Key Lime Air

A Cirrus SR22 and a Swearingen AS226TC were approaching to land on parallel runways and being controlled by different controllers on different control tower frequencies. The pilot of the Swearingen was established on an extended final approach for the left runway, while the pilot of the Cirrus was flying a right traffic pattern for the right runway. Data from an on-board recording device showed that the Cirrus’ airspeed on the base leg of the approach was more than 50 kts above the manufacturer’s recommended speed of 90 to 95 kts. As the Cirrus made the right turn from the base leg to the final approach, its flight path carried it through the extended centerline for the assigned runway (right), and into the extended centerline for the left runway where the collision occurred. At the time of the collision, the Cirrus had completed about ½ of the 90° turn from base to final and its trajectory would have taken it even further left of the final approach course for the left runway. The pilot of the Swearingen landed uneventfully; the pilot of the Cirrus deployed the airframe parachute system, and the airplane came to rest upright about 3 nautical miles from the airport. Both airplanes sustained substantial damage to their fuselage. During the approach sequence the controller working the Swearingen did not issue a traffic advisory to the pilot regarding the location of the Cirrus and the potential conflict. The issuance of traffic information during simultaneous parallel runway operations was required by Federal Aviation Administration Order JO 7110.65Y, which details air traffic control procedures and phraseology for use by persons providing air traffic control services. The controller working the Cirrus did issue a traffic advisory to the Cirrus pilot regarding the Swearingen on the parallel approach. Based on the available information, the pilot of the Cirrus utilized a much higher than recommended approach speed which increased the airplane’s radius of turn. The pilot then misjudged the airplane’s flight path, which resulted in the airplane flying through the assigned final approach course and into the path of the parallel runway. The controller did not issue a traffic advisory to the pilot of Swearingen regarding the location of the Cirrus. The two airplanes were on different tower frequencies and had the controller issued an advisory, the pilot of the Swearingen may have been able to identify the conflict and maneuver his airplane to avoid the collision.

The airline transport pilot delayed his scheduled departure for the night cargo flight due to thunderstorms along the route. Before departing, the pilot explained to the flight follower assigned to the flight that if he could not get though the thunderstorms along the planned route, he would divert to the alternate airport. While en route, the pilot was advised by the air traffic controller in contact with the flight of a "ragged line of moderate, heavy, and extreme" precipitation along his planned route. The controller also stated that he did not see any breaks in the weather. The controller cleared the pilot to descend at his discretion from 7,000 ft mean sea level (msl) to 3,000 ft msl, and subsequently, the controller suggested a diversion to the northeast for about 70 nautical miles that would avoid the most severe weather. The pilot responded that he had enough fuel for such a diversion but concluded that he would "see what the radar is painting" after descending to 3,000 ft msl. About 1 minute 30 seconds later, as the airplane was descending through 7,000 ft msl, the controller stated, "I just lost you on radar, I don't show a transponder, it might have to do with the weather." About 40 seconds later, the pilot advised the controller that he intended to deviate to the right of course, and the controller told the pilot that he could turn left and right as needed. Shortly thereafter, the pilot stated that he was going to turn around and proceed to his alternate airport. The controller cleared the pilot direct to his alternate and instructed him to maintain 3,000 ft msl. The pilot acknowledged the instruction, and the controller then stated, "do you want to climb back up? I can offer you any altitude." The pilot responded that he would try to climb back to 3,000 ft msl. The controller then recommended a heading of 180° to "get you clear of the weather quicker," and the pilot responded, "alright 180." There were no further communications from the pilot. Shortly thereafter, radar data showed the airplane enter a right turn that continued through about 540°. During the turn its airspeed varied between 198 and 130 knots, while its estimated bank angles were between 40 and 50°. Examination of the wreckage indicated that airplane experienced an in-flight breakup at relatively low altitude, consistent with radar data that showed the airplane's last recorded altitudes to be around 3,500 ft msl. The symmetrical nature of the breakup, damage to the outboard wings, and damage to the upper fuselage were all signatures indicative that the left and right wings failed in positive overload almost simultaneously. All of the fracture surfaces examined had a dull, grainy appearance consistent with overstress separation. There was no evidence of pre-existing cracking noted at any of the separation points, nor was there evidence of any mechanical anomalies that would have prevented normal operation. Review of base reflectivity weather radar data showed that, while the pilot was maneuvering to divert to the alternate airport, the airplane was operating in an area of light precipitation that rapidly intensified to heavy precipitation, as shown by radar scans completed shortly after the accident. During this time, the flight was likely operating in clouds along the leading edge of the convective line, where the pilot most likely would have encountered updrafts and severe or greater turbulence. The low visibility conditions that existed during the flight, which was conducted at night and in instrument meteorological conditions, coupled with the turbulence the flight likely encountered, were conducive to the development of spatial disorientation. Additionally, the airplane's maneuvering during the final moments of the flight was consistent with a loss of control due to spatial disorientation. The pilot's continued flight into known convective weather conditions and his delayed decision to divert the flight directly contributed to the accident. Although the operator had a system safety-based program, the responsibility for the safe outcome of the flight was left solely to the pilot. Written company policy required completion of a flight risk assessment tool (FRAT) before each flight by the assigned flight follower; however, a FRAT was not completed for the accident flight. The flight followers responsible for completing the FRATs were not trained to complete them for night cargo flights, and the operator's management was not aware that the FRATs were not being completed for night cargo flights. Further, if a FRAT had been completed for the accident flight, the resultant score would have allowed the flight to commence into known hazardous weather conditions without any further review. If greater oversight had been provided by the operator, it is possible that the flight may have been cancelled or re-routed due to the severity of the convective weather conditions present along the planned route of flight.

The pilot was conducting an early morning repositioning flight of the cargo airplane. Shortly after takeoff, the pilot reported to air traffic control that he had “lost an engine” and would return to the airport. Several witnesses reported that the engines were running rough and one witness reported that he did not hear any engine sounds just before the impact. The airplane impacted trees, a wooden enclosure, a chain-linked fence, and shrubs in a residential area and was damaged by the impact and postimpact fire. The airplane had been parked outside for 5 days before the accident flight and had been plugged in to engine heaters the night before the flight. It was dark and snowing lightly at the time of the accident. The operator reported that no deicing services were provided before the flight and that the pilot mechanically removed all of the snow and ice accumulation. The wreckage and witness statements were consistent with the airplane being in a right-winglow descent but the airplane did not appear to be out of control. Neither of the propellers were at or near the feathered position. The emergency procedures published by the manufacturer for a loss of engine power stated that pilots should first secure the engine and feather the propeller following a loss of engine power and then turn the fuel selector for that engine to “off.” The procedures also cautioned that continued flight might not be possible if the propeller was not feathered. The right fuel selector valve and panel were found in the off position. Investigators were not able to determine why an experienced pilot did not follow the emergency procedures and immediately secure the engine following the loss of engine power. It is not known how much snow and ice had accumulated on the airplane leading up to the accident flight or if the pilot was successful in removing all of the snow and ice with only mechanical means. The on-scene examination of the wreckage and the teardown of both engines did not reveal any preimpact mechanical malfunctions or failures. While possible, it could not be determined if water or ice ingestion lead to the loss of engine power at takeoff.

The accident involved 2 Swearingen airplanes. The pilot of the first airplane reported that he had taxied north for departure. There were several company aircraft in front of him in line for departure so he came to a complete stop. The pilot of the second airplane reported that he was also taxiing north for departure. He had seen the lights from an aircraft holding short of runway 17R; however, he did not see the lights of the first airplane until it was too late. The pilot of the second airplane reported he applied full brakes and used reverse thrust but was unable to avoid hitting the first airplane. Both airplanes were substantially damaged.

According to the pilot, he was told to enter left base and was cleared to land. The pilot stated that, when he reduced the airspeed to lower the landing gear, he "heard the gear come down," and he verified "three green in the [landing] gear indicator." He landed the airplane on its "main [landing gear] wheels first" and slowly let the nose of the airplane drop. Although both main landing gear assemblies remained down and locked, the nose landing gear collapsed, allowing the nose of the airplane and both propellers to strike the runway. The airplane slid approximately 3,000 feet, coming to a stop on the right edge of the runway. Several fractured propeller pieces impacted the left and right sides of the fuselage substantially damaging two fuselage station bulkheads. The fuselage bulkhead, forward of the nose landing gear well, was also substantially damaged due to contact with the runway. The pilot said that, during the approach, from base to final, he did not hear a landing gear warning horn. An air traffic control specialist, stated that he told the pilot to enter a left base and that he was cleared to land. The specialist stated that he observed the airplane roll out on a 2-mile final "with the gear down." As the airplane was rolling down the runway the "nose wheel collapsed." An FAA inspector examined the airplane and noted that, according to the Fairchild SA226 Maintenance Manual, the nose landing gear's up-lock mechanism was not properly lubricated, a "critical clearance" measurement between the nose landing gear's bell crank roller and positioning cam was found to be out of tolerance, and when the throttles were retarded, the landing gear warning horn activated, but it was "barely audible." According to the Fairchild SA226 Maintenance Manual, the landing gear should be lubed every 200 hours. The FAA inspector stated that the approved maintenance inspection sheet for the operator, did not show the requirement for the main landing gear or nose landing gear to be lubed every 200 hours.

The airplane was on a non-scheduled cargo flight which was projected to fly an approximate 240 degree course for 92 nm. The accident site was located on a heavily forested steep mountain side, 15 to 16 nm north of the airplane's projected course. The debris field began at an east-west ridge line, and progressed for 300 feet on a 010 degree track to the downed airplane. Examination of the airframe and engines revealed no evidence of preimpact discrepancies. The accident site was in an area where the Fall color of the aspens was at its peak. Additionally, it was an area where elk were sometimes observed.

The purpose of the flight was for the instructor pilot to administer second-in-command (SIC) flight training to the commercial pilot in the twin-engine aircraft. According to the training manual, SIC training encompassed 4 hours of normal and emergency flight maneuvers to include stalls in the landing and takeoff configuration and while turning at a 15-30 degree bank. A witness heard the airplane's engines and observed the airplane from her driveway. The witness stated that as "the [engine] noise was getting louder and louder, I spotted it spiraling downward." The witness thought that the airplane was performing aerobatics; however, the airplane was getting too close to the ground. The witness heard a loud thud, and approximately 3 seconds later, she heard a loud boom and saw black smoke billow up. Another witness stated that she observed the airplane "going nose first straight down and spinning...counterclockwise." She thought the airplane was performing aerobatic maneuvers; however, the airplane did not stop descending. The airplane disappeared behind trees and the witness heard a loud explosion and saw smoke. She added that she did not observe what the airplane was doing prior to seeing it in a "downward spiral." Radar data depicted the airplane at 8,400 feet msl for the last 2 minutes and 26 seconds of the flight. The recorded aircraft ground speed during that time period fluctuated between 75 and 59 knots. The final radar returns depicted the airplane as making a 180 degree turn before radar contact was lost. No mayday calls were received from the airplane. The airplane impacted the ground in a near wings level attitude and was consumed by a post-crash fire. No anomalies were noted with the airplane or its engines during a post-accident examination. It is unknown which of the pilots was flying the airplane at the time of the accident.