Aviation Accident Summaries

Aviation Accident Summary ANC07FA068

Ketchikan, AK, USA

Aircraft #1

N995WA

de Havilland DHC-2

Analysis

The air taxi float-equipped airplane was the second of three airplanes on an air tour flight over a remote scenic area in southeast Alaska. As the flight of three airplanes flew into mountainous terrain, the first pilot reported low clouds, with rain and fog, which required him to descend to 700 feet msl to maintain VFR flight conditions. The pilot of the third tour airplane, which was about 5 minutes behind the accident airplane, stated that as he approached the area around the accident site, he encountered "a wall of weather" which blocked his intended flight route, and he turned around. The accident airplane's fragmented wreckage was discovered in an area of steep, tree-covered terrain, about 2,500 feet msl, near the area where the third airplane turned around. The NTSB discovered no mechanical problems with the airplane during postaccident inspections. An NTSB weather study revealed instrument meteorological conditions in the area at the time of the accident. Photographs recovered from a passenger's camera depicted deteriorating weather conditions as the flight progressed. A charter boat captain, who had seen numerous float-equipped tour airplanes operating in adverse weather conditions, called the local FAA Flight Standards District Office (FSDO) 9 days before the accident, to report his sightings. According to the FAA, no specific tour operator could be identified during their ensuing investigation, and no enforcement actions or additional surveillance of any operators was initiated. According to the FSDO manager, the local FSDO had lost inspectors due to downsizing. He reported they had not attempted to observe operators' adherence to weather minimums via ground-based viewing locations along the heavily traveled tour routes, and noted that FAA inspectors used to purchase air tour tickets to provide en route, on-board surveillance, but had not done so for approximately the last 10 years. He noted that additional inspector assistance from other FAA offices was not requested.

Factual Information

HISTORY OF FLIGHT On July 24, 2007, about 1405 Alaska daylight time, a float-equipped de Havilland DHC-2 airplane, N995WA, was destroyed when it impacted mountainous tree-covered terrain, about 40 miles northeast of Ketchikan, Alaska. The airplane was being operated as a visual flight rules (VFR) sightseeing flight under the provisions of 14 Code of Federal Regulations (CFR) Part 135, when the accident occurred. The airplane was operated by Venture Travel LLC, dba Taquan Air Service, of Ketchikan. The airline transport pilot and the four passengers were fatally injured. Instrument meteorological conditions (IMC) were reported in the area at the time of the accident. The flight departed Ketchikan about 1319, for a tour through Misty Fjords National Monument. A company VFR flight plan was in effect. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on July 24, the operator's president reported that the accident airplane departed Ketchikan as the second of three float-equipped de Havilland DHC-2 airplanes on air tour flights over the Misty Fjords National Monument. He said each airplane departed from Ketchikan about 5 minutes apart, and the standard route of flight was northeast, over an area of remote inland fjords, coastal waterways, and mountainous tree-covered terrain. The 1 hour and 15 minute flightseeing tour included a landing on one of the inland ocean fjords before returning to Ketchikan. During an interview with the NTSB IIC on July 26, the pilot of the first tour airplane stated that initial weather conditions along his flight route consisted of about 10 miles visibility with an overcast layer about 1,500 feet msl. As the flight of three progressed into mountainous terrain, while approaching an area known as Punchbowl Lake, the pilot reported "there were lots of misty clouds hanging around the cliffs." The flight continued along the preplanned flight route, towards a shallow mountain pass known to local tour pilots as "the cut." The first pilot said that before entering the cut, he transmitted a radio message on a common radio frequency asking other tour pilots flying in the area if the cut was open, meaning was the weather good enough to fly through it. He said that an unknown pilot responded, saying that the cut was open, and that he would need to be about 2,500 msl to get through. The first pilot said that after passing through the cut he encountered low clouds, rain and fog, with a visibility of 2 to 3 miles. He said that he was able to maintain VFR flight conditions by descending to about 700 feet msl, over an ocean fjord. According to the pilot of the first tour airplane, he estimated that the second airplane, the accident flight, was about 5 to 7 minutes behind him. In an interview with the NTSB IIC on July 26, the pilot of the third tour airplane stated that he was about 5 minutes behind the accident airplane as his airplane approached Punchbowl Lake. He said he heard the first airplane's pilot radio call inquiring about the weather conditions in the cut, as well as the unknown pilot's response concerning current conditions within the cut. Additionally, he recalled hearing a standard position report from the accident airplane's pilot reporting that he was over Punchbowl Lake. The pilot of the third airplane stated that just after entering the cut, he encountered "a wall of weather" which blocked his intended flight route. He said that the weather conditions consisted of low clouds, rain, and fog. He said he turned around, took an alternate route, and completed his tour. When the accident airplane failed to return to Ketchikan by 1435, and company dispatch personnel were unable to establish radio contact, a company aerial search was initiated. The flight was officially reported overdue to the Federal Aviation Administration (FAA) at 1500. About 1730, the pilot of a Ketchikan based helicopter operator that joined the aerial search, discovered the airplane's fragmented wreckage in an area of steep, tree-covered terrain, about 2,500 feet msl. PERSONNEL INFORMATION The pilot held an airline transport pilot certificate with an airplane multiengine land rating, and commercial pilot privileges with airplane single-engine, airplane single-engine-sea rating. In addition, he held a commercial rotorcraft helicopter certificate, and instrument helicopter rating. He also held a flight instructor certificate with airplane single-engine land ratings. The pilot's most recent second-class medical certificate was issued on April 2, 2007, and contained the limitation that he must wear corrective lenses for near/distant and intermediate vision. In the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1) submitted by the operator, the pilot's total aeronautical experience was listed as 5,273 hours, with 178 hours in the accident airplane make and model. The report noted that in the preceding 90 and 30 days prior to the accident, the pilot accrued a total of 178 hours and 91.7 hours. According to operator's president, the accident pilot flew for other Part 135 and Part 121 operators in Arizona, flying de Havilland DHC-6 and DHC-8 airplanes, before being hired by Taquan Air Service. A review of the accident pilot's personal pilot logbook, which was provided to the NTSB by a family member, revealed that on April 11, 2007, just before being hired by Taquan Air Service, the pilot obtained a single-engine sea rating from Kenmore Air, Kenmore, Washington. During his 3-day training course, he received about 3.1 hours of instruction flight time in a float-equipped Piper PA-18, followed by an .8-hour check ride. During an interview with the NTSB IIC on July 26, Taquan Air Service's chief pilot said that the accident pilot first reported to work in Ketchikan on April 30, and he immediately began his initial ground and flight training. A review of company training records revealed that the pilot completed his initial ground training on May 4, which consisted of 34 hours of ground instruction, and included 2 hours of instruction concerning Controlled Flight Into Terrain (CFIT) avoidance. Taquan Air Service's chief pilot provided the CFIT avoidance training. Additionally, the pilot received 8 hours of ground training in the use and operation of the Capstone equipment installed in all Taquan Air Service airplanes. Taquan Air Service's director of operations provided the Capstone use and operation training. On May 9, the pilot completed his initial flight training in float-equipped de Havilland DHC-2 airplanes. The pilot's most recent FAA Part 135.293 and 135.299 check ride was on May 9. Taquan Air Service's director of operations, the FAA approved company check airman, administered the check ride. Once the pilot completed the company's training program and passed a check ride, the pilot was officially hired. At that time, his total flight experience was reported to be 5,100 flight hours, with 10 hours of single-engine sea flight time, and 7 flight hours of flight time in Alaska. From May 14, through May 29, the pilot received 10.5 flight hours of Initial Operating Experience (IOE) in float-equipped de Havilland DHC-2 airplanes, while flying to various locations served by Taquan Air Service. During the pilot's IOE period he flew with Taquan Air Service's director of operations, and chief pilot. On May 29, the pilot received a 1.1-hour route check along the Misty Fjords tour route, which was accomplished by Taquan Air Service's director of operations. The pilot was then assigned to fly float-equipped De Havilland DHC-2 airplanes at the company base in Ketchikan, eventually accruing 178 flight hours. The pilot's normally scheduled duty day was from 0545 to 1945. In the three days prior to the accident, the pilot was off duty on July 21 and 22. On July 23, his duty day started at 0700, and he flew 2.5 hours. On the accident date of July 24, he flew 2.2 hours. The accident flight was the pilot's third Misty Fjords tour flight that day. AIRCRAFT INFORMATION According to the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1) submitted by the operator, the airplane had a total time in service of 17,356.0 flight hours. The most recent annual inspection of the engine and airframe was on May 26, 2007. The last recorded inspection of the engine and airframe was a 100-hour inspection, on July 21, 2007, about 20 hours before the accident. The engine was overhauled on May 31, 2005, by Covington Aircraft Engines, Inc., and had about 182.1 hours since overhaul. The airplane was equipped with Edo 4930 floats. The FAA implemented national automatic dependent surveillance-broadcast (ADS-B) technology in Alaska, and the accident airplane was equipped with an avionics package as part of that program. Formerly known as Capstone, the joint industry/FAA program (which includes ground-based stations, satellites, and aircraft avionics) currently provides pilots with situational awareness by displaying the airplane's position over terrain, while using GPS technology, coupled with an instrument panel mounted, moving map display. Additionally, the Capstone equipment installed in the accident airplane provided the pilot with color shading on the moving map, which depicts terrain elevation changes. Terrain displayed on the pilot's moving map that is within 300 feet of the airplane will be displayed in red, alerting the pilot of close proximity to terrain. Although the effort in Alaska to utilize ADS-B is projected to also have the capability of presenting weather radar and textual observations to pilots, these enhancements were not fully implemented at the time of the accident. METEOROLOGICAL INFORMATION The closest official weather observation station was Ketchikan, 40 miles west-southwest of the accident site. On July 24, at 1353, an Aviation Routine Weather Report (METAR) was reporting, in part: Wind, 140 degrees at 9 knots; visibility, 10 statute miles; clouds and sky condition, 2,000 feet scattered, 2,600 feet broken, 3,100 feet overcast; temperature, 61 degrees F; dew point, 52 degrees F; altimeter, 30.13 inHg. The next closest official weather observation station was Metlakatla, 41 miles south-southwest of the accident site. On July 24, at 1356, an Aviation Routine Weather Report (METAR) was reporting, in part: Wind, 190 degrees at 5 knots; visibility, 10 statute miles; clouds and sky condition, 2,500 feet few, 5,000 feet broken, 7,500 feet overcast; temperature, 61 degrees F; dew point, 55 degrees F; altimeter, 30.16 inHg. The next closest official weather observation station was Annette Island Airport, Alaska, about 50 miles south-southwest of the accident site. On July 24, at 1354, an Aviation Routine Weather Report (METAR) was reporting in part: Wind, 150 degrees at 9 knots; visibility, 10 statute miles; a few clouds at 5,500 feet, ceiling 8,500 feet overcast; temperature, 61 degrees F; dew point, 52 degrees F; altimeter, 30.15 inHg. Witnesses characterized the weather conditions along the accident airplane's route as very low visibility with rain, fog and varied layers of cloud cover. An NTSB senior meteorologist conducted a weather study, which included satellite imagery around the accident site. The satellite imagery depicts a band of low stratiform clouds in the vicinity of the accident, and instrument metrological conditions (IMC) at the time of the accident. A copy of that report is included in the public docket for this accident. WRECKAGE AND IMPACT INFORMATION Continuous poor weather conditions prevented the NTSB IIC, and an FAA representative, from reaching the accident site until July 27. All of the airplane's major components were found at the main wreckage site. The accident site was an area of steep, mountainous, tree-covered terrain, at an elevation of about 2,500 feet msl. An area believed to be the initial impact point was discovered atop a tundra-covered, rock outcropping, about 100 feet above the main wreckage point of rest. After initial impact, the fragmented airplane wreckage fell down the vertical embankment, and came to rest about 100 feet below the initial impact point. The airplane's left wing and left float were discovered next to the initial impact point. The left wing had extensive spanwise leading edge aft crushing, and the left float sustained extensive crushing damage to the front portion. Scattered downslope of the 100-foot tall embankment, in a line between the initial impact point, and the final resting point of the main wreckage, were small portions of wreckage debris, paint chips, broken Plexiglas, and passenger personal effects. The airplane's severed right wing was discovered within the wreckage path, about 20 feet uphill from the main wreckage site. The right wing had extensive spanwise leading edge crushing. The propeller bolts attaching the propeller to the engine crankshaft remained attached to the crankshaft flange. All three propeller blades were loose in the propeller hub, but remained attached to the propeller hub assembly. All three of the propeller blades had multiple leading edge gouges, substantial torsional "S" twisting, and chordwise scratching. The engine assembly remained attached to the engine firewall, which was located within the fragmented wreckage. The engine sustained impact damage to the front and underside. The exhaust tubes were crushed upward. The crushed and folded edges of the exhaust tubes were not cracked. The airplane's empennage was torn from its fuselage attachment point, but all of the flight control surfaces remained connected to their respective attach points. Due to extensive impact damage, continuity of the flight control cables could not be established. There were no preaccident mechanical problems discovered during the NTSB IIC's on-scene wreckage examination. 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 July 26, 2007. The cause of death for the pilot was attributed to blunt force, traumatic injuries. The FAA's Civil Aeromedical Institute (CAMI) conducted a toxicological examination on August 24, 2007. The toxicological examination revealed that 0.497 ug/ml of citalopram, 0.151 ug/ml N-desmethylcitalopram and 0.065 ug/ml di-N-desmethylcitalopram were detected in the pilot's blood, and unspecified levels of the same substances were detected in his urine samples. Citalopram and its metabolites (N-desmethylcitalopram, and di-N-desmethylcitalopram) are not distinguishable in FAA toxicology laboratory evaluations from escitalopram and its metabolites. During a telephone conversation with the NTSB IIC on March 7, 2008, a family member confirmed that the pilot was being treated for depression, and that he pilot had been taking antidepressant medication, prescribed by his primary care physician. Additionally, the family member noted that the pilot had also been receiving treatment for high blood pressure [hypertension] and a thyroid disorder [hypothyroidism]. A review of the pilot's medical records by the NTSB's medical officer revealed a history of depression, for which the pilot was prescribed escitalopram following an emergency room visit on February 4, 2004 due to suicidal thoughts. There was no indication in the records reviewed of any formal psychiatric evaluation. The FAA's guide for Aviation Medical Examiners states, in part: "The use of a psychotropic drug is considered disqualifying. This includes all sedatives, tranquilizers, antipsychotic drugs, antidepressant drugs, analeptics, anxiolytics, and hallucinogens." A review of the pilot's most recent second-class medical certificate application dated April 2, 2007, revealed that the pilot indicated "No" in response to "Do You Currently Use Any Medications" and "No" to all items under "Medical History" except for "Yes" to "Hay fever or allergy." The application also notes a "No" to "Visits To Health Professional Within Last 3 Years." SEARCH AND RESCUE After being notified of an

Probable Cause and Findings

The pilot's decision to continue under visual flight rules into an area of instrument metrological conditions. Contributing to the accident was the pilot's inadequate weather evaluation, and the FAA's inadequate surveillance of the commercial air tour operator.

 

Source: NTSB Aviation Accident Database

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