On July 4, 2004, at 1500 eastern daylight time, a Cessna 172C, N38RA, was substantially damaged when it impacted the ground after takeoff from the Pottstown Municipal Airport (N47), Pottstown, Pennsylvania. The certificated private pilot and three passengers were not injured. Visual meteorological conditions prevailed and no flight plan was filed for the local personal flight which was conducted under 14 CFR Part 91. A witness observed the airplane land on runway 25 at Pottstown, and porpoise four times before coming to rest. Three passengers then boarded the airplane, and the pilot taxied back to the runway for departure. The witness observed the airplane rotate about 1/3 down the length of the runway, and then began to "teeter," appearing to be slow, with an excessive nose-high pitch. He observed the airplane climb to approximately 400 feet, and then turn to the right. The airplane then made an immediate left turn and initiated an approach to runway 07. The witness observed the airplane drop and bounce on the runway. The airplane bounced several times, and about the second or third bounce, the landing gear collapsed and the propeller came in contact with the ground. The airplane continued to skid down the runway, until it came to rest. According to the pilot, he initiated a short field takeoff from runway 25, with 20 degrees of flaps. He rotated the airplane at 40-50 knots, and as the airplane climbed, he began to hear the stall warning horn. The pilot reported that the airplane handled "sluggishly," and at 400 feet, he retracted the flaps to 10 degrees. He initiated a left turn back to the runway, and the airplane touched down first on the nose wheel, and then began to porpoise down the runway. The pilot reported no mechanical deficiencies with the airplane. Additionally, he reported that he had 150 hours of total flight experience, 1 hour of which was in the make and model of the accident airplane. Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed substantial damage to the firewall. The winds reported at Pottstown-Limerick Airport, 5 miles to the southeast, at 1454, were variable at 6 knots.