N602MC

HISTORY OF FLIGHT

On January 24, 2001, at 1127 mountain standard time, an Aero Vodochody L-39CT, N602MC, was destroyed when it impacted terrain while on departure from Front Range Airport, Watkins, Colorado. The airline transport pilot and his passenger were fatally injured. MAC Flightlease, Inc., of Portland, Oregon, was operating the airplane under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the local flight that was originating at the time of the accident. No flight plan had been filed.

According to airport personnel, on the morning of the accident, the airplane was topped off with 135 gallons of jet fuel. The tip tanks were not fueled, and an employee of the pilot said that the pilot always flew with them empty. Several witnesses observed the airplane taxi to runway 26 for departure (a tail wind departure). A pilot, in his airplane on the run up pad for runway 26, observed the accident airplane begin its takeoff roll while there was a Cessna 172 (possibly a 182) over the numbers on the departure end of the runway.

A pilot in a Cessna 182, who was on 3/4 to 1 mile final when the accident airplane took the active runway, said she was surprised to see the jet on the runway in front of her. She didn't hear any radio calls from him to indicate that he was taking the active runway for departure. She said that she had to slow down and do a couple of "S" turns to allow for spacing. Another witness said that the accident airplane lifted off after a ground roll about 3,800 to 4,000 feet, but appeared to be flying really slow. Several witnesses observed the airplane make a sharp left turn, at approximately 100 to 300 feet above the ground, just past the end of the runway. Another pilot observed the accident airplane taking off and thought it was "very low" and then observed it make a sharp left turn (estimated to be 70 to 90 degrees of bank). He said he could see the whole top of the airplane in the turn. Another pilot said that the Cessna in front of the jet was flying its crosswind leg when the accident airplane began its turn over the departure end of runway 26. One pilot said that she heard no radio transmissions from the accident airplane through his entire departure sequence from Front Range Airport.

Federal Aviation Administration (FAA) radar data indicates that at 1126:19, the airplane crossed the departure end of runway 26 at approximately 173 knots. At 1126:33, the airplane was turning southbound, and had lost an estimated 15 knots of airspeed. No altitude information could be retrieved from the radar data because the airplane's transponder was not emanating any signals. Approximately 2 nautical miles (nm) south of runway 26, the last raw radar return was recorded at 1126:56; the accident airplane's airspeed was estimated to be 200 knots.

A witness, driving south on Imboden Road, reported seeing a cloud of debris depart aft of the airplane, and flutter in the sunlight to the ground. She said it looked like the airplane was discharging trash. She said the airplane suddenly nosed down and headed straight for the ground. A pilot driving north on Imboden Road said he saw the airplane fly nearly straight at him at approximately 300 feet. He said the airplane rolled left, and went straight down. A retired airline mechanic also driving north on Imboden Road said he estimated that the airplane was 400 feet above the ground and flying straight at him. He said that it was moving up and down "very quickly, in a real quick jerky manner [short frequent longitudinal oscillations]."

A pilot flying approximately 1.5 nm behind the accident airplane said that she observed the jet to enter a very slight left bank, and climb slightly. Suddenly, she saw the jet's nose "go straight vertical," as if entering an aerobatic maneuver. The pilot then observed the jet nose-over to the right (west) and impact the ground. A witness standing outside of his home said he saw the airplane's right wing suddenly drop, and the airplane nosed down approximately 45 degrees. He said that there was never any discernible change in its engine noise. The witness said the airplane appeared to be flattening its dive and may have rotated slightly clockwise before disappearing from sight.

The first police and fire/rescue personnel arrived on the scene at approximately 1140.

PERSONNEL INFORMATION

According to FAA records, the pilot received his airline transport pilot certificate on August 30, 1999; he was also a certificated flight instructor and ground instructor. On his last FAA flight medical application dated July 26, 2000, he reported that he had 5,100 hours of flight experience with 250 hours during the previous 6 months. The pilot reported on his last insurance application, dated August 27, 2000, that he had successfully completed a flight review and instrument competency check on August 15, 2000.

The pilot flew his first demonstration flight in the airplane on October 21, 1997, then purchased it and registered it with the FAA on December 16, 1997. During the months of March and April of 1998, he received 13 hours of ground school and 11 hours of flight training in the airplane . On April 17, 1998, a Letter of Authorization (LOA) was issued to the pilot by the FAA; it was good through April 30, 2000. The only flight limitation of his LOA was that he could not fly in formation with another airplane. The letter also required the pilot to make at least three takeoffs and landings in this model airplane within the preceding 6 calendar months, or the privileges of the LOA were rescinded. On July 15 and 16, 2000, the pilot received an estimated 2 hours of ground instruction and two flights in the airplane with an instructor for a total of 2.3 hours. The FAA issued the pilot a new LOA which was good through July 31, 2002.

A pilot flight logbook, documenting the pilot's L-39 flight time could not be found. The pilot reported on the airplane's insurance application, dated August 2000, that he had 150 hours in L-39s. His L-39 flight instructor estimated that the pilot had between 40 to 50 hours of L-39 flight experience. Maintenance logbooks, an aircraft flight log tracking sheet, and statements from other L-39 pilots suggest that the pilot had a total 38.6 hours of L-39 flight experience and 6.6 hours during the last 18 months.

An employee of the pilot said the pilot flew to Washington D.C. in his Boeing Business Jet (BBJ) for the Presidential inauguration and associated events on January 20, 2001. On January 21 and 22, he flew (with three other crew members) to Europe and on to Shang hai, China, with stops at several locations for business meetings. On January 23, he was in Seattle, Washington, for a 5 hour meeting, and then flew home to Denver that evening. The next morning he flew the accident flight with the L-39.

AIRCRAFT INFORMATION

The airplane was a Czech Republic military single engine, turbofan (jet) trainer, two seat tandem airplane (39.8 feet in length; 31 feet total wing span), which was manufactured by the Aero Vodochody Company in 1991 (approximately 3,000 were built). It was never delivered to the original buyer, and was refurbished and recertified in 1996. It was powered by an AI-25TL turbofan engine which had two shafts, by-pass flow, 12-stages of compressor, annular combustion chamber, three stages of gas turbine, which had a maximum sea level static thrust of 3,790 pounds. One pilot, who flew the airplane, said that at 25,000 feet, the airplane easily cruised at a true airspeed of 320 knots; the airplane's flight manual states that the airplane's maximum airspeed, without wing tanks or external stores, was 490 knots.

The airplane was certified for a maximum takeoff weight of 10,600 pounds, and a maximum landing weight of 10,582 pounds. The fuselage fuel tank held 289 gallons (1,936 pounds), and two 58 gallon wing tanks held an additional 104 gallons of usable fuel (704 pounds). The engine had an estimated 180 to 200 gallon per hour fuel burn rate. The maintenance records indicated that the last annual inspection was performed in Oklahoma City, Oklahoma, between August 14, 2000, and October 28, 2000. The previous annual was performed in Gadson, Alabama, between September 27, 1999, and October 19, 1999.

The airplane's empty weight when it left the factory in the Czech Republic, was 7,362 pounds; its center of gravity (CG) was 27.8 percent of mean aerodynamic cord (MAC). The manufacturer's manuals state that the airplane's CG, in its empty weight condition, must be 27.7 percent, plus or minus 0.5 percent of MAC. The manuals further state that a standard aircraft load (with two occupants and main fuel tank full) should have an approximate flight CG of 23 percent, not to exceed 25.5 percent, for the airplane's self-dampening characteristics to be effective. That is, if a sharp, spontaneous elevator movement is made by the pilot, the plane is designed to self-dampen long period longitudinal and short period longitudinal oscillations, if the CG is in the 23 percent to 25.5 percent envelope. As the CG moves aft of this envelope, aircraft control becomes progressively more sensitive, and the flight regime of negative static stability (divergent stability) increases.

The accident airplane was last weighed in Oklahoma on November 17, 2000; its empty weight was 7,349 pounds and maintenance personnel calculated its CG to be 34.42 percent of MAC. A representative from the airplane's manufacturer, using the November 17, 2000 weight figures, computed the airplane's CG to be 34.98 percent of MAC. He further stated that with two pilots and main fuel tank full the CG would be 29.58 percent of MAC. The CG flight envelope, according to manufacturer’s specification, is 21 to 26 percent MAC. Calculations by an L-39 maintenance consultant indicate that the loss of the rear seat's canopy transparency would move the CG aft an additional .25 ...