The pilot of the amphibious airplane reported that during takeoff, when the airplane was about 1,000 ft down the 2,750-ft-long grass runway, he was unable to raise the airplane’s nosewheel. He increased the flap setting, but the airplane could not leave the ground. Because the airplane was beyond the pilot’s normal takeoff abort point, he reduced the throttle fully and applied the brakes. The airplane then departed the runway end and impacted a fence and two roadside ditches before coming to rest. The airplane’s fuselage was substantially damaged during the accident sequence. After coming to rest, a fire ignited in the dry grass under the airplane’s right main tire and was extinguished by the pilot and passenger. Following the accident, the pilot towed the airplane back to his hangar, and noticed during that process that the right wheel brake was sticking and that the right wheel had left a groove through the grass. A subsequent examination of the right wheel and brake revealed that the right wheel rotated freely but with some resistance noted from the brake. The pilot reported that there were no other mechanical anomalies with the airplane. Given this information, it is likely that the airplane’s right brake was partially engaged during the takeoff, which restricted the airplane’s ability to accelerate to an adequate flying speed and the pilot’s ability to pitch to a normal takeoff attitude. This condition resulted pilot’s eventual decision to abort the takeoff, and the subsequent runway overrun. Had the pilot noted this lack of acceleration earlier during the takeoff, it is possible that the takeoff could have been aborted with sufficient runway remaining to avoid the runway overrun.