(CNN) – Investigators say the pilot of a private plane that crashed into power lines and cut electricity to 120,000 people was flying too low for miles.
In a just-released report, data accessed by the National Transportation Safety Board shows the pilot was below key minimum altitudes required to land in poor visibility at Montgomery County Airpark in Gaithersburg, Maryland.
“The airplane descended as low as 475 feet” above sea level, before it slammed into a Pepco transmission tower, the agency said in its preliminary findings. The tower is 600 feet above sea level, the NTSB notes.
The crash, in dark mist on November 27, triggered a massive response of more than a hundred firefighters.
After he remained inside the mangled single-engine Mooney aircraft for eight hours, special equipment was used to rescue the pilot, 65-year-old Patrick Merkle and his female passenger. Both survived the crash with serious injuries.
The NTSB notes that Merkle said in media interviews that he thought his altimeter was malfunctioning. The NTSB now says it removed the altimeter for testing and found it “well within the test allowable error at all ranges.”
In their report, investigators also say around the time Merkle began his approach to land, the pilot of another airplane ahead of him found the weather to be too poor and “requested a diversion to another airport.”