Factual Report: Cheyenne/Cessna 172 midair in Denver

 - January 4, 2008, 9:32 AM

Piper PA-31T and Cessna 172, Denver, Colo., Jan. 24, 2003–At about 5 p.m. CST, Cessna 172P N52241 departed from Denver Centennial Airport (APA) en route to Cheyenne, Wyo. N52241 was rented from Key Lime Flight based at Centennial Airport. About 10 minutes later Piper Cheyenne N360LL departed Jefferson County Airport (BJC) in the Denver area en route to APA.

Operating under Part 91, the pilots were not required to contact ATC; however, both pilots requested and received VFR flight following. As a result, one controller was providing basic radar services to both pilots, which included safety alerts, traffic advisories and limited rada r vectoring when requested by the pilot.

At 5:17 p.m. the Cheyenne pilot reported to Denver Approach Control that he was at 7,800 feet. About 90 seconds later the Cessna pilot contacted the controller requesting a climb from 7,300 to 8,500 feet. The request was granted and approximately 10 seconds later the controller again asked the Cheyenne pilot to report his altitude. According to the NTSB, the transponder in the Cheyenne was either inoperative or not turned on, depriving  ATC of an altitude read out on radar.

The Cheyenne pilot reported to ATC that he was flying at 7,600 feet, and the controller then issued a traffic advisory to the Cheyenne pilot advising that there was a Cessna at the Cheyenne’s 12 o’clock position and one mile at 7,700 feet. A witness described the Piper making a “steep, sharp bank” to the left immediately before impact. The collision and subsequent crashes destroyed both aircraft, killed all five occupants of the two airplanes and injured seven people on the ground, though none seriously.

The FAA-recommended local area procedure for aircraft flying north from Centennial is to fly at an altitude of 7,500 feet just west of Interstate 25. Southbound aircraft out of Jeffco are to fly at 8,500 feet to the west of Wadsworth Boulevard, putting the aircraft at 2,000 feet and 3,000 feet agl, respectively. Though the procedure is only recommended, the northbound Cheyenne appeared to be adhering to it while the southbound Cessna was not, setting the stage for the conflict.

The Denver coroner identified the victims in the Cheyenne as Leo Larson, 57, and Fred Greg White, 51. Larson, who held a commercial pilot certificate with flight instructor and ground instructor ratings, owned an aircraft brokerage company and was trying to sell the Piper for $615,000. White, who was also a commercial pilot and an A&P mechanic, specialized in the Piper aircraft and often appraised aircraft for Larson. It is unclear who was flying the Cheyenne.

The occupants of the Cessna 172 were Jonathan Ross Ladd 20, the pilot; Isaac Louis Murrow (22) and Curtis Paul Maxey 22. Ladd was a survivor of the 1999 Columbine High School massacre.

Weather is not considered to be a contributing factor since the reported visibility was about 10 to 15 miles and the cloud conditions were reported as broken and scattered from 6,000 to 14,000 feet msl. Investigators have noted, however, that the sun had set about 20 minutes before the collision, and the NTSB is exploring the effects that lighting may have had on the pilots’ ability to see other aircraft.

According to a January 26 Denver Post article, Denver mayoral spokesman Andrew Hudson said officials would look into neighborhood concerns about the number of small airplanes flying over the area. “How this occurred during rush hour on an average day is something we have to look at and learn how we can prevent this from happening in the future,” Hudson said. Mayor Wellington Webb held a conference call a day after the accident with senior FAA officials and asked for an investigation into the number of low-flying aircraft over Denver. According to the FAA there are an average of 16 GA midair collisions annually over the U.S. Statistically, both aircraft manage to land safely in 44 percent of midair accidents.