About 5:00 pm Saturday, I was out walking my dogs in Mountain View (aprox. 40 miles south of San Francisco), when I heard the unmistakable sound of a pair of big o' radials, running strong.

Looking northwest, I spotted a large twin-tailed plane heading north from left to right, on a course towards Palo Alto Airport. it was fairly low and running fast, maybe 400-600 feet and 200-250 mph, as if he was going to make a low & fast pass over the runway of P.A. I was in a field, maybe 100 yards from some 2-story apartments, and it was just visible above the rooftops, perhaps a few miles distant.

Maybe a mile or 2 before reaching the airport, it banked hard left away from me as if to change course towards S.F., then disappeared from view behind the rooftops while still banked. It looked like it was going to follow highway 101 northwest towards S.F., but I could not tell...I saw or heard nothing after that.

It could have been an old Beech D18 or Lockheed, but the shape looked very much like a Mitchell (I won't bet any paychecks on it though). The sun was on the far side of him, so I mainly just saw a dark profile, but I DEFINITELY saw the twin tails and heard the roar/rumble of early round engines. Too far to spot any details like turrets and such, and it happened too fast.

Did anyone else in the south bay or on the S.F. peninsula spot such a bird late Sat afternoon/early evening?