The crash occurred near Rothbury Drive and Goshen Road, according to Pete Piringer, the spokesman for the county fire and rescue service. The site is north of Montgomery Village and close to a commercial area.
The cause of the crash was not immediately known. There is an airstrip for small aircraft in upper Montgomery, and it was unclear whether the plane was on an approach or takeoff. Rainy weather may have lowered operational ceilings.
Photographs of the site show the presence of transmission lines and the number of outages indicated that the transmission lines were involved.
On its website, Pepco listed outages, mainly in Montgomery, affecting about 85,000 customers as of about 6:30 p.m. The number of utility customers does not reflect the actual number of people served, since a large apartment house with scores of residents may be listed as a single customer.
It was not immediately known whether or how many of the customers could be served through other transmission lines or cables. Also unclear was how long might be needed for repairs.
One estimate indicate that the plane may have hit lines as high as 10 stories up. That could not be immediately confirmed.