Aviation Accident Summaries

Aviation Accident Summary WPR16FA054

Cedar Fort, UT, USA

Aircraft #1

N711BX

CESSNA 525

Analysis

The airline transport pilot and passenger departed on a cross-country flight in instrument meteorological conditions in the light business jet. About 1 minute after departure, air traffic control instructed the pilot to climb and maintain an altitude of 14,000 ft mean sea level (msl). About 3 minutes later, the pilot stated that the airplane's flight management system (FMS) had failed. Shortly thereafter, he requested a climb and stated that he was "trying to get to clear skies." Over the next several minutes, the controller provided the pilot with headings and altitudes to vector the airplane into visual meteorological conditions. During this time, and over the course of several transmissions, the pilot stated that he was "losing instruments," was hand-flying the airplane (likely indicating the autopilot was inoperative), and that he wanted to "get clear of the weather." Radar data indicated that, during the 10-minute flight, the airplane conducted a series of climbs and descents with large variations in airspeed. About 2 minutes before the loss of radar contact, the airplane entered a climbing right turn, reaching its highest altitude of about 21,000 ft, before it began a rapidly descending and tightening turn. Performance data revealed that, during this turn, the airplane entered a partially-inverted attitude, exceeded its design maneuvering speed, and reached a peak descent rate of about 36,000 ft per minute. Radar contact was lost at an altitude of about 16,000 ft msl, and the airplane subsequently experienced an inflight breakup. The wreckage was distributed over a debris path that measured about 3/4-mile long and about 1/3-mile wide.  Postaccident examination and testing of various flight instruments did not indicate what may have precipitated the inflight anomalies that the pilot reported prior to the loss of control. Additionally, all airframe structural fractures were consistent with ductile overload, and no evidence of any preexisting condition was noted with the airframe or either engine. The airplane was equipped with three different sources of attitude information, all three of which were powered by separate sources. It is unlikely that all three sources would fail simultaneously. In the event the pilot experienced a dual failure of attitude instrumentation on both the pilot and copilot sides, airplane control could have been maintained by reference to the standby attitude indicator. Further, the pilot would have been afforded heading information from the airplane's standby compass. Although the pilot did not specifically state to the controller the nature of the difficulties he was experiencing nor, could the investigation identify what, if any, anomalies the pilot may have observed of the airplane's flight instruments, the pilot clearly perceived the situation as one requiring an urgent ascent to visual conditions. As a single pilot operating without the assistance of an additional crewmember in a high-workload, high-stress environment, the pilot would have been particularly susceptible to distraction and, ultimately, a loss of airplane control due to spatial disorientation.

Factual Information

On January 18, 2016, about 1000 mountain standard time, a Cessna 525, N711BX, was destroyed following a loss of control and in-flight breakup while maneuvering at altitude near Cedar Fork, Utah. The airline transport pilot and his sole passenger sustained fatal injuries. Instrument meteorological conditions prevailed in the area, and an instrument flight rules (IFR) flight plan was filed for the personal cross-country flight, which was operated under the provisions of 14 Code of Federal Regulations Part 91. The flight departed Salt Lake City International Airport (SLC), Salt Lake City, Utah, about 0950, with an intended destination of Tucson International Airport (TUS), Tucson, Arizona. According to air traffic control voice communication and radar information, the pilot contacted the SLC departure controller at 0951:59 and reported that he was climbing through 7,500 ft mean sea level (msl) for 10,000 ft (all altitudes are expressed as msl unless otherwise noted). The controller then cleared the pilot to climb to and maintain Flight Level 230 (FL230), and to delete speed restrictions; the pilot confirmed the clearance. At 0952:21, the controller instructed the pilot to maintain 14,000 ft, to delete all speed restrictions, and asked him what speed he was climbing at; the pilot confirmed the clearance and stated that he was climbing at 200 knots (kts). At 0955:01, while approaching 14,000 ft the pilot reported that he had a failure with his Flight Management System (FMS), that he was "switching to NAV for a second," and would be exceeding the assigned altitude. This was followed by an unintelligible transmission. At 0955:16, the controller instructed the pilot to descend and maintain 14,000 ft and to fly his present heading. About 10 seconds later, the pilot advised the controller that he had an autopilot failure, and requested a climb to visual meteorological conditions. The controller instructed the pilot to climb and maintain FL180. At 0955:47, the pilot responded by confirming the climb to FL180. The controller then asked the pilot if he needed assistance. The pilot did not immediately respond, and the controller asked him a second time. At 0956:16, the pilot responded "negative," saying that he was "just trying to get to clear skies," and was climbing to FL180. The pilot stated that his "number 2" was working, and that his "altitude" had failed. The pilot concluded the transmission by saying, "…so, uh, my number two is working, climbing to one eight thousand." At 0956:32, the controller advised the pilot that traffic would be crossing above him at FL190, and that it was important that he level the airplane at FL180; the pilot replied, "We'll be watching." At 0956:45, the controller advised the pilot of two areas of light precipitation directly ahead of the airplane, and asked the pilot if he would need vectors to clear the weather. At 0956:59, the pilot responded that he would appreciate any vectors possible. Shortly thereafter, at 0957:06, the controller asked the pilot to "...paint a picture for me of where you think the clearest skies would be. I can vector you wherever you need to go." At 0957:12, the pilot replied that he was heading to TUS, his altitude would not hold, and that he was hand flying the airplane. About this time, radar showed the airplane beginning a right turn from its previously-established southerly heading to a southwesterly heading, though the airplane had neither been cleared to do so by the controller nor had the pilot informed the controller of the deviation. About 0957:20, the pilot transmitted that he would appreciate any vectors possible. About 15 seconds later, the controller advised the pilot that he was showing him at 17,500 ft, directed the pilot to fly his present heading, and stated that the airplane would be clear of the precipitation in about 4 miles. About 17 seconds later, the pilot transmitted, "...ok, MAYDAY. I do need to get up higher. I am losing different instruments. I'd really like to get clear of weather." At 0958:01, the controller issued the pilot a clearance to climb and maintain FL230, which the pilot confirmed. About 0958:26, the controller amended the previous clearance and instructed the pilot to climb to and maintain FL310, which the pilot initially confirmed, but shortly thereafter stated, "...yeah. I can't even dial that in. Still climbing, passing twenty thousand, so I'm just going to be reading it out to be sure my second is operating correctly." At 0958:46, the controller stated that he was showing the airplane climbing through 20,200 ft, and asked the pilot if he wanted to continue to TUS; the pilot replied, "That is affirmative." At 0958:53, when the airplane was at 20,700 ft, the controller issued the pilot a no-gyro turn to the left for vectors to the southeast; this occurred about 1 minute 41 seconds after the airplane had turned southwest. Radar data showed that the pilot initiated a right turn from a southwesterly heading at an altitude of 20,700 ft. At 0959:12, the airplane reached an altitude of 21,300 ft. msl, and was still in the right turn. At 0959:13, the controller stated, "November one bravo x-ray. I show you in a right turn. Can you turn left?" At 0959:17, while climbing out of 21,300 ft, the pilot replied that he was "trying to climb." About 0959:47, the controller advised the pilot that he had lost the airplane's altitude readout, and asked the pilot the airplane's altitude. There were no further transmissions received from the pilot. Between 0959:49 and 0959:58, the airplane descended from an altitude of 21,300 ft to 16,000 ft, with its rate of descent during this time increasing from 9,600 ft per minute (fpm) to 36,000 fpm. The Utah County Sheriff's Office collected four witness statements. One witness heard a loud boom and about 45 seconds later heard a motor sputtering, followed by seeing a piece of the airplane falling; the piece that he observed was on fire, but the witness could not identify what it was. The witness stated that he heard the plane crash but never saw it. A second witness said he heard a boom but did not report seeing [the airplane]. Another witness heard an explosion while in his house, then went outside and saw debris falling from the sky. The fourth witness reported hearing a loud explosion and heard the airplane descend, but did not hear the impact. Within hours of the accident, a Federal Aviation Administration (FAA) inspector responded to the accident site. The inspector reported that he did not observe ice accumulation on any of the airplane's surfaces during his onsite examination. The inspector stated that it was snowing at the accident site throughout the day. PERSONNEL INFORMATION The pilot was issued an airline transport pilot certificate with an airplane multiengine land rating on April 8, 2008, which included commercial privileges for single-engine land airplanes, and a A/CE-525S type rating for single-pilot operations. A review of the pilot's personal logbook revealed that, at the time of the accident, he had accumulated a total flight time of 3,336 hours, of which 3,138 hours was as pilot-in-command, and 2,015 hours was multiengine time. The pilot had 1,588 total hours of turbojet time, all in the accident airplane. The pilot had flown 8.8 hours, 8.8 hours, and 7.9 hours in the last 90, 60, and 30 days respectively. The pilot was current and qualified to operate the airplane in single-pilot flight operations. On December 1, 2014, the pilot was issued an FAA third-class airman medical certificate with the restriction, "Must wear corrective lenses." At the time of the application, the pilot reported a total flight time of 3,232 hours, of which 55 hours was accumulated in the previous 6 months. Records provided by FlightSafety International's (FSI) San Antonio Learning Center, San Antonio, Texas, revealed that, since 2011, the pilot had attended CE-525 recurrent training on a semi-annual basis. The pilot attended his most recent CE-525 recurrent training from August 7, 2015 through August 9, 2015. At the time of his training, the pilot reported a total time of 3,113 hours, with 1,563 hours of turbo-jet time in multiengine airplanes. The FSI recurrent training course consisted of 12.5 ground training hours, and 6 hours of flight simulator time, each of which the pilot completed satisfactorily. As annotated on the FSI Client Information Sheet, the pilot reported under Type of Flight Director: [Garmin] G750; dual Garmin GTN 750 units were installed in the accident airplane in October 2014. According to the FSI Director of Training Operations, FSI does not possess any Citation simulators configured with this avionics suite. Further, the Director of Training stated that FSI did not provide the accident pilot with training specific to the operation and use of the two Garmin GTN 750. At the time of the accident, the pilot had accumulated a total of 97.8 hours of flight time in the accident airplane since the modification had been completed. Additionally, and in a telephone conversation with the NTSB IIC, the FAA Certificate Management Office, which is located in Wichita, Kansas, and who manages the FSI certificate, reported that while recommended to do so, FSI was not required to provide the pilot with specific training for the Garmin 750 and GTX 33 equipment. AIRCRAFT INFORMATION The airplane, serial number 525-0299, had a low-wing, T-tail configuration, with retractable tricycle landing gear. The cabin was pressurized, and the airplane was capable of operating at a maximum pressure altitude of 41,000 ft. The airplane was configured for up to 7 occupants, including the pilot(s). It was approved for single-pilot operations provided the pilot-in-command held a CE525 (single-pilot) type rating. The airplane was equipped with two Williams International FJ44-1A medium-bypass turbofan engines installed on the rear fuselage pylons, each of which produced 1,900 lbs. of thrust. Maintenance According to Cescom Maintenance Transaction Records provided by Textron Aviation, the airplane's most recent maintenance occurred on January 4, 2016, when the left and right horizontal stabilizer deice boots were replaced at Mesa Citation Service Center, Mesa, Arizona. At the time of the inspection, the airframe had accumulated 2,301.9 hours, the #1 (left engine) 2257.1 hours, and the #2 (right engine) 2205.4 hours. At the time of the accident, the airplane had accumulated about 3 hours since this inspection. Avionics During the investigation Sierra Industries provided the following information relative to the Garmin GTN 750 flight management system as installed in the accident airplane: In October 2014, Sierra Industries installed a Dual Garmin GTN 750 system into a Cessna Citation Jet, Model 525, Serial Number 525-0299. The Garmin GTN 750 is a fully integrated Global Positioning System (GPS), Navigation (NAV), Communication (COMM), and Multi-Functional Display (MFD) system. The installation was approved under FAA Form 337, dated 10/10/2014. The Garmin GTN 750 is a fully integrated GPS/NAV/COM/MFD system. Each unit is 6.25-inch-wide x 6-inch-high and provides an 800 x 600-pixel display on a 6.9-inch diagonal color liquid crystal display (LCD) screen with touchscreen controls. The unit simplifies pilot workload by providing a visual display of controls and functions. The GTN 750 system has its own Global Positioning System/Satellite-based augmentation system (GPS/ SBAS) and navigator and flight planning function. In addition, the GTN 750 provides VHF Com and VHF Nav radios. The GTN 750 is a certified component with an FAA TSO C146c, and is certified for primary domestic, oceanic, and remote navigation, including en route, terminal, and non-precision approaches, and approach in vertical guidance, such as localizer performance with vertical guidance (LPV), lateral navigation (LNAV), and vertical navigation (VNAV). The airplane was equipped with a Honeywell SPZ-5000 integrated flight guidance system (IFGS), which provided, in part, flight director guidance, an altitude alerting system, and autopilot. For engagement of the autopilot and yaw damper, the autopilot system requires a single directional gyro and two vertical gyro sources; the VG-14A vertical gyro is the primary source for the flight guidance system. This system comprised a display guidance computer (IC-500), air data system, attitude and heading reference (vertical and directional gyros), electronic attitude director indicator (EADI), electronic horizontal situation indicator (EHSI), autopilot controller, mode selector, and autopilot servos. The IC-500 display guidance computer (DGC) was the focal point for the flow of information within the IFGS. It received information from various sensors and control system inputs, and converted this information to pilot-selected formats for display on the pilot's EADI and EHSI. The #1 VG-14A supplied data to the IC-500 for the pilot's side EADI and EHSI. The #2 VG-14A provided data to the IC-500 for comparison to the #1 VG-14A data and supplied data directly to the co-pilot's side attitude indicator. A cockpit panel-mounted switch allowed the pilot to switch between the #1 VG-14A and the #2 VG-14A to display information on the pilot's side EADI/EHSI. The two AC inverters provided power to the two VG-14A gyros. The #1 inverter supplied power to the #1 VG-14A, and the #2 inverter supplied power to the #2 VG-14A. Should one of the inverters fail, both gyros can be powered by one inverter when the pilot switches to the inverter that remains powered. The airplane was also equipped with a standby jet gyro attitude indicator with a separate power supply, which supplied emergency power for 30 minutes. A review of the airplane's maintenance records showed that during October 2014, several avionics components were removed. The replacement avionics consisted of several Garmin GA55 antennas, a Skylight Converter, dual Garmin GTN 750s, which incorporated a Global Positioning System, Navigation and Communication capabilities, a Multi-Functional Flight Display, a Garmin GDL69A XM Weather and Radio remote sensor, a Shadin ADC-200 Fuel Flow Indicator, and dual Garmin GTX33 transponders. The airplane was also equipped with two AM-250 Barometric altimeters as part of the reduced vertical separation minimums (RVSM) modification. The pilot's AM-250 supplied ARINC 429 air data information to the Number 1 Garmin GTX33 transponder (XPDR 1) and to the IC-500 DGC; it also supplied ATC encoded altitude data to the IC-500 DGC. The co-pilot's AM-250 supplied air data information to the Number 2 Garmin GTX33 transponder (XPDR 2). Additionally, the airplane was equipped with one encoding altimeter, P/N 44929-013, S/N 1783. This altimeter was found installed within the left or (pilot's side) instrument panel located below the vertical speed indicator. The altimeter indicated 5,280 feet, and a barometric setting of 30.09 inHg, which was observed at the accident site. METEROROLOGICAL INFORMATION At 0954, the weather reporting facility at the Provo Municipal Airport (PVU), Provo, Utah, which was located about 16nm southeast of the accident site, reported wind calm, visibility 10 miles, scattered clouds at 3,000 ft above ground level (agl), broken clouds at 3,500 ft agl, overcast clouds at 4,000 ft agl, temperature 0°C, dew point -3°C, and an altimeter setting of 30.11 inches of mercury. At 0955, the weather reporting facility at the South Valley Regional Airport (U42), Salt Lake City, Utah, which was located about 18nm north-northeast of the accident site, reported wind calm, visibility 10 miles, scattered clouds at 3,800 ft agl, broken clouds at 4,300 ft agl, overcast clouds at 4,900 ft agl, temperature 2°C, dew point -1°C, and an altimeter setting of 30.09 inches of mercury. In a review of the weather conditions that the pilot may have encountered during the 10-minute flight, an NTSB Senior Meteorologist reported that the airplane would have ascended through an icing layer during the climb to FL210, with solid instrument meteorological conditions (IMC) likely from 9,000 ft msl through FL250. The flight would have then encountered layered clouds from FL250 through FL320; however, there were no pilot reports available to

Probable Cause and Findings

The pilot's loss of control due to spatial disorientation while operating in instrument meteorological conditions, which resulted in an exceedance of the airplane's design stress limitations, and a subsequent in-flight breakup. Contributing to the accident was the pilot's reported inflight instrumentation anomaly, the origin of which could not be determined during the investigation.

 

Source: NTSB Aviation Accident Database

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