code

AZ

Crash of a Beechcraft C90 King Air near Wikieup: 2 killed

Date & Time: Jul 10, 2021 at 1255 LT
Type of aircraft:
Operator:
Registration:
N3688P
Flight Phase:
Flight Type:
Survivors:
No
Site:
Schedule:
Marana - Marana
MSN:
LJ-915
YOM:
1980
Location:
Crew on board:
1
Crew fatalities:
Pax on board:
1
Pax fatalities:
Other fatalities:
Total fatalities:
2
Circumstances:
On July 10, 2021, about 1255 mountain standard time, a Beech C-90, turbo prop airplane, N3688P, was destroyed when it was involved in an accident near Wikieup, Arizona. The pilot and Air Tactical Group supervisor were fatally injured. The airplane was operated as a public-use firefighting aircraft in support of the Bureau of Land Management conducting aerial reconnaissance and supervision. The airplane was on station for about 45 minutes over the area of the Cedar Basin fire. Preliminary radar data showed that the airplane had accomplished multiple orbits over the area of the fire about 2,500 ft above ground level (agl). The last radar data point showed the airplane’s airspeed about 151 knots, its altitude about 2,300 ft agl, and that it was in a descent, about 805 ft east southeast of the accident site. According to a witness, the airplane was observed in a steep dive towards the ground. Subsequently, the airplane impacted side of a ridgeline in mountainous desert terrain about 15 miles northeast of Wikieup. The wreckage was consumed by a post-crash fire. Debris was scattered over an area of several acres. The left wing was located about 0.79 miles northeast of the main wreckage and did not sustain thermal damage. No distress call from the airplane was overheard on the radio.

Crash of a Swearingen SA226T Merlin IIIB in Winslow: 2 killed

Date & Time: Apr 23, 2021 at 1530 LT
Operator:
Registration:
N59EZ
Flight Phase:
Flight Type:
Survivors:
No
MSN:
T-394
YOM:
1981
Location:
Crew on board:
2
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
2
Circumstances:
On April 23, 2021, about 1530 mountain standard time, a Swearingen SA226-T(B) twin-engine airplane, N59EZ, was destroyed when it was involved in an accident near Winslow, Arizona. The pilot and passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The airplane departed from Scottsdale Airport (SDL), Scottsdale, Arizona, about 1412 and was destined for Winslow-Lindbergh Regional Airport (INW), Winslow, Arizona. No flight plan was filed and there was no contact with air traffic control during the flight. Radar tracking depicted the airplane accomplishing several turning maneuvers in the vicinity of the Winslow airport and general accident area at elevations ranging from 7,100 ft mean sea level (msl) to 4,850 ft msl for about two minutes before the radar track ends. The airplane came to rest in a rock quarry adjacent to Arizona State Route 87 about 4 miles east of the Winslow Airport. The entire airplane was contained within a flat portion of the quarry; the sides of the rock quarry were about 40 ft in elevation and surrounded the accident site. A postcrash fire consumed the wreckage. The first identified point of impact was a disturbance to the ground about 10 ft from a barb-wire fence; the wood posts were fractured, and the barbwire was pulled out, the two metal posts about 12 ft apart were not damaged or disturbed. The debris path was on a 028° heading that led to the main wreckage. The main wreckage was about 410 ft from the first identified point of impact and came to rest inverted. Both wings separated from the fuselage, and both engines separated from their respective wings. The two four-bladed propellers were found at the accident site, both propeller assemblies had separated from their respective engines and were found in the debris field.

Crash of a Hawker 800XP in Scottsdale

Date & Time: Mar 14, 2020 at 1600 LT
Type of aircraft:
Operator:
Registration:
N100AG
Flight Type:
Survivors:
Yes
Schedule:
Rogers – Scottsdale
MSN:
258747
YOM:
2005
Crew on board:
2
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
0
Aircraft flight hours:
4823
Circumstances:
On March 14, 2020, about 1600 mountain standard time, a Raytheon Aircraft Company Hawker 800XP, N100AG, was substantially damaged after veering off the runway and impacting a sign at the Scottsdale Airport, Scottsdale, Arizona. The pilot and co-pilot were not injured. The airplane was being operated under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. The pilot stated that the flight departed from Roger, Arkansas about 1315 with the planned destination of Scottsdale. After an uneventful flight, the pilot made a stabilized approach to runway 21. Upon landing, the airplane touched down on the runway centerline in light and variable winds. The pilot recalled that the touchdown felt normal. During the landing roll, the airplane began to veer to the right and the pilot added left rudder in an effort to correct. Despite his attempts of full left rudder deflection, the airplane continued to veer off the runway. The airplane continued off the runway surface and encountered large rocks located between the runway and taxiway. The airplane collided with runway lights and a sign puncturing the left wing and resulted in substantial damage; the engines both sustained foreign object damage from the rocks. The pilot opined that the loss of control was a result of the nosewheel steering wheel not being aligned correctly.

Crash of a Piper PA-46-310P Malibu in Prescott

Date & Time: May 29, 2018 at 2115 LT
Registration:
N148ME
Flight Type:
Survivors:
Yes
Site:
Schedule:
Santa Ana – Prescott
MSN:
46-8608009
YOM:
1986
Crew on board:
1
Crew fatalities:
Pax on board:
2
Pax fatalities:
Other fatalities:
Total fatalities:
0
Captain / Total flying hours:
3100
Captain / Total hours on type:
3.00
Circumstances:
According to the pilot, about 15 minutes before reaching the destination airport during descent, the engine lost power. The pilot switched fuel tanks, and the engine power was momentarily restored, but the engine stopped producing power even though he thought it "was still running all the way to impact." The pilot conducted a forced landed on a highway at night, and the right wing struck an object and separated from the airplane. The airplane came to rest inverted. According to the Federal Aviation Administration (FAA) aviation safety inspector (ASI) that performed the postaccident airplane examination, the fuel lines to the fuel manifold were dry, and the fuel manifold valves were dry. He reported that the fuel strainer, the diaphragm, and the fuel filter in the duel manifold were unremarkable. Fuel was found in the gascolator. The FAA ASI reported that, during his interview with the pilot, "the pilot changed his story from fuel exhaustion, to fuel contamination." The inspector reported that there were no signs of fuel contamination during the examination of the fuel system. According to the fixed-base operator (FBO) at the departure airport, the pilot requested 20 gallons of fuel. He then canceled his fuel request and walked out of the FBO.
Probable cause:
The pilot's improper fuel planning, which resulted in fuel exhaustion and the subsequent total loss of engine power.
Final Report:

Crash of a Beechcraft 300 Super King Air in Tucson: 2 killed

Date & Time: Jan 23, 2017 at 1233 LT
Operator:
Registration:
N385KA
Flight Phase:
Flight Type:
Survivors:
No
Schedule:
Tucson - Hermosillo
MSN:
FA-42
YOM:
1985
Location:
Crew on board:
1
Crew fatalities:
Pax on board:
1
Pax fatalities:
Other fatalities:
Total fatalities:
2
Captain / Total flying hours:
15100
Aircraft flight hours:
9962
Circumstances:
The pilot and the passenger departed on a cross-country, personal flight in the airplane that the operator had purchased the day before the accident. Shortly after takeoff from runway 11L, after reaching an altitude of about 100 to 150 ft above the runway in a nose-high pitch attitude, the airplane rolled left to an inverted position as its nose dropped, and it descended to terrain impact on airport property, consistent with an aerodynamic stall. Post-accident examination of the accident site revealed propeller strike marks separated at distances consistent with both propellers rotating at the speed required for takeoff and in a normal blade angle range of operation at impact. Both engines exhibited rotational scoring signatures that indicated the engines were producing symmetrical power and were most likely operating in the mid-to upper-power range at impact. The engines did not display any pre-impact anomalies or distress that would have precluded normal engine operation before impact. No evidence was found of any preexisting mechanical anomalies that would have precluded normal operation of the airplane. Toxicology testing revealed the pilot's use of multiple psychoactive substances including marijuana, venlafaxine, amphetamine, pseudoephedrine, clonazepam, and pheniramine. The wide variety of psychoactive effects of these medications precludes predicting the specific effects of their use in combination. However, it is likely that the pilot was impaired by the effects of the combination of psychoactive substances he was using and that those effects contributed to his loss of control. The investigation was unable to obtain medical records regarding any underlying neuropsychiatric disease(s); therefore, whether these may have contributed to the accident circumstances could not be determined.
Probable cause:
The pilot's exceedance of the airplane's critical angle of attack during takeoff, which resulted in an aerodynamic stall. Contributing to the accident was the pilot's impairment by the effects of a combination of psychoactive substances.
Final Report:

Crash of a Rockwell Shrike Commander 500S in Fort Huachuca: 1 killed

Date & Time: May 17, 2014 at 1020 LT
Operator:
Registration:
N40TC
Flight Phase:
Flight Type:
Survivors:
Yes
Schedule:
Fort Huachuca - Fort Huachuca
MSN:
500-3091
YOM:
1976
Crew on board:
2
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
1
Captain / Total flying hours:
13175
Captain / Total hours on type:
600.00
Copilot / Total flying hours:
16560
Copilot / Total hours on type:
4100
Aircraft flight hours:
21660
Circumstances:
The commercial pilot reported that the purpose of the flight was to perform a check/orientation flight with the airline transport pilot (ATP), who was new to the area; the ATP was the pilot flying. The airplane was started, and an engine run-up completed. The commercial pilot reported that, during the takeoff roll, all of the gauges were in the “green.” After reaching an airspeed of 80 knots, the airplane lifted off the ground. About 350 ft above ground level (agl), the pilots felt the airplane “jolt.” The commercial pilot stated that it felt like a loss of power had occurred and that the airplane was not responding. He immediately shut off the boost pumps, and the ATP initiated a slow left turn in an attempt to return to the airport to land. The airplane descended rapidly in a nose-low, right-wing-low attitude and impacted the ground. A witness reported that he watched the airplane take off and that it sounded normal until it reached the departure end of the runway, at which point he heard a distinct “pop pop,” followed by silence. The airplane then entered an approximate 45-degree left turn with no engine sound and descended at a high rate with the wings rolling level before the airplane went out of sight. Another witness made a similar statement. Based on the witnesses’ statements and photographs of the twisted airplane at the accident site, it is likely that a total loss of engine power occurred and that, during the subsequent turn back to the airport, the ATP did not maintain sufficient airspeed and exceeded the airplane’s critical angle-of-attack, which resulted in an aerodynamic stall and impact with terrain. Although a postaccident examination of the airframe and engines did reveal an inconsistency between the cockpit control positions and the positions of the fuel shutoff valves on the sump tank, this would not have precluded normal operation. No other anomalies were found that would have precluded normal operation.
Probable cause:
The pilot’s failure to maintain adequate airspeed and his exceedance of the airplane’s critical angle-of-attack after a total loss of engine power during the takeoff initial climb, which resulted in an aerodynamic stall and impact with terrain. The reason for the total loss of engine power could not be determined because an examination of the airframe and engines did not reveal any anomalies that would have precluded normal operation.
Final Report:

Crash of a Cessna T207A Turbo Stationair 7 in Page: 1 killed

Date & Time: May 10, 2014 at 1545 LT
Operator:
Registration:
N7311U
Survivors:
Yes
Schedule:
Page - Page
MSN:
207A-0395
YOM:
1977
Location:
Crew on board:
1
Crew fatalities:
Pax on board:
6
Pax fatalities:
Other fatalities:
Total fatalities:
1
Captain / Total flying hours:
6850
Captain / Total hours on type:
48.00
Aircraft flight hours:
14883
Circumstances:
During a local sightseeing flight, the pilot noticed that the engine had lost partial power, and he initiated a turn back toward the airport while troubleshooting the loss of power. Despite the pilot's attempts, the engine would not regain full power and was surging and sputtering randomly. The pilot entered the airport's traffic pattern on the downwind leg, and, while on final approach to the runway, the airplane encountered multiple downdrafts and wind gusts. It is likely that, due to the downdrafts and the partial loss of engine power, the pilot was not able to maintain airplane control. The airplane subsequently landed hard short of the runway surface and nosed over, coming to rest inverted. The reported wind conditions around the time of the accident varied between 20 and 70 degrees right of the runway heading and were 14 knots gusting to greater than 20 knots. In addition, a company pilot who landed about 8 minutes before the accident reported that he encountered strong downdrafts and windshear while on final approach to the runway and that he would not have been able to reach the runway if he had a partial or total loss of engine power. Postaccident examination of the airframe and engine revealed no evidence of any preexisting mechanical malfunctions or failures that would have precluded normal operation. The engine was subsequently installed on a test stand and was successfully run through various power settings for several minutes. The reason for the partial loss of engine power could not be determined.
Probable cause:
The pilot's inability to maintain aircraft control due to a partial loss of engine power and an encounter with downdrafts and gusting crosswinds while on final approach to the runway. The reason for the partial loss of engine power could not be determined because postaccident examination revealed no mechanical malfunction or failure that would have precluded normal operation.
Final Report:

Crash of a Cessna 340A in Paulden: 4 killed

Date & Time: Oct 4, 2013 at 1300 LT
Type of aircraft:
Registration:
N312GC
Flight Phase:
Flight Type:
Survivors:
No
Schedule:
Bullhead City – Prescott
MSN:
340A-0023
YOM:
1975
Location:
Crew on board:
1
Crew fatalities:
Pax on board:
3
Pax fatalities:
Other fatalities:
Total fatalities:
4
Captain / Total flying hours:
4006
Circumstances:
Witnesses located at a gun club reported observing the airplane make a high-speed, low pass from north to south over the club's buildings and then maneuver around for another low pass from east to west. During the second low pass, the airplane collided with a radio tower that was about 50 ft tall, and the right wing sheared off about 10 ft of the tower's top. The tower's base was triangular shaped, and each of its sides was about 2 ft long. One witness reported that the airplane remained in a straight-and-level attitude until impact with the tower. The airplane then rolled right to an almost inverted position and subsequently impacted trees and terrain about 700 ft southwest of the initial impact point. One witness reported that, about 3 to 4 years before the accident, the pilot, who was a client of the gun club, had "buzzed" over the club and had been told to never do so again. A postaccident examination of the engines and the airframe revealed no evidence of a mechanical malfunction or failure that would have precluded normal operation.
Probable cause:
The pilot's failure to maintain sufficient altitude to clear a radio tower while maneuvering at low altitude and his decision to make a high-speed, low pass over the gun club.
Final Report:

Crash of a Beechcraft E90 King Air in Casa Grande: 2 killed

Date & Time: Feb 6, 2013 at 1135 LT
Type of aircraft:
Registration:
N555FV
Flight Type:
Survivors:
No
Schedule:
Marana - Casa Grande
MSN:
LW-248
YOM:
1977
Crew on board:
2
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
2
Captain / Total flying hours:
1079
Captain / Total hours on type:
112.00
Copilot / Total flying hours:
8552
Copilot / Total hours on type:
325
Aircraft flight hours:
8345
Circumstances:
The lineman who spoke with the pilot/owner of the accident airplane before its departure reported that the pilot stated that he and the flight instructor were going out to practice for about an hour. The flight instructor had given the pilot/owner his initial instruction in the airplane and flew with the pilot/owner regularly. The flight instructor had also given the pilot/owner about 58 hours of dual instruction in the accident airplane. The pilot/owner had accumulated about 51 hours of pilot-in-command time in the airplane make and model. It is likely that the pilot/owner was the pilot flying. Several witnesses reported observing the accident sequence. One witness reported seeing the airplane pull up into vertical flight, bank left, rotate nose down, and then impact the ground. One witness reported observing the airplane go from east to west, turn sharply, and then go north of the runway. He subsequently saw the airplane hit the ground. One witness, who was a pilot, stated that he observed the airplane enter a left bank and then a nose-down attitude of about 75 degrees at an altitude of about 300 feet above ground level, which was too low to recover. It is likely that the pilot was attempting a go-around and pitched up the airplane excessively and subsequently lost control, which resulted in the airplane impacting flat desert terrain about 100 feet north of the active runway at about the midfield point in a steep nose-down, left-wing-low attitude. The airplane was destroyed by postimpact forces and thermal damage. All components necessary for flight were accounted for at the accident site. A postaccident examination of the airframe and both engines revealed no anomalies that would have precluded normal operation. Additionally, an examination of both propellers revealed rotational scoring and twisting of the blades consistent with there being power during the impact sequence. No anomalies were noted with either propeller that would have precluded normal operation. Toxicological testing of the pilot was negative for drugs and alcohol. The flight instructor’s toxicology report revealed the presence of tetrahydrocannabinol (THC). Given the elevated levels of metabolite in the urine and kidney, the absence of quantifiable THC in the urine, and the low level of THC in the kidney and liver, it is likely that the flight instructor most recently used marijuana at least several hours before the accident. However, the effects of marijuana use on the flight instructor’s judgment and performance at the time of the accident could not be determined. A review of the flight instructor’s personal medical records indicated that he had a number of medical conditions that would have been grounds for denying his airman medical certificate. The ongoing treatment of his conditions with more than one sedating benzodiazepine, including oxazepam, simultaneously would also likely not have been allowed. However, none of the prescribed, actively sedating medications were found in the flight instructor’s tissues, and oxazepam was only found in the urine, which suggests that the flight instructor used the medication many hours and possibly several days before the accident. The toxicology findings indicate that the flight instructor likely did not experience any impairment from the benzodiazepine medication itself; however, the cognitive effects from the underlying mood disturbance could not be determined.
Probable cause:
The pilot’s loss of control of the airplane after pitching it excessively nose up during a go-around, which resulted in a subsequent aerodynamic stall/spin.
Final Report:

Crash of a Piper PA-31-350 Navajo Chieftain near Payson: 1 killed

Date & Time: Dec 18, 2012 at 1825 LT
Operator:
Registration:
N62959
Flight Phase:
Flight Type:
Survivors:
No
Site:
Schedule:
Holbrook - Payson - Phoenix
MSN:
31-7752008
YOM:
1977
Flight number:
AMF3853
Location:
Crew on board:
1
Crew fatalities:
Pax on board:
0
Pax fatalities:
Other fatalities:
Total fatalities:
1
Captain / Total flying hours:
1908
Captain / Total hours on type:
346.00
Aircraft flight hours:
19188
Circumstances:
The pilot began flying the twin piston-engine airplane model for the cargo airline about 11 months before the accident. Although he had since upgraded to one of the airline’s twin turboprop airplane models, due to the airline’s logistical needs, the pilot was transferred back to the piston-engine model about 1 week before the accident. The flight originated at one of the airline’s outlying destination airports and was planned to stop at an interim destination to the southwest before continuing to the airline’s base as the final destination. The late afternoon departure meant that the flight would arrive at the interim destination about 10 minutes after sunset. That interim destination was situated in a sparsely populated geographic bowl just south of terrain that was significantly higher, and the ceilings there included multiple broken and overcast cloud layers near, or lower than, the surrounding terrain. Although not required by Federal Aviation Administration (FAA) regulations, the airline employed dedicated personnel who performed partial dispatch-like activities, such as providing relevant flight information, including weather, to the pilots. Before takeoff on the accident flight, the pilot conferred briefly with the dispatch personnel by telephone, and, with little discussion, they agreed that the flight would proceed under visual flight rules to the interim destination. Information available at the time indicated that the cloud cover almost certainly precluded access to the airport without an instrument approach; however, the airplane was not equipped to conduct the only available instrument approach procedure for that airport. Additionally, the pilot did not have in-flight access to any GPS or terrain mapping/database information to readily assist him in either locating the airport or remaining safely clear of the local terrain. Although the airplane was not being actively tracked or assisted by air traffic control (ATC) early in the flight, review of ground tracking radar data showed that the flight initially headed directly toward the interim destination but then began a series of turns, descents, and climbs. The airplane then disappeared from radar as the result of radar coverage floor limitations due to high terrain and radar antenna siting. The airplane reappeared on radar about 24 minutes after it disappeared and about 9 minutes after the FAA-defined beginning of night. Based on the flight track, it is likely that the pilot made a dedicated effort to access the airport, while concurrently remaining clear of the clouds and terrain, strictly by visual means. This task was made considerably more difficult and hazardous by attempting it in dusk conditions, and then darkness, instead of during daylight hours. About 15 minutes after the airplane reappeared on radar, when it was at an altitude of about 13,500 ft, the pilot contacted ATC and requested and was granted an instrument flight rules clearance to his final destination. About 3 minutes later, the controller cleared the flight to descend to 10,000 ft, and the airplane leveled off at that altitude about 6 minutes later. However, upon reaching 10,000 ft, the pilot requested a lower altitude to escape “heavy” upand down-drafts, but the controller was unable to comply because the ATC minimum vectoring altitude was 9,700 ft in that region. About 1 minute later, radar contact was lost. Shortly thereafter, the airplane impacted terrain in a steep nose-down attitude in a near-vertical trajectory. Although examination of the wreckage did not reveal any preimpact mechanical deficiencies that would have prevented normal operation and continued flight, the extent of the damage precluded, except on a macro scale, any determination of the preimpact integrity or functionality of any systems, subsystems, or components, including the ice protection systems, autopilot, and nose baggage door. Analysis of the radar data indicated that the airplane was above 10,000 ft for at least 41 minutes (possibly in two discontinuous periods) and above 12,000 ft (in two discontinuous periods) for at least 18 minutes. Although the airplane was reportedly equipped with supplemental oxygen, the investigation was unable to verify either its presence or its use by the pilot. Lack of supplemental oxygen at those altitudes for those periods could have contributed to a decrease in the pilot’s mental acuity and his ability to safely conduct the light. Analysis of air mass data revealed that mountain-wave activity and up- and downdrafts with vertical velocities of about 1,000 ft per minute (fpm) were present near the accident site and that the largest and most rapid transitions from up- to down-drafts occurred near the accident site, which was also supported by the airplane’s altitude data trace. The analysis also indicated that the last radar target from the airplane was located in a downdraft with a velocity of between 600 and 1,000 fpm. Other meteorological analysis indicated that the airplane encountered icing conditions, likely in the form of supercooled large droplets (SLD), several minutes before the accident. Aside from pilot reports from aircraft actually encountering SLD, no tools currently exist to detect airborne SLD. Further, the tools and processes to reliably forecast SLD do not exist. SLD is often associated with rapid ice accumulation, especially on portions of the airplane that are not served by ice protection systems. Airframe icing, whether due to accumulation rates or locations that exceed the airplane’s deicing system capabilities, mechanical failure, or the pilot’s failure to properly use the system, can impose significant adverse effects on airplane controllability and its ability to remain airborne. Because of the pilot’s recent transition from the Beechcraft BE-99, in which the pitot heat was always operating during flight, he may have forgotten that the accident airplane’s pitot heat procedures were different and that the pitot heat had to be manually activated when the airplane encountered the icing conditions. If the pitot heat is not operating in icing conditions, the airspeed information becomes unreliable and likely erroneous. Erroneous airspeed indications, particularly in night instrument meteorological conditions when the pilot has no outside references, could result in a loss of control. The investigation was unable to determine whether the pitot heat was operating during the final portion of the flight. The investigation was unable to determine whether the pilot used the autopilot during the last portion of the flight. If he was using the autopilot, it is possible that, at some point, he was forced to revert to flying the airplane manually due to the unit’s inability and to a corresponding Pilot’s Operating Handbook prohibition against using it to maintain altitude in the strong up- and downdrafts, which would increase the pilot’s workload. Another possibility is that the autopilot was unable to maintain altitude, and, instead of disconnecting it, the pilot overpowered it via the control wheel. If that occurred and the pilot overrode the autopilot for more than 3 seconds, the pitch autotrim system would have activated in the direction opposite the pilot’s input, and, when the pilot released the control wheel, the airplane could have been significantly out of trim, which could result in uncommanded pitch, altitude, and speed excursions and possible loss of control. Whether the pilot was hand-flying the airplane or was using the autopilot, the encounter with the strong up- and downdrafts and consequent altitude loss likely prompted the pilot to input corrective actions to regain the lost altitude, specifically increasing pitch and possibly power. Such corrections typically result in airspeed losses; those losses can sometimes be significant as a function of downdraft strength and the airplane’s climb capability. If that capability is compromised by the added weight, drag, and other adverse aerodynamic effects of ice, aerodynamic stall and a loss of control could result. Radar tracking data and ATC communications revealed that another, similar-model airplane flew a very similar track about 6 minutes behind the accident airplane, except that that other airplane was at 12,000 ft not 10,000 ft. The 10,000-ft ATC-mandated altitude placed the accident airplane closer to the underlying high terrain and into the clouds with the icing conditions and the strong vertical air movements. In contrast, the pilot of the second airplane reported that he was in and out of the cloud tops and did not report any weather-induced difficulties. The accident pilot did not have any efficient in-flight means for accurately determining the airborne meteorological conditions ahead, and the ATC controller did not advise him of any adverse conditions. Therefore, the pilot did not have any objective or immediate reason to refuse the ATC-assigned altitude of 10,000 ft. Ideally, based on both the AIRMET and the ambient temperatures, the pilot should have been aware of the likelihood of icing once he descended into clouds. That, particularly combined with his previously expressed lack of confidence in the airplane’s capability in icing conditions, could have prompted him to request either an interim stepdown altitude of 12,000 ft or an outright delay in a direct descent to 10,000 ft, but, for undetermined reasons, the pilot did not make any such request of ATC. Based on the available evidence, if the ATC controller had not descended the airplane to 10,000 ft when he did, either by delaying or by assigning an interim altitude of 12,000 ft, it is likely that the airplane would not have encountered the icing conditions and the strong up- and downdrafts. In addition, if the presence of SLD and/or strong up- and downdrafts had been known or explicitly forecast and then communicated to the pilot either via his weather briefing, his onboard equipment, or by ATC, it is likely that the pilot would have opted to avoid those phenomena to the maximum extent possible. The flight’s encounter with airframe icing and strong up-and downdrafts placed the pilot and airplane in an environment that either exacerbated or directly caused a situation that resulted in the loss of airplane control.
Probable cause:
The airplane’s inadvertent encounter, in night instrument meteorological conditions, with unforecast strong up- and downdrafts and possibly severe airframe icing conditions (which
likely included supercooled large droplets that the airplane was not certificated to fly in) that led to the pilot's loss of airplane control.
Final Report: