On August 6, 2005, at 1515 mountain daylight time, a Cessna 172RG, N5136R, operated by Colorado Contrails and piloted by a commercial pilot under the supervision of a flight instructor, was substantially damaged when it departed the runway and struck a taxiway sign while landing at Fort Collins/Loveland Airport (FNL), Fort Collins, Colorado. Visual meteorological conditions prevailed at the time of the accident. The local instructional flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The pilot, instructor, and passenger reported no injuries. The flight originated at Fort Collins, Colorado, approximately 1400. In his written statement, the right seat pilot, who was working on his CFI (certified flight instructor) certificate, stated he was on final approach to runway 33. There was a "light" crosswind from the right (4 to 7 knots), and he crabbed the airplane into the wind. The instructor said that he told the pilot several times to apply "more left rudder." The airplane touched down on the left main gear and the left wing tip scraped the ground. The pilot decided to abort the landing and applied full power. The airplane veered off the runway and struck a taxiway sign. The instructor took control and terminated the attempted abort. AWOS (Automated Weather Observation Station) recorded wind at the time of the accident as 060 degrees at 3 knots. Postaccident inspection revealed the left wingtip was cracked, the skin behind the wing strut was torn, the skin behind the main landing gear was rippled, the horizontal stabilizer leading edge was crushed, and the rear bulkhead was deformed.