Investigation Summary
The accident occurred during simultaneous parallel runway operations, a high-workload environment for both pilots and controllers. The Swearingen Metroliner (Key Lime 970) was established on a 5.5-mile final for runway 17L. Simultaneously, the Cirrus SR22 was flying a right-hand traffic pattern for runway 17R. Data from the Cirrus's Remote Data Module revealed it was flying the base leg at approximately 150 knots, significantly higher than the recommended 90 to 95 knots. This excessive speed increased the aircraft's turn radius, causing it to overshoot the 17R centerline. The Cirrus collided with the Metroliner at 1023:52 MDT at an altitude of approximately 6,400 feet. The impact nearly severed the tail section of the Metroliner and destroyed a large portion of the upper cabin area. Remarkably, the Metroliner pilot maintained control and landed on 17L. The Cirrus pilot, finding his aircraft uncontrollable, deployed the Cirrus Airframe Parachute System (CAPS), which allowed the plane to descend vertically into Cherry Creek State Park.
Final Conclusions
The NTSB determined the probable cause was the Cirrus pilot's failure to maintain the final approach course for his assigned runway, resulting in the collision. Contributing factors included the Cirrus pilot's decision to fly at a higher-than-recommended approach speed, which led to the overshoot, and the air traffic controller's failure to issue a traffic advisory to the Metroliner pilot regarding the proximity of the Cirrus. The two aircraft were on different tower frequencies, which prevented the pilots from hearing each other's instructions and hindered their situational awareness.
Video Analysis
Two General Aviation Aircraft Collide | How Did This Happen?! — An investigation into the mid-air collision between a Key Lime Air Metroliner and a Cirrus SR22 near Denver, Colorado, exploring how both aircraft managed to land without injuries.
If playback is blocked, the owner has disabled embedding — use the link above.
Crew Experience
Captain
Pilot of the Swearingen Metroliner.
Private Pilot
Pilot of the Cirrus SR22.
Systems & Failure Modes
CAPS (Cirrus Airframe Parachute System)
A whole-plane ballistic parachute system that allowed the Cirrus to descend safely to the ground after becoming uncontrollable.
ADS-B
Automatic Dependent Surveillance-Broadcast data was used by investigators to reconstruct the precise flight paths and speeds of both aircraft.
Interesting Facts
- 01The Metroliner was 43 years old at the time of the accident, manufactured in 1978.
- 02The Cirrus SR22 was 5 years old, manufactured in 2016.
- 03The collision occurred over Cherry Creek State Park in Arapahoe County.
- 04The Cirrus was flying more than 50 knots above the recommended approach speed during its turn to final.
- 05The two aircraft were being handled by different controllers on different frequencies.
Safety Actions & Advisories
ATC Traffic Advisory Compliance
The investigation highlighted the necessity of following FAA Order JO 7110.65Y, which requires controllers to issue traffic advisories during simultaneous parallel operations even if the aircraft are on different frequencies.