History of Flight
On October 6, 2009, at approximately 1450 central daylight time, a Beech 100, registration N2TX, was substantially damaged following a dual loss of engine power near Aurora, Texas. The commercial pilot and three passengers on board were seriously injured. The airplane was owned and operated by a private individual. Visual meteorological conditions prevailed, and an instrument flight plan was filed for the personal flight under 14 CFR Part 91. The flight departed Wiley Post Airport (KPWA), Oklahoma City, Oklahoma, at about 1350, destined for Fort Worth Meacham International Airport (KFTW), Fort Worth, Texas.
According to a witness, the airplane's engines were making a "popping" sound during the descent. The propellers were still turning, and the airplane was moving at a "good rate of speed" as it passed through the witness's field of view. The witness did not observe the impact.
On the NTSB Form 6120.1, the pilot reported that the airplane had approximately 260 to 270 gallons of fuel on board at departure from KPWA. While planning to arrive at KFTW, the pilot checked the fuel gauges and noted that the right fuel gauge indicated the right main tank appeared "nearly empty," while the left gauge read "about half full." The pilot initiated the crossfeed procedure to feed both engines from the left main tank. Shortly after beginning crossfeed, one engine shut down, followed by the other. The pilot notified air traffic control (ATC) and selected a field for a forced landing. The pilot considered attempting an air start but "gave up the attempt" to focus on flying. Shortly before touchdown, the right engine produced a surge of power that rolled the airplane to the left; the surge abruptly ended. The pilot continued the forced landing, lowering the landing gear and extending the flaps before impact. The pilot could not recall the accident sequence. While waiting for first responders, the pilot reported that he may have attempted to secure fuel and electric switches.
A fuel receipt obtained from the fixed base operator indicated that the airplane had been fueled with 50 gallons of Jet-A prior to departing KPWA.
Personnel Information
The pilot, age 64, held a commercial pilot certificate for airplane single-engine land, multi-engine land, and instrument airplane. A second-class airman medical certificate was issued on July 16, 2009. The pilot's previous flight review was conducted on March 31, 2008, in a Beechcraft B-90. On the NTSB Form 6120.1, the pilot reported approximately 4,120 hours total time and about 103 hours in the same make and model. The pilot had not flown this make and model in the 90 days prior to the accident.
Aircraft Information
The dual turboshaft engine, low-wing, retractable gear airplane, serial number BE-103, was manufactured in 1981. It was powered by two supplemental type certificate (STC) modified TPE331-6-511B turboshaft engines, each rated at 715 horsepower. According to engine logbook entries, both engines were installed on May 21, 2001. The airplane completed Phase III and Phase IV inspections on May 22, 2007, at a recorded total airframe time of 6,285 hours. On August 15, 2008, Hawker Beechcraft Services completed Phase I through Phase IV inspections at a total airframe time of 6,563.4 hours and a Hobbs meter time of 831.4 hours. During these inspections, the repair facility deemed the airplane unairworthy, with entries placed in the airframe and engine logbooks. At the time of the accident, the Hobbs meter read 1,063.7 hours.
Meteorological Information
At 1453, an automated weather reporting facility at Fort Worth Alliance Airport (AFW), located 13 nautical miles southeast of the accident site, reported wind from 020 degrees at 12 knots gusting to 20 knots, visibility 10 miles, few clouds at 1,000 feet, ceiling overcast at 1,600 feet, temperature 21 degrees Celsius, dew point 16 degrees Celsius, and a barometric pressure of 29.90 inches of mercury.
Wreckage and Impact Information
An inspection of the wreckage was conducted by members of the National Transportation Safety Board, Federal Aviation Administration (FAA), Hawker Beechcraft Corporation, and Honeywell Aerospace. Initial ground scars were consistent with the airplane impacting terrain on a 210-degree magnetic heading. The main wreckage came to rest in an open field at an elevation of 740 feet mean sea level. The fuselage was generally aligned with 120 degrees. The nose was crushed upward and to the right. The left side of the fuselage was impact-damaged and showed signs of gouging. The left wing was separated from the fuselage and found in a nearby body of water along with the left horizontal stabilizer and both engines. The right wing was intact, but the right engine was separated at the firewall. The landing gear and flaps appeared configured for landing.
Although both fuel tanks were ruptured, the accident scene did not contain a large amount of residual fuel. A small fuel slick was found on the surface of a nearby farm pond. The area underneath both wings did not present signs of grass kill.
Test and Research
TPE331-6-511B Turboshaft Engines
Both engines were shipped and examined at National Flight Services, Toledo, Ohio, under the oversight of the Safety Board. Neither engine could be run due to impact damage and water intrusion. Both engines' fuel systems were found intact prior to disassembly. The left engine contained approximately 150 ml of residual fuel throughout its systems. Mud was packed into the first-stage compressor impeller. Rotational scoring was found on the second-stage compressor. No anomalies were detected with the right engine. The right engine contained approximately 370 ml of fuel. The torsion shaft was found fractured approximately 7.25 inches forward of the aft end. The first-stage compressor section had rotational scoring and blades bent opposite the direction of travel. The second-stage compressor section had rotational scoring. The second- and third-stage turbine sections had evidence of rotational scoring and metal spray. No anomalies were detected with the right engine.
Fuel Control Units (FCUs)
Both FCUs were removed and examined at Woodward Governor Company, Rockford, Illinois, under the oversight of the Safety Board. Of note, the right engine's FCU had been set to 0.65 specific gravity (lower than the specific gravity of Jet-A fuel). No further anomalies were detected with either FCU.
Constant Speed Propeller Governor
Both propeller governors were removed and examined at Woodward Governor Company. Both governors were found to be modified to allow for higher operating RPMs. No further anomalies were detected.
McCauley Propeller
Both propellers were shipped and examined at McCauley Propeller Systems, Wichita, Kansas, under the oversight of the Safety Board. No anomalies were detected.
Beech Fuel Panel and Fuel Probes
The airplane’s fuel panel and fuel probes were removed and examined at Hawker Beechcraft Corporation, Wichita, Kansas, under the oversight of the FAA. Current was applied to simulate current from the fuel probes. The left-hand fuel gauge displayed 720 pounds of fuel regardless of current applied. The right-hand fuel gauge operated but contained a range of errors from 65 pounds below to 20 pounds over the expected amount.
Left Fuel Gauge
The left fuel gauge was removed and examined at Parker-Hanafin, Smithtown, New York, under FAA oversight. Internal components revealed signatures consistent with impact damage that kept the display's needle from operating normally. Once documented and reset, the gauge operated normally. No anomalies were detected.
Additional Information
Crossfeed Procedure
Prior to both engines experiencing a total loss of power, the pilot attempted to feed both engines from the left main tank using the crossfeed procedure. Under the Fuel section of the Pilot Operating Handbook's Section III Emergency Procedures, a caution states: "The crossfeed is to be used for one-engine-inoperative operations only. Do not feed both engines simultaneously from one side." This caution is not printed on the airplane's fuel panel; instead, a caution on the panel states: "Turn Aux Trans Off during crossfed (side being fed)." This caution closely resembles the caution located in Section VII System Description.