Auburn, CA, USA
N16133
Hughes 269B
The helicopter impacted the ground at a high rate of descent during a local instructional flight. Some minutes prior to the accident, a witness on a farm about 3 miles from the accident site heard and observed the helicopter performing maneuvers consistent with multiple practice autorotations to a power recovery. The helicopter then flew off in the direction of the airport. Witnesses near the accident site observed the helicopter in level controlled flight about 500 feet above ground level flying in the direction of the airport. They observed the helicopter's nose drop and then it dove toward the ground and disappeared behind a tree line. These witnesses heard normal sounds coming from the engine. Ground scars and the wreckage exhibited evidence consistent with the helicopter colliding with the ground at a high rate of descent in a level upright attitude and rolling on its right side. The main rotor blades displayed evidence consistent with having flexed downward and slicing into the tail boom at a high rotational rate and a driven energy state. Other evidence in the drive train was consistent with engine rotation and power production. An airframe and engine inspection revealed no preimpact anomalies that would have precluded normal operation and functionality of the control system.
HISTORY OF FLIGHT On April 10, 2003, about 1730 Pacific daylight time, a Hughes 269B, N16133, collided with terrain about 1 mile south of the Auburn Municipal Airport (AUN), Auburn, California. Heli-Fun, Inc., operated the helicopter under the provisions of 14 CFR Part 91. The helicopter was destroyed. The certified flight instructor (CFI) and student pilot were fatally injured. The local area instructional flight departed AUN about 1615. Visual meteorological conditions prevailed, and no flight plan had been filed. A witness, located about 3 miles northwest of the accident site, saw and heard the helicopter maneuvering over his farm, about 1700. He stated that the engine was running normally, it was just really loud, like it was powered up. He reported that the engine got quiet and the helicopter hovered, powered up again, and then "dropped" into a ravine area northwest of his location. As he was walking back towards his house he heard the helicopter again. He looked back and saw the helicopter had regained some altitude, and was headed back towards the airport. Another witness, located about a mile southwest of the accident site, in a parking lot, stated that he saw the helicopter "really low." His first thoughts were that it was either an air show, or the police department searching for someone. He stated that the helicopter's main rotors were almost perpendicular to the ground. The helicopter looked like it was attempting to turn, but was descending. He further stated that the helicopter had forward momentum, but it appeared it was not getting any lift. The helicopter dropped below the tree line, and he did not see it again. The next morning he saw an article about the accident in the newspaper. Witnesses interviewed by the Placer County Sheriff's Department reported that from their varied locations they observed the helicopter in level controlled flight, about 500 feet above the ground flying towards the airport. Then all of a sudden the helicopter nose-dived to the ground. The witnesses that were able to hear the helicopter indicated that there were no unusual noises emanating from the engine. PERSONNEL INFORMATION A review of Federal Aviation Administration (FAA) airman records revealed the CFI held a commercial pilot certificate with ratings for rotorcraft-helicopter, and instrument helicopter. The CFI also held a certified flight instructor certificate with a rating for rotorcraft-helicopter. The CFI held a second-class medical certificate that was issued on August 30, 2002, with no limitations or waivers. An examination of the pilot's logbook indicated an estimated total flight time of 5,100 hours. He logged 150 hours in the last 6 months, 27.2 hours in the last 90 days, and 16.2 in the last 30 days. Since 2002, the pilot had logged 16.8 hours in the accident make and model helicopter. The Placer County Sheriff's Department employed the CFI as a deputy/pilot. A review of Federal Aviation Administration (FAA) airman records revealed the student held a student pilot certificate with no ratings. The student held a second-class medical certificate issued on March 26, 2003, with no limitations or waivers. An examination of the student pilot's logbook indicated a total flight time of 15.8 hours, which were accumulated in the accident make and model helicopter. He logged 15.8 hours in the last 90 days, and 12.8 in the last 30 days. AIRCRAFT INFORMATION The helicopter was a 1968 Hughes 269B, serial number 180348. A review of the helicopter's logbooks revealed a total airframe time of 6,406.3 hours at the last 100-hour annual inspection, completed on April 9, 2003, at a Hobbs hour meter time of 433.3. An annual inspection was completed on December 12, 2002, at a Hobbs hour meter time of 235.8. The helicopter had a Textron Lycoming HIO-360-A1A engine, serial number L-6202-51A. Total time on the engine at the last annual inspection was 1,737.6 hours. Fueling records from Grass Valley, California, established that the helicopter was last fueled on April 10, 2003, with the addition of 23.5 gallons of 100-octane Low Lead (100LL) aviation fuel. The helicopter was refueled the same day with 17.0 gallons of 100LL aviation fuel. Examination of the maintenance and flight department records revealed no unresolved maintenance discrepancies against the helicopter prior to departure. WRECKAGE AND IMPACT INFORMATION The accident site was located on a sandbar approximately 3/4-mile south of AUN, in Wise Canal, at an elevation of 1,489 feet. Wise Canal feeds into Rock Creek Lake Reservoir. The helicopter was submerged in approximately 4 feet of water. The surrounding area contained vegetation and terrain indicative of northern California; rolling hills, trees, and tall brush. The helicopter came to rest on an easterly heading. Pacific Gas and Electric (PG&E) manages the water flow area. When the water flow into Rock Creek Lake and Wise canal was stopped, there were no identified points of contact observed on the surrounding rocks or sandbars. The helicopter was laying on its right side, not completely inverted, with the belly and landing gear skids exposed. The engine was inverted and was positioned towards the front end of the helicopter. There were no obvious signs of preimpact catastrophic mechanical damage noted. The main rotor blades were accounted for on scene. Two of the main rotor blades remained attached to the main rotor mast assembly. The third blade had separated from the assembly at the root. All three main rotor blades showed downward bending and trailing edge delamination the length of the blades. The tail boom remained attached to the frame but rotated 90 degrees from its original position. Investigators noted two cuts observed on the tail boom. One cut was forward of the tail rotor blades and tail rotor gearbox. The second cut, which was almost the circumference of the tail boom, was aft of the beacon light. Both cuts were located on the left side of the tail boom. The tail rotor blades remained intact. MEDICAL AND PATHOLOGICAL INFORMATION The Placer County Coroner completed autopsies on both pilots on April 14, 2003. The medical examiner listed the cause of death for both pilots as multiple blunt-force trauma (immediate). The medical examiner further reported that both pilots were wearing lap belts that were released by rescue personnel. The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicological testing of specimens of the CFI. The results of analysis of the specimens were negative for carbon monoxide, cyanide, volatiles, and tested drugs. The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, performed toxicological testing of specimens of the student pilot. The results of analysis of the specimens were negative for carbon monoxide, cyanide, and volatiles. The report contained the following positive results for tested drugs: 0.0058 (ug/ml, ug/g) Tetrahydrocannabinol (Marihuana) detected in blood 0.0164 (ug/ml, ug/g) Tetrahydrocannabinol Carboxylic Acid (Marihuana) detected in blood 0.5998 (ug/ml, ug/g) Tetrahydrocannabinol Carboxylic Acid (Marihuana) detected in urine TESTS AND RESEARCH The Safety Board investigator-in-charge (IIC), Textron Lycoming, and The Boeing Company, parties to the investigation, examined the airframe and engine at Plain Parts, Pleasant Grove, California, on April 11, 2003. Schweizer Aircraft Corporation is the type certificate holder for the accident make and model helicopter. The flight control tubes, bellcranks, pulleys, and cables were accounted for; however, they were all either displaced or fractured. The 8 V-belt drive bands and pulleys were in place with no discrepancies noted. The transmission was manually rotated with no binding encountered. The fuel tank, located on the right side of the helicopter, was destroyed. The Boeing representative noted that the damage to the main rotor blades included paint transference and contact marks that were indicative of blade contact with the other main rotor blades and the fuselage. He further reported that the damage noted to the main rotor blades, and main rotor head, were consistent with main rotor contact at high rpm (revolutions per minute), in an engine-driven power applied condition. The tail rotor system remained intact and attached to the tail empennage. The tail rotor transmission was intact on its mounts at the end of the tail boom. The tail rotor gearbox was manually manipulated and operated normally. The tail rotor gearbox was removed and examined with no discrepancies noted that would have precluded normal operation. Two cuts were noted in the tailboom; the first measured 1.9 inches from the tail rotor assembly, the second cut, measured 5.10 inches from the tail rotor assembly. According to the manufacturer's representative, the cuts appeared to be made from main rotor blade contact with the tail boom. Investigators noted that the tail rotor blades remained intact and attached to the tail rotor hub with very little damage. One tail rotor blade (s/n 5077) had flexed and contacted the tail boom at station FS 247.0. The Boeing representative was not able to establish flight control continuity of the cyclic, collective control grips, and pedals due to impact damage. However, he was able to account for all the hardware for each flight control system, and attributed the fractures and disconnects to overstress/overload as a result of impact forces during the crash sequence. The right landing gear skid tube was separated about midspan. The landing gear arm remained intact. The left landing gear skid tube was separated in three different places, and the landing gear arm remained intact. The center frame section of the fuselage, right aft cluster fitting, showed evidence of corrosion inside the tube. The left forward cluster fitting, the right rear cluster fitting, and an 11-inch portion of airframe tubing were shipped the National Transportation Safety Board's metallurgical laboratory in Washington, D.C., for further examination. The Safety Board's mechanical engineer reported a light corrosion on the inner surface of one tubular member, but measurements indicated no overall loss of material thickness. The mechanical Engineer further reported that all of the fracture surfaces for the cluster fittings and airframe tubing displayed 45-degree shear lips that were consistent with an overload event that included some bending. Mechanical continuity was established on the engine via manual rotation of the crankshaft. Compression was obtained in all cylinders in proper firing order. The cylinders were visually inspected with a borescope; sand was noted in the number 2 cylinder intake valve. No other discrepancies were noted with the cylinders. The top and bottom spark plugs were removed. According to the Champion Aviation Check-A-Plug chart AV-27, the spark plugs showed coloration consistent with normal operation. Both magnetos were displaced from their respective mounting pads, but both drives were intact and secure. Manual rotation of the left and right magneto produced spark at their respective leads. The fuel injector nozzles, fuel injector air inlet, fuel filter screen, and oil suction screen were clear of debris. Rotational scoring was observed on the right side of the fan housing. No mechanical discrepancies were noted with the engine. ADDITIONAL INFORMATION The IIC released the wreckage to the owner's representative on August 11, 2003.
the misjudged flare maneuver by an unknown crewmember during a likely practice autorotation that resulted in an in-flight collision with terrain.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
