Kotzebue, AK, USA
N56467
Maule M-6-235
The certificated private pilot, with one passenger, was departing southbound from an airport under special VFR conditions. Witnesses reported that weather conditions to the south, and specifically in the direction of accident site, were momentarily much worse than that being reported at the airport. About two minutes after takeoff, the airplane collided with a 335 feet tall commerical radio antenna tower. The tower was situated about 395 feet above sea level, and located 4.3 nautical miles south of the departure airport. The tower was installed in 1986, and was depicted as an obstruction on the VFR aviation sectional map covering the area around the departure airport. The tower was painted in an alternating aviation orange/aviation white pattern. Two sets of red light fixtures were installed about the 110 and 220 feet levels. Each set of lights had two lamps. A large flashing red light fixture was installed at the top of the tower. One of the two light fixture lamps, located on the lower portion of the tower, was not operating, and was scheduled for replacement. However, the second light fixture lamp located at that this position was still operating. A light sensitive switch (photocell), was installed that would automatically turn the tower lights "ON" when the surrounding ambient light decreased, and would turn the tower lights "OFF" when ambient light increased. At the time of the accident, the lights were configured so that they were in the "ON" position 24 hours per day. The accident took place during daylight hours. The antenna complied with the governing FCC's rules and regulations regarding marking and lighting of antennas, as well as the FAA's obstruction standards.
HISTORY OF FLIGHT On August 13, 2001, about 1049 Alaska daylight time, a Maule M-6-235 airplane, N56467, collided with a 335 feet high commercial radio antenna tower, located about 4.3 nautical miles south of the Kotzebue Airport, Kotzebue, Alaska. The airplane was being operated as a visual flight rules (VFR) personal flight under Title 14, CFR Part 91, when the accident occurred. The airplane was owned by Arctic Camps and Equipment, Inc., Anchorage, Alaska. The certificated private pilot received fatal injuries, and the sole passenger sustained serious injuries. Instrument meteorological conditions prevailed, and a VFR flight plan was filed. The flight originated about 1047 at the Ralph Wien Memorial Airport, Kotzebue, and was en route to Deering, Alaska. About 1036, the accident pilot contacted the Kotzebue Flight Service Station (FSS) to request an airport advisory, and to file a VFR flight plan. The Kotzebue FSS specialist on duty advised the pilot that the weather at the Kotzebue Airport was below VFR minimums, and that VFR flight was not recommended. The Kotzebue FSS specialist then requested what the pilot's intentions were. The pilot responded by requesting a special visual flight rules (SVFR) clearance out of the Class E surface area to the south. About 1047, the pilot was issued a SVFR clearance to the south, advised to maintain VFR conditions, and was requested to report clear of the active Class E airspace. About 1048, the accident airplane departed on runway 17, and proceeded southbound. About 1049, the accident pilot contacted the Kotzebue FSS specialist on duty and reported that he was clear of the active Class E airspace. No further radio contact was received from the accident pilot. A pilot operating a Cessna 207 east of Kotzebue reported that he was monitoring the Kotzebue flight service station frequency on 122.6, in conjunction with listening to the local radio station, KOTZ AM 720. He said that he heard the accident pilot report to the Kotzebue FSS specialist on duty that he was clear to the south. At the same time, the sound of static was produced on the pilot's AM radio. The pilot added that he did not associate the loss of the AM radio frequency to the accident until later, when he learned of the accident. About 1120, while investigating the loss of the AM radio signal, two radio station employees discovered the airplane wreckage, and alerted emergency crews. OTHER DAMAGE The commercial radio antenna was severely damaged. PERSONNEL INFORMATION The pilot held a private pilot certificate with an airplane single-engine land rating; he did not hold an instrument rating. His most recent second-class medical certificate was issued on May 25, 1999, and contained the limitation that the pilot shall wear a contact lens in the left eye. According to the pilot's log book that was recovered at the accident site, the pilot's total aeronautical experience consisted of about 860.5 hours, of which about 250 hours were accrued in the accident airplane make and model. In the preceding 30 days prior to the accident, the pilot logged about 16 hours of flight time in the accident airplane. AIRCRAFT INFORMATION No aircraft logbooks were located for the accident aircraft. METEOROLOGICAL INFORMATION The closest weather observation facility is Kotzebue, which is about 4.3 nautical miles north of the accident site. On August 13, 2001, at 1012, an aviation special weather report (METAR) was reporting in part: Wind, 220 degrees (true) at 11 knots; Visibility, 10 statute miles in light rain and mist; sky conditions and clouds, 1,000 feet scattered, 1,500 feet broken, 2,200 overcast; temperature, 48 degrees F; dew point, 46 degrees F; altimeter, 29.91 inHg. Witnesses located in Kotzebue reported that weather conditions to the south, and specifically in the direction of accident site, were momentarily much worse than that being reported at the airport. At 1037, about 12 minutes before the accident, an updated special weather report (METAR) was reporting the Kotzebue weather conditions as: Wind, 210 degrees (true) at 7 knots; Visibility, 4 statute miles with mist; sky conditions and clouds, 700 feet scattered, 1,500 feet broken, 2,000 overcast; temperature, 48 degrees F; dew point, 46 degrees F; altimeter, 29.92 inHg; remarks, visibility to the east, 2.5 statute miles. Selawik, Alaska, is located about 63 nautical miles east of the accident site. At 1015, an unaugmented automated weather observation system (AWOS) was reporting, in part: Wind, calm; visibility, 3 statute miles; clouds, 600 feet scattered, 1,100 feet broken, 1,500 feet overcast; temperature, 51 degrees F; dew point, 51 degrees F; altimeter, 29.97 inHg. Buckland, Alaska, is located about 62 nautical miles southeast of the accident site. At 1015, an unaugmented AWOS was reporting, in part: Wind, 150 degrees (true) at 8 knots, peak gusts to 15 knots; visibility, 10 statute miles; clouds, 1,900 feet few, temperature, 55 degrees F; dew point, 48 degrees F; altimeter, 29.93 inHg. Deering, Alaska, the pilot's intended destination, is located about 46 miles south of the accident site. At 1013, an unaugmented AWOS was reporting, in part: Wind, 060 degrees (true) at 4 knots; visibility, 10 statute miles; clouds, 1,900 feet few, 2,800 feet scattered, 5,000 feet overcast; temperature, 50 degrees F; dew point, 48 degrees F; altimeter, 29.91 inHg. An AIRMET valid until 1200, was forecasting mountain obscuration in clouds and precipitation along the pilot's planned route of flight from Kotzebue to Deering. The terminal forecast for Kotzebue, valid from 1000 until August 14 at 1000, was reporting, in part: Wind, 200 degrees at 12 knots: Visibility 6 statute miles with light rain and mist; clouds and sky condition, 700 feet scattered, 1,200 feet overcast. Temporary changes expected between the valid forecast times, light rain showers; clouds and sky condition, 600 feet overcast; visibility, 3 statute miles. COMMUNICATIONS Review of recorded telephone communications between the pilot and the Fairbanks FSS, revealed that at 1018:31, the pilot called the flight service station specialist at the preflight position. During the course of the conversation, the pilot received current and forecast weather conditions for the surrounding area, and along the intended route of flight. A complete transcript of the recorded conversations between the pilot and the Fairbanks FSS is included in this report. AERODROME INFORMATION The Kotzebue Airport is located on the 248 degree radial, 1.4 nautical miles from the Kotzebue VORTAC. The airport is not served by an air traffic control tower, nor is any terminal area radar service available. The Kotzebue AFSS is located on the field. The airport is equipped with two runways. One hard-surfaced runway is on a 080 and 260 degree magnetic orientation. The second, gravel-covered runway, is on a 170 and 350 degree magnetic orientation. WRECKAGE AND IMPACT INFORMATION The National Transportation Safety Board investigator-in-charge examined the airplane wreckage at the accident site on August 13 and 14, 2001. Numerous pieces of airplane wreckage, and antenna tower debris, were observed from the initial point of tower contact, to the wreckage point of rest. The direction of the debris trail was on a magnetic heading of about 150 degrees, (all heading/bearings noted in this report are oriented toward magnetic north). After the initial impact, the tower separated into three main segments. The top segment of the tower was separated about 90 feet from the top, or about 240 feet above the ground. The point of separation exhibited inward crushing and buckling, with red paint transfers noted on the white-painted tower sections. The tower's top flashing light fixture was destroyed. A 200 feet segment of the tower remained standing, supported by steel guy-wires. The antenna was broken free of the antenna-mounting base. Two feet of the airplane's left wingtip was located about 35 feet north of the tower base. The leading edge of the wingtip displayed witness marks that matched the steel support guy-wire weave. The point of rest for the airplane wreckage was about 400 feet south of the tower. The nose of the airplane was oriented toward the east. The airplane came to rest upright with the forward portion of the fuselage partially submerged in shallow water. The fuselage and firewall were crushed and distorted. The forward left side of the fuselage, from the firewall to the forward edge of the doorpost was torn, and crushed aft to the mid-line of the door opening. The empennage was buckled in an upward direction from the longitudinal axis of the fuselage, at a point just forward of the vertical stabilizer's attach point. The right wing was attached to the fuselage at its upper attach point, but the wing was pivoted forward about 30 degrees. The leading edge of the wing had an extensive area of aft-crushing, about 3 1/2 feet inboard from the wingtip. The left wing remained attached to the fuselage, but was pivoted forward about 70 degrees. A two feet section of the wingtip was torn from the wing. The remaining portion of the left wing displayed substantial aft-crushing of the leading edge. Due to impact damage, the flight controls could not be moved by their respective control mechanisms. Flight control system cable continuity was established to the point of impact related damage. The propeller assembly separated from the engine crankshaft. The propeller assembly was not recovered, and is presumed to have sunk in shallow water that surrounded the accident site. MEDICAL AND PATHOLOGICAL INFORMATION A postmortem examination of the pilot was conducted under the authority of the Alaska State Medical Examiner, 4500 South Boniface Parkway, Anchorage, Alaska, on August 15, 2001. The cause of death was attributed to multiple impact injuries. A toxicological examination was conducted by the FAA's Civil Aero medical Institute (CAMI) on October 11, 2001, and was negative for drugs or alcohol. ADDITIONAL INFORMATION A local radio station owns the antenna tower. The commercial radio station, KOTZ, utilized the tower for AM radio broadcasts on 720 KHz. The tower was installed next to a wooden control building adjacent to the tower. The top of the tower rose about 335 feet above ground level, which was about 395 feet above sea level. The tower was installed in 1986, and was depicted as an obstruction on the VFR aviation sectional map covering the area around Kotzebue. The tower was mounted on a concrete-filled mounting base, and stabilized by several guy-wires. It was painted in an alternating aviation orange/aviation white pattern. Two sets of red obstruction lights were installed, and each set of lights had two lamps. The light sets were located about the 110 and 220 feet levels. A large flashing red light fixture was installed at the top of the tower. Electrical power for the tower light fixtures was routed inside sections of metal pipe, and attached to the tower. A light sensitive switch (photocell), was installed on a junction box, positioned next to the tower base. The switch would automatically turn the tower lights "ON" when the surrounding ambient light decreased, and would turn the tower lights "OFF" when ambient light increased. A staff systems engineer employed by the radio station reported that on the day of the accident, one of the two lower light fixture lamps, located on the lower portion of the tower, was not operating, and was scheduled for replacement. He said that the second light fixture lamp located at this position was still operating. He noted that at the time of the accident, the lights were configured so that the lights were in the "ON" position 24 hours per day. The engineer reported that following this accident, the damaged tower has been replaced with one matching the original height specifications. He added that a medium intensity strobe light has been added to the top on the tower. The authorization to operate a communications tower is governed by the FCC. The FCC's rules and regulations regarding marking and lighting of antennas, is governed under Title 47, CFR Part 17. Title 47 CFR Part 17, 'Construction, Marking, and Lighting of Antenna Structures', states, in part, that the FAA must be notified of any construction or alteration to an antenna. The notification includes antennas that are more than 200 feet above the ground; construction in an imaginary surface area extending upward and outward at a slope of 100 to 1 for a horizontal distance of 20,000 feet (3.29 nautical miles) from the nearest point of the nearest runway that is more than 3,200 feet long; and those in an instrument approach area that may exceed an obstruction standard. Under Part 17, the owner of any proposed or existing antenna structure that requires notice of construction to the FAA, must register the antenna with the FCC. Each owner of any proposed construction must obtain a valid FAA determination of "no hazard." The owner of an antenna structure is responsible for maintaining the painting and lighting, and shall clean or repaint a structure as often as necessary to maintain good visibility. The owner of each antenna shall maintain a record of any lighting extinguishment, and shall inspect the lighting either visually or by an automatic monitor, each 24 hours. Each new or altered antenna structure must conform to the FAA's painting and lighting recommendations. For the purposes of Part 17, the specifications, standards, and general requirements contained in FAA Advisory Circulars AC 70/7460-1K, and AC 150/5345-43E, are mandatory. The placement of objects that may interfere with aviation safety, is governed by Title 14 CFR Part 77, 'Objects Affecting Navigable Airspace', of the FAA's Federal Aviation Regulations (FARs). Part 77 establishes standards for determining obstructions to navigable airspace, requires notification to the FAA of proposed construction or alteration of objects, provides for aeronautical studies of obstructions to determine their effect on the safe and efficient use of airspace, provides for public hearings on the hazards of proposed construction, and provides for establishment of antenna farms. The FAA's aeronautical study (84-AAL-263-OE) of the KOTZ tower's proposed construction states, in part: "The proposed construction would not exceed FAA obstruction standards, and would not be a hazard to air navigation. However, the following applies to the construction proposed: The structure should be obstruction marked and lighted per FAA Advisory Circular AC 70/7460-1K, 'Obstruction Marking and Lighting.' Chapters: 4,5, and 13." Chapter 4 describes various lighting systems for obstructions. Chapter 5 describes the use of red obstruction lighting standards. Chapter 13 describes marking (painting) and lighting specifications. Advisory Circular, AC 70/7460-1K, includes marking and lighting guidelines for objects over 200 feet above the ground. These guidelines include painting objects in particular patterns to provide visibility during daylight hours; lighting of objects by the use of aviation red obstruction lights during nighttime; flashing white lights utilized for marking during daylight and nighttime; or dual lighting with red lights during nighttime, and flashing white lights utilized for marking during daylight. AC 70/7460-1K establishes paint standards, but no specific maintenance schedule for repainting. It states that surfaces should be repainted when the color of the paint changes noticeably, or its effectiveness is reduced by scaling, oxidation, chipping, or layers of industrial contamination. Color tolerance charts may be purchased from a supplier. On August 15, 2001, a Federal Communications Commission (FCC) resident agent, from the Anchorage Resident Agent Office, examined the antenna at the accident site. The agent reported that the antenna compiled with the FCC's obstruction lighting requirements. In the agent's written report, he
The pilot's failure to maintain adequate clearance from an obstruction (antenna tower), and his continued flight into instrument meteorological conditions. Factors associated with the accident were low ceilings, and low visibility.
Source: NTSB Aviation Accident Database
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