the wings' spoilers immediately after touchdown. He tested the brakes and noted normal brake pedal pressure. However, during rollout, he noted a lack of deceleration and applied more brake pressure, with no discernible deceleration. The airplane's optional thrust reversers had been previously rendered non-operational by company maintenance personnel and were therefore not functional. The captain stated that he thought about performing a go-around but believed that insufficient runway remained to ensure a safe takeoff. While trying to stop, he did not activate the emergency brakes (which would have bypassed the anti-skid system) because he thought that there was insufficient time, and he was preoccupied with maintaining control of the airplane. He asked the first officer to apply braking with him, and together the crew continued applying brake pedal pressure; however, when the airplane was about 2,000 feet from the runway's end, it was still traveling about 100 knots. As the airplane rolled off the departure end on runway 30, which was wet, both pilots estimated that the airplane was still travelling between 85 and 90 knots. The airplane traveled 618 feet through a rain-soaked grassy runway safety area before encountering a drainage swale that collapsed the nose gear. As the airplane was traversing the soft, wet field, its wheels partially sank into the ground. While decelerating, soil impacted the landing gear wheels and struts where wiring to the antiskid brake system was located. The crew said that there were no indications on any cockpit annunciator light of a system failure or malfunction; however, after the airplane came to a stop they observed that the annunciator light associated with the antiskid system for the No. 2 wheel was illuminated (indicating a system failure). The other three annunciator lights (one for each wheel) were not illuminated. During the approach, the first officer had completed the landing data card by using a company-developed quick reference card. The quick reference card’s chart, which contained some data consistent with the landing charts in the Airplane Flight Manual (AFM), did not have correction factors for tailwind conditions, whereas the charts in the AFM do contain corrective factors for tailwind conditions. The landing data prepared by the first officer indicated that 3,240 feet was required to stop the airplane on a dry runway in zero wind conditions, with a wet correction factor increasing stopping distance to 4,538 feet. The Vref speed was listed as 127 knots for their landing weight of 11,000 pounds, and the first officer’s verbal and written statements noted that they crossed the runway threshold at 125 knots. During the investigation, Bombardier Lear calculated the wet stopping distances with an 8-knot tailwind as 5,110 feet. The touchdown zone for runway 30 is 1,000 feet from the approach end. The crew’s estimate of their touchdown location on the runway is about 1,200 feet from the approach end, yielding a remaining runway of 5,400 feet. On-duty controllers in the tower watched the landing and said that the airplane touched down in front of the tower at a taxiway intersection that is 1,881 feet from the approach end, which would leave about 4,520 feet of runway to stop the airplane. The controllers observed water spraying off the airplane’s main landing gear just after touchdown. Post accident testing indicated that the brake system, including the brake wear, was within limits, with no anomalies found. No evidence of tire failure was noted. The antiskid system was removed from the airplane for functional tests. The control box and the left and right control valves tested within specifications. The four wheel speed sensors met the electrical resistance specification. For units 1, 2 and 3, the output voltages exceeded the minimum specified voltages for each of the listed frequencies. Unit 4 was frozen and could not be rotated and thus could not be tested. Sensors 1 and 2 exceeded the specified 15% maximum to minimum voltage variation limit. Sensor 3 was within the limit and 4 could not be tested. Based on all the evidence, it is likely that the airplane touched down on the water-contaminated runway beyond the touchdown zone, at a point with about 600 feet less remaining runway than the performance charts indicated that the airplane required for the wet conditions. Since a reverted rubber hydroplaning condition typically follows an encounter with dynamic hydroplaning, the reverted rubber signatures on the No. 2 tire indicate that the airplane encountered dynamic hydroplaning shortly after touchdown, and the left main gear wheel speed sensor anomalies allowed the left tires to progress to reverted rubber hydroplaning. This, along with postaccident testing, indicates that the anti-skid system was not performing optimally and, in concert with the hydroplaning conditions, significantly contributed to the lack of deceleration during the braking attempts.

The pilot reported that he planned to fly a round trip cross-country flight. Prior to takeoff, he ascertained the quantity of fuel on board based upon the airplane's fuel totalizer gauge indication, which indicated 89 gallons. The flight to the destination was uneventful, and upon landing, 20 gallons of fuel was purchased. Thereafter, the pilot departed for the return flight back to his originating airport. According to the pilot, on takeoff the fuel tank gauges indicated the tanks were between 1/3 and 1/4 full. While cruising, the pilot contacted an air traffic control facility and notified them that he had lost power in one engine. About 5 minutes later, the pilot broadcasted that both engines were without power. Unable to reach the nearest airport, the pilot landed on soft, uneven terrain. During rollout, the airplane nosed over and was substantially damaged. The calculated post accident fuel burn-off for the round trip flight was about 106 gallons. During the post accident inspection, an FAA inspector reported finding an estimated 2 gallons of fuel in one tank. The other tank was dry. No fuel was observed in the main fuel lines to the engines, and no mechanical malfunctions were reported by the pilot.

The pilot removed the airplane from a hangar that was kept heated to about 60 degrees Fahrenheit, and parked it on the ramp while awaiting the arrival of the passengers. The outside temperature was below freezing, and a steady light to moderate snow was falling. The airplane sat in the aforementioned ambient conditions for at least 45 minutes before the initiation of the takeoff roll. Prior to attempting the takeoff, the pilot did not remove the accumulated snow or the snow that had melted on the warm airframe and then refroze as ice. The surviving passengers said that the takeoff ground run was longer than normal and the airplane lifted off at 100 knots indicated and momentarily touched back down, and then lifted off again. Almost immediately after it lifted off the second time, the airplane rolled into a steep right bank severe enough that the surviving passengers thought that the wing tip might contact the ground. As the pilot continued the takeoff initial climb, the airplane repeatedly rolled rapidly to a steep left and right bank angle several times and did not seem to be climbing. The airplane was also shuddering, and to the passengers it felt like it may have stalled or dropped. The pilot then lowered the nose and appeared to attain level flight. The pilot made a left turn of about 180 degrees to a downwind for the takeoff runway. During this turn the airplane reportedly again rolled to a steeper than normal bank angle, but the pilot successfully recovered. When the pilot initiated a left turn toward the end of the runway, the airplane again began to shake, shudder, and yaw, and started to rapidly lose altitude. Although the pilot appeared to push the throttles full forward soon after initiating the turn, the airplane began to sink at an excessive rate, and continued to do so until it struck a hangar approximately 1,300 feet southwest of the approach end of runway 35. No pre-impact mechanical malfunctions or failures were identified in examinations of the wreckage and engines.

The corporate jet airplane experienced a loss of elevator trim control (runaway trim) that resulted in an uncommanded nose-low pitch attitude. The pilot reported that following the loss of elevator trim authority the airplane was extremely difficult to control and the elevator control forces were extremely high. The pilot continued to maneuver the airplane, but eventually ditched it into a nearby marine cove. The runaway trim condition was not immediately recognized by the pilot and he stated that, by that point in the event sequence, the control forces were so great that he had little time to troubleshoot the system and elected to continue on his established heading and ditch the airplane. Pulling the circuit breaker, which is called for by the checklist in the event of a trim runaway, would have arrested the trim movement. Post accident examination and functional testing of the airplane's electric pitch trim printed circuit board (PCB) showed a repeatable fault in the operation of the PCB's K6 relay, resulting in the relay contacts remaining closed. This condition would be representative of the autopilot pitch trim remaining engaged, providing an electrical current to drive continuous nose-down trim to the elevator trim motor. Examination of the airplane's maintenance records showed that the PCB was removed and replaced in conjunction with the
phase inspection prior to the accident. Further examination of the airplane's maintenance records revealed that the replacement PCB was originally installed in an airplane that experienced an "electric trim runaway on the ground." Following the trim runaway, the PCB was removed and shipped to the manufacturer. After receiving the PCB the manufacturer tested the board and no discrepancies were noted. The unit was subsequently approved for return to service and later installed on the accident airplane. The investigation revealed a single-point failure of trim runaway (failed K6 relay) and a latent system design anomaly in the autopilot/trim disconnect switch on the airplane's pitch trim PCB. This design prohibited the disengagement of the electric trim motor during autopilot operation. As a result of the investigation, the FAA issued three airworthiness directives (AD 2003-21-07, AD 2003-23-20, and AD 2004-14-20), and the pitch trim printed circuit board was redesigned and evaluated for compliance with safety requirements via system safety assessment.