N525EG

HISTORY OF FLIGHTOn November 30, 2018, about 1028 central standard time, a Cessna 525A (Citation) airplane, N525EG, was destroyed when it was involved in an accident near Memphis, Indiana. The pilot and two passengers were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 business flight.

The cross-country flight originated from Clark Regional Airport (JVY), Jeffersonville, Indiana, and was en route to Chicago Midway International Airport (MDW), Chicago, Illinois. The airplane was equipped with automatic dependent surveillance–broadcast (ADS-B), which recorded latitude and longitude from GPS, pressure and geometric altitude, and selected altitude and heading. The airplane was also equipped with a cockpit voice recorder (CVR), which recorded the accident flight and annunciations from the enhanced ground proximity warning system (EGPWS). It was not equipped with a flight data recorder (FDR) nor was it required to be.

Review of the CVR transcript showed that the pilot operated as a single pilot but verbalized his actions as he configured the airplane before departure. He referenced items from the Before Taxi checklist and included in his crew briefing that in the event of a problem after takeoff decision speed, he would handle it as an in-flight emergency and “fly the airplane, address the problem, get the autopilot on, talk on the radios, divert over to Stanford.” The air traffic controller provided initial clearance for the pilot to fly direct to the STREP intersection and to climb and maintain 3,000 ft mean sea level. Before the departure from JVY, the pilot announced on the common traffic advisory frequency that he was departing runway 36 and verbalized in the cockpit “this is three six” before he advanced the throttles.

The flight departed JVY about 1024:36 into instrument meteorological conditions. The CVR recorded the pilot state that he set power to maximum cruise thrust, switched the engine sync on, and turned on the yaw dampers. The pilot also verbalized his interaction with the autopilot, including navigation mode, direct STREP, and vertical speed climb up to 3,000 ft. According to the National Transportation Safety Board’s (NTSB) airplane performance study, the airplane climbed to about 1,400 ft msl before it turned left onto a course of 330° and continued to climb. The CVR recorded the pilot state he was turning on the autopilot at 1025:22.

At 1025:39, the pilot was cleared up to 10,000 ft and asked to “ident,” and the airplane was subsequently identified on radar. The pilot verbalized setting the autopilot for 10,000 ft and read items on the After Takeoff/Climb checklist. The performance study indicated that the airplane passed 3,000 ft about 1026, with an airspeed between 230 and 240 kts, and continued to climb steadily.

At 1026:29, while the pilot was conducting the checklist, the controller instructed him to contact the Indianapolis Air Route Traffic Control Center; the pilot acknowledged. At 1026:38, the pilot resumed the checklist and stated, “uhhh lets seeee. Pressurization pressurizing anti ice de-ice systems are not required at this time.” The performance study indicated that, at 1026:45, the airplane began to bank to the left at a rate of about 5° per second and that after the onset of the roll, the airplane maintained airspeed while it continued to climb for 12 seconds, consistent with engine power not being reduced in response to the roll onset.

At 1026:48, the CVR recorded the airplane’s autopilot disconnect annunciation, “autopilot.” The performance study indicated that about this time, the airplane was in about a 30° left bank. About 1 second later, the pilot stated, “whooooaaaaah.” Over the next 8 seconds, the airplane’s EGPWS annunciated six “bank angle” alerts. At 1026:57, the airplane reached its maximum altitude of about 6,100 ft msl and then began to descend rapidly, in excess of 11,000 ft per minute. At 1026:58, the bank angle was about 70° left wing down, and by 1027:05, the airplane was near 90° left wing down.

At 1027:04, the CVR recorded a sound similar to an overspeed warning alert, which continued to the end of the flight. The performance study indicated that about the time of the overspeed warning, the airplane passed about 250 kts calibrated airspeed at an altitude of about 5,600 ft. After the overspeed warning, the pilot shouted three expletives, and the bank angle alert sounded two more times. According to the performance study, at 1027:18, the final ADS-B data point, the airplane was about 1,000 ft msl, with the airspeed about 380 kts and in a 53° left bank. At 1027:11, the CVR recorded the pilot shouting a radio transmission, “mayday mayday mayday citation five two five echo golf is in an emergency descent unable to gain control of the aircraft.” At 1027:16, the CVR recorded the EGPWS annunciating “terrain terrain.” The sound of impact was recorded about 1027:20. The total time from the beginning of the left roll until ground impact was about 35 seconds.

The accident site was located about 8.5 miles northwest of JVY. PERSONNEL INFORMATIONThe pilot received his single-pilot Cessna 525 type rating to his airline transport pilot certificate on February 28, 2018, after completing training at Simuflite and prior to the installation of the Tamarack Aerospace Group Active Technology Load Alleviation System (ATLAS) on the accident airplane. On his application to add the Cessna 525 type rating, the pilot reported 3,291 total hours of flight experience and 453 hours of instrument experience. On previous applications filed on February 14, 2017, and on August 29, 2016, the pilot reported the same hours. On his application for a Federal Aviation Administration (FAA) medical certificate dated March 15, 2018, the pilot reported 3,500 total hours. Logbooks for the pilot were not located, and no online logbook was discovered during the investigation. The pilot’s total hours and experience could not be verified. AIRCRAFT INFORMATIONAutopilot

The airplane was equipped with an autopilot system. The pilot can disengage the autopilot, and the autopilot can also disengage during abnormal situations. Abnormal disconnects can occur if the stick shaker activates, there is a yaw damper or internal autopilot failure (such as an excessive autopilot roll rate of 10°/second into a bank), there is an attitude heading reference system failure or miscompare, there is a loss of power to the normal (main) DC buses, or excessive attitudes are reached (25° nose up, 15° nose down, or 45° left or right wing down).

EGPWS

The airplane was equipped with a Honeywell Mark VIII EGPWS that interfaced with various airplane systems and provided six modes of alerts for the flight crew, including advisory callouts through the cockpit audio system for “bank angle” to alert the pilot to excessive bank angles. According to the Citation Aircraft Flight Manual, the aural advisory for bank angle above 2,450 ft above ground level occurs at 55°.

Aircraft Recording System

The airplane was equipped with an aircraft recording system (AReS), which recorded aircraft system maintenance data to help with maintenance troubleshooting procedures. Data were stored on a compact flash card installed in the AReS recording unit. The unit was not required to be installed, nor was it certified to FDR regulatory standards for crashworthy data storage or required parameters.

Active Technology Load Alleviation System

Tamarack Aerospace Group designed and manufactured the ATLAS and used Cranfield Aerospace Solutions Ltd. (CAeS) to provide support for a European Union Aviation Safety Agency (EASA) supplemental type certificate (STC). On December 22, 2015, EASA approved STC 10056170, and on December 27, 2016, the FAA issued STC SA03842NY after validation of the EASA STC.

Tamarack modified the original airplane design by removing the wing tip assemblies and adding winglets and wing extensions that contain active aerodynamic surfaces. The system was designed to provide increased aerodynamic efficiency without adverse structural effects due to the winglet installation. ATLAS operates independently of all other airplane systems. The main components of ATLAS consist of two wing extensions and two winglets with an ATLAS control unit (ACU), two Tamarack active camber surfaces (TACS), two TACS control units (TCUs), an annunciator line replaceable unit (LRU), and an ATLAS INOP button.

The TACS are active aerodynamic control surfaces mounted on the wingtip extensions that either hold their position in trail with the wing or deploy symmetrically to alleviate structural loads. The TACS attach to the wing-tip extensions through two hinges and connect to the TCUs via pushrods, a bellcrank, and a walking beam. The ACU, which was mounted to the fuselage near the airplane’s center of gravity, is an analog device with no software or nonvolatile memory, , contains two accelerometers to measure acceleration along the vertical axis, and provides commands to the TCUs to actuate the TACS symmetrically as required based on varying loading conditions.

The TCU communicates with the ACU for fault monitoring and system operation. In the event of a fault being detected, the ACU signals the TCU to depower the motor. The TCUs contain electronic limits to actuator travel (soft stops) and hardware limits (hard/mechanical stops). (These hard stops are internal to the TCU; additional hard stops are located within the bellcrank.) When power is not applied to the TCUs, the TACS are free to move with an applied force of 10 lbs or less. The ATLAS installation allows the TACS to travel 21° ±1° trailing edge up and 10° ±1° trailing edge down to mechanical stops located in the bellcrank assembly. The nominal operational travel is 20° trailing edge up and 9° trailing edge down using the electronic stops within the TCU. During normal operations, due to the electronic limits, the bellcrank should not contact the hard stops. The bellcrank contai...