On July 27, 2010, approximately 1215 central daylight time, N8159B, a low-wing Piper PA-32R-301, collided with N78659, a high-wing Piper PA-11, while both airplanes were maneuvering over Ripon, Wisconsin, to fly the FISK visual flight rules (VFR) arrival to Oshkosh (KOSH), Wisconsin. Visual meteorological conditions prevailed at the time of the accident. Both flights were being conducted under the provisions of 14 Code of Federal Regulations Part 91 without flight plans. The commercial pilot aboard the Piper PA-32R-301 and the commercial pilot and passenger aboard the Piper PA-11 were not injured. The Piper PA-32R-301 departed Juneau, Wisconsin, and the Piper PA-11 departed Fort Wayne, Indiana. Both airplanes were en route to KOSH. According to a verbal statement taken from the pilot of N8159B, he was monitoring the frequency for FISK Approach and heard the controllers advise the airplanes to “keep their speed up.” He had joined the arrival route just west of Ripon and was at 1,800 feet mean sea level (msl). Upon hearing the advisory to keep their speeds up, he increased his airspeed to between 95 and 100 knots. He observed a Cessna one mile ahead of him and followed that Cessna. Approximately two miles east of Ripon he heard a soft “thud.” Shortly thereafter he heard another airplane transmit that an airplane had just hit them. He responded that he had hit the other airplane. N8159B continued to KOSH and landed on runway 18 right. During the landing roll, the pilot was not able to maintain directional control and departed the runway to the left. The pilot’s written statement confirmed the verbal statement provided the day of the incident. In addition, he elaborated that prior to arriving at Ripon, he performed S-turns in order to scan for other traffic in the area, and it was at this time that he observed the Cessna. He did not perform any S-turns after Ripon to look for traffic, as the NOTAM prohibits this activity. He also elaborated that he was at 90 knots while approaching Ripon and only increased his airspeed when the controller advised aircraft to “keep their speed up.” He also stated that after passing Ripon his altitude was constant at 1,800 feet msl and was neither climbing or descending prior to or at the time of the impact. He never observed N78659 prior to the impact. When asked to elaborate on what he heard or understood regarding the controller’s statement to “keep their speed up,” he stated that it was not an announcement such as that made when an airport terminal information system (ATIS) is updated but rather a general statement of keeping the speed up to the field. He stated that it was not associated with a specific airplane description and was stated several times during the 15 minutes he had been monitoring FISK prior to the impact. An examination of N8159B revealed damage to the left main landing gear tire and wheel. An examination of the remaining systems revealed no further impact damage and no anomalies. According to a verbal statement taken from the pilot of N78659, he was just east of FISK when an airplane struck his airplane from above. The other airplane continued to fly past him to the east and he reported the collision on the FISK frequency. The pilot noted a vibration in the engine; however, he was able to reduce power and continue to KOSH. The pilot performed a straight in landing to runway 09 without further incident. The pilot’s written statement confirmed the verbal statement provided the day of the incident. In addition, he elaborated that prior to flying the required procedure he performed a 360 degree turn to clear for traffic. An examination of N78659 revealed damage to one propeller blade. An examination of the remaining systems revealed no further impact damage and no anomalies. Both aircraft were inbound to KOSH to attend the 2010 AirVenture. At the time, special flight procedures were in effect which were communicated to the aviation community through the Federal Aviation Administration Notice to Airman (NOTAM). This NOTAM was effective from July 23, 2010, through August 2, 2010. The procedures for the FISK VFR arrival to KOSH required pilots to approach Ripon at 1,800 feet or 2,300 feet msl. Aircraft at 1,800 feet were to maintain 90 knots or maximum cruise speed (if slower than 90 knots). After arriving at Ripon, aircraft were to follow the railroad tracks to FISK and then follow air traffic control (ATC) instructions from that point. Both pilots confirmed that they had the NOTAM. The NOTAM is very specific that pilots shall “maintain a minimum of ½ mile in-trail spacing behind the aircraft” they are following. In addition, the NOTAM prohibits S-turns. The EAA AirVenture website page "Understanding Air Traffic Control at EAA AirVenture Oshkosh" states that there may be times when air traffic volume is low and Fisk controllers request pilots to keep their speed up. The page states that if an airplane receives permission to increase their speed, they must remember to reduce their speed back to 90 knots upon passing Fisk. According to an Air Traffic Control Manager, when aircraft receive the instruction to increase speed, they are not expected to climb up to the higher altitude.