CEN20MA044

The pilot’s loss of airplane control due to spatial disorientation during the initial climb in instrument meteorological conditions.

The personal flight departed from Lafayette Regional Airport/Paul Fournet Field (LFT), Lafayette, Louisiana, and entered the clouds when the airplane was at an altitude of about 200 ft above ground level. Before takeoff, the controller issued an instrument flight rules clearance to the pilot, instructing him to turn right onto a heading of 240° and climb to and maintain an altitude of 2,000 ft mean sea level (msl) after takeoff. Automatic dependent surveillancebroadcast (ADS-B) data for the accident flight started at 0920:05, and aircraft performance calculations showed that the airplane was climbing through an altitude of 150 ft msl at that time. The calculations also showed that the airplane then turned slightly to the right toward the assigned heading of 240° and climbed at a rate that varied between 1,000 and 2,400 ft per minute and an airspeed that increased from about 151 to 165 knots. At 0920:13, the airplane started rolling back toward wings level and, 7 seconds later, rolled through wings level and toward the left. At that time, the airplane was tracking 232° at an altitude of 474 ft and an airspeed of 165 knots. The airplane’s airspeed remained at 165 knots for about 10 seconds before it started increasing again, and the airplane continued to roll steadily to the left at an average roll rate of about 2° per second. The aircraft performance calculations further showed that, at 0920:40, the airplane reached a peak altitude of 925 ft msl. At that time, the airplane was tracking 200°, its bank angle was about 35° to the left, and its airspeed was about 169 knots. The airplane then started to descend while the left roll continued. At 0920:55, the airplane reached a peak airspeed of about 197 knots, which then started decreasing. At 0920:57, the airplane descended through 320 ft at a rate of descent of about 2,500 ft per minute and reached a bank angle of 75° to the left. At 0920:58, the controller issued a low altitude alert, stating that the pilot should “check [the airplane’s] altitude immediately” because the airplane appeared to be at an altitude of 300 ft msl. The pilot did not respond, and no mayday or emergency transmission was received from the airplane. The last ADS-B data point was recorded at 0920:59; aircraft performance calculations showed that, at that time, the airplane was descending through an altitude of 230 ft msl at a flightpath angle of about -7°, an airspeed of 176 knots, and a rate of descent of about 2,300 ft per minute. (The flightpath angle is in the vertical plane—that is, relative to the ground. The ground track, as discussed previously, is in the horizontal plane—that is, relative to north.) The airplane struck trees and power lines before striking the ground, traveled across a parking lot, and struck a car. The car rolled several times and came to rest inverted at the edge of the parking lot, and a postcrash fire ensued. The airplane continued to travel, shedding parts before coming to rest at the far end of an adjacent field. At the accident site, the surviving passenger told a local police officer that “the plane went straight up and then straight down.” Weight and balance calculations showed that the airplane’s total weight and center of gravity were within limits, with the center of gravity near the aft limit. The pilot likely obtained weather information for the flight about 0736 on the day of the accident. This information indicated that lowvisibility conditions would be present at the time of takeoff. The pilot would most likely have been aware of these conditions because, according to his wife, he had mentioned (on the night before the accident flight) that cloud ceilings would be “low” during takeoff. In addition, the pilot told the controller that he had the current automatic terminal information service report, which was based on the 0853 automated surface observing system observation. That observation indicated a visibility of 0.75 mile in mist and a vertical visibility of 200 ft above ground level. These weather conditions were conducive to the development of spatial disorientation. The surviving passenger also recalled that the airplane “pitched up like the pilot was trying to get above or over the clouds” and that a “harder than normal pitching movement” had occurred. Thus, the pilot had likely become spatially disoriented at this point in the initial climb due to the lack of visual references and the airplane’s increasing pitch attitude. Another indication that the pilot had become spatially disoriented was the airplane’s continuing and tightening turn to the left away from the intended course. The pilot’s most recent recurrent training in the airplane occurred in April 2019, but the training was conducted by a pilot whose Federal Aviation Administration-issued flight instructor certificate had expired in February 2019. No Federal Aviation Administration records indicated that the flight instructor’s certificate had been reinstated at the time of the training event. (The National Transportation Safety Board [NTSB] recognizes that the accident pilot might not have been aware that the flight instructor’s certificate had expired.) The flight instructor stated that the accident pilot’s training was conducted in visual meteorological conditions and that he did not simulate instrument conditions by having the pilot wear a hood (a view-limiting device). Further, the available pilot logbook evidence did not note the accident pilot’s recent flight experience or flight time in instrument meteorological conditions. As a result, the NTSB was unable to determine if the accident pilot met the regulatory requirements in Title 14 Code of Federal Regulations 61.57(c)(1) for instrument experience. The left and right engines were impact and fire damaged. The damage to the turbine engine blades and shrouds was consistent with operation at the time of impact. No anomalies were found that would have precluded normal operation of both engines. The damage to the propellers was symmetrical and consistent with impact forces. In addition, surveillance cameras at two private residences captured the sounds of the accident airplane as it passed overhead. No abnormal propeller sounds were heard on either recording. The NTSB’s sound spectrum analysis of the audio recording from one of these residences found that the recorded passing frequency was consistent with a four-bladed propeller rotating between 2,000 and 2,100 rpm, which was just below the propeller’s maximum continuous and takeoff allowable speed of 2,200 rpm. Aircraft performance calculations showed that each engine’s horsepower began decreasing from 500 horsepower at 0920:55, consistent with the decrease in airspeed after that time. The left engine torque gauge needle, as found in the wreckage, pointed to a value of about 525 lb-ft. This torque level, at a propeller speed between 2,000 and 2,100 rpm, would produce about 200 horsepower, indicating a power reduction on both engines during the last 5 seconds of flight. At that time, the airplane would have been descending through the clouds. The performance calculations indicated that the power applied to the airplane after 0920:56 would have been negligible. The airplane was not equipped, and was not required to be equipped, with a flight data recorder or a cockpit voice recorder. As a result, to determine the operational status of the autopilot during the accident flight, the NTSB conducted examinations of the annunciator panel and the autopilot servos. An analysis of light bulb filaments from the annunciator panel showed that none of the filaments from the autopilot, yaw damper, and flight director light bulbs were stretched, indicating that these annunciators were likely not illuminated at the time of impact. None of the examined autopilot servo components had failed, and no witness marks were noted

The Louisiana Forensic Center, Broussard, Louisiana, performed an autopsy on the pilot. His cause of death was blunt force injuries. Toxicology testing performed at the FAA Forensic Sciences Laboratory detected no carboxyhemoglobin, ethanol, or drugs of abuse in the pilot’s blood specimens. The pilot held a commercial pilot certificate with an airplane multiengine land rating. The pilot also held a second-class medical certificate, dated November 14, 2019, with a limitation that required him to wear corrective lenses. According to FAA medical records, the pilot wore bifocal glasses “all the time.” On his most recent medical application, dated November 4, 2019, the pilot reported 1,531 hours of total flight experience, 46 hours of which were accumulated during the preceding 6 months. The pilot also had about 730 hours of flight experience in the accident airplane make and model. The pilot’s most recent logbook was not located. The last entry in the pilot’s previous logbook showed that he had 1,194 hours of total flight experience and 910 hours of flight experience in a multiengine airplane as of July 25, 2017. The owner of the company for which the pilot worked stated that he and the accident pilot would generally hand fly the airplane up to an altitude of at least 2,000 ft (rather than engage the autopilot soon after takeoff). The company owner also stated that the accident pilot was “proficient” in the airplane. According to the owner of the airplane (who was also a pilot), the accident pilot had “a lot of involvement” with the airplane and “wanted to be the very best that he could be” at operating it. The airplane owner stated that the accident pilot was involved in selecting and installing the airplane’s flight instruments and that he was “very meticulous” about understanding the flight instruments. The pilot’s most recent recurrent training in the airplane occurred on April 22, 2019. The training was conducted by a pilot whose FAA-issued flight instructor certificate had expired in February 2019, and no FAA records indicated that his certificate had been renewed or reinstated at the time of the training. The flight instructor reported that the accident pilot’s most recent recurrent training was conducted at the same time as the airplane owner’s recurrent training. The flight instructor stated that ground training included using the airplane manuals and discussing any anomalies that either pilot had experienced during the previous 12 months. The flight instructor stated that, according to the pilots, no “big anomalies” had occurred during that timeframe. During flight training, the pilots performed stall recovery maneuvers at the first indication of an impending stall, steep turns at 5,000 ft, and go-arounds with a simulated failed engine at 4,000 ft. After the maneuvers were completed, the pilots returned to the airport to conduct instrument landing system and VOR approaches. (A VOR approach uses a very-high-frequency omnidirectional radio range system for navigation.) The flight instructor stated that all the training was conducted in visual meteorological conditions. He did not simulate instrument conditions by having the pilots wear a hood (a viewlimiting device) but stated that he could “load a pilot up enough so he would not have a chance to look outside.” The flight instructor also stated that the accident pilot was a “great stick and rudder guy” and that he “was not an autopilot pilot as he enjoyed [manually] flying the airplane.” The accident airplane’s flight log showed that, on April 22, 2019, the airplane flew from LFT to David Wayne Hooks Memorial Airport, Spring, Texas, for the pilots’ training and then returned to LFT. The entry included the accident pilot’s initials and showed a total flight time of 2.7 hours. As stated above, the accident pilot’s most recent logbook was not found, and the accident pilot’s previous logbook did not include a flight review endorsement for this training. The last flight review endorsement recorded in that logbook was dated March 12, 2017. The airplane owner’s logbook did not include a flight review endorsement but showed the training event; the logbook entry stated, “Recurrent training per FAR [Federal Aviation Regulation] Part 91. Steep turns, Engine out, Emergency and Normal procedures.” The entry also included the signature of the flight instructor and his pilot certificate number, but “CFI” (certificated flight instructor) and the CFI certificate expiration date did not appear after his pilot certificate number, as required for flight reviews. The accident airplane, which was owned by Cheyenne Partners LLC, was equipped with two Pratt & Whitney Canada PT6A-28 turbopropeller engines with two Hartzell constantspeed, fourbladed propellers. The airplane was configured with pilot and copilot seats, an aft-facing seat and a forward-facing seat on both the left and right sides of the airplane, and a side-facing seat opposite the left-side main entry door. The airplane was equipped with a King (now Honeywell) autopilot and a KAP 315 annunciator panel that displayed vertical and lateral flight director and autopilot system modes. The airplane was also equipped with a Garmin G600 integrated avionics display system that presented primary flight instrumentation, a full-color moving map with navigation information, and supplemental data. A Garmin GRS 77H attitude heading and reference system (AHRS) unit provided attitude and heading information to the airplane’s Garmin G600 flight deck displays. The Garmin G500/G600 Pilot’s Guide stated, “any failure of the internal AHRS inertial sensors results in loss of attitude and heading information. This is indicated by red ‘X’ flags over the corresponding flight instruments.” There were no maintenance writeups or reported anomalies with the display system before the accident flight. A standby digital attitude indicator was located directly beneath the Garmin G600 flight deck displays. In addition, the airplane was equipped with a Collins Aerospace stability augmentation system (SAS), which was designed to improve the static longitudinal stability of the airplane by providing variable elevator forces through tension changes to the elevator down spring. A major component of the SAS is the angle-of-attack (AOA) sensor vane, which is mounted on the right side of the airplane’s nose. The SAS computer uses the information from the AOA sensor vane to drive the servo actuator, which is attached to the elevator down spring. The SAS includes a stall margin indicator that is mounted on the upper left side of the instrument panel. This indicator receives a signal from the AOA vane to provide a pilot with a visual representation, via the indicator needle, of the ratio of airspeed to stall speed. The indicator face presents (from top to bottom) a red “stall” area, a red and black barber pole stall warning area, a yellow “slow” area, a white “1.3 VS” (stall speed) area, and a green (cruise) area. The last entry recorded in the airplane’s flight log was a flight from West Houston Airport, Houston, Texas, to LFT on December 18, 2019. The accident airplane was stored in a hangar at LFT, and the manager of that hangar reported that he added about 200 gallons of Jet A fuel to the airplane after it arrived on December 18. The airplane’s total weight was 8,869 pounds, which was less than the maximum takeoff weight of 9,000 pounds. The calculated center of gravity was 137.3 inches aft of datum; the center-of-gravity aft limit was 138.0 inches aft of datum. The airplane was not equipped, and was not required to be equipped, with a cockpit voice recorder or flight data recorder. The airplane impacted trees and transmission lines on the south edge of a road. A scar on the first tree that was struck indicated that the airpla