NTSB Factual Report

HISTORY OF FLIGHT

On April 30, 2005, about 1715 Alaska daylight time, a tundra tire equipped F-19 Taylorcraft, N3691T, sustained substantial damage following a loss of engine power and loss of control during the takeoff/initial climb from runway 36 at the Chena Marina Airpark, Fairbanks, Alaska. The commercial certificated pilot was fatally injured, and the sole, pilot-rated passenger, received serious injuries. Visual meteorological conditions prevailed for the 14 CFR Part 91 personal cross-country flight. The flight was operated by the pilot/airplane owner and his wife, who was the pilot-rated passenger. The intended destination was Bettles, Alaska, and a VFR flight plan was filed.

The NTSB investigator-in-charge (IIC) interviewed several witnesses at the accident site and via telephone. They all related essentially the same information. All the witnesses were either at the Chena Marina airstrip, or along the perimeter road system north of the airstrip. The witnesses stated the airplane made a normal takeoff run from runway 36, and had reached an altitude of approximately 300-500 feet above the ground, when the engine abruptly lost all power. The airplane made an almost immediate, steeply banked turn to the left, pitched nose down, and entered a left turn spin, of one to two turns duration. The spin stopped, and the witnesses described a partial recovery, with the airplane's nose attitude starting to return to level prior to impact. One of the witnesses, who was closest to the airplane when it lost power, stated that she was unsure if the engine actually stopped, as it sounded as if the engine had continued to run, or idle, at a very low power, and may have had a momentary burst of power prior to impact. The airplane crashed in a boggy area of low brush and small, under 20-foot high, trees. It came to rest upright, with the nose of the airplane in a pond, and the engine under water.

The airplane's co-owner/passenger was initially interviewed by the IIC via telephone while she was hospitalized, on May 9, and in person at the hospital, on May 17. The IIC also had additional telephone conversations with her after her discharge. She stated that she has a private pilot's license, and is qualified to operate the accident airplane. She indicated that on the day of the accident flight, she preflighted the airplane, and found no indications of any mechanical problems or fuel contamination. She said the airplane was last fueled on April 27, with 100 low lead fuel from a fuel vendor, Alaska Air Fuel, at the nearby Fairbanks International Airport. Shortly before the accident flight, she drained fuel samples from both wing auxiliary tanks' quick drain sumps and the main header tank. She recalled that the auxiliary tanks were full, and the main tank had 3/4 or more. Her husband was the pilot-in-command, and prior to takeoff, he performed a pretakeoff engine run-up and systems check with no apparent mechanical problems. He then back-taxied about 2/3 of the way toward the takeoff end of runway 36 (4,700 feet long), and began the takeoff roll. The takeoff and initial climb were normal, until they had passed the departure end of the runway, and were about 300-500 feet above the ground, when the engine suddenly lost power, as if the engine throttle had been abruptly pulled to the idle. She said her husband immediately made a hard, steep, left turn to the south, towards the departure end of 36, and as the airplane rolled into the turn, it entered an inadvertent stall, the nose pitched nearly straight down, and the airplane started a spin to the left. She was unsure how far the airplane rotated to the left, but stated that the rotation stopped, and a partial recovery to a nearly level attitude was accomplished prior to crashing into a swamp. She also said that the engine never completely quit running, and it may have regained some power just prior to impact.

The passenger stated that they had purchased the accident airplane in October, 2003, and that it had an infrequent yet recurring problem of power losses during takeoff/initial climb. She reported that it had occurred once while she was flying the airplane, on or about October 2, 2004, while taking off from Fairbanks International Airport, with her husband as a passenger. She said the loss of power scenario was almost exactly the same as the accident flight, and about 300 feet above the ground, the engine suddenly lost power, but never completely stopped. Her husband immediately took the flight controls, and made an abrupt, hard turn to return to the airport. He was able to make a successful landing on a taxiway without damaging the airplane. After landing, engine power returned, and the airplane was able to taxi under its own power to the ramp area, where it was run-up to full power, without any apparent mechanical problems. They left the airplane at the airport, and it was recovered later by her husband. The passenger stated that she was aware of possibly two other loss of engine power events that happened while her husband was flying the airplane. On those occasions, like the incident at Fairbanks International Airport, he was able to return and land at the departure airstrip.

INJURIES TO PERSONS

The commercial pilot was fatally injured. His shoulder harness failed at the point where the single anchor, or tail strap, attached to the V-shaped shoulder restraint straps. The passenger received serious injuries, and was hospitalized for several weeks. Her shoulder restraint system did not fail. Additional information regarding the restraint systems for the pilot and passenger are contained in the Tests and Research portion of this report, and in the Public Docket for this report.

PERSONNEL INFORMATION

The pilot held commercial privileges for airplane, single engine land and instrument ratings, and private privileges for airplane, single-engine sea. According to his personal flight log, he had accumulated approximately 1068 flight hours at the time of the accident. He had logged approximately 36 hours in the accident airplane. His second class FAA medical was issued October 19, 2004, with the limitation that he must wear correctives lenses for distant vision.

The pilot was employed by Colorado State University as a biologist, and was working under contract to the United States Army at Fort Wainwright, Alaska. As part of his duties as a biologist, he was authorized to fly certain government-owned airplanes, and on March 24, 2005, had successfully completed a recurrent Pilot Evaluation/Qualification Check written and check flight in a Aviat Husky A-1, administered by a Department of the Interior (DOI) check pilot and FAA certificated flight instructor. As part of the flight check, according to the evaluation form and an interview with the check pilot/instructor, the accident pilot successfully performed stalls, and one low level simulated loss of engine power and forced landing approach to a meadow. The check pilot/instructor indicated that the accident pilot did not attempt to complete a 180-degree turn during the maneuver, and appropriately selected an emergency landing site ahead of the airplane.

On September 12, 2004, the pilot was awarded a certificate from the FAA for completing a safety seminar, "Practical Risk Management For Pilots" FAA-Wings-024. The pilot had also completed a flight course in an aerobatic airplane, titled: "Emergency Maneuvering-Modules 1, 2, 3" from CP Aviation, Santa Paula, California, on November 24, 2002. According to the CP web site, modules 1, 2, and 3, cover stall spin awareness, in-flight emergencies, and basic aerobatics, including unusual attitude recoveries.

AIRCRAFT INFORMATION

The airplane was a single-engine, 1977 model year Taylorcraft F19 tailwheel airplane, with two seats in a side-by-side configuration. It was equipped with a Continental O-200, 100 horsepower-rated engine. At the time of the accident, available logbook information, tachometer and Hobbs meter readings indicated that the total service hours on the engine was 1,545, and the service hours since major overhaul were 561. The airplane's engine maintenance log book covers the period from April 15, 1989, to the last entry, the date of the annual inspection, February 15, 2005. The first entry notes: "Previous Eng[ine] logs lost. Engine removed for major overhaul. Engine time is same as airframe tach time at time of removal."

The airplane had been modified with a climb pitch propeller, and retro-fitted shoulder harness and seat belt combinations at both the pilot and passenger seats. The airplane did not originally come equipped with shoulder harnesses, and there was no logbook entry regarding their installation. Additional shoulder harness information is contained in the Tests and Research section of this report.

The pilot's logbook indicates two prior power loss events, on August 7, 2004, when he was flying the airplane, and on or about October 2, 2004, when his wife was flying and he took the controls and landed at Fairbanks International Airport. His logbook entry for the August 7 loss of power is followed by the phrase "carb ice?". A witness to the August 7 event at the Chena Marina airstrip said that he was on the road to the south of the airstrip, and the airplane passed nearly overhead, when he heard the engine cut out, and the airplane banked very steeply, like a "wing-over", and turned towards the runway. The witness, a student pilot, said he didn't think the airplane would be able to make it back to the runway, but it did. There's also an entry dated October 8, 2004, that alludes to a loss of engine power at Fairbanks International the preceding weekend, (the flight with his wife) and that a magneto was replaced. The pilot's wife believes there may have been one more loss of engine power that occurred while her husband was out hunting in the Fall of 2004, during takeoff from a remote airstrip in the Alaska Range. The pilot's logbook reflects that he went hunting with the airplane in September 2004, but it does not indicate that there was a loss of engine power during that period.

The airplane's last annual inspection was completed at the Chena Marina Airpark by Apex Aviation on March 15, 2005. During that inspection, the carburetor was opened, the float assembly adjusted as needed, reassembled, and the fuel system flow tested with no observed anomalies. The aviation mechanic who completed the work and certified the airplane as airworthy, indicated that the engine was run-up, and no discrepancies noted.

A review of the airplane's engine logbook entries and invoices from Apex Aviation, disclosed that the airplane's engine had repairs accomplished on September 13, 2004, to resolve a rough running engine. The discrepancy, or "squawk sheet" that accompanied the invoice noted, in part: "Will not run-up over 1500 rpm. Trouble shoot eng[ine]. Run up, found cold cyl[linder] number 1...found stuck valve... ." According to the work order, the valves for that cylinder were removed and repaired, and the post-repair engine run was satisfactory. Another invoice from Apex Aviation, dated November 30, 2004, for work performed October 8, noted, in part: "Cruise to FAI [Fairbanks Airport] and troubleshoot rough eng[ine]. R&R R/H mag [remove and replace right-hand magneto] due inop, time to engine, ops chk."

On May 12, 2005, the NTSB IIC had a telephone interview with a friend of the accident pilot. During the interview, the friend related that during a conversation with the accident pilot on April 28 or 29, 2005, the accident pilot indicated that he was still concerned about the loss of engine power events, and thought they might be related to fuel flow problems.

METEOROLOGICAL INFORMATION

Visual meteorological conditions prevailed. Fairbanks International Airport, about a mile southeast of the accident site, was reporting at 1739, about 19 minutes after the accident: clouds, few at 2,000 feet; 10 statute miles visibility; temperature 71 F, Dew point 23 F; wind, 110 degrees at 12 knots, with gusts to 17 knots.

AIRPORT INFORMATION

The Chena Marina Airpark runway has a gravel surface, and is approximately 4,700 feet long, and 50 feet wide. It is located to the west of and immediately adjacent to the Chena Marina Seaplane waterway, at an elevation of 427 feet msl. The Chena Marina complex is privately owned and maintained. The area to the north of the airport, in the general vicinity of the accident site, is essentially flat, with minor relief, a marshland swamp of approximately 2 acres, a gravel roadway with lightly traveled, smaller connecting roads, and scattered small trees and brush. The area north of the accident site had been mostly cleared in preparation for proposed housing sites.

WRECKAGE AND IMPACT INFORMATION

An on-site inspection by the NTSB IIC, with FAA aviation safety inspectors from the Fairbanks Flight Standard District Office assisting, commenced on May 1, at 0800, and was completed on May 2.

The airplane came to rest about 175 yards north of, and about 75 yards west of, the north end of runway 36. It was upright, at the north edge of a shallow pond located in a marsh, with the engine and propeller mostly underwater. The pond was approximately 3 feet deep at its deepest, and about 30 feet in diameter. The longitudinal axis of the airplane was on an approximate 180 to 360 magnetic degree orientation, with the nose of the airplane pointing to 180 degrees, towards the departure runway. There were a few small trees, approximately 2 to 3 inches in diameter, just aft of the wreckage, that were bent over, and may have been struck by the airplane prior to impact. There was no significant soil disruption at the airplane's point of rest.

All major components of the airplane were accounted for at the immediate crash site. The portion of the fuselage aft of the wings' trailing edge was intact with little to no deformation. The wings were bent down, nearly uniformly, resembling a partially inverted "V", and the trailing edges of both wings were detached from the fuselage. Both wing spars were broken near their respective lift struts. The left aileron control actuator rod had fractured. The lift struts for both wings were bent and compressed. The main landing gear, which was equipped with over-sized "Tundra" tires, was collapsed. The top of the cockpit section had been modified with a skylight, and a portion of the top of the cabin had been removed by rescue personnel. The cockpit bench seat frames for the pilot and passenger were distorted. The pilot's seat frame was pushed upwards, and the passenger's was compressed downwards. Both flight control wheels were extended and bent towards the floorboards. The engine throttle was pulled out to approximately mid-span, and captured by impact damage. The mixture control was in, and the fuel cut-off was out. The carburetor heat was in (OFF). The throttle and mixture cables were attached at their respective ends. Flight control continuity was established from the ailerons to the control wheel, and from the rudder to the rudder pedals. The elevator cables were followed to the cabin/cockpit area, but could not be moved due to cockpit deformation/crushing. The two-bladed propeller was nearly straight, with only slight forward bending at one tip. The leading edges of the propeller did not display any significant gouges, chord-wise scratches, or other impact damage.

The airplane was equipped with one, 12-gallon main header tank located aft of the engine firewall, and two, 6-gallon wing tanks, one mounted in each wing. The fuel system only allows fuel to flow from the main header tank to the engine; the wing tanks are used to replenish the header tank via gravity flow as needed. The wing tanks' respective cockpit valves to the header tank were found in the "off", or closed, position. The right wing tank tested positive for water contamination at the lowest portion of the tank, when a paste that reacts to water was inserted into the tank on a stick. The left tank did not react to the water paste. Both tanks appeared to be full, or nearly full, with what resembled and smelled like 100 octane

NTSB Probable Cause

The pilot's failure to maintain a minimum airspeed during a low-altitude turn to return to the airport, and his improper in-flight decision to initiate a steep, low altitude turn, which resulted in an inadvertent stall/spin, and an in-flight collision with terrain. Contributing to the accident was the loss of engine power for undetermined reasons.