HISTORY OF FLIGHTOn August 17, 2015, about 0830 mountain standard time, a Quest Kodiak 100, N771RT, sustained minor damage when the pilot's seat slid aft and the airplane veered from the landing strip during the takeoff roll near Page, Arizona. The commercial pilot and five passengers were not injured. Redtail Partners, LLC owned the airplane and Arrow West Aviation (dba Redtail Aviation) was operating it under the provisions of Title 14 Code of Federal Regulations Part 135. Visual meteorological conditions prevailed and a company flight plan had been filed for the non-scheduled cross country flight. The flight was originating at the time of the accident with a planned destination of Canyonlands Field Airport, Moab, Utah.
The pilot stated that the purpose of the flight was to transport the passengers back to Moab, which required him to depart from a remote paved road that was regularly used as a runway. The airplane began the takeoff roll, and after about 100 feet down the road, the pilot's seat slid back abruptly to the full aft position. Because his right hand was positioned on the power lever for takeoff, the pilot inadvertently retarded the lever to the idle position as the seat slid aft. The pilot released his grip on the control yoke in an effort to keep the nose down. His feet were unable to reach the rudder pedals and with the seatbelt in the locked position, he was not able to manipulate his body forward to regain control.
The pilot further stated that the airplane began to veer to the left, continued off the pavement, and collided into a wire fence. After the airplane came to rest, the pilot was able to move the seat forward where he could reach the shoulder harness unlock-lever. The pilot and passengers egressed the airplane without incident. AIRCRAFT INFORMATIONThe Quest Kodiak 100 is a high-wing, unpressurized, single-engine turboprop-equipped fixed tricycle landing gear airplane manufactured by Quest Aircraft. The airplane was configured with 10-seats, two of which were adjustable seats in the pilot (left) and co-pilot (right) position. According to the records examined, the airplane, serial number 100-0059, was manufactured in November 2011, and was purchased by the operator in 2012. At the time of the accident, the airframe had accumulated a total time in service of 953.4 hours. The operator reported that the most recent annual inspection was completed on May 23, 2015, at which time it had accumulated 864 total hours in service.
Standard seating for the airplane consists of six-way adjustable pilot and front passenger seat each equipped with a four-point passenger restraint system. They may be moved forward or aft, adjusted up or down and the seat back angle may be changed.
The incident seat was part number 100-825-5010-01 and manufactured by Millennium Concepts, Inc. The seat was designed with two latches located on both the right and left side that are lifted to enable the seat to move along the track. The seat track consisted of two metal rails that were affixed to the floor along the longitudinal axis. The rails had two scalloped edges facing toward one another at one-inch spacing, creating numerous circular receptacles where the seat stop would engage when the seat was locked into position. The foot weldments would slide in the rails' channel under the scalloped upper layer.
The latches were comprised of a plastic rocker-type handle that rotated about a plastic pin when raised upward. When lifted, two swages from the latch-end of the seat stop actuator cable would be pulled and in response the swaged end from the seat-track end would raise the seat stop (a pin-like metal cylinder that engages in the seat track receptacles). Each latch contained a swaged-end from both a left and a right side seat-stop actuator cable enabling both the left and the right seat stops to raise at the same time.
The seat stop contains a groove where the actuator cable swages (one from the right and one from the left latch) are captured. The locking foot cap, a four pronged housing, encages the seat stop and the locking foot spring is located between it and the seat stop pin. With a latch raised, one of the swages captured in the seat stop pin (depending on if it was the right or left side latch) would override the force of the spring that normally holds the seat stop pin down against the lip of the foot weldment. This in turn would raise the seat stop pin leaving room between it and the bottom of the weldment lip (where the scalloped edges of the seat track rail can slide between). The latch gives no positive indication (feel) when effectively raised or lowered.
The airplane's Pilot Operating Handbook contains a checklist in the "Before Takeoff" section that lists "seat locked and secure." AIRPORT INFORMATIONThe Quest Kodiak 100 is a high-wing, unpressurized, single-engine turboprop-equipped fixed tricycle landing gear airplane manufactured by Quest Aircraft. The airplane was configured with 10-seats, two of which were adjustable seats in the pilot (left) and co-pilot (right) position. According to the records examined, the airplane, serial number 100-0059, was manufactured in November 2011, and was purchased by the operator in 2012. At the time of the accident, the airframe had accumulated a total time in service of 953.4 hours. The operator reported that the most recent annual inspection was completed on May 23, 2015, at which time it had accumulated 864 total hours in service.
Standard seating for the airplane consists of six-way adjustable pilot and front passenger seat each equipped with a four-point passenger restraint system. They may be moved forward or aft, adjusted up or down and the seat back angle may be changed.
The incident seat was part number 100-825-5010-01 and manufactured by Millennium Concepts, Inc. The seat was designed with two latches located on both the right and left side that are lifted to enable the seat to move along the track. The seat track consisted of two metal rails that were affixed to the floor along the longitudinal axis. The rails had two scalloped edges facing toward one another at one-inch spacing, creating numerous circular receptacles where the seat stop would engage when the seat was locked into position. The foot weldments would slide in the rails' channel under the scalloped upper layer.
The latches were comprised of a plastic rocker-type handle that rotated about a plastic pin when raised upward. When lifted, two swages from the latch-end of the seat stop actuator cable would be pulled and in response the swaged end from the seat-track end would raise the seat stop (a pin-like metal cylinder that engages in the seat track receptacles). Each latch contained a swaged-end from both a left and a right side seat-stop actuator cable enabling both the left and the right seat stops to raise at the same time.
The seat stop contains a groove where the actuator cable swages (one from the right and one from the left latch) are captured. The locking foot cap, a four pronged housing, encages the seat stop and the locking foot spring is located between it and the seat stop pin. With a latch raised, one of the swages captured in the seat stop pin (depending on if it was the right or left side latch) would override the force of the spring that normally holds the seat stop pin down against the lip of the foot weldment. This in turn would raise the seat stop pin leaving room between it and the bottom of the weldment lip (where the scalloped edges of the seat track rail can slide between). The latch gives no positive indication (feel) when effectively raised or lowered.
The airplane's Pilot Operating Handbook contains a checklist in the "Before Takeoff" section that lists "seat locked and secure." ADDITIONAL INFORMATIONFollowing the examination, Quest queried their operators to see if any similar incidents had happened. A pilot reported that during takeoff, with the airplane configured in a steep nose-up attitude, his seat slid back and he asked the co-pilot to take the controls. The pilot stated he never adjusted the seat to see if the seat latch was engaged, rather entered into the cockpit and flew. TESTS AND RESEARCHThe seat was removed and examined by investigators from the NTSB and Quest Aircraft. The complete examination notes with pictures are in the public docket for this accident.
An external examination of the pilot's seat revealed that both the left and the right locking foot caps were damaged. Specifically, they were bent and the locking foot spring was displaced from the ridge it rests on. The forward tabs were bent forward resting outside of their respective foot weldments, the steel piece that slides on the bottom of the track that is positioned in between the stop halves. The aft tabs were bent forward and crushed about the aft foot weldment groove.
Investigators removed the copilot seat and installed it on the pilot seat tracks. On the first attempts, the seat operation appeared normal and throughout the course of all the testing conducted, it was not possible for investigators to disengage the seat from the engaged position unless a latch was raised.
Over numerous tests sliding the seat back on the rail with the locking pin initially disengaged, investigators were able to get the seat to move freely (not automatically lock the locking pin) only when applying an extreme side load or pulling one swage taught on the latch. Since the two feet are on independent systems, it was not understood how that could have occurred. The lack of positive response of the finger actuated latch made it difficult to verify if the seat was actually engaged.
Investigators were able to replicate the position the seat would need to be manipulated to bend the locking foot cap. This could occur if the front legs weldments were out of the seat track and the seat was tilted backward. This likely would take place during maintenance and/or installation if the aft feet were not disengaged from the seat track and the technician wanted to push the seat all the way aft to the passengers' seats. The manufacturer provided detailed procedures illustrating the proper way to remove and install the crew seats. It is unknown if the damaged locking foot caps contributed to the incident.