DAMERON, MD, USA
N43459
Taylorcraft BC12D-4-85
During an evaluation flight for a seaplane rating, the pilot-applicant approached the water for landing. The seaplane landed on calm water, left float first. The seaplane continued a short distance on the surface before the floats separated, and the airplane contacted the water. The EDO model 01320 floats were manufactured April 24, 1946. Examination of the maintenance records revealed that the airplane was stored for 10 years, with the floats and the wings removed. The owner stated that he did not disassemble the spreader bars from the floats for inspection, prior to reassembly of the airplane. Examination of the wreckage revealed the left aft spreader bar mount was attached to the left float. The upper and lower spreader bar mount straps were intact, with three spreader bar strap bolts inside. However, no portion of the spreader bar remained between the straps. Examination of the spreader bar mount bolts revealed heavy corrosion. No scraping, scoring, scratching, or sanding of the bolt surfaces were noted. All three bolts revealed a slight bend, with the bolt heads deflected inboard. Examination of the components revealed modifications not depicted in the manufacturer's parts diagram, and several repairs. The aft right lower spreader strap had a repair weld, and was broken in the area of the weld.
HISTORY OF FLIGHT On April 7, 2000, at 1145 Eastern Daylight Time, a Taylorcraft BC12D-4-85, N43459, was substantially damaged during landing on Saint Jerome's Creek, Dameron, Maryland. The certificated private pilot and the airline transport pilot were not injured. Visual meteorological conditions prevailed for the evaluation flight that originated at Wingfield Airport (MD01), Dameron, Maryland, approximately 1135. No flight plan was filed for the flight conducted under 14 CFR Part 91. The airline transport pilot was an aviation safety inspector with the Federal Aviation Administration (FAA). He was administering an evaluation flight for a seaplane rating to the private pilot. The private pilot provided an interview and a written statement. According to his statement: "Turned base at 400 feet and had power at 1,800-2,000 rpm. Flared correctly as plane sank, in nose high attitude, left float touched water surface causing the plane to pivot left and submarine." During the interview, the pilot said: "We took off on the step and made a standard pattern at 500 feet. I was at 80 miles per hour on approach and touched down around 70. The plane was okay and the engine was okay. Everything was great. No problems. The wind was forecast from the south about 8 knots. I landed straight into the wind. The nose was on line with the wind streaks, the rudder was centered, and the ball in the turn coordinator was centered perfectly. The left float touched first, [the plane] swerved to the left and submarined. It touched and jerked to the left immediately." When questioned about the inspector's input during the approach and landing, the pilot said the inspector made no verbal corrections and that the inspector did not take the flight controls at any time. According to the inspector's statement: "[The pilot] arrived on final, over water, a little low. He stated his landing point and carried power all the way down; 2,000-1,800 rpm [and] 70 mph. At the correct point, in my view, he started a slow flare. Left float touched first and flat. [The pilot] relaxed the controls at this point and I tried to grab them and pull back. I missed, [the] left float dug in, left wing hit water, floats departed, and airplane sank quickly." During the interview, the inspector said: "We took off and he came around about a hundred feet low. He started his approach about 400 feet. On approach, his speed control was good. He was holding 1,800 to 2,000 rpm. He was using power the whole way. The power came off as we touched. We just kissed the water, then we touched down a little flat, but he was coming back on the yoke. He was slowly coming back as we touched. The left float touched first. We were dead into the wind so I don't know why the left float touched first." One witness provided a statement to the Maryland State Police. According to the police report: "According to [the witness], the aircraft landed in the water and traveled about (80) eighty feet, then the nose went into the water. He then heard a loud bang, when the propeller and engine apparently stopped. The aircraft's tail went upward as the plane submerged into the water." The accident occurred during the hours of daylight approximately 38 degrees, 07 minutes north latitude, and 76 degrees, 20 minutes west longitude. PERSONNEL INFORMATION The inspector held an airline transport pilot certificate with ratings for airplane single-engine land, multi-engine land, single-engine sea, and instrument airplane. He held instructor ratings for airplane single-engine land, multi-engine land, and single-engine sea. The inspector held a ground instructor's certificate with ratings for basic, advanced, and instruments. The inspector's most recent Federal Aviation Administration (FAA) first class medical certificate was issued on June 6, 1999. His most recent biennial flight review was completed in October 1999. The inspector reported 12,772 hours of flight experience, 47 hours in floatplanes as pilot in command, and 15 hours in make and model. The private pilot was issued a private pilot's certificate with ratings for airplane single-engine land on June 22, 1999. His most recent FAA third class medical certificate was dated June 9, 1998. The private pilot reported 171 hours of flight experience, 5.7 hours of which were in make and model. AIRCRAFT INFORMATION The airplane was a 1942 Taylorcraft BC12-D. The airplane had accrued 1,396 hours of aircraft time prior to the accident. The airplane was on an annual inspection program, and the most recent inspection was completed on November 1, 1999, at 1,340 aircraft hours. The airplane was configured with a pontoon float landing gear system. The EDO model 01320 floats were manufactured April 24, 1946. The floats were held apart by forward and aft horizontal spreader bars. The mounts on each end of the spreader bars consisted of an upper and lower spreader strap, three bolts, a spreader pad, and a wire pull bracket. Strut assemblies and cables attached the system to the fuselage. Examination of the maintenance records revealed that the airplane was stored for 10 years, with the floats and the wings removed from April 10, 1988 to June 30, 1998. The current owner then reassembled the airplane. The owner stated that he did not disassemble the spreader bars from the floats for inspection, prior to reassembly of the airplane. The paint on the spreader bar attach bolts was unbroken, and there was no record of when the airplane was last painted. METEOROLOGICAL INFORMATION At 1055, the winds reported at the Patuxent Naval Air Station, 10 miles north of the accident site were from 130 degrees at 8 knots. AERODROME INFORMATION The Wingfield Airport in Dameron, Maryland consisted of both turf and water landing surfaces. The turf runway was 1,200 feet long, 50 feet wide, and oriented 110/290 degrees magnetic. The water runways were oriented approximately North/South and East/West. The runways were depicted 1W/19W and 14W/32W respectively. Runway 1W/19W was 4,200 feet long and 500 feet wide. Runway 14W/32W was 3,600 feet long and 300 feet wide. WRECKAGE AND IMPACT INFORMATION The airplane was viewed from a boat at the scene on April 7, 2000. The airplane was submerged, but near the surface, with the vertical fin and rudder above the water. Upon returning to shore, the landing gear floats were found secured in the back of a pickup truck. The floats were removed from the truck and examined. Examination of the floats revealed that both floats were intact with no structural deformation. The airframe mounts were not installed. The airframe mount attachment points on both floats were fractured above the swivel mounts. Each mount revealed surfaces fractured at a 45-degree angle. The forward spreader bar was attached at each end, but fractured with a middle segment missing. The aft spreader bar was not installed, and was not recovered. The left aft spreader bar mount was attached to the left float. The upper and lower spreader bar mount straps were intact, with three spreader bar strap bolts inside. However, no portion of the spreader bar remained between the straps. Examination of the spreader bar mount bolts revealed heavy corrosion. No scraping, scoring, scratching, or sanding of the bolt surfaces were noted. All three bolts revealed a slight bend, with the bolt heads deflected inboard. The right aft spreader bar strap mount was still attached to the right float. The upper and lower spreader bar mount straps were separated from the mount, with their respective mount studs fractured. Examination of the fracture surfaces revealed heavy corrosion across the entire surface. No bare metal was exposed. The four mounts and the forward spreader bar segments were removed for examination and forwarded to the NTSB Materials Laboratory in Washington, DC. The aft spreader bar was not recovered, despite searches of St. Jerome's Creek subsequent to the accident. TESTS AND RESEARCH The four mounts and the forward spreader bar segments were examined at the NTSB Materials Laboratory in Washington, DC, on October 20, 2000. Examination of the components revealed modifications not depicted in the manufacturer's parts diagram, and several repairs. The spacers inside the forward spreader bars at the attachment points were aluminum. The manufacturer's parts diagram depicted wooden spacers inside the spreader bars. Examination of the spreader bar strap attachment hardware revealed hexagonal-head bolts installed in lieu of the flat-head bolts depicted in the manufacturer's parts diagram. The heads from flat head bolts consistent with the original design were cut from their shafts, drilled out, and installed as washers in the countersunk spreader straps. The aft right lower spreader strap had a repair weld, and was broken in the area of the weld. According to the Safety Board Materials Engineer's report: "The welded tab was pulled out at the weld location and the tab contained significant bending deformation in the weld area, indicative of overstress separation. Portions of the weld, as viewed by scanning electron microscopy, had dimpled features consistent with overstress separation, but other areas were smooth consistent with incomplete fusion." ADDITIONAL INFORMATION According to an FAA airworthiness inspector, "The aircraft and floats were certified under Civil Air Letter 7. Other than an external visual inspection, there are no other inspections required for these floats." The airplane wreckage was released to the owner on April 14, 2000.
The failure of the float landing gear system due to non-standard repairs, improper modifications, and corrosion.
Source: NTSB Aviation Accident Database
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