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On March 22, 2001, at 1140 Hawaiian standard time, an Agusta A109A twin engine helicopter, N293G, made a hard landing, bounced into the air, and came to rest on its right side, at the Port Allen Airport, Hanapepe, Kauai, Hawaii. The helicopter was registered to and operated by Niihau Helicopters, Makaweli, Hawaii, under the provisions of 14 CFR Part 91 as an Federal Aviation Administration (FAA) Part 135.293 check ride. The commercial pilot and the check airman, who was an FAA inspector, were not injured. The helicopter sustained substantial damage. Visual meteorological conditions prevailed, and a flight plan was not filed for the local area flight. The flight departed Robinson Ranch, a private helipad on the island of Niihau, about 1120, and was scheduled to terminate there.
Check Airman Statement
According to the check airman's written statement, he provided the pilot with a preflight briefing "as to the conduct of the check ride." He informed the pilot they would be performing a confined area takeoff and landing, settling with power demonstration, pinnacle operations, an instrument competency check, simulated emergency procedures, and engine failures.
The check airman said the pilot "seemed well versed in the aircraft systems and emergency procedures." The check airman then elected to give the pilot a "stuck left pedal" situation to test the pilot's ability to determine the difference between an anti-torque failure and a stuck pedal scenario.
The check airman blocked the anti-torque pedals with the "left pedal slightly forward of neutral." The pilot "seemed a bit unfamiliar with the currently accepted procedure," and the check airmen "explained his options on the approach so that he may make an informed decision and take appropriate action." When the helicopter came to a 5- to 6-foot hover, the check airman informed the pilot he could either make a "slight reduction of power and slight pitch increase to allow the aircraft to settle to the ground without going into an uncontrollable spin," or "go around." The pilot was also told that only enough power should be reduced "to effect a slight heading change and that it should be done very slowly."
According to the check airman, the pilot "reached for the power levers and started to very slowly reduce the power and then suddenly, without warning, snapped both power levers to the idle detent." The pilot then initiated a hovering auto rotation and "retook control of the pedals." The check airman "removed [his] feet from the pedals immediately." The helicopter yawed to the left about 60 to 70 degrees before the pilot stopped the yaw with right pedal input. The check airman indicated the pilot started "pulling collective immediately rather [than] waiting until 2 feet above the ground," and he continued to monitor the situation. About 2 feet off the ground, the check airman realized the pilot had pulled too much pitch too soon," and they would hit the ground hard.
The helicopter impacted the ground, bounced into the air slightly, and "suddenly rolled right," striking the ground with the main rotor blades.
The check airman stated he did not provide a preflight description to the pilot concerning the "stuck pedal" maneuver.
According to the pilot's written statement, the check airman briefed him on the intended maneuvers and added, "he had something new to show [the pilot]." After completing the maneuvers and a few engine out procedures, the check airman held the left pedal in an offset position during takeoff to simulate a stuck left pedal emergency. The pilot removed his feet from the pedals and flew the traffic pattern with the pedal held by the check airman.
As the pilot set up for the simulated emergency landing with the stuck pedal, the check airman explained a "new way to handle this type of emergency situation." The check airman told the pilot to pick a spot on the runway adjacent to the windsock and to bring the helicopter to a hover above that spot. Though the pilot was "totally unfamiliar" with the procedure, the check airman was talking him through the approach. The check airman instructed the pilot to reduce airspeed and increase collective pitch as the helicopter neared the selected spot.
The helicopter arrived over the spot approximately 15- 20 feet above the runway. The check airman instructed the pilot to increase the collective pitch in order to keep the nose of the helicopter straight. Approximately 10 feet above the ground, the check airman told the pilot to reach up and "pull the throttle back in order to let the [helicopter] settle to the ground."
As the pilot reduced the power, the helicopter "made a violent 180-degree turn to the left, and the main rotor rpm quickly bled off, and [the pilot and check airman] struggled with the controls to stabilize the [helicopter]." The helicopter landed hard on its right main landing gear, which collapsed, allowing the helicopter to roll over on the right side. The check airman shutoff the engines, and the pilot turned off the electrical power.
In an additional statement provided by the pilot, he added that during the downwind leg of the last traffic pattern, the check airman told the pilot to remove his feet from the pedals. The pilot said he did so and could not remember if or when he placed his feet back on the pedals. He stated that at the time he reduced the engine power, he only had his right hand on the cyclic and the "check airman was fully on the [helicopter] controls."
The pilot stated he was not familiar with the maneuver, the check airman had not demonstrated the maneuver, and it had not been explained to him prior to the flight check.
Two witnesses were standing at the west end of the runway. One witness stated his attention was drawn to the helicopter because he heard the engines "slowing down." The other witness stated his attention was drawn to the helicopter because it was "looking funny." Both witnesses observed the helicopter fall from about 10 feet. The helicopter bounced up "slightly," and then rolled over onto its side.
The pilot held a commercial pilot certificate with airplane single engine land, helicopter, and instrument airplane and helicopter ratings. He also held a flight instructor certificate for helicopters. The pilot indicated he had logged a total of 7,500 hours of flight time, of which 7,100 hours were flown in helicopters, and 300 hours were flown in the same make and model as the accident helicopter. His last flight review was conducted on March 17, 2000. The pilot was issued a second-class medical certificate on September 20, 2000, with no limitations.
Check Airmen Information
The check airmen held an airline transport pilot certificate with airplane single engine land, airplane multiengine land, helicopter, and instrument airplane and helicopter ratings. He also held a flight instructor certificate for airplane single engine land, airplane multiengine land, helicopter, and instrument airplanes. The check airmen reported he had logged 12,000-plus hours of total flight time, of which 3,000-plus hours were accumulated in rotorcraft and 9.5 hours were accumulated in the same make and model as the accident helicopter. He was issued a second-class medical certificate on April 13, 2000, with a limitation to wear corrective lenses.
The Augusta A109A utilizes a counterclockwise rotating main rotor system (when viewed from above). During operations with higher power, more left anti-torque pedal is needed to offset the fuselage's right turning tendency produced by the torque from the main rotor system.
The manufacturer reported that the stuck pedal maneuver, as performed, was not an authorized or approved maneuver in the A109A. An anti-torque system failure should be briefed prior to conducting a practical demonstration. The procedure is demonstrated with the anti-torque pedals in a neutral position. Otherwise when power is reduced, the nose will travel in the direction of the depressed pedal. The maneuver is to conclude with a run on landing, not in a hover. There is no stuck pedal emergency procedure listed in the A109A pilot operating handbook.
The helicopter's tail rotor system utilizes a single hydraulic system with two servos. Optimum usage is when both servos are operating. However, if one servo fails the pilot can maintain control of the helicopter with additional force on the anti-torque pedals (15 kilos of force for one servo as opposed to 1 kilo of force for two servos). According to the manufacturer, there has been no report of a stuck pedal incident in an A109A.
WRECKAGE AND IMPACT INFORMATION
A post accident inspection revealed that the gear down locks were broken on both of the main landing gear. On the right landing gear, the mounting brackets were broken in an outward direction (towards the gear doors). The actuator was pulled out from the lower mounting bracket. All of the fracture surfaces were angular, granular, and rough in appearance. The left landing gear mounting brackets were broken in an outward direction. The fracture surfaces were angular, granular, and rough in appearance.
The fuselage belly, in the vicinity of the landing gear, was buckled and scraped. The main and tail rotor blades (with the exception of one main rotor blade and one tail rotor blade) separated in two sections (inboard and outboard). The intact main rotor blade was fractured in two segments, but remained attached via the leading edge strip. The vertical stabilizer and right horizontal stabilizer sustained structural damage.
FAA Order 8400.11 CHG 11, page 3-283, paragraph 511.C states that the competency check required by FAR 135.293 "may include any of the maneuvers and procedures currently required for the original issuance of the particular pilot certificate, for the operations authorized, and appropriate to the category, class, and type of aircraft involved." In the case of the pilot, the proficiency check flight was conducted for commercial pilot (rotorcraft/helicopter) operations. According to the FAA's Commercial Practical Test Standards (FAA-S-80810-16), section C, "Systems and Equipment Malfunctions," the pilot is to "analyze the situation and take action, appropriate to the helicopter used for the practical test, in at least four of the following areas." The areas that follow include flight control/trim and rotor and/or anti-torque malfunctions.
The FAA's Rotorcraft Flying Handbook (FAA-H-8083-21) describes anti-torque failures under system malfunctions. The handbook describes the failure of the anti-torque system in two separate scenarios; failure of tail rotor drive and therefore complete loss of anti-torque, or the failure of mechanical controls where the pilot is unable to change or control tail rotor thrust even though the tail rotor may still be providing anti-torque thrust.
The Rotorcraft Flying Handbook indicates the procedures and techniques outlined in the FAA approved rotorcraft flight manual for the helicopter being flown should be used. It continues to describe how to land with a stuck left pedal. According to the handbook, "a stuck left pedal, such as might be experienced during takeoff or climb conditions, results in the helicopter's nose yawing to the left when power is reduced. Rolling off the throttle and entering an autorotation only makes matters worse. The landing profile for a stuck left pedal is best described as a normal approach to a momentary hover at 3 to 4 feet above the surface. Following an analysis, make the landing. If the helicopter is not turning, simply lower the helicopter to the surface. If the helicopter is turning to the right, roll the throttle toward flight idle the amount necessary to stop the turn as you land. If the helicopter is beginning to turn left, [the pilot] should be able to make the landing prior to the turn rate becoming excessive. However, if the turn rate becomes excessive prior to the landing, simply execute a takeoff and return for another landing."
The Niihau Helicopters' training program outline indicates that tail rotor failures are to be discussed orally.