Teterboro

On May 15, 2017, about 1529 eastern daylight time, a Learjet 35A, N452DA, departed controlled flight while on a circling approach to runway 1 at Teterboro Airport (TEB), Teterboro, New Jersey, and impacted a commercial building and parking lot. The pilot-in-command (PIC) and the second-in-command (SIC) died; no one on the ground was injured. The airplane was destroyed by impact forces and postcrash fire. The airplane was registered to A&C Big Sky Aviation, LLC, and was operated by Trans-Pacific Air Charter, LLC, under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91 as a positioning flight. Visual meteorological conditions prevailed, and an instrument flight rules flight plan was filed. The flight departed from Philadelphia International Airport (PHL), Philadelphia, Pennsylvania, about 1504 and was destined for TEB. The accident occurred on the flight crew’s third and final scheduled flight of the day; the crew had previously flown from TEB to Laurence G. Hanscom Field (BED), Bedford, Massachusetts, and then from BED to PHL. The PIC checked the weather before departing TEB about 0732; however, he did not check the weather again before the flight from PHL to TEB despite a company policy requiring that weather information be obtained within 3 hours of departure. Further, the crew filed a flight plan for the accident flight that included altitude (27,000 ft) and time en route (28 minutes) entries that were incompatible with each other, which suggests that the crew devoted little attention to preflight planning. The crew also had limited time in flight to plan and brief the approach, as required by company policy, and did not conduct an approach briefing before attempting to land at TEB. Cockpit voice recorder data indicated that the SIC was the pilot flying (PF) from PHL to TEB, despite a company policy prohibiting the SIC from acting as PF based on his level of experience. Although the accident flight waslikely not the first time that the SIC acted as PF (based on comments made during the flight), the PIC regularly coached the SIC (primarily on checklist initiation and airplane control) from before takeoff to the final seconds of the flight. The extensive coaching likely distracted the PIC from his duties as PIC and pilot monitoring, such as executing checklists and entering approach waypoints into the flight management system. Collectively, procedural deviations and errors resulted in the flight crew’s lack of situational awareness throughout the flight and approach to TEB. Because neither pilot realized that the airplane’s navigation equipment had not been properly set for the instrument approach clearance that the flight crew received, the crew improperly executed the vertical profile of the approach, crossing an intermediate fix and the final approach fix hundreds of feet above the altitudes specified by the approach procedure. The controller had vectored the flight for the instrument landing system runway 6 approach, circle to runway 1. When the crew initiated the circle-to-land maneuver, the airplane was 2.8 nautical miles (nm) beyond the final approach fix (about 1 mile from the runway 6 threshold) and could not be maneuvered to line up with the landing runway, which should have prompted the crew to execute a go-around because the flight did not meet the company’s stabilized approach criteria. However, neither pilot called for a go-around, and the PIC (who had assumed control of the airplane at this point in the flight) continued the approach by initiating a turn to align with the landing runway. Radar data indicated that the airplane’s airspeed was below the approach speed required by company standard operating procedures (SOPs). During the turn, the airplane stalled and crashed about 1/2 nm south of the runway 1 threshold.

The pilot was attempting a circling approach with a strong gusty tailwind. Radar data and an air traffic controller confirmed that the airplane was circling at or below the minimum descent altitude of 720 feet (708 feet above ground level [agl]) while flying in and out of an overcast ceiling that was varying between 600 feet and 1,100 feet agl. The airplane was flying at 100 knots and was close to the runway threshold on the left downwind leg of the airport traffic pattern, which would have required a 180-degree turn with a 45-degree or greater bank to align with the runway. Assuming a consistent bank of 45 degrees, and a stall speed of 88 to 94 knots, the airplane would have been near stall during that bank. If the bank was increased due to the tailwind, the stall speed would have increased above 100 knots. Additionally, witnesses saw the airplane descend out of the clouds in a nose-down attitude. Thus, it was likely the pilot encountered an aerodynamic stall as he was banking sharply, while flying in and out of clouds, trying to align the airplane with the runway. Toxicological testing revealed the presence of zolpidem, which is a sleep aid marketed under the brand name Ambien; however, the levels were well below the therapeutic range and consistent with the pilot taking the medication the evening before the accident. Therefore, the pilot was not impaired due to the zolpidem. Examination of the wreckage did not reveal any preimpact mechanical malfunctions.

The crew stated that the preflight examination, takeoff checks, takeoff roll, and rotation from runway 26 were "normal." However, once airborne, and with the landing gear down and the flaps at 20 degrees, the airplane began a roll to the right. The captain used differential thrust and rudder to keep the airplane from rolling over, and as he kept adjusting both. He noted that as the airspeed increased, the airplane tended to roll more; as the airspeed decreased, the roll would decrease. The captain also recalled thinking that the airplane might have had an asymmetrical flap misconfiguration. Both pilots stated that there were no lights or warnings. As the airplane continued a right turn, runway 13 came into view. The captain completed a landing to the right of that runway, landing long and in the grass with a 9-knot, left quartering tailwind. The airplane then paralleled the runway and ran into an airport perimeter fence beyond the runway's end. The cockpit voice recorder revealed that the crew initially used challenge and reply checklists and that after completing the takeoff checklist, engine power increased. About 7 seconds after the first officer called "V1," the captain stated an expletive, and the first officer announced "positive rate." During the next 50 seconds, the captain repeated numerous expletives, an automated voice issued numerous "bank angle" warnings, and the first officer asked what he could do, to which the captain later told him to declare an emergency. There were no calls by either pilot for an emergency checklist nor were there callouts of any emergency memory items. Each of the airplane's wings incorporated four hydraulically-actuated spoiler segments. The outboard segment, the roll control spoiler, normally extends in conjunction with its wing aileron after the aileron has traveled more than about 3 degrees, and extends up to 50 degrees at full control wheel rotation. When the airplane was subsequently examined in a hangar, hydraulic power was applied to the airplane via a ground hydraulic power unit, and the right roll spoiler elevated to 7.9 degrees above the flush wing level. Multiple left/right midrange turns of the yoke, with the hydraulic ground power unit both on and off, resulted in the roll spoiler being extended normally, but still returning to a resting position of 7.8 to 7.9 degrees above the flush position. When the yoke was turned full right and left, whether the aileron boost was on or off, both wings' roll spoilers extended to their full positions per specifications; however, once the full deflection testing was completed, the right roll spoiler returned to 6.1 degrees above the flush position. A final yoke turn resulted in the roll spoiler being elevated to 5.5 degrees. The right wing roll spoiler actuator was subsequently examined at the airplane manufacturer, and the roll spoiler was found to jam. The roll spoiler actuator was disassembled, but no specific reason(s) for the jamming were found. The roll spoiler parts were also examined and no indications of why the actuator may have jammed were found. According to the flight manual, if any of the spoiler segments should float, moving the spoiler hold down switch to "Spoiler Hold Down" locks all spoiler panels down. The roll control spoilers may then be used in the roll mode by turning on the auxiliary hydraulic pump. Also, an "Aileron/Spoiler Disconnect" T-handle is available to release the tie between the ailerons and the roll control spoilers in the event of a jam in either system. When used, the pilot's yoke controls only the ailerons, and the copilot's yoke controls only the roll control spoilers. Although the jamming of the right spoiler initiated the event, the crew's proper application of emergency procedures should have negated the adverse effects. Memory items for an uncommanded roll include moving the spoiler hold-down switch to the "on" position, which was not done; the spoiler hold-down switch was found in the "off" position. (The captain thought that he may have had an asymmetrical flap configuration; however, if an asymmetry had been the initiating event, the flap system would have been automatically disabled and the flap segments would have been mechanically locked in their positions.) The aileron/spoiler disconnect T-handle was found pulled up, which the crew indicated had occurred when the first officer's shoe hit it as he evacuated the airplane. While pulling the aileron/spoiler disconnect T-handle would have been appropriate for a different emergency procedure to release the tie between the ailerons and the roll control spoilers in the event of a jam in either system, it would have actually hindered the captain's attempts to control the airplane in this case because it would have disconnected the left roll spoiler from the captain's yoke, making it more difficult to counter the effects of the displaced right roll spoiler. Although the crew indicated that the t-handle was pulled during the first officer's exit of the airplane, its position, safety cover, and means of activation make this unlikely. In addition, precertification testing of the airplane showed that even with the right roll spoiler fully deployed, as long as the pilot had the use of the left roll spoiler in conjunction with that aileron, the airplane should have been easily controlled.

Although the pilot filed an instrument flight rules flight plan through the Direct User Access Terminal System (DUATS), no evidence of a weather briefing was found. The flight departed in visual meteorological conditions and entered instrument meteorological conditions while climbing through 12,800 feet. The air traffic controller advised the pilot of moderate rime icing from 15,000 feet through 17,000 feet, with light rime ice at 14,000 feet. The controller asked the pilot to advise him if the icing worsened, and the pilot responded that he would let them know and that it was no problem for him. The controller informed the pilot that he was coordinating for a higher altitude. The pilot confirmed that, while at 16,800 feet, "…light icing has been present for a little while and a higher altitude would be great." About 15 seconds later, the pilot stated that he was getting a little rattle and requested a higher altitude as soon as possible. About 25 seconds after that, the flight was cleared to flight level 200, and the pilot acknowledged. About one minute later, the airplane reached a peak altitude of 17,800 feet before turning sharply to the left and entering a descent. While descending through 17,400 feet, the pilot stated, "and N731CA's declaring…" No subsequent transmissions were received from the flight. The airplane impacted the paved surfaces and a wooded median on an interstate highway. A postaccident fire resulted. The outboard section of the right wing and several sections of the empennage, including the horizontal stabilizer, elevator, and rudder, were found about 1/4 mile southwest of the fuselage, in a residential area. Witnesses reported seeing pieces of the airplane separating during flight and the airplane in a rapid descent. Examination of the wreckage revealed that the outboard section of the right wing separated in flight, at a relatively low altitude, and then struck and severed portions of the empennage. There was no evidence of a preexisting mechanical anomaly that would have precluded normal operation of the airframe or engine. An examination of weather information revealed that numerous pilots reported icing conditions in the general area before and after the accident. At least three flight crews considered the icing "severe." Although severe icing was not forecasted, an Airmen's Meteorological Information (AIRMET) advisory included moderate icing at altitudes at which the accident pilot was flying. The pilot operating handbook warned that the airplane was not certificated for flight in severe icing conditions and that, if encountered, the pilot must exit severe icing immediately by changing altitude or routing. Although the pilot was coordinating for a higher altitude with the air traffic controller at the time of the icing encounter, it is likely that he either did not know the severity of the icing or he was reluctant to exercise his command authority in order to immediately exit the icing conditions.

While in instrument meteorological conditions flying 800 feet above the airplane’s service ceiling (30,000 feet), with no icing conditions reported, the pilot reported to the air traffic controller that he, “...lost [his] panel.” With the autopilot most likely engaged, the airplane began a right roll about 36 seconds later. The airplane continued in a right roll that increased to 105 degrees, then rolled back to about 70 degrees, before the airplane entered a right descending turn. The airplane continued its descending turn until being lost from radar in the vicinity of the accident site. The airplane impacted in a nose-down attitude in an open field and was significantly fragmented. Postaccident inspection of the flight control system, engine, and propeller revealed no evidence of preimpact failure or malfunction. The flaps and landing gear were retracted and all trim settings were within the normal operating range. Additionally, the airplane was within weight and balance limitations for the flight. The cause of the pilot-reported panel failure could not be determined; however, the possibility of a total electrical failure was eliminated since the pilot maintained radio contact with the air traffic controller. Although the source of the instrumentation failure could not be determined, proper pilot corrective actions, identified in the pilot operating handbook, following the failure most likely would have restored flight information to the pilot’s electronic flight display. Additionally, a standby attitude gyro, compass, and the co-pilot’s electronic flight display units would be available for attitude reference information assuming they were operational.

The airplane encountered in-flight icing, and the pilot diverted to an airport to attempt to knock the ice off at a lower altitude. During the instrument approach, the pilot advised the tower controller of the ice, and that it depended on whether or not the ice came off the airplane if she would land. As the airplane broke out of the clouds, it appeared to tower personnel to be executing a missed approach; however, it suddenly "dove" for the runway. The tower supervisor noticed that the landing gear were not down, and at 75 to 100 feet above the runway, advised the pilot to go around. The airplane continued to descend, and by the time it impacted the runway, the landing gear were only partially extended, and the propellers and airframe impacted the pavement. The pilot then attempted to abort the landing. The damaged airplane became airborne, climbed to the right, stalled, and nosed straight down into the ground.

During takeoff from the departure airport, as the pilot advanced the throttles, the aircraft made a "sudden turn to the right." The pilot successfully aborted the takeoff, performed an engine run-up, and then took off without incident. The pilot experienced no anomalies during the second takeoff or the flight to the destination airport. As he reduced the power while in the traffic pattern, at the destination airport, the left engine accelerated to 60 percent power. The pilot reported to the tower that he had "one engine surging and another engine that seems like I lost control or speed." The pilot advanced and retarded the throttles and the engines responded appropriately, so he continued the approach. As the pilot flared the airplane for landing, the left engine surged to 65 percent power with the throttle lever in the "idle" position. The airplane immediately turned to the right; the right wing dropped and impacted the ground. Disassembly of the engines revealed no anomalies to account for surging, or for an uncommanded increase in power or lack of throttle response. Functional testing of the fuel control units and fuel pumps revealed the flight idle fuel flow rate was 237 and 312 pounds per hour (pph), for the left and right engines, respectively. These figures were higher than the new production specification of 214 pph. According to the manufacturer, flight idle fuel flow impacts thrust produced when the power levers are set to the flight idle position and differences in fuel flow can result in an asymmetrical thrust condition.

On February 2, 2005, about 0718 eastern standard time, a Bombardier Challenger CL-600-1A11, N370V, ran off the departure end of runway 6 at Teterboro Airport (TEB), Teterboro, New Jersey, at a ground speed of about 110 knots; through an airport perimeter fence; across a six-lane highway (where it struck a vehicle); and into a parking lot before impacting a building. The two pilots were seriously injured, as were two occupants in the vehicle. The cabin aide, eight passengers, and one person in the building received minor injuries. The airplane was destroyed by impact forces and postimpact fire. The accident flight was an on-demand passenger charter flight from TEB to Chicago Midway Airport, Chicago, Illinois. The flight was subject to the provisions of 14 Code of Federal Regulations (CFR) Part 135 and operated by Platinum Jet Management, LLC (PJM), Fort Lauderdale, Florida, under the auspices of a charter management agreement with Darby Aviation (Darby), Muscle Shoals, Alabama. Visual meteorological conditions prevailed for the flight, which operated on an instrument flight rules flight plan.

The flight was cleared for the ILS Runway 19 approach, circle-to-land on Runway 24; a 6,013-foot-long, 150-foot wide, asphalt runway. The auto throttle and autopilot were disengaged during the approach, about 800 feet agl. However, the auto throttle reengaged just prior to touchdown, about 35 feet agl. The flightcrew did not recall reengaging the auto throttle, and were not aware of the autothrottle reengagement. According to the auto throttle computers, the reengagement was commanded through one of the Engage/Disengage paddle switches located on each power lever. The target airspeed set for the auto throttle system was 138 knots. After touchdown, as the airplane decelerated below 138 knots, the auto throttle system gradually increased the power levers in an attempt to maintain the target airspeed. Without the power levers in the idle position, the ground spoilers and thrust reversers would not deploy. While the flightcrew was pulling up on the thrust reverser levers, they may not have initially provided enough aft force on the power levers (15 to 32 lbs.) to override and disconnect the auto throttle system. The flight data recorder indicated that the autothrottle system disengaged 16 seconds after the weight-on-wheels switches were activated in ground mode. As the airplane neared the end of the runway, the pilot engaged the emergency brake, and the airplane departed the right side of the runway. The autothrottle Engage/Disengage paddle switches were not equipped with switch guards. Although the autothrottle system provided an audible tone when disengaged, it did not provide a tone when engaged. The reported wind about the time of the accident was from 290 degrees at 16 knots, gusting to 25 knots, with a peak wind from 300 degrees at 32 knots.

After a normal taxi and takeoff, the airplane's landing gear would not retract after liftoff. After unsuccessfully attempting to raise the landing gear manually, the flight crew elected to return to the airport. During the landing flare, the ground spoilers deployed when the throttles were brought to idle. The airplane descended rapidly and landed hard, and the right main landing gear collapsed. The investigation determined that a mechanic had wedged wooden sticks into the airplane's weight-on-wheels (WOW) switches to force them into the ground mode while the airplane was on jacks during maintenance. The mechanic said that he used the sticks to disable the WOW switches to gain access to the maintenance data acquisition unit, which was necessary to troubleshoot an overspeed alert discrepancy. After the maintenance was performed, the sticks were not removed, and the airplane was returned to service. No notation about the disabled WOW switches was entered in the work logs. Postaccident ground testing of the accident airplane's cockpit crew alerting system and examination of flight data recorder (FDR) data determined that the system was functioning properly and that it produced a blue WOW fault message, an amber WOW fault message, and a red GND SPOILER warning message when the accident flight conditions were recreated. The messages produced were consistent with FDR and cockpit voice recorder (CVR) information. Ground spoilers will deploy when the throttles are brought to idle if the spoilers are armed and the WOW switches are in the ground mode. The G-V Quick Reference Handbook (QRH) cautions flight crews not to move thrust reverser levers and to switch the GND SPOILER armed to off following an amber WOW FAULT message. A red GND SPOILER message calls for the flight crew to disarm the ground spoilers and pull the circuit breakers to make sure the spoilers are not rearmed inadvertently. Based on CVR information, there was no indication that the flight crew followed checklist procedures contained in the G-V's QRH that referenced WOW faults or GND SPOILER faults. Preflight checklist procedures also called for the flight crew to conduct a visual inspection of the WOW switches.