NTSB Factual Report

HISTORY OF FLIGHT

On August 30, 2009, about 0950 eastern daylight time, a Bond S-9, N463NB, was substantially damaged after an in-flight structural failure near Saylorsburg, Pennsylvania. The experimental, amateur-built airplane was owned and operated by the pilot. The certificated sport pilot was killed. Visual meteorological conditions prevailed at the time, and no flight plan was filed for the local personal flight conducted under the provisions of 14 Code of Federal Regulations Part 91. The flight originated at Pegasus Air Park, Stroudsburg, Pennsylvania, at 0945.

A friend of the accident pilot, who also witnessed the accident, reported the following. He spoke with the pilot about 0920 on the morning of the accident. The pilot performed his preflight inspection and stated that he was going to fly locally for about 40 minutes to perform slow flight and turns at altitude. The friend agreed to communicate with the pilot while airborne via a hand-held radio. About 0940, the pilot reported that he was at 4,000 feet and 70 mph. The pilot made a left turn, similar to a clearing turn, and then a right turn. During the right turn, the nose dropped and the airplane completed one turn of a spiral or spin. The friend called the pilot and asked him what he was doing, and told him to get the nose of the airplane up. The friend then observed the spiral or spin cease and the nose came up, but not high enough. He again told the pilot to get the nose up. As the nose came up, the friend observed something red and silver come off the airplane. He believed the parts to be the right elevator and one of the wing struts. The nose again dropped and the airplane spiraled toward the ground. As the airplane descended, he saw the wing break and instructed the pilot to get out of the airplane.

Another witness was in her bedroom when she heard a loud noise. When she looked out of her bedroom window, she observed a small airplane flying without a wing. She then saw the airplane descend before it crashed.

A third witness was walking his dog when he observed the accident airplane. He stated that the pilot appeared to pull up when the wing came off. The airplane then spiraled to the ground.

PERSONNEL INFORMATION

The pilot held a sport pilot certificate issued on July 11, 2006. He also held an experimental aircraft builder and repairman certificate, limited to the S-9.

The pilot’s wife provided a pilot logbook with entries through March 15, 2009. The total time recorded in the logbook was 315.4 hours, including 4.3 hours in the S-9. Additional information provided by a friend of the pilot indicated that the pilot flew about 52 hours in the S-9, after March 15, 2009.

AIRCRAFT INFORMATION

According to records supplied by the pilot’s wife, the airplane, serial number 0493121, was originally sold in kit form on May 17, 1993. The pilot maintained a spiral notebook that chronicled the inspection and building of the accident airplane. On March 29, 2005, an “Inventory of Kit” was performed, and the following statement was noted, “Checked inventory of parts found to be OK 6.5 hours.” The time frame for the building of the airplane continued from April 1, 2005 until March 5, 2009, when a condition inspection was performed by the pilot. All inspection items received a “Pass” grade with no defects noted.

A friend of the pilot reported that he assisted the accident pilot with the building of the airplane. He recalled that the accident pilot purchased the S-9 about 5 years ago and he first saw the airplane when the accident pilot showed it to him on a flatbed trailer. The airplane was partially assembled, and he believes that the 'tail feathers,' or what he calls the tail section, were assembled, skinned, and painted red. They tested the condition of the skin and found it to be in good condition.

The friend reported that there were 73.8 Hobbs hours on the airplane when the accident occurred. He had flown about 18 hours in the accident airplane and the remaining hours were flown by the accident pilot. To his knowledge, the airplane had never been flown prior to the accident pilot purchasing it. He stated that neither he nor the accident pilot performed any welding on the airplane during its manufacture. They purchased numerous pieces of hardware from a vendor to complete the project.

METEOROLOGICAL INFORMATION

The 0951 weather observation for Allentown, Pennsylvania (ABE), located 18 nautical miles south of the accident site, included the following: sky clear, surface winds calm, 10 statute miles visibility, temperature 22 degrees Celsius, dew point 17 degrees Celsius, and an altimeter setting of 29.91 inches of mercury.

WRECKAGE AND IMPACT INFORMATION

An inspector from the Federal Aviation Administration (FAA) inspected the wreckage following the accident. The airplane crashed in a residential area. The right elevator was found approximately 0.25 miles from the fuselage. The left wing was separated at its attachment points and found about 75 to 80 feet from the fuselage.

After it was recovered to a barn, the wreckage was examined by an NTSB senior air safety investigator on October 8, 2009. The right wing remained attached to the airframe and exhibited impact damage at the outboard section. The right flap remained attached and the right aileron remained partially attached to the right wing. The left wing had separated from the airframe at the wing root and the fracture surfaces exhibited features consistent with overstress. The left flap and left aileron remained attached to the left wing. The propeller, engine, and forward section of airframe remained intact with little damage noted. The cockpit remained intact, with some deformation noted.

The upper section of empennage was crushed, but the vertical stabilizer and rudder remained attached. The left horizontal stabilizer remained partially attached to the empennage and the left elevator remained attached to the left horizontal stabilizer. The right horizontal stabilizer remained partially attached to the empennage; however, the right elevator had separated from the right horizontal stabilizer.

MEDICAL AND PATHOLOGICAL INFORMATION

Postmortem examination of the pilot was performed by Forensic Pathology Associates, Inc., Allentown, Pennsylvania. The cause of death was listed as, "MASSIVE TRAUMATIC INJURY DUE TO FALL FROM PLANE." The autopsy report included the following circumstances, "He self-ejected, however, the ejection was too low for the chute to open effectively. He landed on the deck of a home suffering massive trauma." The report also stated that, "He is wearing a "National 360" parachute which is open. The pull cord is still present in his left hand."

Forensic toxicology was performed on specimens of the pilot by the FAA Bioaeronautical Sciences Research Laboratory (CAMI), Oklahoma City, Oklahoma. The CAMI toxicology report was negative for carbon monoxide and drugs. Testing for carbon monoxide and cyanide was not performed.

TESTS AND RESEARCH

Two guy wires from the right horizontal stabilizer and the right elevator outboard hinge were forwarded to the NTSB Materials Laboratory, Washington, DC, for further examination. Magnified optical examinations of the fractured end of both cable sections revealed either yielding and necking or slant fractures on all of the individual wires, consistent with overstress separations. No indications of progressing cracking or corrosion were noted on either guy wire.

The elevator hinge consisted of a short steel tube welded to adjacent structure along two sides. Magnified visual examinations found fractures through the structure adjacent to the weld. The fractures displayed features and deformations consistent with overstress separations. No evidence of progressing cracking such as fatigue or corrosion was noted. However, a lack of weld fusion was visible in the portions of the welds at the ends of the barrel.

After the examination of the guy wires and right elevator outboard hinge was completed, the Chief Scientist for the NTSB examined the wreckage, assisted by a senior air safety investigator. He reported that all available evidence was consistent with a static, aerodynamic overload starting in the right elevator as a result of inputs to the flight controls. No evidence of substandard structure or fatigue was found. There was bowing of the right stabilizer and elevator, consistent with a large downward aerodynamic load on the elevator. The torque created by the bowing of both surfaces resulted in the fracture and separation of the hinge from the tube. The hinge fracture was through the tube in the area where the tube and hinge barrel were welded. The weld was adequate along both sides of the hinge barrel. The left wing and strut failed in down bending as a result of high negative air loads on the wings.

NTSB Probable Cause

The pilot’s excessive flight control inputs that resulted in an overload failure of the right elevator and horizontal stabilizer.