History of Flight
On March 23, 2012, at approximately 1143 mountain daylight time, a Cessna 172S (N10468) and a Cessna 180 (N9325C) were substantially damaged in a mid-air collision near Longmont, Colorado. The Cessna 172 impacted an embankment adjacent to a roadway about 5 miles east of Vance Brand Airport (LMO). The Cessna 180 impacted power lines and a chain link fence during a forced landing adjacent to LMO. The flight instructor and private pilot receiving instruction aboard the Cessna 172 were fatally injured. The pilot of the Cessna 180 sustained minor injuries.
The Cessna 172 was registered to MountainAir Aviation Services LLC and operated by McAir Aviation LLC under 14 CFR Part 91 as an instructional flight. It departed Rocky Mountain Metropolitan Airport (BJC) around 1130. The Cessna 180 was registered to and operated by the pilot under Part 91 as a personal flight, departing Erie Municipal Airport (EIK) around 1136. Visual meteorological conditions prevailed; both flights operated without flight plans.
Radar track data from Denver TRACON showed the Cessna 172's flight path converging with the Cessna 180's. At 1142:28, the airplanes were separated laterally by about 393 feet and vertically by about 200 feet. Radar data for the Cessna 180 was lost between 1142:29 and 1142:41, consistent with close proximity during the collision. After the collision, the Cessna 180 descended and entered a turning descent, while the Cessna 172 continued north before descending. The final radar point for the Cessna 172 was at 1142:46 at 6,300 feet msl; the accident site was 0.14 miles north-northeast.
The Cessna 180 pilot reported hearing a loud bang, followed by a pitch-up and roll. She maintained flight with limited elevator control and executed a forced landing. A witness observed the Cessna 180 with its right horizontal stabilizer bent downward approximately 90 degrees at mid-span.
Personnel Information
The Cessna 172 flight instructor held a commercial pilot certificate with single- and multi-engine and instrument ratings, and a flight instructor certificate renewed April 29, 2011. He had about 796 total flight hours, including 789 in single-engine airplanes, 743 as pilot-in-command, and 565 as flight instructor. His most recent flight review was July 27, 2011.
The Cessna 172 private pilot held a private pilot certificate with a single-engine land rating. He reported 312 total flight hours, with 4 hours in the previous 6 months, on his October 6, 2011 medical certificate application.
The Cessna 180 pilot held a commercial pilot certificate with single- and multi-engine and instrument ratings, a flight instructor certificate, and was an FAA designated pilot examiner. She had about 6,315 total flight hours, including 6,250 in single-engine airplanes, 825 in Cessna 180 models, and 4,656 as flight instructor. Her most recent flight review was November 12, 2010.
Aircraft Information
The Cessna 172S (N10468) was a high-wing, single-engine airplane with fixed tricycle landing gear, powered by a 180-horsepower Lycoming IO-360-L2A engine. It received its FAA airworthiness certificate on May 16, 2005. The most recent annual inspection was on February 2, 2012, at 1,955 hours airframe time. The engine had 1,955 hours total time. The last maintenance (strobe light bulb replacement) was on March 22, 2012, at 2,017 hours.
The Cessna 180 (N9325C) was a high-wing, single-engine airplane with conventional landing gear, powered by a 225-horsepower Continental O-470-J engine. It was originally issued an FAA airworthiness certificate on May 24, 1955. The most recent annual inspection was on March 12, 2012, at 4,209 hours airframe time. The engine had about 2,028 hours total time, with 1,027 hours since overhaul. The accident flight was the first after the inspection.
Meteorological Information
The Automated Weather Observing System at Rocky Mountain Metropolitan Airport (BJC), about 13 miles south of the accident site, recorded at 1147: variable wind at 7 knots; 60 miles visibility; scattered clouds at 25,000 feet above ground level; temperature 19°C; dew point -12°C; altimeter 30.02 inches of mercury.
Wreckage and Impact Information
Cessna 172 (N10468): The airplane impacted an embankment on the east side of Weld County Road 1. A ground impact scar oriented at about 135° magnetic. The nose came to rest near the bottom of the embankment. The engine separated and was embedded in the embankment. The fuselage was crushed and fragmented; the cockpit/cabin was completely compromised. Both wings were crushed from leading edge to rear spar. The left wing outboard 6 feet was displaced upward and rotated 180°. The lower surface of the left aileron had a black streak about 9 inches long and 1 inch wide, angled at about 45°. The empennage was oriented upward; vertical stabilizer crushed, rudder deformed. Both horizontal stabilizers deformed. Control cable continuity confirmed at elevator and rudder. The propeller blades exhibited twisting and bending. No precollision anomalies were found.
Cessna 180 (N9325C): The airplane sustained damage to the left wing, aft fuselage, empennage, and firewall. The cockpit/cabin area was intact. The aft fuselage was partially separated. The right horizontal stabilizer and elevator were bent downward about 170° near mid-span and came to rest against a chain link fence. The left wing tip separated; the left aileron partially attached with outboard half deformed upward. Left wing leading edge damage consistent with a wire strike, with paint missing and discolored holes oriented at 45-55°. A skin fragment with serrated paint pattern indicated contact with a braided cable. The right aileron outboard portion bent downward about 90°. Aileron, flap, elevator, and rudder control continuity confirmed. The engine separated from the airframe at the firewall; all three propeller blades bent aft near the tips with chordwise scratches. No precollision anomalies were found.
Additional Information
FAA regulations (14 CFR 91.113(b)) require pilots to maintain vigilance to see and avoid other aircraft. When aircraft converge, the aircraft to the other's right has the right-of-way. The FAA Pilot's Handbook of Aeronautical Knowledge notes that pilots should yield if another aircraft seems too close. Both high-wing and low-wing aircraft have blind spots; pilots should execute clearing procedures during sustained straight-and-level flight and gentle banks during climbs and descents.
The Cessna 172 was equipped with a Garmin G1000 that can provide traffic advisories via Traffic Information Service - Broadcast (TIS-B), derived from air traffic surveillance radars. The FAA AIM notes TIS-B is advisory only and not for collision avoidance. No secondary data card was found, so no flight parameter data was available. The Cessna 180 had no traffic alert system; neither airplane was required to have one.