On September 28, 2014, about 1000 Atlantic daylight time, a Britten-Norman BN-2A-26, N906GD, collided with a ditch after the pilot reported that he lost consciousness while taxiing for takeoff at Jose Aponte de la Torre Airport (TJRV), Ceiba, Puerto Rico. The airline transport pilot received minor injuries and the six passengers were not injured. The airplane sustained substantial damage. Visual meteorological conditions prevailed and no flight plan was filed. The airplane was registered to Air Charter Incorporated, and operated by Air Flamenco under the provisions of Title 14 Code of Federal Regulations Part 135 as an on-demand air taxi flight from TJRV to Benjamin Rivera Noriega Airport (TJCP), Isla de Culebra, Puerto Rico.The pilot reported that prior to the flight, it was extremely hot that day and he did not eat breakfast. While taxiing to the runway, he felt dizzy, lost consciousness, and subsequently the airplane veered off the taxiway and came to rest in a ditch. When the pilot regained consciousness the engines were still running and the passengers were asking the pilot "what should they do." The pilot shut down the engines and instructed the passengers to open and exit through the rear of the airplane. The passengers exited through the rear doors and gathered on the taxiway behind the airplane. The pilot exited the airplane, verified that there were no injuries, and called for emergency services. Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed that the airplane sustained substantial damage to the nose gear firewall. A review of the pilot's most recent medical evaluation dated September 25, 2014, for an FAA first-class medical certificate, revealed that the pilot was in good health and only had limitations for wearing corrective lenses. There were no reports of any medications or any visits to health care providers in any of the medical history forms supplied as part of his medical exams. The 0853 recorded weather at the TJRV, included wind from 160 degrees at 5 knots, 10 statute miles visibility, and clear, temperature of 28 degrees C, dew point temperature of 25 degrees C, and an altimeter setting of 30.01 inches of mercury.