A rare visit of the P-3 Orion.

The Lockheed P-3 Orion is a four-engine turboprop anti-submarine and maritime surveillance
aircraft developed for the United States Navy introduced in the 1960s.
The distinctive tail is used for the magnetic detection of submarines [wiki]

It was a frequent visitor across the Santa Clara Valley as it flew to the
Naval Air Station Moffet Field in Sunnyvale during the 1990's.

The visits stopped when the NAS Moffet Field was closed and turned over to
NASA Ames Research Center in 1994.

Shot from the backyard.