Board Could Not Find A Definitive Reason For Kyle And Amanda's Airplane To Lose Power

The NTSB has released what many will likely find to be an unsatisfying probable cause report in the accident which eventually cost Amanda Franklin her life. In its official report, the board said the airplane lost engine power "for undetermined reasons."

Photo From NTSB Report

According to the NTSB report, Kyle Franklin told the board the airplane was transported to the air show venues via trailer and then assembled as necessary for flight. The day prior to the accident, he completed a solo air show performance and during the taxi back to the ramp with the throttle at the idle position, the engine quit. The airplane was towed to the ramp for inspection. After completing a visual inspection of the engine with no problems noted, Kyle test-ran the engine at various power settings for approximately 15 minutes. No anomalies with the engine were noted during the test run.

Approximately one hour before the accident flight, Kyle completed a solo air show performance with no anomalies.

A preflight inspection was conducted about 20 minutes prior to the wingwalker performance flight and no discrepancies were found. Approximately 15 minutes prior to takeoff, the airplane's engine was started, and it ran without any problems. Prior to takeoff, an engine run-up and magneto check were conducted with no discrepancies noted. During the first 4 to 5 minutes of the wingwalking performance flight, Kyle said he noted no abnormal engine instrument readings or engine operations. About 5 minutes into the flight, the engine lost power. An attempted engine restart was unsuccessful. Kyle then signaled to Amanda to enter the forward cockpit, and he executed a forced landing to vegetation-covered terrain adjacent to the runway.

Witness videos and still photograph images showed the airplane was maneuvering in a shallow climb when the engine lost power. Several images show fire and smoke emanating from the engine exhaust during the engine power loss.

Kyle reported that during the flight, the engine power was set at maximum, which was 36 inches of manifold pressure and 2,300 RPM. The pilot did not change the engine power configuration during that portion of the wingwalker performance. In addition, the airplane's fuel tank was topped off prior to each of the 2 solo and wingwalker flights.

Kyle holds a commercial pilot certificate with a single-engine land rating. The pilot's second class medical certificate was issued on April 2, 2010. The pilot reported 2,273 total flight hours of which 728 were in the accident airplane.

A review of the airframe and engine maintenance records showed a major overhaul on the Pratt & Whitney R-985 AN-14B engine (serial number 11482) was completed on November 6, 2009, at an engine total time of 8,204.45 hours, and was installed on the airframe on January 22, 2010. The Bendix RS-10B2 (part number 391783-4, serial number 638) servo fuel injector was overhauled on January 18, 2010.

The most recent conditional inspection was completed on January 22, 2010, at a total airframe time of 4,222.3 hours, and a HOBBS time of 223.3 hours. The pilot reported on the National Transportation Safety Board (NTSB) aircraft accident form the most recent conditional inspection was completed on February 19, 2011, at a total airframe time of 4,261 hours. On February 28, 2011, which was the last entry in the engine logbook, the number 9 cylinder was removed due to a problem with the exhaust valve, repaired, and reinstalled, at a HOBBS time of 285.2 hours, and 40.2 since major overhaul. The pilot reported the airplane had accumulated approximately 3 flight hours at the time of the accident since the completion of his 2010 air show events.

Examination of the airplane by an FAA inspector revealed the fuselage sustained fire damage aft of the engine firewall. The main landing gear collapsed and the airplane came to rest upright. An unspecified amount of fuel was noted in the center wing fuel tank. A fitting on the smoke oil system was found fractured and separated from the respective connection.

Kyle, located in the rear seat, sustained facial injuries and briefly lost consciousness after the impact. Shoulder harnesses were not available in the rear seat, and the pilot was not wearing a helmet. Kyle exited the airplane and attempted to extricate Amanda from the front seat. He reported the electric smoke oil pump was continuing to operate after the airplane came to rest. The smoke oil pump ON/OFF switch was located in the rear seat compartment, and the pilot did not recall turning the switch OFF prior to exiting the airplane.

The front seat, which was comprised of the smoke oil container and a lap belt restraint, was the position the wingwalker sat during the takeoff and landing phases of flight. After the impact, rescue personnel arrived at the airplane and assisted the pilot in attempting to extricate Amanda. She was restrained in the front seat area via the tethering cable that was used for safety purposes during the wingwalking activity. Rescue personnel cut the cable in order to extricate her, but she sustained burns to approximately 70 percent of her body and succumbed to her injuries on May 27, 2011.

On April 4, 2011, at the facilities of Tulsa Aircraft Engines, Tulsa, Oklahoma, the engine and fuel system components were examined by the NTSB investigator-in-charge. Examination of the engine showed damage to the number 5 and 6 cylinders. The cylinder damage was consistent with the impact sequence. The cylinders were removed and replaced to accommodate an engine functional test. The servo fuel injector was separated from the engine mount structure and could not be tested with the engine. A slave carburetor was installed and the engine was functionally tested for approximately 30 minutes at various power settings with no anomalies noted.

The fuel injector was examined and functionally tested at Mike's Aircraft Fuel Metering Service, Tulsa, Oklahoma. Visual examination of the servo showed the mixture control linkage was fractured. The linkage arm was removed and replaced. All fuel lines and fuel strainer were found clear of debris. The idle mixture adjustment was in the mid-range position. The servo was functionally tested in accordance with the manufacturer approved test procedure. The fuel servo test was found within limits at the high (full throttle) setting and slightly rich at the low and mid-range settings. After the functional test, the fuel servo was partially disassembled. The regulator lever, which is located between and within the air and fuel chambers, was found to be bent when rolled on a sheet of glass. The air chamber was found to be dry and absent of fuel.

The fuel pump was examined and functionally tested at Aircraft Specialties Services, Tulsa, Oklahoma. No anomalies were noted during the visual examination. The pump was functionally tested in accordance with the manufacturer approved test procedure. The fuel pump functional test was found within specifications.

FMI: www.ntsb.gov