History of Flight
On February 2, 2020, at approximately 1355 mountain daylight time, a Piper PA28-150 airplane, registration N5969W, was substantially damaged during an accident near Florence, Colorado. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as an instructional flight. The flight instructor and one passenger sustained serious injuries, while another passenger was fatally injured.
The flight was a second exploration flight for the passenger seated in the front left seat. The brother of that person occupied the aft right seat, and the flight instructor was seated in the front right seat. According to the flight instructor, he rotated the airplane after using about 2,000 ft of the 5,399-ft-long runway. The airplane climbed and then settled back onto the runway. About 2,500 ft down the runway, the instructor rotated again and entered ground effect. He did not recall the climbout but remembered executing a 180° turn to land on runway 11. The airplane descended and impacted rolling terrain about 1,000 ft southwest of the departure end of runway 29.
An eyewitness observed the airplane depart from about midfield. They reported that the airplane sounded as if it were producing expected power, but the subsequent climb was described as "anemic."
Personnel Information
The flight instructor had purchased the airplane on December 31, 2019, approximately one month before the accident. His logged flight time included experience in the accident airplane as well as in Cessna 210-5A, Piper PA28-180, and Cessna 182T aircraft.
Aircraft Information
According to the most recent weight and balance data, the accident airplane was operated about 100 pounds below its maximum gross weight.
Meteorological Information
The calculated density altitude at the airport was 7,931 ft. At the time of the accident, the airport weather observation recorded a temperature of 24°C (75°F), a dewpoint of -15°C (5°F), and a barometric pressure of 29.78 inHg. The flight instructor noted that this was the highest temperature at the airport (1V6) since he purchased the airplane. Using the Koch Chart from the FAA's Density Altitude document, a takeoff distance increase of 140% and a climb performance reduction of 65% would be expected.
Airport Information
The airport elevation and runway length were previously stated; the accident occurred near Florence, Colorado.
Wreckage and Impact Information
The initial impact point was identified by scuff marks along the ground leading up an embankment on a magnetic heading of 125°. The airplane came to rest upright on a heading of 347°. The left wing had separated and was broken in several locations; the left-wing fuel tank was breached but contained some fuel. The right wing remained attached, and its fuel tank contained fuel. Approximately 20 to 25 gallons of fuel were drained from the airplane. The tachometer read 2,995.81 hours, and the Hobbs meter showed 610.4 hours.
Flight control continuity was confirmed from the controls to the control surfaces. The flap handle was set to the first notch, corresponding to 10° flap extension. The trim screw displayed about 1 inch (7 threads visible), approximating a neutral-to-nose-up pitch trim setting. The propeller remained attached to the engine crankshaft flange, with the spinner crushed aft against the propeller hub. One propeller blade was bent aft about 90° with chordwise polishing, leading-edge denting and chipping. The other blade was straight with no evidence of scraping or chipping.
All engine filters and screens were clear of debris. Valve train continuity and thumb compression were obtained for each cylinder. The magnetos produced spark at each terminal. The carburetor had separated and showed signatures of hydraulic pressure to one float, consistent with fuel being present in the carburetor at impact. No preimpact anomalies were detected with the airframe or engine.
Additional Information
The FAA document FAA-P-8740-2, "Density Altitude" (2008), states that reduced air density adversely affects aerodynamic performance and decreases engine horsepower output, increasing takeoff distance and reducing climb rate. At power settings below 75% or density altitude above 5,000 ft, leaning normally aspirated engines for maximum power on takeoff is essential to avoid an excessively rich mixture that further degrades performance.
A student pilot who flew with the flight instructor about one month before the accident provided a video of that earlier flight. The video showed that, when rotated at about 72 mph, the stall warning light illuminated and flickered as the airplane climbed and accelerated toward 85 mph. When the student asked if that was normal, the flight instructor replied, "yeah, it’s pretty sensitive but we are nowhere near a stall." Later during the climb, the instructor remarked that the airplane "is not climbing today." Weather data for that flight indicated a temperature of 46.4°F and a pressure altitude of 5,122 ft, with the Koch Chart showing a climb performance decrease of about 50%.