Pueblo, CO, USA
N311CP
Schweizer 269C
According the flight instructor during the second traffic pattern, they "climbed to approximately 1000 feet AGL with the intention of practicing an autorotation entry and glide with a power recovery and go-around at about 200-300 [feet] AGL." The flight instructor stated that both pilots were at the controls on final. He stated that after lowering collective, the engine rpm "went straight to [zero]." The flight instructor stated that he took control of the helicopter while his student attempted an engine restart. He did not recall any further events until after the impact. According to one witness the helicopter impacted the runway hard, splitting both landing skids out laterally. The helicopter rolled over on its left side and a fire ensued. Density altitude was calculated to be 7,162 feet. According to the weight and balance calculations performed by the student and flight instructor prior to the accident, the helicopter's weight was calculated to be 1,859.6 pounds. According to the Pilot's Flight Manual (PFM), performance figure 5-3 (gross weight versus density altitude diagram), based on the density altitude of 7,162 feet, the helicopter should have been at a maximum weight of 1,600 pounds in order to maintain the autorotation characteristics of the helicopter presented in performance figure 5-2 (height/velocity diagram). An examination of the helicopter's engine and systems revealed no anomalies.
HISTORY OF FLIGHT On June 14, 2005, approximately 1905 mountain daylight time, a Schweizer 269C, N311CP, operated by Silver State Helicopters, was destroyed when it impacted the runway while landing at Pueblo Memorial Airport (PUB), Pueblo, Colorado. A postimpact fire ensued. Visual meteorological conditions prevailed at the time of the accident. The instructional flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The commercial flight instructor and student pilot received serious injuries. The local flight departed PUB approximately 1830. According to Pueblo Air Traffic Control Tower, the helicopter had been conducting multiple approaches to runway 8R and had been "cleared for the option." One witness stated that the helicopter appeared to make a steeper approach than the previous approaches. The helicopter impacted the runway hard, splitting both landing skids out laterally. The helicopter rolled over on its left side and a fire ensued. According to a written statement submitted by the flight instructor on August 8, 2005, during the second traffic pattern, they "climbed to approximately 1000 feet AGL with the intention of practicing an autorotation entry and glide with a power recovery and go-around at about 200-300 [feet] AGL." The flight instructor stated that both pilots were at the controls on final. He stated that after lowering collective, the engine rpm "went straight to [zero]." The flight instructor stated that he took control of the helicopter while his student attempted an engine restart. He did not recall any further events until after the impact. Due to the student's injuries, he remained in a drug-induced coma for several weeks. The student did not submit any statement to the events leading up to the accident. PERSONNEL INFORMATION The flight instructor, age 23, holds a commercial pilot certificate with a rotorcraft helicopter rating, in addition to a rotorcraft helicopter flight instructor certificate. The flight instructor certificate was issued on March 24, 2005. The flight instructor was issued a second class airman medical certificate on January 10, 2005. The certificate contained no limitations. According to the flight instructor's logbooks, he had logged approximately 392 hours total time; 184 of which were in the make and model of the accident helicopter. Approximately 190 hours had been logged in the previous 90 days; 180 of which was acting as a flight instructor. According to the Federal Aviation Administration's pilot database, the flight instructor received a Notice of Disapproval of Application in the Area of Operation X. Task B Straight-In Autorotation (Touchdown) during the examination for the addition of the Flight Instructor Rotorcraft-Helicopter Certificate. According to the National Transportation Safety Board, Accident Database, the flight instructor was involved in an accident on May 19, 2005, in Pueblo, Colorado, in a Schweizer 269C. The flight instructor was giving instruction at the time of this accident. The student pilot, age 30, held a student pilot certificate, and a second-class airman medical certificate which was issued on December 9, 2004. The certificate contained the limitations "must wear corrective lenses." According to the student pilot's logbook, he had logged 23.1 hours total time; 15.6 of which was in the make and model of the accident helicopter. Fourteen hours had been logged in the previous 90 days. AIRCRAFT INFORMATION The accident helicopter, a Schweizer 269C (serial number S1311), was manufactured in 1988. It was equipped with a Lycoming HIO-360-D1A engine, rated for 190 horsepower. The helicopter was registered to L J Air Corporation and operated by Silver State Helicopters, both of Las Vegas, Nevada. The helicopter was based in Pueblo, Colorado, for the purpose of flight instruction. The helicopter was maintained under a 100-hour inspection program. The maintenance records indicate that the helicopter underwent a 100-hour inspection on June 6, 2005, at a Hobbs time of 2387.4. The last annual inspection was performed on April 5, 2004. The helicopter had been flown 54.8 hours since the 100-hour inspection. METEOROLOGICAL INFORMATION According to the Pueblo routine aviation weather report (METAR) at 1853, the weather was winds, 090 degrees at 9 knots; visibility, 10 statute miles; sky condition, clear below 12,000 feet; temperature 27 degrees Celsius (C); dewpoint, 05 degrees C; altimeter, 30.02 inches. Density altitude was calculated to be 7,162 feet. WRECKAGE AND IMPACT INFORMATION The National Transportation Safety Board arrived on-scene approximately 0830 on June 15, 2005. The accident site was located on airport property, in the center of runway 8R, 2,110 feet from the approach end of runway 8R. The accident site was at an elevation of 4,726 feet msl. The initial ground impact point was located in the center of the runway, 2,060 feet from the approach end of the runway 8R, or 50 feet west of the main wreckage. The first ground scar was 2 inches in length and 1 inch in depth. It was followed by a faint blue paint transfer mark 6 inches in length and a second ground scar 13 inches in length and 1.5 inches at its widest point. A second series of ground scars was located 31 feet west of the main wreckage or 19 feet from the initial impact point. The three scars were 8 inches, 25.5 inches and 21.5 inches respectively, parallel and overlapping in dimension. The first and third scars were two inches at their widest point and the second scar was 4 inches at its widest point. Parallel and to the south of the third ground scar was a blue scrape, 9 inches in length and 3 inches at its widest point. The scars were filled with paint chips and oil. The debris path extended from the second series of ground scars to the main wreckage and contained red lens fragments, splinters of fiberglass, tail rotor blade fragments, a first aid kit, Plexiglas fragments, and the tailskid. The main wreckage consisted of the fuselage, both the left and right landing skids, the engine assembly, and all three main rotor blades. The wreckage came to rest in a left nose down attitude, inverted, on a heading of 180 degrees. Portions of the wreckage had been exposed to fire and a 10-foot diameter area north of the wreckage had been charred. Both landing skids were spread out laterally. The forward tubing of the left landing skid was bent up 90 degrees at the joint, the forward tip resting under the left side of the helicopter. The fiberglass nose of the helicopter contained longitudinal scrapes, and the left side was charred and partially melted by fire. The engine assembly remained attached to the airframe. The exhaust manifolds on both sides were bent and crushed, exhibiting longitudinal scratches. The throttle body venturi was fractured and the support frame surrounding the engine was bent and broken. The fuselage, to include the canopy, cabin area, cabin doors, and both fuel tanks, was bent and twisted. The Plexiglas from the canopy and cabin door windows were fragmented. The frame on the right side of the fuselage had separated towards the top of the frame. The right fuel tank had been charred, and partially consumed by fire. The fuel tank cap was not attached to the tank and was located 5 feet north of the main wreckage. The left fuel tank exhibited partial charring. Examination of the cockpit instruments revealed the following settings: Airspeed - zero knots; Kolsman window - 30.10 inches; RPM - zero; Manifold Pressure - 17.25 inches; engine gauges - zero. Two of the three main rotor blades remained attached at the rotor hub. The blades were arbitrarily named for identification purposes. Blade A exhibited exposure to heat along the inboard 55 inches of the blade and remained attached to the hub. Blade B was torn laterally, 8 inches outboard from the blade hub. The remaining blade was bent aft towards Blade A with an additional 180-degree bend 92 inches from the initial point of separation. Blade C remained attached to the hub and extended vertically into the air. The blade exhibited slight bending 8 inches outboard from the hub with a 40-degree bend 4 feet from the blade tip. The empennage, to include the tail boom, tail boom support struts, vertical fin, horizontal stabilizer, and tail rotor assembly, separated from the main wreckage. The tail boom came to rest 63 feet east of the main wreckage. The boom exhibited a 16-inch tubular crush along the bottom of the boom. The tail rotor gearbox remained attached to the tail boom; however, the tail rotor blades had separated. One blade was located under the main wreckage and fragments from the other blade were located within the debris path and up to 120 feet west of the main wreckage. The tip of the tail rotor drive shaft was bent down 90 degrees 18 inches inboard of its attachment point. The vertical fin was crushed up and aft longitudinally. The tip of the vertical fin exhibited longitudinal scratches. The horizontal stabilizer separated from the tail boom and was located 45 feet south of the main wreckage. Both tail boom support struts also separated and were located 74 feet northeast and 64 feet southeast of the main wreckage. TESTS AND RESEARCH The wreckage was recovered and transported to Greeley, Colorado, for further examination. The engine and airframe were examined on August 16, 2005. No anomalies were noted that would have been causal or contributory to this accident. The fuel servo was sent to Seattle, Washington, for further examination under the auspices of the National Transportation Safety Board. No anomalies were noted that would have precluded the unit from functioning properly. ADDITIONAL INFORMATION According to the Silver State Helicopters Company Training Guidelines and Procedures, the flight instructor is required to perform the following "A weight a balance and density altitude by means of calculations will be done before every flight, and filed for administrative purposes." According to the weight and balance calculations performed by the student and flight instructor prior to the accident, the helicopter's weight was calculated to be 1,859.6 pounds. The longitudinal center of gravity was calculated to be 97.9 and the lateral center of gravity was calculated to be .8, both values being within the center of gravity limitations. The Silver State Helicopters Company Training Guidelines and Procedures states that "No practice autorotations will be performed in the 300C with a gross weight greater than 1,750 pounds." According to the Schweizer Aircraft 269C Helicopter Pilot's Flight Manual (PFM), performance figure 5-3 (gross weight versus density altitude diagram), based on the density altitude of 7,162 feet, the helicopter should have been at a maximum weight of 1,600 pounds in order to maintain the autorotation characteristics of the helicopter presented in performance figure 5-2 (height/velocity diagram). In addition, the PFM states that an engine restart should not be attempted below 2,000 feet agl. According to FAA Publication FAA-H-8083-21 Rotorcraft Flying Handbook, "the time required, and therefore, altitude necessary to attain a steady state autorotative descent is dependent on the weight of the helicopter and the density altitude." The height velocity diagram is valid only when the helicopter is operated in accordance with the gross weight versus density altitude chart. "At gross weights above those recommended by the gross weight vs. density altitude chart, the [height velocity] diagram is not restrictive enough." Parties to the investigation included Lycoming Engines, Schweizer Aircraft Corporation, and the Federal Aviation Administration, as represented by an inspector from the Denver Flight Standards District Office. The wreckage was released to a representative of the insurance company on December 29, 2005.
the flight instructor's failure to maintain control of the helicopter during the attempted autorotation after the loss of engine power for reasons undetermined. Contributing factors include the flight instructor's improper preflight planning, the high density altitude, and the attempted autorotation.
Source: NTSB Aviation Accident Database
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