On April 28, 1999, approximately 0745 mountain daylight time, a Cessna 172I, N46204, and a Cessna 172N, N738UF, were substantially damaged when they collided during landing at Las Cruces International Airport, Las Cruces, New Mexico. The private pilot aboard N46204 and the airline transport rated flight instructor and his student on board N738UF were not injured. Both flights were being conducted under Title 14 CFR Part 91. The flight of N46204 had originated approximately 5 minutes before the accident, and was en route to Portales, New Mexico. The flight of N738UF was for instruction and had originated 30 minutes before the accident. Visual meteorological conditions prevailed at the time of the accident, and no flight plans had been filed by either pilot. According to the pilot of N46204, the aircraft experienced an electrical failure shortly after takeoff from runway 26. After losing the electrical system, the pilot turned the airplane 180 degrees, and entered the downwind to return for landing. Just prior to touching down on the runway, N46204 landed on top of N738UF. The pilot of N738UF was performing touch and go landings with his student, and had just touched down on the runway when N46204 landed on top of the aircraft's right wing section. The pilot of N738UF recalled the airplane accelerating down the runway and then it became uncontrollable as it veered to the left of the runway. The propeller of N46204 caused substantial to the right aileron and right horizontal stabilizer of N738UF. N46204 sustained damage to the left horizontal stabilizer and left aileron. Several witnesses reported that the pilot of N46204 requested assistance starting the airplane on the morning of the accident due to a low battery, and the aircraft needed to be hand-propped in order to start. According to Title 14 CFR Part 91.113 (b) (Right-of-way rules: Except water operations) of the Federal Aviation Regulations (FARs), "When weather conditions permit, regardless of whether an operation is conducted under instrument flight rules or visual flight rules, vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft." In addition, according to 91.113 (g), "When two or more aircraft are approaching an airport for the purpose of landing, the aircraft at the lower altitude has the right-of-way, but it shall not take advantage of this rule to cut in front of another which is on final approach to land or to overtake that aircraft."