On October 4, 2004, about 1430 Pacific daylight time, a Cessna 152, N24373, while flying in the pattern on the downwind leg, collided with a suspected bird at Reid-Hillview Airport of Santa Clara County (RHV), San Jose, California. California In Nice, Inc., was operating the airplane under the provisions of 14 CFR Part 91. The certified flight instructor (CFI) pilot and the student pilot undergoing instruction (PUI) were not injured; the airplane sustained substantial damage to the right wing. The local instructional flight departed RHV about 1320. Visual meteorological conditions prevailed, and no flight plan had been filed. The CFI reported that while flying on the downwind leg for landing on runway 31L at RHV, after the tower controller cleared them to land and while abeam the numbers, a bird collided with the airplane's right wing. The CFI stated that neither he nor the PUI saw what kind of bird it was. They only saw a flash of the bird's wing. The CFI could tell that there was damage to the right wing, but the airplane appeared to be controllable. The CFI took control of the airplane and landed on runway 31L. After landing and clearing the runway they informed the tower of the bird strike. The damage to the leading edge of the right wing was approximately 2 feet across with about 8 to 12 inches of crushing on the longitudinal axes of the wing. The pilot stated that the airplane had no mechanical failures or malfunctions during the flight, or prior to the collision.