Aviation Accident Summaries

Aviation Accident Summary DFW07LA078

Athens, TX, USA

Aircraft #1

N14685

Cessna T182T

Analysis

The newly manufactured single-engine airplane had a complete loss of engine power and the commercial pilot made a forced landing to a field 3.6 hours after the airplane had been delivered from the factory. During the forced landing, the airplane landed hard, nosed-over and came to rest in the inverted position. Examination of the engine revealed that the input fuel line to the fuel transducer was not properly torqued during the manufacturing process and had loosened to the point where the engine was starved of fuel. The investigation revealed that an unauthorized person was allowed to torque the fuel line to the transducer during the initial build-up of the engine. The Team Leader failed to check the torque on the fuel line fittings; however, he signed the airplane's production inspection report that the fittings were properly torqued. This failure to follow a published procedure resulted in a loss of engine power during the airplane's first production test flight. The test pilot was able to make a successful power-off landing to an airport. As a corrective action, the manufacturer impounded the airplane and determined that the output line to the transducer was loose and weeping fuel. A Lead Inspector, who had been instructed by the manufacturer's Director of Quality Assurance to re-torque all of the fuel lines forward of the firewall, only checked the torque on the output line to the transducer even though he made an entry on the airplane's Flight Squawk/Repair Record that stated, "re-torqued all fuel lines."

Factual Information

HISTORY OF FLIGHT On February 27, 2007, approximately 1506 central daylight time, a single-engine Cessna T182T airplane, N14685, was substantially damaged during a forced landing to a field near Athens, Texas, following a loss of engine power. The commercial pilot was seriously injured and the two passengers sustained minor injuries. The airplane was registered to a private corporation and operated by one of the passengers. No flight plan was filed for the cross-country flight that originated at a private airstrip near Berryville, Texas, about 1455, and was destined for the Midland International Airport (MAF), near Midland, Texas. Visual meteorological conditions prevailed for the personal flight conducted under 14 Code of Federal Regulations Part 91. The registered owner purchased the airplane from Cessna Aircraft Company on February 26, 2007. The sale was completed at the manufacturer's facility in Independence, Kansas, and at the time of the sale, the airplane had accrued a total of 5.3 flight hours. Upon completion of the sale, the pilot and the two passengers flew from Independence to Tyler, Texas, where they serviced the airplane with 37.8 gallons of 100LL aviation fuel. They then flew to a private airport near Berryville, Texas, and spent the night. The following afternoon, the pilot and the two passengers departed for Midland, Texas. According to the pilot, he stated that the airplane was operating normally until it reached an altitude of 5,000 feet, when the turbine-inlet-temperature (TIT) warning light illuminated on the multi-function display unit, followed by a sudden loss of engine power. The pilot reduced the engine throttle setting and adjusted the pitch of the airplane to establish best glide speed and attempted to reach the Athens Municipal Airport (F44), near Athens, Texas. He also contacted air traffic control and declared an emergency. The pilot asked the front seat passenger to assist him with the emergency checklist, and he made several attempts to restart the engine. When the pilot realized that he would not be able to reach the Athens Municipal Airport, he elected to execute a forced landing to a grass field southeast of the airport. The pilot stated that the airplane was traveling approximately 50 knots when it touched down in the field. The left main landing gear dug into the ground and the airplane nosed-over, coming to rest in the inverted position. PERSONNEL INFORMATION The pilot held a commercial pilot certificate with ratings for airplane single-engine and multi-engine land, and instrument airplane. He was also a certificated flight instructor for airplane single-engine and multi-engine land, and instrument airplane. His last second class Federal Aviation Administration (FAA) medical was issued on January 11, 2007. The pilot reported a total of 1,342 flight hours of which, 200 hours were in make and model. METEOROLOGICAL INFORMATION Weather at the Tyler Pounds Regional Airport (TYR), near Tyler, Texas, approximately 24 miles northeast of Athens, Texas, at 1453, was reported as wind from 160 degrees at 12 knots, visibility 10 statute miles, clear skies, temperature 79 degrees Fahrenheit, dew point 39 degrees Fahrenheit, and a barometric pressure setting of 29.84 inches of Mercury. AIRCRAFT INFORMATION The airplane was a 2007-model Cessna T182T single-engine, 4-seat airplane powered by a Textron-Lycoming TSIO-540-AK1A turbo-charged, fuel-injected, reciprocating engine. The airplane was also equipped with a Garmin G1000 integrated navigation system. Several attempts were made to obtain the airplane's maintenance logbooks; however, they were never located. The airplane's hour meter indicated that the airplane had accrued a total of 8.9 hours at the time of the accident. A review of aircraft documentation provided by Cessna Aircraft Company revealed the airplane underwent an annual inspection on February 23, 2007. At that time, the airplane's airworthiness certificate was signed. The airplane had accrued 5.3 hours at the time it was delivered to the customer. WRECKAGE AND IMPACT INFORMATION A Federal Aviation Administration (FAA) aviation safety inspector conducted an on-scene examination of the airplane on February 28, 2007. Representatives from Cessna Aircraft Company and Textron-Lycoming assisted him. The airplane came to rest inverted on a magnetic heading of 070 degrees at a field elevation of approximately 461 feet mean sea level. The initial impact point was a series of ground scars that were located approximately 120-feet from the resting place of the airplane. The airplane sustained structural damage to both wings and the vertical stabilizer. In addition, the left main wheel had separated from the strut, and the nose-wheel assembly had sheared from the airplane. The airbags that were installed on the front and rear seat shoulder harnesses did not deploy. The airplane was recovered to a salvage facility and the engine was examined on March 2, 2007. An external examination revealed that the B-nut fitting that secured the input fuel line to the fuel flow transducer was loose. Green colored anti-tamper paint was noted on top of the fitting, but it was cracked and slightly displaced. When pressure was applied via the electric-driven fuel pump to the fuel system, fuel was observed leaking from the fitting. The B-nut fitting was then tightened by hand and the engine was started. The engine started immediately and was allowed to warm up before additional power was applied. The engine power was then increased to 1,500 rpm. At this point, an airframe and power plant mechanic slowly loosened the fitting by hand to the position it was originally found after the accident (about a 3/8-inch turn), and the engine immediately lost power. The fitting was then re-tightened and engine power returned to normal. The engine was then run through its full power band without interruption. All engine instrument readings were normal during the test-run. TESTS AND RESEARCH On March 5, 2007, non-destructive testing of the fuel flow transducer including both the input and output fuel lines was conducted at Cessna Aircraft Company, Wichita, Kansas, under the supervision of the Safety Board. Representatives from Cessna Aircraft Company, Textron-Lycoming, and the FAA Wichita Aircraft Certification Office (ACO) were also present. The examination revealed that both fuel lines and the transducer were the appropriate components for the Cessna T182T aircraft as per the Cessna and Textron-Lycoming Parts Catalog. The output line fitting, which exhibited white anti-tamper paint over the transducer/fuel line connection point, was tight and could not be turned by hand. A calibrated-digital torque wrench was used to measure the torque value of the output line fitting. The value measured at 136-inch-pounds, which was within Cessna's Torque Value Limits for this particular fitting (-4 line, steel). In addition, a small amount of green anti-tamper paint was observed under the white anti-tamper paint. According to Cessna, green anti-tamper paint was used only by mechanics on the assembly line as a visual reference that a particular fitting had been torqued. White anti-tamper paint was assigned to assembly line Inspector's only. The small amount of green anti-tamper paint that was visible under the Inspector's white anti-tamper paint on the output fitting was indicative that a mechanic had performed the original installation. A review of the airplane's product inspection record (PIR) confirmed this action. The male fitting of the input fuel line was examined using an optical comparator in conjunction with the engineering specifications called out in MS 33656. No deformations or cross threading were identified. In addition, the threads were tested using a go/no-go thread gauge. The internal threads on the female fitting were also tested with a go/no-go thread gauge specific to that fitting. No anomalies were noted with the fuel lines/fittings or the transducer. The items were functional and did not contribute to the loss of engine power. On March 6, 2007, the investigative team assembled at Cessna's Independence manufacturing facility, in Independence, Kansas, and met with management personnel, who were directly responsible for the Quality Assurance of the new single-engine production series aircraft (Cessna models 172, 182, and 206). The investigative team also walked through the entire assembly line process and reviewed the airplane's Production Inspection Record (PIRs), Quality Assurance Checklists, and Flight Squawk and Repair Records. As a result of this meeting and review of records, the Safety Board learned that the airplane had experienced a loss of engine power during its first production flight on February 19, 2007. According to Cessna, shortly after the test pilot departed, he reported a complete loss of engine power as the airplane was climbing through an altitude of 5,000 feet, approximately 10 minutes into the flight. The pilot was able to make a "dead-stick landing" at the Independence Airport without incident. Cessna impounded the airplane and determined that the output line to the transducer was "weeping fuel." Cessna's Director of Quality Assurance held a "stand-down" meeting and instructed a Lead Inspector to check the torque on all of the fuel lines forward of the engine firewall. According to Cessna, this instruction was not properly communicated to the Lead Inspector, who only torqued the output line to the transducer as well as changed the ignition harness to the right magneto. When the inspector torqued the output line to the transducer, he applied white anti-tamper paint on the fitting. The inspector then made an entry on the airplane's Flight Squawk/Repair Record, which stated, "re-torqued all fuel lines." Cessna also revealed that an intern, who was not qualified to torque fuel lines, was instructed by his Team Leader to install the fuel lines onto the fuel transducer of the accident airplane during the initial engine build-up. The Team Leader was aware that the intern was not qualified to install/torque fuel lines. The intern installed the lines and only finger-tightened the fittings. The Team Leader did not check the fittings for proper installation and signed the PIR indicating that the fuel lines were properly installed and torqued. SURVIVAL FACTORS On March 8, 2007, the Safety Board conducted an examination of the airplane's survival features including the airbag equipped inertial reel shoulder harnesses, 26-g seats, and the Artex 406 emergency locator transmitter (ELT). Present for the examination were the Safety Board's Investigator-in-Charge, a Safety Board Survival Specialist, and a Research Specialist from the Safety Board's Office of Research and Engineering. Also present were a representative from Cessna Aircraft Company and AmSafe, incorporated. Examination of the Artex 406 ELT revealed that it was triggered on impact, and successfully notified the registered owner as designed. In addition, all four seatbelt assemblies, seats, and the two electronic module assemblies (EMAs) used to deploy the front and rear seat airbags were properly installed. Loading signatures (material stretch) was noted on the #1, #2, and #3 shoulder harnesses, indicative that all three occupants were wearing their respective seatbelt/shoulder harnesses at the time of the accident. The EMAs were removed and tested at AmSafe Incorporated, Phoenix, Arizona, on May 16, 2007, under the supervision of the FAA. The tests were conducted to verify that the parts were manufactured in accordance to production requirements and functioned properly at the time of the accident. The tests were conducted in two parts. The first test inspected the circuitry of the assembly to determine the output voltage and open circuits as required by the system to perform correctly. The second test inspected the trigger timing or "time to fire." This test ensured that the units sent a signal to the system when subjected to a 21g/60ms or 26g/50ms crash pulse as defined in AmSafe's production drawing 508358 and the sensor specification E508645. Upon completion of the tests, both EMA units functioned normally and performed as designed. ADDITIONAL INFORMATION The airplane was released to a representative of the owner's insurance company on July 18, 2007.

Probable Cause and Findings

The loss of engine power as result of the failure of a mechanic to properly check the torque on the input and output fuel lines to the fuel transducer during the manufacturing process. A contributing factor was the lack of suitable terrain for the forced landing.

 

Source: NTSB Aviation Accident Database

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