BROOMFIELD, CO, USA
HBHOO
Pilatus PC-7
The pilot was ferrying the aircraft from the company's headquarters in Switzerland for a buyer in the United States. While approaching the airport to land, he requested to perform a low approach to runway 29R, which was approved by the airport tower. According to multiple witnesses in the airport tower and on the ground, they observed the aircraft with the landing gear retracted overfly runway 29R. At the midfield point, the aircraft was observed to roll 360 degrees twice to the right, followed by a 360-degree roll to the left. The nose pitched up, then descended toward the ground. The right wing impacted on an adjacent taxiway and the airplane cartwheeled and exploded. During a postaccident examination of the aircraft, no airframe or engine anomalies were identified. Radar data provided evidence that the aircraft was traveling at 215 knots seconds prior to impact. The airport is located within the boundaries of Class D airspace and according to FAR 91.303, aerobatic flight within the surface area of Class D airspace is prohibited.
HISTORY OF FLIGHT On January 14, 2000, at 1318 mountain standard time, a Pilatus PC-7, HB-HOO, registered to and operated by Pilatus Aircraft Ltd., was destroyed when it collided with the ground and was subsequently consumed by fire while performing a low pass over runway 29R at Jefferson County Airport, Broomfield, Colorado. The Swiss-registered commercial pilot, the sole occupant aboard, was fatally injured. Visual meteorological conditions prevailed, and an IFR flight plan was filed for the ferry flight being conducted under Title 14 CFR Part 91. The flight originated from Goshen, Indiana, at 0948 eastern standard time. According to a representative of Pilatus Aircraft, the pilot was ferrying the aircraft from the company's headquarters in Stans, Switzerland, for a buyer in the United States. The pilot initiated the 5-day trip on January 10, with a final destination of Broomfield, Colorado, where the company has a completion facility. According to Federal Aviation Administration (FAA) transcripts, the pilot of HB-HOO made initial contact with Denver TRACON (Terminal Radar Approach Control) at 1259. At 1315, the pilot was instructed to turn right to a heading of 290 degrees and to report the Jefferson County Airport (BJC) in sight. The pilot then reported that he had the airport in sight and the controller cleared the airplane for a visual approach to runway 29R at BJC. The pilot was then instructed to begin slowing to a final approach speed and to contact the tower. At 1316:06, the pilot contacted the BJC tower and reported being on a long final approach to runway 29R. The controller acknowledged and advised the pilot that he was in sequence to be number two for landing. At 1316:29, the pilot asked, "May I do a low go around or a fly by?" The controller cleared the pilot for an optional approach, and instructed him to remain in a right traffic pattern following the approach. That was the last radio transmission received from the pilot. According to an air traffic controller stationed in the airport tower at the time of the accident, he observed HB-HOO execute a low approach to runway 29R. At the midfield point of the runway, the aircraft "began to pitch up to [the] right. In its bank, HB-HOO made two rapid right 360-degree rolls, tail down. HB-HOO then stopped [the] roll upright, severe tail down, right bank (10 - 20 degrees), then descend rapidly. [The] right wing impacted adjacent taxiway A13. [The] aircraft continued to roll (cartwheel), explode and break up." According to several pilots who were taxiing their aircraft on adjacent taxiways on the airport, they observed an aircraft with its landing gear in a retracted position overfly runway 29R at a low altitude. According to one pilot, he observed the aircraft level off with its wings level. The aircraft then began to pitch up and transitioned into a roll to the right at a fast rotation. It then traveled right off course with its flight path over the taxiway, and the nose began to pitch up. During the roll, the airplane "appeared in control" and the roll itself was "somewhat crisp." The airplane then began a second roll to the right, which was "much slower" and "fairly sloppy -- not well done at all." The aircraft's nose then fell through the horizon and pitched down toward the ground. He then lost sight of the aircraft as it flew overhead in an inverted position. Another witness located in the terminal building stated that his attention was drawn to the "sound of a fast moving turboprop airplane" which caused him to look out the window. At the time he observed the aircraft, it was flying down the runway at 50 to 100 feet agl in a steep left bank. The airplane completed a "very sloppy roll" to the left, "followed by a continued descending deep stall" with the aircraft's nose at a 20 to 30 degree pitch up attitude as it "rocked from right to left to right, wing low, until impact." Another witness also positioned inside the terminal building "heard the distinct sound of a PT-6 engine at high speed. I immediately looked up and out the window and noticed the PC-7 in a wings level, slightly nose low attitude, approximately 150 feet off the ground. Right after this the aircraft pitched up and rolled to the left. This happened quite abruptly. The aircraft had a low elevator position once it had 180 degrees rotation (canopy towards the ground). Once the aircraft completed 360 degrees of rotation (canopy up), the nose was high/elevator low, and the wings were obviously stalled... The right wing struck the ground. This followed by the prop[eller] striking the ground and then a cartwheeling crash." PERSONNEL INFORMATION The pilot, a citizen of Switzerland, was born in 1958. He held a Swiss Commercial Pilot's License dated January 24, 1996. He held endorsements in both VFR and IFR aircraft, and ratings in single and multi-engine aircraft, the PC-12, PC-6T and the PC-7. In addition, he held a United States issued Private Pilot Certificate (foreign based), dated August 11, 1998, with single and multi-engine land ratings. The license had the limitation, "Issued on basis of and valid only when accompanied by Switzerland pilot license number 32458. All limitations and restrictions on the Switzerland pilot license apply." He possessed a first class airman medical certificate, dated June 12, 1998, with the restriction, "Holder shall wear correcting lenses while exercising the privileges of his Airman Certificate." AIRCRAFT INFORMATION HB-HOO, a PC-7 Turbo Trainer, was a Swiss-registered aircraft manufactured by Pilatus Aircraft Ltd. in 1982. It was originally designed and certified as a low-wing aerobatic training aircraft. It was equipped with a Pratt & Whitney PT6A-25A turboprop engine, rated at 550 shaft horsepower, a Hartzell three-blade, all-metal, constant-speed, full-feathering propeller, and retractable landing gear. The left and right wing were originally constructed as one complete unit. According to the aircraft's maintenance records, the last annual inspections on the engine and airframe were accomplished on December 17, 1999, at a tachometer time of 2931.41 hours. The engine and airframe had accrued 24 hours since the last inspections were performed, the total time of the ferry flight from Switzerland to the United States. METEOROLOGICAL INFORMATION At 1250, weather conditions at BJC were winds variable at 4 knots, visibility 75 statute miles, broken clouds at 12,000 and 20,000 feet, temperature 16 degrees C. (61 degrees F.), dew point minus 13 degrees C. (9 degrees F.), and an altimeter setting of 30.23 inches of mercury. Density altitude was calculated to be 6,835 feet. AERODROME INFORMATION BJC is a tower-controlled airport located 9 miles northwest of Denver, Colorado, at an elevation of 5,670 feet above mean sea level (msl). The three runways are 2/20, 11L/29R, and 11R/29L. Runway 11L/29R is asphalt/grooved and is 9,000 feet long by 100 feet wide. WRECKAGE AND IMPACT INFORMATION The fuselage and wings came to rest approximately 500 feet from the initial point of impact. An area of burned grass began off taxiway A-13 and led up the main wreckage. The wings were separated and found 15 feet from the main fuselage. The left external underwing tank was found 130 feet forward of the main wreckage, the right external underwing tank was located 50 feet forward, with additional aircraft debris scattered along the ground scar leading from the point of initial impact to the main wreckage. The propeller was separated from the engine and was located on the terminal parking cemented ramp, 75 feet from the main wreckage and slightly to the right of the scatter path. All three of the propeller blades were missing the first one-third of each of the blade's tips. All major components of the aircraft were accounted for at the accident scene. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on July 17, 2000, by the Jefferson County Coroner's Office in Golden, Colorado. A toxicological protocol was performed by the FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma. No carbon monoxide or cyanide were detected in the blood, and no ethanol or drugs were detected in the urine. TESTS AND RESEARCH On February 3, 2000, the wreckage was examined at the facilities of Beegles Aircraft in Greeley, Colorado. Flight control continuity was established to the left wing and to the tail section of the aircraft; however, continuity to the right wing was unable to be established due to impact damage. The attitude indicator displayed a 30 degree nose down and 80 degree right wing down. The engine exhibited severe impact damage, including complete structural separation of the reduction and accessory gearboxes. An examination of the engine revealed contact signatures to its internal components characteristic of the engine developing power in a high power range at the time of impact. No preimpact engine or airframe anomalies, which might have affected the airplane's performance, were identified. According to radar data provided by Denver TRACON two minutes prior to impact, HB-HOO was traveling at a speed of 175 knots. After turning left to a heading of 293 degrees for a straight-in approach to runway 29R, the airplane continued to descend and gain airspeed. The last recorded radar target provided evidence that the airplane was traveling at a speed of 215 knots seconds prior to impact. ADDITIONAL INFORMATION According to Title 14 CFR Part 91.303 (Aerobatic flight) of the Federal Aviation Regulations (FARs), "No person may operate an aircraft in aerobatic flight (c) Within the lateral boundaries of the surface areas of Class B, Class C, Class D, or Class E airspace designated for an airport... For the purposes of this section, aerobatic flight means an intentional maneuver involving an abrupt change in an aircraft's attitude, an abnormal attitude, or abnormal acceleration, not necessary for normal flight." Jefferson County Airport is located within the boundaries of Class D airspace. According to a representative with Pilatus Aircraft, it was common practice for the pilot to perform a low approach/fly-by over the runway as a method to signal his arrival to the company; however, it is not common practice for him to perform aerobatics while performing the low approach. In addition to the Federal Aviation Administration, parties to the investigation were Pilatus Aircraft Ltd., Pratt & Whitney Canada engines, and the Colorado Division of Aeronautics. The wreckage was released to a representative of Pilatus Aircraft Ltd. on February 3, 2000.
The pilot's loss of aircraft control while performing low level aerobatics at an altitude insufficient to make a safe recovery.
Source: NTSB Aviation Accident Database
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