CHARLES CITY, VA, USA
N4576B
Ercoupe (Eng & Research Corp.) 415-CD
THE AIRPLANE WAS ON A VFR LOCAL FLIGHT WHEN AN IN-FLIGHT BREAK-UP OCCURRED. WRECKAGE WAS SCATTERED OVER A HALF SQUARE MILE AREA. THERE WAS EVIDENCE THAT THE CENTER SECTION BEAM ASSEMBLY (ATTACHED TO THE WINGS FRONT SPARS) FAILED IN POSITIVE OVERLOAD. ALL FRACTURE SURFACES EXHIBITED FEATURES TYPICAL OF OVERSTRESS. PRIMARY RADAR RETURNS ( REFLECTION OF RADAR SIGNAL WHICH INDICATE A TWO DIMENSIONAL POSITION IN SPACE -RANGE AND AZIMUTH) WERE THE ONLY DATA RECORDED FOR THE AIRPLANE. SECONDARY DATA, WHICH REPORTS THE ALTITUDE OF AN AIRPLANE, WERE NOT RECORDED. NO OTHER AIRCRAFT WERE RECORDED ON RADAR NEAR THE ACCIDENT AREA AT THE TIME OF THE ACCIDENT. AT THE TIME OF THE ACCIDENT, THERE WERE NO SIGNIFICANT WEATHER REPORTS ISSUED FOR THE ACCIDENT AREA. THE POST ACCIDENT EXAMINATIONS OF THE AIRFRAME AND ENGINE DID NOT REVEAL ANY ANOMALIES. AT THE TIME OF THE ACCIDENT, THE AIRPLANE HAD ACCUMULATED A TOTAL FLIGHT TIME OF 2,2421 HOURS AND HAD A 100 HOUR INSPECTION ABOUT 71 HOURS PRIOR TO THE ACCIDENT.
HISTORY OF FLIGHT On Tuesday, September 28, 1993, at 1123 eastern daylight time, an Ercoupe 415-CD, N4576B, owned and operated by the pilot, came apart in flight over a wooded area near Charles City, Virginia. The airplane and its occupants were located on September 29, 1993. The pilot and passenger were fatally injured. The airplane was destroyed. Visual meteorological conditions prevailed at the time of the accident. The local, personal flight departed the Williamsburg-Jamestown Airport about 1100 and no flight plan was filed. The flight was conducted under 14 CFR Part 91. According to the Commonwealth of Virginia Department of State Police, Westpoint Area Office Accident Report, a witness, located on a roof near the accident site stated that about 1130 he heard "sputtering" and looked up to the sky. He stated he saw an airplane's wing and fuselage which were separated from each other, floating toward the ground. He stated he did not see the airplane prior to the break-up. Portions of the airplane's flight path were recorded by the Washington Air Route Traffic Control Center (ARTCC). A set of primary radar returns (reflection of radar signal which indicate a two dimensional position in space - range/azimuth) were the only data recorded near the accident site location at the time of the accident. Secondary data, which reports the altitude of an airplane, were not recorded for the accident airplane. See the attached Specialist's Report of Investigation for a plot of the last 2 minutes and 13 seconds of data recorded for the airplane. The accident occurred during the hours of daylight, about 37 degrees 16 minutes and 15 seconds north latitude and 76 degrees 56 minutes and 58.2 seconds west longitude. PERSONNEL INFORMATION At the time of the accident, the private pilot had accumulated about 283 total flight hours, of which, about 82 hours were in a Ercoupe 415-CD. AIRCRAFT INFORMATION The Ercoupe is a two seat, low wing monoplane of metal construction and fabric covered wings. It was originally manufactured with a non-conventional two-control system. The Ercoupe's elevators, rudders, ailerons, and nose wheel are mechanically coordinated and are manipulated by moving the control wheel. The original two-control system Ercoupe can be modified with a independent rudder control system utilizing rudder pedals like a conventional airplane. The accident airplane, N4576B, was a 1946 Ercoupe 415-CD, serial number 4219, and was equipped with a Continental C-75-12F engine. N4576B was modified with a independent rudder control system. At the time of the accident, the airplane had accumulated a total flight time of 2,421 hours. N4576B received a 100 hour inspection on March 15, 1993, at a total flight time of 2350.5 hours. METEOROLOGICAL INFORMATION At the time of the accident, the Williamsburg National Weather Service reported the winds were coming from a magnetic bearing of 280 degrees at a velocity of 6 knots. No significant weather was forecast for the accident area, nor were there any reports of significant weather. Additional weather information is on page 4 of this report. WRECKAGE AND IMPACT INFORMATION The airplane wreckage was examined at the accident site on September 29 and 30, 1993. The examination revealed that the airplane separated into five major pieces and were strewn over one half square mile. The five major pieces were: the engine and cockpit area; the fuselage area; the tail section; the right wing; and the left wing. The location of each piece of wreckage can be found in the attached Specialist's Report of Investigation. The right wing was in a near vertical position resting on trees with the wing front spar resting on the ground. The right main landing gear was attached to the wing. The wing front spar was fractured at the right wing root. The right wing aileron was located about 100 feet from the wing. The aileron control rod was fractured. The painted fabric covering the wing was intact and in some areas the paint was missing. After initial examination of the wing, the fabric was torn away from the wing to examine the internal structural members. All the structural members exhibited varying degrees of distortion and bending. (See attached excerpts from the Ercoupe Parts Catalog for part identifications.) The left wing was intact and in a near vertical position resting on trees with the front wing spar attached to a portion of the center section beam assembly. The front wing spar and center section beam assembly were bent upward in positive overload. The left main landing gear was attached to the wing. The fabric covering the wing was distorted and streaks of paint were missing. After initial examination, the fabric was torn away from the wing and the wing's internal structural members were examined. All of the structural members exhibited varying degrees of distortion and bending. The fuselage came to rest upside down and the bottom of the fuselage was ripped open. The Emergency Locator Transmitter (ELT) was found attached to the fuselage and was not armed. The tail section was upright and had separated from the fuselage at the connecting bolt. Structural material surrounding this area was twisted in a clockwise direction toward the right side of the airplane. The elevators were intact and bowed up between the hinge points. The rudders were intact. The cockpit area and engine remained attached to each other and came to rest upright. The cockpit and instrument panel were destroyed. All control cables were accounted for in the wreckage. The control cable ends were attached to their respective attachment points but the cables were broken in the middle of the cable. Examination of the airframe and engine did not reveal any anomalies. MEDICAL AND PATHOLOGICAL INFORMATION The autopsy was performed by Dr. Samuel Land, Medical Examiner at the Office of the Chief Medical Examiner for the Commonwealth of Virginia, Richmond, Virginia, on September 30, 1993. According to the report of autopsy, no evidence of physical incapacitation or impairment existed. The toxicology was performed by Dr. Barry Levine, Chief, Forensic Toxicology Laboratory, Armed Forces Institute of Pathology, Department of Defense. Negative results were reported for screened volatiles and drugs. TESTS AND RESEARCH The center section beam assembly and right wing spar fracture surfaces, the right wing aileron control rod, and the fuselage-tail attachment structure were removed from the wreckage and brought to the Safety Board's Materials Laboratory located in Washington, D.C., for examination. All fracture surfaces exhibited features typical of overstress. (See attached Metallurgist's Factual Report). ADDITIONAL INFORMATION It was noted in the airplane's log book regarding airworthiness directive 54-26-2, "The fuselage and complete control system appear to be from a Forney F-1 series aircraft...." According to a Univair Aircraft Corporation Engineer (Univair is the Type Certificate Holder of Record for the Ercoupe), "...the Forney F-1 fuselage and Ercoupe 415 CD fuselage are interchangeable." The wreckage was released to Mr. Kevin J. Twiss, Claims Manager, Phoenix Aviation Managers, Inc., located in Atlanta, Georgia, on January 4, 1994.
the pilot exceeded the design stress limits of the airplane which resulted in an in-flight break-up.
Source: NTSB Aviation Accident Database
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