CEN15FA135

The pilot's loss of airplane control due to spatial disorientation and light ice accumulation while operating in night, instrument meteorological conditions with gusting wind.

The instrument-rated private pilot was conducting a personal cross-country flight in the airplane. A review of the air traffic control transcripts and radar data revealed that the pilot was executing the RNAV GPS Y instrument approach to the runway. The air traffic controller then canceled the pilot's approach clearance and issued a heading change off of the approach course to provide spacing between a preceding aircraft. The pilot acknowledged the heading assignment. Radar data indicated that, after the controller cancelled the approach, the airplane began a left climbing turn from 5,600 to 5,800 ft, continued the left turn through the assigned 270 heading, and then descended rapidly. At that point, the airplane was no longer visible on the controller's radar display, and contact with the pilot was lost. The final recorded radar return showed the airplane at 5,100 ft. The airplane impacted a television tower guy wire, several power lines, and terrain, and then came to rest in an open field about 800 ft from the tower. A postaccident examination of the airplane and engine revealed no anomalies that would have precluded normal operation. A postaccident examination of the engine revealed rotational signatures on the first-stage compressor blades and light rotational signatures in the compressor and power turbines, and debris was found in the engine's gas path, all of which are consistent with engine rotation at impact. A witness in the parking lot next to the television tower stated that he heard the accident airplane overhead, saw a large flash of light that filled his field of view, and then observed the television tower collapse on top of itself. Surveillance videos located 1.5 miles north-northeast and 0.3 mile north-northwest of the accident site showed the airplane in a left descending turn near the television tower. After it passed the television tower, multiple bright flashes of light were observed, which were consistent with the airplane impacting the television tower guy wire and then the power lines. Further, the radar track and accident wreckage were consistent with a rapid, descending left turn to impact. Weather conditions were conducive to the accumulation of ice at the destination airport about the time that the pilot initiated the left turn. It is likely that the airplane accumulated at least light structural icing during the descent and that this affected the airplane's controllability. Also, the airplane likely encountered wind gusting up to 31 knots as it was turning; this also could have affected the airplane's controllability. The night, instrument meteorological conditions at the time of the accident were conducive to the development of spatial disorientation, and the airplane's rapid, descending left turn to impact is consistent with the pilot's loss of airplane control due to spatial disorientation. Therefore, based on the available evidence, it is likely that, while initiating the climbing left turn, the pilot became spatially disoriented, which resulted in his loss of airplane control and his failure to see and avoid the tower guy wire, and that light ice accumulation on the airplane and the gusting wind negatively affected the airplane's controllability.

A chronological summary of communications with the Lubbock Air Traffic Control Tower (LBB ATCT). 1907:20 The accident pilot first contacted LBB reporting an altitude of 16,700 ft and descending to 14,000 ft. The LBB radar controller instructed the pilot to descend at his discretion to 7,000 ft and confirmed the pilot's receipt of the current ATIS information "Whiskey." 1907:58 The LBB radar controller informed the pilot that a regional jet had reported moderate rime icing at 5,000 feet approximately 10 miles south of the airfield, and the pilot acknowledged with "okay, I'll be looking." 1909:32 The pilot requested the current ceiling and the radar controller informed him that bases had been previously reported 3,900 feet. The pilot acknowledged stating that it was better than "his weather information" which had indicated an 800 ft ceiling. The controller then explained that the bases were reported in msl, which would make the ceiling approximately 800 feet agl. The pilot acknowledged, and stated his information was in agreement. 1912:23 A position relief briefing took place on the LBB radar controller in which all pertinent information was passed to the relieving radar controller to include current ATIS information, PIREP information, approach in use, and traffic information including N301D who had been cleared to 7,000 ft. 1914:19 The radar controller announced on the recorded line that the required controller two minute overlap after relief was complete. 1918:02 The radar controller asked the pilot what type of approach was being requested and the pilot stated that he wanted the RNAV RWY 35L, but that he was having a little trouble getting his instruments set up and wanted to circle until he could get things worked out. The radar controller then asked the pilot to advise once he knew what he wanted to do. 1918:41 The radar controller instructed the pilot to maintain at or above 8,000 ft, that he could continue on his present heading, and told him he would just box him back in once he had figured out his instrument issues. The pilot acknowledged with a correct read back. 1921:24 The pilot stated that he wanted to turn south direct to ZOVOC for the RNAV RWY 35L. The radar controller instructed him to turn right to a 160 heading and descend and maintain 7,000 ft. The pilot acknowledged the turn, but not the descent. 1922:20 The radar controller asked the pilot for his current altitude, and the pilot stated that he was descending through 9,340 ft to 7,000 ft. 1923:00 The radar controller asked the pilot how many flying miles he would need to make his descent to the airport. The pilot responded that he just wanted to continue his present direction for a bit further and then he could start his turn back to the west and continue on his flight plan to ZOVOC. 1923:17 The radar controller instructed the pilot to turn right to a 220 heading. The pilot acknowledged with a correct read back. 1924:39 The radar controller instructed the pilot to turn right to a 260 heading. The pilot acknowledged with a correct read back. 1925:19 The radar controller cleared the flight for the RNAV Y RWY 35L approach and instructed the pilot to cross ZOVOC at or above 6,000 ft. The pilot acknowledged the "direct ZOVOC", but had some trouble understanding the remainder of the controller's instructions. After some clarification, the accident pilot acknowledged the approach clearance and altitude crossing restriction. 1926:13 The tower controller called down and informed the radar controller that he might have to cancel N301D's approach because he had another inbound (N319ME) that had remained faster than he expected, and had also requested to circle to another runway and the controller would need room to do that. The tower controller further stated that N319ME was "flying crazy…", so the radar controller stated that he would just take N301D off the approach and bring him back around for another. 1929:29 The radar controller cancelled N301D's approach clearance and instructed the pilot to climb to 7,000 ft and fly a heading of 275 degrees for re-sequencing. The pilot acknowledged and then confirmed the turn which the controller amended to 270 degrees. 1929:56 The last recorded transmission from the accident pilot was a read back of the 270 heading assignment. 1930:50 After a couple of attempts to contact the accident pilot with no response, the radar controller explained to the local controller that they had just experienced a "power spike" and that he was going to attempt contact via the portable radio in the event the power spike had effected their ground based communication equipment. 1932 LBB requested another aircraft on the frequency to attempt to contact the accident pilot. No response was received. 1934 The tower controller called the radar controller and advised him there had been a plane crash. TV Tower Information The TV tower, constructed on June 26, 1963 was designated as a "TOWER – Free standing or guyed structure used for communication." The tower was located at latitude 33°32'32.0"N, longitude 101°50'16.0"W and stood 814 ft tall. An FAA study, SW-OE-4136, was issued on January 17, 1963. Video 1 summary A review of surveillance video from a building located 1.5 miles north-northeast of the accident site revealed the airplane's lights moving from right to left. At 1930:29, two of the airplane's lights were observed and the airplane appeared to be in a left descending turn. At 1930:32 the airplane passed behind the tower, after which time the airplane's lights were not seen again. At 1930:34 multiple large flashes of light were observed to the left of the tower. At 1930:52 a final large flash of light is observed to the left of the tower. Video 2 Summary A review of surveillance video from a building located 0.3 miles north-northwest of the accident site revealed that the airplane entered the cameras field of view on the upper right side and proceeded to the left. Two of the airplane's lights were observed and the airplane appeared to be in a left descending turn. The airplane passed behind the tower. Multiple large flashes of lights were observed to the left of the tower. Radar Data Radar data indicated that the accident pilot followed all course and altitude instructions that were provided by ATC without noted deviation. According to audio recordings, the last instruction provided by ATC to the pilot was the approach clearance cancellation and instructions to turn left to a heading of 270 and climb to 7,000 ft. Immediately after the pilot's correct read back acknowledging the controllers instructions, radar data indicated that the accident airplane began a left climbing from of 5,600 ft altitude. It reached an altitude of 5,800 ft, entered a continued left turn through the assigned heading of 270 and then descended rapidly. Radar data revealed only two recorded returns over a 10 second time span after the airplane had reached 5,800 ft. The last recorded radar return indicated an altitude of 5,100 ft at 1930:21. The radar track and accident location were consistent with a rapid continued descending left turn to impact. Engine Examination On April 21, 2015, an engine examination was performed at Pratt & Whitney Engine Services, Bridgeport West Virginia, under the auspices of an FAA inspector. The examination revealed that the engine exhibited extensive impact damage. The accessory gearbox was completely separated from the engine. Compressive damage was found on the exhaust case and gas generator case. The engine's compressor showed no evidence of pre-impact damage. Rotational signatures were found on the first stage compressor blades. The compressor turbine and power turbine disks and blades exhibited no evidence of pre-impact damage. Light rotational signatures were found in the compressor and power turbines and debris was found in the gas path. There was no evid