On July 24, 1999, approximately 0900 mountain daylight time, a Piper PA-22-150, N4540A, was substantially damaged when it collided with terrain shortly after taking off from Limon, Colorado. The private pilot was not injured but a private pilot-rated passenger, the operator of the airplane, received minor injuries. Visual meteorological conditions prevailed, and no flight plan had been filed for the business flight being conducted under Title 14 CFR Part 91. The flight had originated minutes before the accident. According to the pilot's accident report, trip legs were swapped between the two pilots. The accident occurred on the leg during which the owner-operator was serving as a pilot-rated passenger. One notch of flaps (half flaps) were used for the takeoff from runway 34. As the airplane passed over the departure end of the runway, it began to "sag." He initiated a right turn to take "advantage of the [climb] prop[eller]." Airspeed and engine power dropped to 70 mph and 2,000 rpm, respectively, and the airplane began to sink. The pilot made a forced landing in a field. To avoid a ditch, he intentionally forced the airplane onto the ground crossing the controls. Upon exiting the airplane, the pilot noted "a 10 to 15 knot wind with gusts from the south. . .I suspect the 10 to 15 knot tailwind and gusts were the main factor, or maybe even a thermal." In a telephone interview with the owner-operator, he said the engine sounded normal to him throughout the short flight, and he did not believe it had lost power. According to the 0855 Limon METAR observation, the wind was from 160 degrees (direct tailwind) at 6 knots. The temperature was 28 degrees C. (82.4 degrees F.), and the altimeter setting was 30.20 inches of mercury. Limon Municipal Airport is 5,365 feet msl (above mean sea level). Pressure and density altitudes were computed to be 5,085 and 7,690 feet msl, respectively.