CEN22FA073

The pilot was operating the helicopter in an area of low cloud ceilings, fog, and mist. Flight data showed that the helicopter’s altitude varied and that the maximum altitude reached was 175 ft above ground level. The last recorded altitude was 75 ft. The helicopter subsequently collided with a guy wire suspended between two transmission line trusses and impacted the highway below. A postimpact fire ensued and destroyed the helicopter. Postaccident examination of the airframe and engine revealed no anomalies that would have precluded normal operation of the helicopter. The pilot did not receive an official weather briefing before the flight. After the accident, a US Coast Guard pilot was deployed to the accident area. The Coast Guard pilot stated that a “wall of clouds” extended from the power lines westward to the accident area. Thus, the accident pilot likely could not see the power lines due to the reduced visibilities in mist and clouds at the accident time.

On December 14, 2021, about 1236 central standard time, a Bell 407 helicopter, N150AS, was destroyed when it was involved in an accident near LaPlace, Louisiana. The pilot was fatally injured. The helicopter was operating as a Title 14 Code of Federal Regulations Part 91 personal flight. The helicopter departed from the Gonzales, Louisiana, area and was en route to New Orleans Lakefront Airport (NEW), New Orleans, Louisiana. Automatic dependent surveillance-broadcast (ADS-B) data tracked the helicopter’s flightpath as it flew toward NEW. The helicopter’s altitude varied between 75 and 175 ft above ground level (agl). About 0.88 miles from the accident site, the helicopter descended to 50 ft agl. The last ADS-B data point, at 1236:26, indicated that the helicopter was near the intersection of transmission lines over Interstate 10. At that time, the helicopter was traveling at a groundspeed of about 104 knots and an altitude of 75 ft agl. The helicopter subsequently collided with a western guy wire suspended between two transmission line trusses. The guy wire was estimated to be about 130 ft above a trestle bridge on the highway. Several commercial vehicle video cameras captured the helicopter’s descent and impact with the highway. A postimpact fire ensued and destroyed the helicopter. A review of meteorological information revealed that no frontal boundaries were near the accident site. The closest official aviation weather observation station reported 4 miles visibility, mist, in addition to a broken ceiling at 400 ft, and an overcast ceiling at 1,000 ft. An upper air sounding displayed the potential for cloud formation between 600 to 3,250 ft. Weather satellite imagery of the accident site showed cloud cover above the accident site and to the north and west. At the time of the accident, the clouds were moving south to north. AIRMET Sierra, issued at 0845, forecast instrument meteorological conditions with mist and fog through 1500 near the accident site. The pilot did not receive a weather briefing from Leidos Flight Service or ForeFlight. After the accident, a US Coast Guard (USCG) helicopter was launched to the scene to provide search and rescue support. The USCG pilot reported that the weather was visual flight rules (VFR) at Louis Armstrong International Airport (MSY), New Orleans, Louisiana, but deteriorated to marginal VFR and instrument flight rules to the west. Because of low-level fog, the stanchions of the power lines were “barely visible” from the east; from the west, the fog layer was above the power lines with high cloud layers that reached about 1,200 ft. The USCG pilot also reported that, from a top down view, “there was very dense fog from all areas with a tall column of clouds to the west of the power line intersection” where the accident occurred. The USCG pilot stated that the helicopter orbited with good visibility at 500 ft over the shoreline but that, on land to the west, a “wall of clouds” to 1,200 ft was present. Areview of the pilot’s logbook revealed that he had 12 hours of instrument flight experience, all of which were logged in fixed-wing aircraft. The pilot’s most recent instrument flight was on May 21, 2019. The helicopter impacted the highway on a trestle bridge in a steep nose-low attitude. The main rotor blades, mast, and transmission separated from the fuselage and fell into Lake Pontchartrain. The postimpact fire consumed most of the fuselage. Postaccident examination of the wreckage revealed markings on two main rotor blades that were consistent with contact with a braided metal wire. No anomalies were found with the airframe or engine that would have precluded normal operation of the helicopter.