N737WF

On April 26, 2005, about 1845 Pacific daylight time, a Cessna 172N, N737WF, impacted the runway following a loss of control during takeoff at Palo Alto Airport of Santa Clara County (PAO), Palo Alto, California. West Valley Flying Club was operating the airplane under the provisions of 14 CFR Part 91. The certified flight instructor (CFI), the student pilot undergoing instruction, and one passenger were not injured; the airplane sustained substantial damage. The local instructional flight departed PAO, about 1845. Visual meteorological conditions prevailed, and no flight plan had been filed. The approximate global positioning system (GPS) coordinates of the primary wreckage were 37 degrees 27.40 minutes north latitude and 122 degrees 06.53 minutes west longitude.

The National Transportation Safety Board investigator-in-charge (IIC) interviewed the CFI, and the student pilot.

The student reported that while on the takeoff roll the airplane was on the centerline of the runway. The airplane started to drift to the right of the centerline. The student either released some of the pressure on the right rudder pedal and or applied some left pedal to correct the drift of the airplane. He thought the airplane was at the "point of takeoff." About that time, the CFI advised the student he was taking control of the airplane. The student relinquished the controls to the CFI.

The CFI reported that during the takeoff roll, with the student at the controls, it "sharply and abruptly" yawed to the left and "very abruptly rotated." The CFI attempted to regain control of the airplane; however, the airplane impacted "sideways on the parallel taxiway." The student and the CFI both stated that the airplane and engine had no mechanical failures or malfunctions during the flight.

The official weather observation station is at PAO, located at accident site. The elevation of the weather observation station was 4 feet mean sea level (msl). Reported weather at 1847, was winds from 330 degrees at 6 knots; visibility 30 miles; clouds few at 4,000 msl; sky condition overcast at 20,000 feet; temperature 66 degrees Fahrenheit; dew point 48 degrees Fahrenheit; and altimeter 29.91 inHg.