On May 24, 1996, approximately 0400 Alaska daylight time, a wheel equipped Piper PA-18 airplane, N83616, registered to and operated by the pilot, crashed after takeoff into the Kivalina river, 15 miles upstream from Kivalina, Alaska. The personal flight, operating under 14 CFR Part 91 was departing the location of the accident and the destination was Kotzebue, Alaska. No flight plan was filed and visual meteorological conditions prevailed. The certificated commercial pilot, the sole occupant, was not injured and the airplane received substantial damage. During a telephone interview with the pilot on May 28, 1996, he stated that he was taking off when the right wheel hit a hole in the ground. He heard the propeller strike a rock. He completed his takeoff and after liftoff the airplane began to vibrate. He was forced to land in the river and nosed over. He examined the propeller after he exited the airplane and saw approximately 3 inches of one propeller blade missing.