Lewisville, TX, USA
N1223S
Cirrus Design Corp. SR-22
During cruise flight, the left aileron separated from one attach point, and the pilot executed a forced landing to a field. Prior to the accident flight, the airplane underwent maintenance for two outstanding service bulletins. During compliance with one of the service bulletins, the left aileron would have been removed and reinstalled. The pilot confirmed with the service center personnel that the maintenance on the airplane was completed and then proceeded to preflight the airplane. After departure, the airplane was level at 2,000 feet mean sea level (msl) for approximately one minute, the pilot noticed that the airplane began "pulling" to the left, and the left aileron was separated at one hinge attach point. The pilot then flew the airplane toward an unpopulated area, shutdown the engine, and deployed the aircraft's ballistic parachute system. Subsequently, the airplane descended to the ground with the aid of the parachute canopy and came to rest upright in a field of mesquite trees. Examination of the left aileron and the airframe aileron hinges revealed that the outboard aileron hinge bolt was missing, and no evidence of safety wire noted. According to maintenance manual procedures, the bolt and washer hardware were to be torqued to a measured 20-25 inch pounds, then safety wired to a actuation fitting. After installation, the manual required a verification of proper hinge bolt installation and torque on the outboard hinge.
HISTORY OF FLIGHT On October 3, 2002, approximately 1440 central daylight time, a Cirrus Design Corporation SR-22 single-engine airplane, N1223S, sustained substantial damage when it impacted trees and terrain during a forced landing following an in-flight separation of the left aileron during cruise flight near Lewisville, Texas. The private pilot, who was the sole occupant of the airplane, was not injured. The airplane was registered to and operated by NS Enterprises, Inc., of Dallas, Texas. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The flight departed the Addison Airport (ADS), Addison, Texas, approximately 1430, and was destined for the Dallas Executive Airport (RBD), Dallas, Texas. In an interview with the NTSB investigator-in-charge (IIC), the pilot reported that on October 2, 2002, a Cirrus authorized service center at ADS completed service bulletin (SB) 22-95-05, Replacement of CAPS (Cirrus Airframe Parachute System) Activation Cable, and SB A22-27-03, Trim Cartridge Self-Locking Nut Replacement, on the airplane. The pilot confirmed with the service center personnel that the maintenance on the airplane was completed and then proceeded to preflight the airplane for a flight to RBD, where the airplane was based. The service center informed the pilot that the logbook entry for completed maintenance was not included in the logbooks at that time. During the preflight and pre-takeoff checks, the pilot noted a "failed" message when testing the autopilot in "navigation" mode, no additional anomalies or discrepancies were noted. The airplane departed from runway 13, and the pilot executed a left turn to the east. After the airplane was level at 2,000 feet mean sea level (msl) for approximately one minute, the pilot noticed that the airplane began "pulling" to the left. The pilot attempted to troubleshoot the problem and concentrated on the autopilot system due to the failure noted during the pre-flight check. After several unsuccessful attempts to disengage the autopilot with the control yoke switch, the pilot attempted to pull the autopilot circuit breaker. As the pilot bent over to pull the circuit breaker, he noticed that the left aileron was separated at one hinge attach point. While attempting to maintain level flight with two hands on the control stick, the pilot declared an emergency to the ADS air traffic control tower controller. The pilot proceeded toward an unpopulated area and climbed to an altitude of 2,500 feet msl. With the nose of the airplane heading into the wind, at 120 knots indicated airspeed, the pilot shutdown the engine and deployed the CAPS. During the deployment sequence of the CAPS, the left aileron separated from the airplane. Subsequently, the airplane descended to the ground with the aid of the parachute canopy and came to rest upright in a field of mesquite trees. According to an FAA inspector who responded to the accident, the left aileron was located approximately 250 yards from the airplane. PERSONNEL INFORMATION The pilot held a private pilot certificate, with airplane single-engine land and instrument airplane ratings. The private pilot was issued a third class medical certificate on December 13, 2000, with the limitation "Holder shall wear corrective lenses." According to the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the pilot reported he had accumulated a total of 366 flight hours, of which 125 hours were accumulated in the same make and model as the accident airplane. The pilot's most recent biennial flight review (BFR) was accomplished on October 21, 2001, in a Cirrus Design Corporation SR-22. A review of the pilot training records revealed the pilot completed the Cirrus Pilot Transition Training course, sponsored by the Cirrus Design Corporation, on October 19, 2001, in Dallas, Texas. According to the course syllabus, the pilot underwent training for the CAPS system in the following areas: components of the CAPS system, activation of system and stages of deployment, decision making process involved in activation of system, hazards of deployment and risk benefit in various situations, and how to deploy the system. AIRCRAFT INFORMATION The 2001-model Cirrus Design Corporation SR-22 airplane, serial number 105, was a low-wing, fixed tri-cycle landing gear, primarily composite, and monocoque design airplane. The airplane was powered by a six cylinder, horizontally opposed, air-cooled, fuel injected Teledyne Continental Motors (TCM) IO-550-N engine (serial number 685853), rated at 310 horsepower. The airplane was equipped with a three-blade Hartzell constant speed, aluminum alloy propeller. The airplane was configured to carry four occupants. The airplane was issued a standard airworthiness certificate on October 18, 2001, and was certificated for normal category operations. The airplane was registered to the owner on April 18, 2002. At the time of the accident, the airplane had accumulated a total time of 145 hours. According to the FAA approved Cirrus Design SR22 Pilot's Operating Handbook (POH), the airplane uses conventional flight controls for the ailerons, elevator and rudder. The control surfaces are pilot controlled through either of the two single-handed side control yokes which are mounted beneath the instrument panel. The flight control system contains a combination of push rods, cables, and bell cranks for the control of the sufaces. The ailerons are a conventional design with skin, spar and ribs manufactured of aluminum. The ailerons are attached to the wing shear web at two hinge points. Aileron control is generated through the control yokes by rotating the yokes in pivoting bearing carriages. Push rods link the carriages to a pulley system in which cables run from a center cockpit sector, beneath the cabin floor, and then aft of the rear spar. The cables are routed in each wing to a vertical crank arm that rotates the aileron through a right angle conical drive arm. According to the FAA approved Cirrus Design maintenance manual 13773-001, revision, dated November 20, 2000, the aileron is attached to the wing at an outboard and inboard fixed hinge bracket. The outboard hinge point attach hardware included: one outer aileron hinge bolt, three thick washers, one thin washer, one self-locking nut, and safety wire. According to maintenance manual procedures, the bolt and washer hardware were to be torqued to a measured 20-25 inch pounds, then safety wired to a actuation fitting. After installation, the manual required a verification of proper hinge bolt installation and torque on the outboard hinge. A review of SB A22-27-03 revealed that during compliance, the left aileron would have been removed and reinstalled. The SB instructions for the reinstallation of the aileron are the following: "Install LH aileron. (Refer to AMM 57-50)". "AMM 57-50" is the following: Airplane Maintenance Manual, Chapter 57 (Wings), -50 (Flight Surfaces). METEOROLOGICAL INFORMATION At 1353, the Denton Municipal Airport Automated Surface Observation System (located approximately 15 nautical miles northwest of the accident site) reported the wind from 110 degrees at 9 knots, gusting to 15 knots, visibility 10 statute miles, few clouds at 4,500 feet, scattered clouds at 5,500 feet, temperature 90 degrees Fahrenheit, dew point 66 degrees Fahrenheit, and an altimeter setting of 29.80 inches of Mercury. WRECKAGE AND IMPACT INFORMATION The airplane impacted mesquite trees and the terrain, and came to rest upright. The accident site was located approximately 33 degrees 02 minutes North latitude, and 096 degrees 57 minutes West longitude, at an estimated elevation of 475 feet. The airplane came to rest intact with the exception of the left aileron separation. The parachute canopy, suspension lines, and fuselage harness of the CAPS remained attached to the fuselage and came to rest in the mesquite trees. According to the FAA inspector who responded to the accident site, flight control continuity was established from the cockpit controls to the flight control surfaces (with the exception of the left aileron). The airplane was recovered to the facility of Air Salvage of Dallas, near Lancaster, Texas. PATHELOGICAL INFORMATION No toxicological tests were performed on the pilot. SURVIVAL ASPECTS The Cirrus Airplane Parachute System consists of a parachute, a solid-propellent rocket, a rocket activation handle, and a harness imbedded within the fuselage structure. A composite box, which is attached to the airframe, houses the parachute and rocket assembly, and the parachute is contained in a deployment bag. The deployment bag creates an orderly deployment process by allowing the canopy to inflate after the rocket has pulled the suspension lines and harness. A three-point harness connects the airplane to the parachute. The aft harness strap is stowed in the parachute canister, and the forward harness straps are routed from the parachute canister to the firewall attach points and stowed under the fuselage skin. The parachute is a 2,400 square foot round canopy connected to the harness straps by suspension lines. The CAPS is activated by pulling the T-handle installed in the cabin ceiling above the pilot's right shoulder. A maintenance safety pin is provided to ensure that the activation handle is not pulled during maintenance. A "Remove Before Flight" streamer is attached to the pin. When CAPS is activated, the rocket is launched, the parachute assembly is pulled outward, and in approximately two seconds, the canopy begins inflation. As the canopy inflates, the airplane's forward speed will be slowed. This deceleration should be less than 3 g's. Eight seconds after activation, the aircraft will configure into an approximate level attitude. The vertical descent rate is expected to be between 1,600 and 1,800 feet per minute, and a ground impact equivalent to touchdown from a height of approximately 13 feet. The horizontal velocity and direction is based on the current wind conditions. The pilot and each passenger seat is equipped with a seatbelt and shoulder harness assembly with inertia reels. Cirrus Design Corporation recommends that the CAPS deployment occur at an altitude of 2,000 feet agl or higher, wings level attitude, fuel, mixture, throttle and magnetos in the OFF position, seatbelts tight, battery and alternator master switches in the OFF position. The POH recommends the CAPS may be appropriate in the following possible scenariors: Mid-air Collision, Structural Failure, Loss of Control, Landing Required in Terrain not Permitting a Safe Landing, and Pilot Incapacitation. The CAPS deployment is expected to result in the destruction of the airframe, and possible severe injury or death to the occupants. TEST AND RESEARCH On October 4, 2002, the airplane was examined by the NTSB IIC, FAA inspectors, representatives of Cirrus Design Corporation, and a representative of Ballastic Recovery Systems (BRS; the manufacturer of the parachute system), at the Air Salvage of Dallas facility. Examination of the left aileron and the airframe aileron hinges revealed that the outboard aileron hinge bolt was missing, and no evidence of safety wire was noted. No damage was noted on the outboard hinge assembly, and the threads on the self-locking nut were intact. The inboard aileron hinge bolt was found pulled from the airframe aileron hinge bearing. The inboard aileron hinge bolt and inboard aileron bearing race remained attached to the aileron, and the outer bearing race remained attached to the hinge structure attached to the wing. The safety wire remained attached to the bolt and the safety wire tab on the aileron. No other anomalies were noted with the airplane or the CAPS. In a written statement, a mechanic, who did not sign off the maintenance that was completed, stated, "Upon completion of work performed on N1223S the replacement of the trim drum screw the work was inspected for proper completion as per the SB. No defects in the completion of the work were noted. Safeties were inspected and found to be intact upon completion of the work." The statement was received by the NTSB IIC on April 17, 2003. ADDITIONAL INFORMATION The airplane was released to the owner's representative on October 4, 2002.
The improper reinstallation of the left aileron by maintenance personnel. A contributing factor was the non-suitable terrain for the forced landing.
Source: NTSB Aviation Accident Database
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