DFW05LA159 · Hughes 269A

A 450-hour commercial helicopter pilot departed approximately 0615, on the return leg of a personal cross-country flight. About 0805 two witness saw the helicopter following a road. The first witness reported seeing the helicopter following the highway heading north at a "normal" height. They then saw the helicopter "lose altitude very quickly". The second witness, who was heading south, said he saw a helicopter low over the [highway] median heading north, "lower than tree line, 20 to 30 feet". The witness also stated, "the pilot was concentrating on the center gauges, [and] console, [and he] was working the controls fast and vigorous." Both the FAA inspector and Department of Public Safety Trooper noted that the helicopter impacted power lines prior to impacting the ground. The top and forward sections of the left and right landing skids showed evidence of a wire strike. The fuel tank had been breached near the top of the tank, however approximately 3 quarts of fuel was drained from the tank through the gascolator. The blades were absent of leading edge gouges. One blade was bent "upwards", the two other blades were bend "downwards", with one of the blades having scuff and paint marks consistent with the tail rotor boom. The scuffed blade also had slight buckling on the trailing edge. The main rotor drive shaft and housing was broken from the transmission; the main rotor drive shaft was bent about 45 degrees and lacked any "twisting" motion. The tail rotor drive shaft was separated in two, with no twisting motion at the break. The shaft had scuff and paint transfer marks longitudinally along the shaft. The tail rotor blades had numerous impact marks on the sides of the blades, removing paint and leaving small dents in the blades. The leading edges of the blades were absent of leading edge gouges. The mixture control cable clamp, on the fuel servo was metal and had no rubber cushion in it. The clamp had no "holding effect" on the mixture cable and the cable was free to move out of the clamp. The bottom set of sparkplugs were examined and all four were worn out-normal to worn out-severe, and lead fouled. Control continuity through the cyclic and collective has established. However, three bolts connecting the cyclic controls were missing the safety cotter pins. Additionally, one of the castled nuts had had backed off, and was within a few threads of "falling" off. A post-accident engine run was accomplished. The engine was started and run through the operating rpm range, with no noted abnormalities. After shut-down, fuel would "leak" through the servo, and out the induction system, when the mixture was left in the full-rich position. The reason for the lost of engine power could not be determined.

Verbatim NTSB analysis and probable cause from the NTSB dataset