Skyhawk 172/Cutlass 172
Flight Crew Private
Flight Crew Last 90 Days 50; Flight Crew Total 130; Flight Crew Type 110
Communication Breakdown; Situational Awareness
ATC Issue All Types; Conflict NMAC
Flight Crew Took Evasive Action
Human Factors; Procedure
Following ATC instructions; I was in a right downwind for Runway 33; cleared to land Runway 33. Suddenly; another Cessna cut in front of us at the same altitude. I estimate that there was only 100 FT of horizontal separation; and no vertical separation; at the nearest point. The plane looked as though it was turning from a right crosswind for Runway 27R into a right downwind; but the pilot had turned crosswind before the end of Runway 27R. I heard the other pilot advise ATC that he had spotted us; but was not previously aware of us. I was also not aware that another plane was in the pattern for Runway 27R. After landing; I asked Oakland Tower for their landline number. I called the Tower and advised the Tower that there had been a loss of separation; and that neither of the Cessna pilots appeared to have been advised of the presence of the other; and neither reported the other in sight. The Cessna in the 27R pattern should have been instructed to continue upwind until I was clear of the pattern and had landed on 33. The Controller I spoke to said that we were in Class C and so we were being separated; but we were at the same altitude and there did not appear to be sufficient horizontal separation. I am not sure that the Controller understood how close the near-miss was. This incident could easily have resulted in a mid-air collision. Because Runway 33 and 27R are both right traffic patterns; it is possible for planes to converge in the patterns if both are in use. At a minimum; ATC must ensure that each pilot is aware of other aircraft and that the pilots can apply visual separation. If not; then ATC should ensure that a pilot in the 27R pattern extends his/her upwind until separation is assured.
Cessna landing Runway 33 at OAK experienced an NMAC with pattern traffic for Runway 27R; no ATC traffic advisories were issued to either aircraft.