History of Flight
On September 2, 2021, at 0951 eastern daylight time, a Cessna 560XLS+ airplane, registration N560AR, was destroyed in an accident near Farmington, Connecticut. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. All four occupants—the pilot, copilot, and two passengers—sustained fatal injuries. One person on the ground sustained serious injuries, and three people sustained minor injuries.
According to FAA air traffic control audio recordings and cockpit voice recorder (CVR) transcripts, about 0913, the copilot contacted Yankee Terminal Radar Approach Control to obtain an instrument flight rules clearance to Dare County Regional Airport (MQI), Manteo, North Carolina. The controller provided the clearance and advised the flight to hold for release. About 0948, the copilot reported taxiing and ready in one minute. The controller instructed the flight to hold for release. The flight taxied toward runway 2. At 0948:20, the controller released the flight for departure, instructing the flight crew to enter controlled airspace on a 20° heading.
The copilot, serving as pilot monitoring (PM) from the right seat, repeated the instruction. The CVR recorded the PM discussing the departure frequency and transponder code while the pilot flying (PF) in the left seat said, “kay flaps. trim three times. pitot heat on.” The copilot responded that the pitot static was coming on. These items were part of the before takeoff checklist. However, there was no challenge-response for the taxi, before takeoff, or takeoff checklists, and the flight crew did not perform a crew briefing. The CVR did not record any mention of releasing the parking brake before takeoff. Flight data recorder (FDR) data did not indicate any flight control movements consistent with a check of the flight controls.
The CVR recorded the copilot make a radio call on the airport common traffic advisory frequency announcing departure from runway 2 straight out and that the final and base legs appeared clear. The sound of engine power advancing was heard at 0950:15. FDR data showed both thrust levers set at about 65°, and both engines remained at 91% N1 throughout the takeoff roll. While accelerating, the copilot called out “power is set…airspeed’s alive… eighty knots cross check… v one” at about 1,670 ft down the 3,665-ft-long runway. At 0950:44, the copilot called “Rotate.” FDR data indicated the airplane was about 2,000 ft down the runway at about 104 knots calibrated airspeed with elevator at about +9° when the rotate callout was made. Three seconds later, the copilot said “Oht oht ‘sa matter,” followed 1.7 seconds later by a sound of heavy strain from the pilot and him stating “it’s [not] rotating.” Then 2.4 seconds later, a grunt was recorded from the pilot.
The airplane continued along the runway centerline with left rudder input between 2° and 4°, decreasing to about 0.3° at about 2,375 ft. The flight crew then applied increasing right rudder to a maximum of about 10°, which remained until about 2,500 ft, when a slight deviation to the right began. Video cameras captured smoke trailing the airplane, and a ground track model determined smoke appeared about 2,685 ft down the runway. While deviating right, left rudder was applied to a maximum of about 18°, and the deviation ended about 0950:52 when the airplane was about 3,125 ft down the runway. Rudder values remained near neutral, and the airplane track remained straight to the end of the runway, offset right of centerline.
When the airplane reached the end of airport terrain, FDR data indicated airspeed increased to about 120 knots, elevator deflection increased to a maximum of about +16°, weight-on-wheels (WOW) remained on-ground, and pitch briefly changed to +1° then decreased to 0°. Past the end of the terrain, ground elevation dropped 20 to 25 ft; WOW changed to air mode, elevator increased to about +17° deflection, and pitch increased to about +22° in less than 2 seconds. As the airplane pitched up, elevator position rapidly decreased to about 1.0°. At 0950:54, the CVR recorded the sound of electronic stall warning followed 0.1 second later by stick shaker activation.
Two witnesses reported seeing a puff of blue smoke behind the airplane during the takeoff roll. One witness noted the airplane seemed “going slower” compared to previous flights and never lifted off. Another witness, located about 280 ft north-northeast of the departure end, saw the airplane come off the runway in a level attitude, then pitch nose-up but not climb. He reported the front of the right engine impacting a nearby pole, followed by sparks and a metallic grinding sound.
FDR data showed No. 2 engine N1 and N2 were 91.0% and 99.4% before impact with the pole. After impact, right engine N1 and N2 decreased to 80.1% and 95.1%, then continued to decrease despite thrust lever angles remaining at 65°. The airplane rolled right and became inverted in about 3.5 seconds, then impacted the ground and an occupied building, activating the building's sprinkler system. The building and contents sustained significant structural and fire damage.
Personnel Information
The pilot was a salaried employee of Interstate Aviation, Inc., the accident operator. He received transition training in a level D simulator for the Cessna 560XL (Excel) at Flight Safety International (FSI) in December 2009, with recurrent training in the Excel in 2017, and in the XLS+ in 2018, 2019, 2020, and 2021. All training was in a level D simulator, and he passed all practical tests on first attempt. The instructor for his latest Citation XLS+ Recurrent Pilot-In-Command course remarked he observed no weaknesses, and strengths included "Good aircraft control, CRM, and procedures."
The operator's president, who normally flew as copilot with the accident pilot, reported that during typical takeoffs, the accident pilot would center the airplane on the runway, then when almost to a full stop, begin the takeoff. He would not normally stop, apply brakes, then advance thrust and release brakes. When they flew together, they used checklists with challenge and response. During takeoff, they would call airspeed alive, 80 knots crosscheck, V1, rotate. At V1, hands moved from thrust levers to control yoke, then autopilot at 400 ft.
The copilot was a contract pilot for the operator. His available training records showed initial training at FSI in a Cessna 525 (Citation Jet) in November 2015, and training in a Gulfstream G450 in 2018 and recurrent training in the Gulfstream G550 on two occasions in 2019. The latest training in a level D simulator from November 18-23, 2019, consisted of 6 hours as PF and 6 hours as PM.
A review of logbook entries revealed no entries showing a sign off as SIC specifically for the accident make and model airplane. Entries between September 2020 and July 29, 2021, showed 11 flights as SIC in the accident airplane totaling 25 hours. The remarks section did not indicate whether he performed engine-out procedures or CRM training. The attorney representing the copilot's estate noted the flights but reported the family could not locate records concerning simulator training and could not recall if he attended training for the Cessna 560 series.
Aircraft Information
According to the airplane's type certificate data sheet and FAA-approved flight manual, the minimum flight crew was one pilot and one copilot. The last scheduled inspection was on July 2, 2021. At the beginning of the accident flight, the airplane had accumulated 11.3 hours since the last inspection. According to the aircraft status report, the parking brake valve, an on-condition item, was original to the airplane manufactured in 2009.
A pilot who flew the airplane on August 10 and 13, 2021, reported "zero squawks" on either flight.
The parking brake knob was located on the tilt panel forward of the left seat, adjacent to the occupant's knee, and was not visible to the right seat occupant.
Per the operating manual, the parking brake is set by depressing toe brakes and pulling out the parking brake pull knob on the left lower side of the tilt panel, mechanically actuating the parking brake valve and trapping fluid. The parking brake is released by pushing the knob in.
The airplane had a crew alerting system (CAS) that did not incorporate parking brake valve position. There was no annunciation when the parking brake was not fully released. A red NO TAKEOFF warning CAS message would display for some conditions like throttles advanced beyond climb setting or flaps not configured for takeoff.
Certification
The parking brake standard in 14 CFR 25.735 was first issued in 1965 and remained until May 2002. Under the original standard, the parking brake had to prevent the airplane from rolling on a paved, level runway with takeoff power on the critical engine. In May 2002, Amendment 25-107 incorporated cockpit indication when the parking brake was not fully released.
The FAA's certification process in 14 CFR 21.101 allowed introduction of derivative models to an existing type certificate. The FAA approved changes if the change was not significant, if compliance for unaffected areas would not contribute materially to safety, or if compliance was impractical. This allowed design updates without full recertification.
When the manufacturer applied for XLS+ certification on February 17, 2006, 14 CFR 21.101 Amendment 21-77 required compliance with regulations in effect on the application date, but the applicant could show compliance with an earlier amendment for a change the FAA found not significant. Although the parking brake knob location and movement changed from the previous design, the parking brake architecture and operation did not change. Because no significant changes were made, the FAA did not require recertification of the parking brake system. The XLS+ was certificated on May 30, 2008, to the 1965 parking brake standard.
Wreckage and Impact Information
Examination of the accident site revealed a broken telephone/electrical pole about 011° and 361 ft past the departure end of the runway, about 27 ft above ground level and about 1.8 ft lower than the runway end. An approximate 3-ft section of the outboard end of the right inboard flap was located in wetlands east of the pole. Additional wreckage was found close to the pole.
North of the pole, ground scars on grass were found about 850 ft from the damaged pole on a magnetic heading of 036°, about 245 ft from the impacted building. The aft empennage came to rest inverted on a heading of 130° outside the building, while the heat-damaged cockpit and cabin were just inside the building. The wing, with extensive impact and fire damage, was both inside and outside the building.
Wreckage including upper cabin material was found along the ground impact energy path, consistent with the airplane being inverted at impact. Flight control surfaces and engine components were noted along the path between the ground scar and the airplane's resting position.
Examination revealed the wings, cockpit, and cabin were damaged or consumed by post-crash fire. All primary and secondary flight control surfaces or their remains, both wingtips, the top of the vertical stabilizer and rudder, and ends of both horizontal stabilizers and elevators were accounted for.
Examination of flight controls for roll, pitch, and yaw showed no evidence of preimpact failure or malfunction. Both speed brakes were retracted. Flap positions could not be determined from actuators, but FDR data indicated they were set to and remained at 15° throughout the recorded data. The two-position horizontal stabilizer was in takeoff/land position and remained there. During takeoff, aileron trim was between 10° and 11° tab trailing edge down (left wing down), elevator trim was 18.02° ANU (beyond maximum limit) and unchanged throughout, and rudder trim actuator measured 1.9 inches (neutral). These trim values were consistent with values for the entirety of recorded data.
Examination of the parking brake handle revealed it remained partially attached to the tilt panel, extended about 2.5 inches, with a bent and fractured sleeve. The parking brake push/pull rod, knob, panel mount, fractured sleeve, and control cable showed consistent overstress fractures or cuts from recovery.
Field examination of both engines revealed no anomalies that would have precluded normal operation. FDR data showed no fault codes for either engine, and both were operating normally until impact with the pole.
Parking Brake Valve, Landing Gear, and Brake System Components
The parking brake valve was separated from structure and thermally damaged. The cable remained attached to a lever bent aft against the parking brake full-on stop. X-ray and CT scanning revealed the shaft flat was adjacent to mechanisms, consistent with the valve being in the closed (brake set) position. Lever-to-shaft interface showed no cracks or abnormalities. High-density particles and debris consistent with burned material were noted. Comparison with an exemplar valve confirmed the accident valve was in a closed position when exposed to elevated temperatures, confirmed upon disassembly. The parking brake valve position was not recorded by the FDR. Other than its closed position during operation, no anomalies were found.
Left and right main landing gear showed postimpact thermal damage but no anomalies precluding normal operation.
The left brake could not be pressurized. One wear pin was bent and unmeasurable; the other measured 0.941 inch with pistons fully retracted. Disassembly showed normal wear on pressure plate, stators, and rotors. No anomalies.
The right brake could not be pressurized. One wear pin extension was 0.285 inch, the other 0.300 inch. Disassembly showed normal wear. No anomalies.
Additional Information
An NTSB performance study involving the airplane manufacturer and FAA used data from FDR, CVR, video footage, tire skid marks, witness information, environmental conditions, and engine performance. (Details not fully provided in source.)