The pilot who crashed his single-engine plane into power lines in Montgomery Village last month made several wrong turns and flew below minimum altitudes, according to a preliminary report by the National Transportation Safety Board issued Monday. 

The Nov. 27 crash triggered a power outage for tens of thousands of households in Montgomery County. The pilot, Patrick Merkle, from Washington D.C., survived the crash, along with his only passenger, Janet Williams, from Marrero. They were stuck in the plane, which was suspended in the power lines, for several hours, and have been recovering from serious injuries.

The report says the controller gave “numerous heading changes and direct clearances” to Merkle, who was on his way to Montgomery County Airpark in Gaithersburg after flying the morning of the crash to Westchester County Airport in White Plains, New York.

“However, the pilot made a series of left and right turns, near course reversals, or continued established headings as the controller repeatedly requested that the pilot turn to a different heading,” the report reads. (“Heading” in this context refers to the direction the plane is pointed).

The plane was also flying several hundred feet below minimum altitudes on its way to the airpark. Merkle acknowledged that he “got down a little lower than I should have” in a conversation with 911 call center personnel, as detailed by the report.

“I thought I was closer to the airport than I was,” Merkle said. “We could see the ground, but we couldn’t see the front.”

Merkle described flying through fog like “pea soup” in conversations with local media after the crash, the report says — there was a severe weather advisory, known as SIGMET, in place at the time. Merkle also expressed concerns to local media about whether his altimeter, which measures altitude, was working properly. His plane, manufactured in 1977, had its latest annual inspection on Feb. 1. The plane’s altitude reporting equipment and altimeter static system were tested on June 22.

Merkle’s licensing was also up to date. He had a private pilot certificate and an updated third-class medical certificate issued on Aug. 1, He had 1,432 total hours of flight experience on the night of the crash.

Information in the preliminary report is subject to change. Merkle said Tuesday that he is planning on issuing a report of his own to investigators Wednesday, as reported by the Washington Post.