On August 27, 1999, at 2015 eastern daylight time (edt), an Aeronca 11BC, N9404E, operated by a private pilot sustained substantial damage when on takeoff from runway 02 (2,600 feet by 200 feet, dry grass/turf) at the Watervliet Municipal Airport, Watervliet, Michigan, the airplane bounced, porpoised, and impacted on the runway. Visual meteorological conditions prevailed at the time of the accident. The personal flight was being conducted under 14 CFR Part 91. No flight plan was on file. The pilot and passenger on board the airplane reported no injuries. The local flight was originating at the time of the accident. In his written statement, the pilot said that during takeoff, the airplane bounced 2-3 times on the runway, and then the landing gear and propeller broke. The passenger on board the airplane stated that "upon liftoff, the airplane ballooned off of the runway. We came back down and bounced once, kind of porpoised twice, and came back down, and the landing gear collapsed." A Federal Aviation Administration (FAA) inspector examined the airplane at the Watervliet Municipal Airport. The airplane's main landing gear was folded rearward underneath the airplane's fuselage. Both main gear struts were broken aft from the landing gear box, just behind the airplane's firewall. The lower portion of the firewall was bent aft. The bottom forward fuselage skin was crushed upward. The airplane's wood propeller was broken and splintered. Flight control continuity was confirmed. Examination of the airplane's engine, engine controls, and other airplane systems revealed no anomalies.