The National Transportation Safety Board (NTSB) has released a preliminary report on the July 23 crash in Maryland that resulted in the deaths of all four aboard.

The Robinson R44 helicopter (N7189W) struck a wire that crossed Interstate 70 near Boonsboro and crashed just off the highway. The certificated commercial pilot and three passengers were killed. Night visual meteorological conditions prevailed and no flight plan had been filed for the flight.

The flight originated from Hagerstown Regional Airport (HGR), Hagerstown, MD, and was en route to Frederick Municipal Airport (FDK), Frederick, MD, when the accident occurred.

The helicopter was based at FDK and maintained by Advanced Helicopter Concepts (AHC), an operator of five Robinson R22 helicopters. The helicopter was privately owned by a trustee of Advanced Helicopter Youth Foundation, a non-profit charity founded by the President of AHC.

The helicopter flew from FDK to HGR to transport a director of the foundation and another passenger to a meeting. The pilot also provided short helicopter rides. The pilot and the third passenger were employees of AHC.

After the business meeting and the rides, the pilot called an employee of AHC, to ask about the weather conditions for the return flight to FDK. The informed the pilot that the weather conditions were "miserable" with severe thunderstorms in the area.

He offered to drive in his car to HGR to return the occupants to FDK; however, the pilot stated they would "wait out" the weather.

The pilot later called back to ask about the weather conditions. The employee told the pilot that the rain had stopped; however, it was still foggy, and windy with lightning in the area. He again offered to drive to Hagerstown, and the pilot stated that he would wait for the weather conditions to improve.

The helicopter is believed to have departed HGR about 2215. The HGR air traffic control tower closed at 2200, and there were no known communications with the helicopter.

A witness driving east on I-70 observed the helicopter pass him over his right side. It was a "dark night," and there was fog present about 50 feet above the roadway surface. The helicopter appeared to fly into "low clouds," turned around, and was heading back toward the west, when it contacted power lines just as his car passed under them. The helicopter impacted the ground and "burst into flames."

Another witness reported that the helicopter was flying parallel with the interstate, and "seemed to be getting lower." It then disappeared from view, which was followed by "sparks in the sky." He then observed the helicopter descend toward the roadway.

The helicopter struck and broke an unmarked, steel guy-wire, which extended perpendicular over I-70, near mile marker 37, and was about 70 feet high. The accident site was at an elevation of about 1,130 feet mean sea level (msl), near the top of South Mountain. According to a power company representative, a 34.5 and a 12-kilovolt power line located below the guy-wire were damaged, with a power interruption noted at 2226.

A ground scar was noted on the center median approximately 30 feet west of the power lines, and the helicopter came to rest on its left side, approximately 42 feet west of the power lines, on a heading of 090 degrees. A post-crash fire consumed the cabin, a majority of the main rotor gearbox housing, and all drive belts.

The pilot was hired by AHC this past January. He held flight instructor certificate, with ratings for rotorcraft, and instrument helicopter. He also held a commercial pilot certificate, with ratings for airplane single-engine land, rotorcraft, instrument airplane, and instrument helicopter.

The pilot reported 630 hours of total flight experience on his most recent application for a Federal Aviation Administration second-class medical certificate, which was issued on July 13, 2009.

According to the Pilot's Operating Handbook, the helicopter was certified to be operated under visual flight rules flight only.