On July 9, 1998, about 1651 eastern daylight time, a Cessna 150M, N9363U, nosed over on landing at Vero Beach Municipal Airport, Vero Beach, Florida. The personal flight was operated by the pilot under the provisions of Title 14 CFR Part 91 and visual flight rules. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed. The airplane was substantially damaged, and both private pilots were not injured. The flight originated from Vero Beach at 1604. According to the pilot, he and his brother were practicing touch and go landings at Vero Beach. On the second touch and go, he added full power, turned carburetor heat off, and retracted the flaps. The airplane rotated and climbed to approximately 10-20 feet before it started to sink back to the runway. The airplane hit the runway and bounced back into the air. The pilot's brother, also a private pilot, then took the controls and attempted to regain control of the airplane on the runway. The airplane bounced a few more times, broke off the nose landing gear, and impacted the ground, nosing over. After the airplane came to rest, both pilots exited the airplane unhurt. The pilot also stated that upon exiting the airplane he noted that the wind had changed to a 10-15 knot tailwind. The second pilot stated that at takeoff the winds were 260 degrees at 6 knots (ATIS reported the winds as 280 degrees at 6 knots). His brother made the first touch and go on runway 29R with no problems. During the second touch and go, he rotated and the airplane began to sink. The second pilot stated he looked at the airspeed indicator and noted it was 45-50 knots. Normal climb is made at 65-70 knots. The airplane bounced several times, during which the second pilot took the controls. After touching down at the end of the runway, the second pilot noted a ditch in front of them, a drainage ditch for runway 22, and attempted to fly over it. The airplane struck the ditch, and the nose gear snapped off, and the airplane bounced into the air. As the airplane slowed, the nose came down, and the airplane nosed over. The second pilot also stated that the wind was from 110 at approximately 10-17 knots when they exited the airplane. According to the pilots, the tower controller had not advised them of any changes in the weather. The pilots also stated that within five minutes after the accident, all traffic was landing on 11R. According to the certified re-recording of the tower tape, which covered the time period between 2032-2056 Zulu, operations continued on runways 29L and 29R. In the second pilots statement, he stated that he had ATIS information Quebec, and the winds were from 260 degrees at 6 knots. Information Quebec, provided by the tower tape, which was current at the time of the accident, is as follows: 1950 Zulu/wind 280 at 06/ visibility 15/ 4000 scattered/25,000 broken/ temp. 33/dew point 23 altimeter 30.01/ DME approach, runway 29/ runways 29L and 29R in use... According to a certified re-recording of the tower tape, the winds were broadcast over the radio by the controller roughly 3 minutes after the accident as 270 degrees at 4 knots. After the accident four airplanes continued using runway 29L and one airplane was in the pattern for 29R, executing a requested, practice missed approach. According to the Flight Training Handbook (AC61-21A), it is possible for an airplane, that is low to the ground, to fly at an airspeed slightly slower than is required to achieve level flight. This is due to the reduction of induced drag at a constant lift coefficient. This is "flying in ground effect" and occurs when the airplane is at or below a height equal to its wing span. The wing span on a Cessna 150 is 33.4 feet. According to the pilot's statement they were at a height of 20-30 feet above the ground when they started to sink back to the runway. The pilot also stated that their airspeed was below the normal airspeed required for climb-out. According to the advisory circular, when an airplane becomes airborne with a deficiency of speed, it will not be able to fly out of ground effect and will settle back to the runway. It is important that no attempt be made to force the airplane to become airborne with a deficiency of speed. According to the pilot, the recommended takeoff speed that is necessary to provide adequate initial climb performance is 65-70 knots. According to the Cessna 150 flight manual, the flaps up, power off stall speed for a Cessna 150 is 55 miles per hour (48 knots).