DEN02FA084

The student pilot and flight instructor were departing for his third flight lesson; the density altitude was calculated to be 8,393 feet. The flight instructor said that the student began to level the airplane 5 to 10 seconds after liftoff. He said that he took hold of the yoke and assisted the student in adjusting the airplane's pitch to resume the departure climb, and then gave full aircraft control back to the student. The instructor said that he looked out of the airplane to see if there were any airplanes landing on the cross runway. Suddenly, and without warning, the flight controls went to the full forward position and the plane began to dive directly towards the runway. He said he grabbed the control yoke, but could not arrest the descent before the airplane impacted the runaway. The student pilot was taking a non-approved for flight, prescription medication.

History of flight

On July 31, 2002, at 1659 mountain daylight time, Cessna 172K, N7383G, was destroyed when it impacted runway 9 approximately 30 seconds after takeoff from Greeley-Weld County Airport, Greeley, Colorado. The flight instructor was seriously injured and the student pilot was fatally injured. Light Plane Rentals of Greeley, Colorado, was operating the airplane under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the local instructional flight which was originating at the time of the accident. The pilot had not filed a flight plan.

The flight instructor said he had flown with the student pilot on two previous occasions, for approximately 3.7 hours. He said that the student had "shown a good feel for the controls and was able to maintain altitude well." The flight instructor said, on the day of the accident, while doing the preflight inspection of the airplane, the student "seemed a bit confused momentarily, having departed from the checklist to borrow the [fuel] strainer, but then he got back in step and completed the remaining items without incident."

The flight instructor said that student performed the engine start up and he taxied to the end of the runway with no apparent difficulty. He said the student taxied onto the runway, advanced the throttle, and accelerated down the runway centerline. He said the student rotated the airplane at 60 mph (miles per hour; the correct speed without flaps), and performed a normal climb for 5-10 seconds, and then began to level off at about 50 feet. The flight instructor said the airspeed increased to above 80 mph. He said he took hold of the yoke and assisted the student in adjusting the airplane's pitch to resume the departure climb, and then gave full aircraft control back to the student.

The flight instructor said that he looked out of the airplane to see if there were any airplanes landing on final approach for runway 34. Suddenly, and without warning, he said "the controls went to the full forward position and we went into a dive directly over the runway at a height of about 100 feet." He said the dive was so steep, that the wind screen was "nothing but runway."

The flight instructor said he "immediately reached forward, grabbed the yoke and pulled it [the airplane] out of the dive." He said he simultaneously exclaimed, "what are you doing?" He said the student did not reply, but maintained his hold on the yoke and offered no resistance. The instructor said that the airplane was too close to the ground to fully recover, subsequently "we crashed into the runway." He said that after the airplane came to rest, "a fire started at the front of the cowling and quickly spread. I told the student to unbuckle his belt and slide his seat back, and simultaneously I unbuckled my own, but realized I had no response from my legs as I tried to move my seat. I dove out of the plane and landed on the ground. My legs were caught in the radio cord, and lying on my back, I pulled the cord to release them." He said he "scooted away from the plane by pushing with my arms."

A witness, who was performing a pre-takeoff engine run up, said the accident airplane's "takeoff roll appeared normal, and the rotation and climb looked good (not too steep)." He said "the airplane got to about 200 feet when suddenly (abruptly) it nosed over very steeply towards the runway. As the airplane neared the runway, it began to level off (with wings level)." He said that a short time after the airplane came to rest on the runway, it began to burn. Another witness, part of an airport construction crew, said he approached the flight instructor to render assistance. He said the instructor said to him, "I couldn't get the controls back from him quick enough."

The flight instructor reported that the airplane's stall horn never sounded during the flight.

Personal information

The flight instructor took his last second class Federal Aviation Administration (FAA) flight medical examination on February 1, 2002. His flight logbook indicates that he started flying in September of 1989, and had accumulated approximately 830 hours of flight experience by the time of the accident. He is an instrument rated commercial pilot, in both single engine and multiengine aircraft. He earned his flight instructor's certificate in December, 2000, and had accumulated approximately 230 hours of instructors experience.

The student pilot did not have a FAA flight medical. The accident flight was his third flight lesson.

Aircraft information

The airplane was a single engine, propeller-driven, fixed gear, four seat airplane, which was manufactured by Cessna Aircraft Company, in 1970. It was powered by a Lycoming O-320-E20, four cylinder, reciprocating, horizontally opposed, direct drive, air cooled, normally aspirated (carbureted) engine which had a maximum takeoff rating of 150 horsepower at sea level. The airplane had a maximum gross weight capability of 2,300 pounds; its empty weight, when last recorded in August 20, 1992, was 1,406 pounds. Aircraft maintenance records indicate that the last annual inspection was accomplished on April 1, 2002. The airplane's tachometer indicated (at the time of the accident) that it had accumulated approximately 7,734 hours of flight time, and the engine had approximately 220 hours since overhaul.

Another pilot said that he flew the accident airplane on the morning of the accident. He said his takeoff climb out was flown at 70 mph, which achieved an approximate 500 feet per minute rate of climb. He said that as the day heated up, climb performance would have deteriorated to approximately 250 to 300 feet per minute. He said "all the [flight] controls appeared to be operating just fine."

Meteorological information

At 1645, the weather conditions at the Greeley-Weld County Airport (elevation 4,697 feet), Greeley, Colorado, was as follows: wind calm; visibility 10 statute miles; clear of clouds; temperature 99 degrees Fahrenheit; dew point 34 degrees Fahrenheit; altimeter setting 29.94 inches. The calculated density altitude was 8,393 feet.

Airport information

The Greeley-Weld County Airport (elevation 4,697 feet), Greeley, Colorado, is not serviced by a control tower. The airport has three asphalt runways: runway 09-27, 6,200' by 100'; runway 34-16, 10,000' by 100'; and runway 35-17, 3,599' by 75 feet. The airport has five instrument approaches, and is serviced by a Common Traffic Advisory Frequency 122.8 MHz.

Wreckage and impact documentation

The airplane came to rest upright, approximately 30 feet left of runway 9's centerline, approximately 5,200 feet down the runway (N40 degrees, 26.14'; W104 degrees, 37.93'; elevation 4,697 feet). A runway surface scar, approximately 532 feet in length, of gouges, scratches, transfer material, and debris led to the airplane. The thermal damaged airplane was longitudinally orientated approximately 140 degrees.

All of the airplane's major components were accounted for at the accident site. Both wings were in place. The flight control surfaces were all identified and their control cable continuity was confirmed. All the cockpit controls and instrumentation were consumed by fire. Both horns (handles) were separated from the left control yoke

The propeller remained attached to the crankshaft flange. Blade "A" displayed "S" bending, leading edge gouging, and was twisted in the direction of low pitch. The "B" blade was twisted in the direction of low pitch, and the outboard 10 inches (the tip) had separated. The broken tip displayed cordwise gouging on the back of the blade. The engine was rotated to confirm internal continuity, and "thumb" compression was obtained on all cylinders.

No preimpact engine or airframe anomalies, which might have affected the airplane's performance, were identified.

Medical and pathological information

An autopsy w