DEN01FA096
DEN01FA096

HISTORY OF FLIGHT

On May 11, 2001, at 1937 mountain daylight time, a Beech 76, N6002H, registered to EDB Air, Inc., and operated by Wings of Denver, a flying club, of Englewood, Colorado, was destroyed when it collided with power lines and impacted the Blue Mesa Reservoir approximately 17 miles west of Gunnison, Colorado. The two commercial pilots were fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight being conducted under Title 14 CFR (Code of Federal Regulations) Part 91. The flight originated from Centennial Airport, Englewood, at 1755.

There is no record that either pilot obtained a weather briefing or filed a flight plan. According to the Centennial Airport Control Tower, the airplane was cleared to taxi at 1743, to position and hold at 1754, for take off on runway 17L at 1755, and to depart to the west at 1756. According to the Denver Air Route Traffic Control Center, a VFR (visual flight rules) target, squawking 1200, was seen departing Centennial Airport at about that time. It climbed to 9,800 feet and steadied up on a southwesterly course before disappearing from radar about 20 miles away.

There were numerous reports of a low-flying airplane. The first was from a resident in Crested Butte, about 25 miles north of Gunnison, who said a twin engine airplane flew low over town and disappeared flying south. Next, a resident on the north side of Gunnison (N. 11th St.) reported seeing an airplane matching the description of N6002H flying south over the Gunnison River "at a high rate of speed." In his written statement, he said the airplane "was below the crest of the (Palisades) bluffs at an estimated altitude of 200 feet or less." The airplane then made "an abrupt 30 degree plus bank to the right" and proceeded towards the Blue Mesa Reservoir. Another resident, located about 2 blocks away (Floresta St.) saw a low flying airplane. "I could see half of the mountain (Palisades) above the plane," he wrote.

The fixed base operator at Gunnison County Airport was waiting outside for a UPS flight to arrive when he saw a twin engine airplane plane flying southwest about 150 to 200 feet above the ground. The airplane banked right and followed the Gunnison River westward. He went back inside and heard voices on the UNICOM frequency "talking about the shoreline and different fingers of water on Blue Mesa Reservoir. It sounded as if the mike (sic) button was stuck," he wrote. At about this time another witness, who was traveling east on U.S. 50 about 5 miles west of Gunnison, saw a twin engine airplane coming straight towards her "no more than 50 feet above the highway." A U.S. National Park Service ranger, who was at the east end of the reservoir, saw a twin engine airplane drop down to the surface of the water. Asked how low the airplane was, the ranger said the propellers were "kicking up a spray."

Numerous other witnesses reported seeing a twin engine airplane collide with power transmission lines that crossed the reservoir and impact the water. Some witnesses said the airplane was on fire after striking the power lines, others said there was fire on the surface of the water that lasted for about 5 minutes. The airplane sank to a depth of 130 feet. Small pieces of wreckage, airplane documents, and a flight logbook, identified as belonging to the left seat pilot, floated to the surface and were recovered.

PERSONNEL INFORMATION

The airplane was equipped with dual flight controls; therefore, which pilot was serving as pilot-in-command during the flight is not known. For the purpose of this report, the left and right seat pilots are referred to as the first and second pilots, respectively.

The first pilot, age 31, held a commercial pilot certificate with airplane single/multiengine land and instrument ratings. He held a flight instructor certificate with a single-engine airplane rating, and an advanced ground instructor certificate. His first class airman medical certificate contained the restriction, "Must wear corrective lenses." His logbook was recovered from the reservoir and revealed the following:

Student pilot certificate September 11,1995
Solo, Cessna 152 October 20, 1995
Private pilot certificate June 17, 1996
Instrument rating June 2, 1999
Advanced ground instructor July 26, 1999
Commercial pilot certificate July 29, 1999
Flight instructor certificate July 18, 2000
Multiengine rating January 12, 2001

The following flight times were recorded (includes the 2-hour accident flight):

Total time 854.4
Multiengine 82.3
Beech 76 72.0
Piper PA-30CR 1.5
Piper PA-44-180T 2.9
Beech 95-C55 3.9
Cessna 340 2.0

The pilot received a B.S. degree from Metropolitan State College of Denver in 1999 with an Air Carrier/General Aviation major.

The second pilot, age 30, held a commercial pilot certificate with airplane single/multiengine land and instrument ratings. He also held a flight instructor certificate with a single-engine airplane rating. His second class airman medical certificate contained no restrictions or limitations. Examination of the second pilot's logbook revealed the following:

Student pilot certificate March 21, 1994
Solo, Cessna 152 April 13, 1994
Private pilot certificate August 15, 1994
Instrument rating April 19, 1996
Commercial pilot certificate July 9, 1996
Multiengine rating June 10, 1998
Flight instructor certificate October 22, 1999

The following flight times were recorded (includes the 2-hour accident flight):

Total time 1,026.3
Multiengine 43.5
Beech 76 10.4
Piper PA-44-180T 25.2
Beech 95-C55 3.9


The pilot also received a B.S. degree from Metropolitan State College of Denver in 1999 with an Air Carrier/General Aviation major.

Both pilots' Daily Planners were examined and compared. Although they had scheduled previous flights together in the Beech 76, their logbooks indicated they had flown together only once, on April 26.

AIRCRAFT INFORMATION

N6002H (s.n. ME-121), a model 76, was manufactured by the Beech Aircraft Corporation in 1978. It was equipped with two Textron Lycoming engines (m.n. O-360-A1G6D, s.n. L-25681-36A, left; m.n. LO-360-A1G6D, s.n. L-462-71A, right), driving two Hartzell 2-blade, all metal, full-feathering propellers (m/n HC-M2YR-2CEUF, s/n FB246, left; HC-M2YR-2CLEUF, s/n FB242, right).

According to the aircraft records, the last maintenance event was a 100-hour inspection done on May 3, 2001, at tachometer times of 4,872.5 and 4,158.5 hours, left and right engine, respectively. At that time, the airframe had accrued 4,872.5 hours total time-in-service, the left engine had accrued 4,872.5 hours total time-in-service, and the right engine had accrued 3,884.09 hours total time-in-service.

The left engine was overhauled on November 9, 1990, after it had accrued 2,006 hours, and the right engine was overhauled on May 26, 1994, after it had accrued 1,976.4 hours. As of the date of the 100-hour inspection, the left and right engines had accrued 2,834.6 and 1,907.69 hours since major overhaul, respectively.

On April 6, 2001, the static system, altimeter, and encoder were tested as required by FAR 91.411, and certified for IFR flight in accordance with FAR 43, Appendix E.

Both propellers received 100-hour inspections on December 6, 2000, at a tachometer time of 4,773.48 hours. At that time, both propellers had accrued 4,773.48 hours total time-in-service. The left propeller had accrued 1,808.08, and the right propeller had accrued 1,118.28 hours since major overhaul, respectively. Both propellers were overhauled on November 22, 1994.

METEOROLOGICAL INFORMATION

The following METAR (Aviation Routine Weather Report) observation was recorded at the Gunnison County Airport, located approximately 16 miles northeast of the accident site, at 1955:

Wind, 350 degrees at 6 knots; visibility, 10 statute miles; sky condition, clear; temperature, 18 degrees C. (64 degrees F.); dew point, 7 degrees C. (45 degrees F.); altimeter setting, 30.28 inches of mercury.

Photographs taken at the accident site on May 21 at the same time of the accident revealed the airplane was flying towards a setting sun. According to the U.S. Naval Observatory, official sunset on the day of the accident was at 2010.

WRECKAGE AND IMPACT INFORMATION

Side-scanning sonar located the wreckage on May 16, in 130-foot deep water. Retrieval operations commenced on May 21, and the wreckage was recovered and the cockpit documented on May 23. The wreckage was further examined at Beegles Aircraft Service in Greeley, Colorado, on June 6.

There was a pronounced crush line at F.S. (fuselage station) 68.0, measuring 27 degrees, that buckled the nose section aft and to the right. The cabin roof was collapsed, predominantly on the right side. The aft portion of the fuselage was buckled to the left behind the rear seats, at F.S. 181.0. Except for a slight upward buckling of the right horizontal stabilizer leading edge about B.L. (body line) 40.0, the empennage was relatively undamaged. There was a black scuff mark on the top surface of the left horizontal stabilizer about B.L. 62.9. There were abraided "chatter" marks along the leading edge of the left flap. There was a cut about W.S. (wing station) 177.0 that traveled aft to the main spar, and the leading edge was curled up and aft. The inboard leading edge and fairing to about W.S. 56.1, was crushed aft to the main spar. The right wing, from the leading edge aft to the main spar, was gone from W.S. 90.8 to W.S. 220.5. The blades on both propellers were bent straight back about 12 inches inboard from each tip.

MEDICAL AND PATHOLOGICAL INFORMATION

Autopsies were performed on both pilots. According to the pathologist, a piece of paper was found clutched in the first pilot's fist. It was later identified as being a portion of the Denver sectional chart, depicting Avion Airport, which is located just south of Crested Butte. In a telephone interview, the pathologist said the injuries exhibited by the second pilot were consistent with (and the injuries exhibited by the first pilot were not consistent with) being at the controls of the airplane.

Both the pathologist and FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, performed toxicological screens on both pilots. According to CAMI's report, no carbon monoxide or cyanide were detected in either pilot's blood, nor was ethanol detected in their urine. There was no evidence of drugs in the first pilot's urine. However, Tetrahydrocannabinol Carboxylic Acid (marijuana) was detected in the second pilot's blood [0.0096 (ug/ml, ug/g)] and urine [0.0768 (ug/ml, ug/g)]. The pathologist's report also indicated a positive finding for Tetrahydrocannabinol in the second pilot's urine.



TESTS AND RESEARCH

The airplane struck and severed a set of four 1/2-inch diameter aluminum high tension power lines. Each cable consisted of nine strands of woven wire. According to power company workmen who restrung the downed lines, three lines carried 26,000 volts and the ground (static) line carried 12,000 volts. Two sets of poles (four poles each) on each side of the reservoir supported the power lines. Each pole was about 40 feet tall. According to the Gunnison County Electrical Association, the poles were 1,245 feet apart. The average droop in the lines was 20 feet. Using an altimeter and a global positioning system (GPS), height measurements were obtained at the base of the support structures and the surface of the reservoir: the power poles were 7,735 feet and 7,732 feet, and the surface of the water was 7,505 feet and 7,503 feet, a difference of 230 feet and 229 feet, respectively. Adding 40 feet for the height of the poles and subtracting 20 feet for the average droop, it was estimated that the power lines were about 250 feet above the water.

Regulations that might pertain to the marking of overhead power lines were reviewed. The first document was FAA's Advisory Circular (AC) 70/7460-1K, dated March 1, 2000, entitled, "Obstruction Marking and Lighting." In Chapter 10, "Marking and Lighting of Catenary and Catenary Support Structures," it is suggested that lighted markers be made available for increased night conspicuity of high-voltage (69KV or greater) transmission line Catenary wire. It states (in part), "These markers should be used on transmission line Catenary wires near airports, heliports, across rivers, canyons, lakes, etc." AC 70/7460-1K is advisory, not regulatory.

Title 14 CFR Part 77, Section 23, defines what constitutes "Objects Affecting Navigable Airspace." Generally, only those objects greater than a height of 500 feet above the ground, or greater than a height of 200 feet above the ground within 3 nautical miles of an airport, are considered to be obstructions to navigable airspace.

Title 14 CFR Part 91, Section 119, states that the minimum safe altitude is (1) at any location, that altitude that will allow, in case of an engine failure, an emergency landing without undue hazard to persons or property on the surface; (2) over congested areas, 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet, and (3) other than congested areas, 500 feet above the surface and no closer than 500 feet of any person, vessel, vehicle, or structure.

Colorado Revised Statutes Title 9, Article 2.5, Section 102, states, "No person shall operate an aircraft within ten feet of any high voltage overhead line."

Both engines and propellers were disassembled and examined on May 30, 2001, at the facilities of Beegles Aircraft Service, Greeley, Colorado. No preexisting mechanical discrepancies were noted that would have precluded development of power.

ADDITIONAL DATA/INFORMATION

According to Wings of Denver, on the Sunday before the accident (May 6), the second pilot was flying with another club instructor in a privately owned Beech Baron. They were en route from Moab, Utah, to Englewood, Colorado. The second pilot suggested that they do some low level flying over the Blue Mesa Reservoir. The pilot in command refused.

In addition to the Federal Aviation Administration, parties to the investigation included the National Park Service, Raytheon Aircraft Corporation, and Textron Lycoming.

The wreckage was released to a representative of the insurance company on May 23, 2001.

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