Aviation Accident Summaries

Aviation Accident Summary ATL04FA046

San Antonio, FL, USA

Aircraft #1

N9085F

Aeronca 11AC

Analysis

The passenger stated the student pilot did one go-around at the airstrip, then returned for landing. The passenger stated that, during final approach, the airplane sank into the trees, then rotated to the left and collided nose-down into the creek. Examination revealed no evidence of flight control or engine malfunction. Examination revealed the seat anchors required for the airplane per Airworthiness Directive (AD) 49-15-01 were absent. A maintenance logbook entry dated May 25, 1995, was the most recent known record of compliance with AD 49-15-01. Maintenance records revealed the airplane's most recent annual inspection was completed on December 1, 2000.

Factual Information

HISTORY OF FLIGHT On December 5, 2003, about 1315 eastern standard time, an Aeronca 11AC, N9085F, registered to and operated by the student pilot, collided with trees and the ground during approach to a private airstrip in San Antonio, Florida. The personal flight was operated under the provisions of Title 14 CFR Part 91 with no flight plan filed. Visual meteorological conditions prevailed. The student pilot received fatal injuries, the private pilot-rated passenger received serious injuries, and the airplane sustained substantial damage. The local flight departed the private airstrip in San Antonio, Florida, on December 5, 2003, about 1130. The student pilot and the private pilot-rated passenger were longtime friends, and an Aircraft Bill of Sale on file with the Federal Aviation Administration (FAA) dated February 21, 2003, showed the student pilot had purchased the airplane from the passenger. The airplane was kept in a hangar at the passenger's home, and the accident flight originated from the private airstrip at the passenger's home. The passenger, who was seated in the left seat, stated the student pilot was flying the airplane from the right seat for the entire flight. He stated the student pilot preferred to operate the airplane from the right seat because of a medical condition with his right hand, and the two of them have flown together for at least three or four years. The passenger stated he does not keep his own airman medical current and he no longer flies airplanes himself. He stated the student pilot was comfortable with the airplane and had landed at the airstrip "many, many times." The passenger stated the flight departed the private airstrip and continued about 30 minutes to another private airstrip, where he and the student pilot stopped to have lunch. He stated the flight then returned to the home airstrip, and the student pilot did one go-around, then returned for landing. The passenger stated that, during final approach, everything seemed fine, then the airplane sank into the trees, with the left wing hitting more trees than the right wing. He stated the airplane then pulled to the left, and then turned to the left and collided nose-down into the creek. The passenger stated he observed no mechanical malfunction with the airplane. The spouse of the passenger was at their home north of the airstrip and heard the airplane on approach to land, but did not see the airplane taxi up the airstrip toward their home as expected. She then looked for the airplane and saw it in the field. She and an acquaintance approached the airplane, and she called the 911 operator to report the accident. PERSONNEL INFORMATION The student pilot held a third class medical certificate issued September 21, 2003, with the restriction, "must have available glasses for near vision." On his application for the medical certificate, he reported 142 total civilian flight hours. His family was unable to locate his pilot logbook. A review of FAA airman medical records revealed the student pilot reported the following medical condition under Item 18(x) Other illness, disability, or surgery, "Feb '68 - farm accident to right hand ... ." The passenger held a private pilot certificate for airplane single-engine land issued September 14, 1968. He held a third class medical certificate issued February 14, 1997. On his application for the medical certificate, he reported 425 total civilian flight hours. His pilot logbook was not recovered for examination. AIRCRAFT INFORMATION The Aeronca 11AC was a two-seat airplane equipped with a Continental A-65, 65-horsepower engine. A review of maintenance logbooks revealed the most recent annual inspection was completed on December 1, 2000, at a tachometer time of 576.66 hours. The tachometer reading on the instrument at the accident site was 664.06. WRECKAGE AND IMPACT INFORMATION Examination of the accident site revealed the wreckage came to rest nose-down on a 330-degree magnetic heading in a shallow, mud and sand-bottomed creek in a field 200 feet west of the airstrip's threshold. A tree located 115 feet south of the airstrip threshold was freshly broken approximately 25 to 30 feet above the ground. Freshly broken treetop branches approximately 10 feet long and two to three inches in diameter were found at the base of the damaged tree. An inspection port cover from the airplane's left wing was found near the base of the damaged tree. Examination revealed the outboard tips of both wings displayed crush damage from the leading edge aft. The right main landing gear was displaced aft, and the right side of the fuselage was buckled at the main gear attachment points. The empennage and tail assembly appeared undamaged. The nose of the airplane was crushed, the engine was displaced aft, and the firewall was buckled aft. Fuel was observed leaking from the wreckage. The left aileron and right aileron were attached to the airframe with their respective bell cranks in place with the control cables connected. Control cable continuity was established from the ailerons to the turnbuckles in the cabin roof, and cable continuity was established from the t-bar for the control yoke to the turnbuckles in the cabin roof. The elevator was found attached to the airframe, and control cable continuity was established from the elevator to the t-bar for the control yoke; the base of the t-bar was found fractured. The elevator trim was operable from the cockpit control. The rudder was attached to the airframe and control cable continuity was established from the rudder to the cockpit pedals. No evidence of airframe or flight control malfunction was observed. Examination of the engine revealed compression developed on all four cylinders when the crankshaft was turned at the propeller and movement of the valves and the accessory gears was observed. Dark-colored oil was observed in the oil screen with a small amount of debris and no evidence of metallic debris. The carburetor was found separated with the throttle, mixture, and carburetor heat controls attached. The carburetor bowl smelled strongly of automotive fuel, the thimble screen contained dirt-like debris, and the mixture control arm was operable from stop to stop. Chordwise scratches were observed on the aft face of the propeller blade. The ignition harnesses for the magnetos appeared aged and displayed impact damage. Magneto timing to the engine was verified with a timing light. The leads from the left magneto for the No. 3 and No. 4 cylinders, and the lead from the right magneto for the No. 4 cylinder produced no spark when the magnetos were rotated. The leads were removed and the left and right magnetos produced spark on all towers when rotated. The spark plugs displayed dark deposits on the electrodes and the exterior barrels were rusted. No evidence of engine or component malfunction was observed. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the student pilot on December 6, 2003, by the Office of the Chief Medical Examiner, District Six, Pasco and Pinellas Counties, Largo, Florida. The cause of death was listed as "multiple blunt trauma." Forensic toxicology was performed by the Federal Aviation Administration Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The report stated no carbon monoxide, no cyanide, and no drugs were detected in the blood, and no ethanol was detected in the urine. ADDITIONAL INFORMATION The airplane was equipped with an adjustable bench seat. The inboard portions of the right and left seat belts were attached to the middle of the seat frame, and the outboard portions of the right and left seats belts were attached to the outboard seat frame. The right occupant belt was found unbuckled, and the left occupant belt was found cut by emergency response personnel. A spring-equipped rod assembly under the forward edge of the seat was equipped with a handle for forward and aft seat position adjustment. The forward portion of the right and left slide tubes in the aircraft cabin were each equipped with a series of five rod holes on the inboard side; the seat adjustment rod assembly could be retracted using the handle, the seat could be positioned forward or aft, and the rod assembly could be extended by releasing the handle, and the rod ends would fit into the corresponding rod holes in the slide tubes. Examination of the seat rod assembly revealed both rod tips were bent aft. Examination of the rod holes on the left slide tube revealed the fourth hole aft was elongated forward through third hole and forward of the third hole. Examination of the rod holes on the right slide tube revealed the fourth hole aft was elongated forward through the third, second, and first holes and forward. The elongations on both slide tubes displayed paint scrapes and exposed shiny metal features. Airworthiness Directive (AD) 49-15-01, for airplane models including the Aeronca 11AC, states, "In order to prevent seat belt anchorage from failing during crash landings ... 1. If there is no need for an adjustable seat, the rear sliding lugs on each side of the seat should be bolted to the slide tube using ... AN bolts ... [or] 2. If the seat is to remain adjustable, two ... steel snare cables looped around each end of the seat frame cross tube ... should be installed ...." A maintenance logbook entry dated May 25, 1995, was the most recent known record of compliance with AD 49-15-01. Examination revealed there were no snare cable loops located in the wreckage. The rear legs on each side of the seat were each found with an AN bolt secured through the lower hole of each leg, with the threaded portion protruding outboard. The bolts were clean and displayed no evidence of damage. The lower bolt holes in the rear seat legs displayed no evidence of elongation. The right and left slide tubes in the aircraft cabin did not have bolt holes aft of the seat adjustment rod holes in the cabin. The right and left slide tubes displayed scrapes in the paint on top of the slide tubes aft of the seat adjustment rod holes. The scrapes exposed both rust-colored and shiny metal features. During examination, when the seat was positioned in the airplane with the seat adjustment rods aligned with the slide tube rod holes, the bolts protruding from the rear seat legs corresponded with the scrape marks on top of the aft slide tubes. The wreckage was released to an owner's representative in McVeytown, Pennsylvania, on February 3, 2004.

Probable Cause and Findings

The pilot's failure to maintain clearance above objects on approach, which resulted in an in-flight collision with trees and the subsequent collision with terrain.

 

Source: NTSB Aviation Accident Database

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