Brunswick, GA, USA
N923RS
PIPER PA-44-180
The pilots of the twin-engine airplane were conducting a cross-country instrument flight rules (IFR) flight. Although both pilots were instrument-rated and IFR-current, the right seat pilot had only 8.8 hours of actual instrument experience, and the left seat pilot had only 1.8 hours of actual instrument experience. While en route and likely operating in IFR conditions, radio and radar contact were lost after the airplane entered a descending, 180-degree right turn. Examination of the wreckage at the accident site revealed signatures consistent with an in-flight breakup of the airframe. The horizontal situation indicator (the only vacuum-system-driven flight instrument that was recovered) exhibited signatures showing that it was likely not operational when the airplane impacted the ground. Both of the engine-driven vacuum pumps exhibited fractured rotors. Although physical examination of the vacuum pumps could not determine whether the rotors fractured before or during impact, the inoperative horizontal situation indicator suggests that both pumps had failed before the impact. The operator reported that the vacuum pump mounted to the airplane's right engine was not operational before the airplane was dispatched on the accident flight and that the pilots had been advised of this deficiency. The operator used the Part 91 minimum equipment limitations for flights, which permitted dispatching the airplane with only one of the two engine-driven vacuum pumps operational. However, the Federal Aviation Administration's master minimum equipment list for the airplane for Part 91 operators, advises operators to limit the airplane to daytime visual flight rules flights when only one of the two vacuum pumps is operational. The operator's decision to dispatch the airplane with a known mechanical deficiency and no operational limitations reduced the safety margin for the flight and directly contributed to the accident. It is likely that the left vacuum pump failed en route rendering the vacuum-driven flight instruments inoperative. Given the pilots' minimal flight experience operating in IFR conditions combined with the difficulty of detecting and responding to the loss of attitude information provided by the vacuum-driven flight instruments, it is likely that the pilots became spatially disoriented and lost control of the airplane, resulting in the subsequent inflight breakup. No definitive determination could be made as to which of the two pilots was acting as pilot-in-command of the airplane at the time of the loss of control.
HISTORY OF FLIGHT On March 24, 2014, about 1738 Eastern Daylight Time, a Piper PA-44-180, N923RS, was destroyed during an inflight breakup and subsequent impact with terrain near Brunswick, Georgia. The flight departed from the Concord Regional Airport (JQF), Concord, North Carolina, about 1551 and was destined for Jacksonville Executive Airport at Craig (CRG), Jacksonville, Florida. Day visual meteorological conditions prevailed and an instrument flight rules (IFR) flight plan was filed. The two private pilots were fatally injured. The personal flight was conducted under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91. According to Federal Aviation Administration (FAA) records and Lockheed Martin Flight Service records, the pilot seated in the right seat filed and IFR flight plan with an intended departure time of 1530, and had requested an enroute cruise altitude of 8,000 feet above mean sea level (msl). PERSONNEL INFORMATION According to FAA and operator records, the right seat pilot, held a private pilot certificate with ratings for airplane single and multi-engine land, and instrument airplane. He held an FAA first-class medical certificate, issued February 4, 2014, with no limitations. At the time of the medical examination, the pilot reported 73 total hours of flight experience and no flight experience within the 6 months prior to the medical application. The pilot's logbook was located within the wreckage and the last recorded entry was dated March 24, 2014, and indicated a flight from JQF to CRG, in a different PA-44-180. Including that entry, the total recorded flight time was 155.3 flight hours and 8.8 hours of actual instrument flight experience. According to FAA and operator records, the pilot seated in the left front seat held a private pilot certificate with ratings for airplane single and multi-engine land , and instrument airplane He held a FAA first-class medical/student pilot certificate issued May 20, 2013, with no limitations. At the time of the medical examination the pilot reported no previous flight experience. The pilot's logbook was located within the wreckage and the last recorded entry was dated March 23, 2014, and indicated a flight from Daytona Beach International Airport (DAB), Daytona Beach, Florida, to JQF. Including that entry, the total recorded flight time was 163.7 flight hours and 1.8 hours of actual instrument flight experience. AIRCRAFT INFORMATION According to FAA and airplane maintenance records, the airplane was issued an airworthiness certificate on August 19, 1976, and was originally registered to ATP Aircraft 2, LLC on January 29, 2008. It was powered by a Lycoming O-360-E1A6D and LO-360-E1A6D engines. The airplane was not equipped with an autopilot, nor was it required to be. According to the operator, the last recorded Hobbs meter entry was 2,290.6 flight hours, which correlated to an airframe total time of 6,664.3 hours. According to maintenance records, the left engine vacuum pump was installed on May 13, 2011, with a recorded Hobbs time of 1,082.8 hours. The right engine vacuum pump was installed on August 31, 2013, with a recorded Hobbs time of 2,118.1 hours; however, the unit's serial number in the maintenance logbook did not coincide with the serial number on the vacuum pump in the accident airplane. According to the operator, the right vacuum pump that was actually installed on the airplane had been installed on January 24, 2014; however, the information submitted to the NTSB did not contain a serial number nor was the information located within the airplane's maintenance logbooks provided by the operator. The Airworthiness Approval Tag, associated with the right vacuum pump, that was at the accident scene, indicated that it had been overhauled on June 18, 2013. According to maintenance records for the accident airplane, the right engine vacuum pump had accumulated about 65 total hours since overhaul. However, information provided by the operator also revealed that this vacuum pump was noted as inoperative and placarded in accordance with Federal Aviation Regulation (FAR) 91.213(d) and their maintenance procedures prior to the accident flight. The operator further determined to have the airplane flown to the maintenance facility at CRG to repair the inoperative vacuum pump. Additionally, the pilots had been verbally advised of this discrepancy and were provided the opportunity to refuse the airplane, prior to departing on the accident flight. According to a representative of the operator, no flight limitations existed, for their airplane, for an inoperative vacuum pump beyond those prescribed by applicable FARs and the airplane Pilot's Operating Handbook. METEOROLOGICAL INFORMATION The 1755 recorded weather observation at Brunswick Golden Isle Airport (BQK), Brunswick, Georgia, located approximately 3.5 miles to the west southwest of the accident location, included wind from 050 degrees at 10 knots with gusts up to 16 knots, visibility 10 miles, overcast clouds at 3,800 feet above ground level (agl), temperature 12 degrees C, dew point 7 degrees C; and barometric altimeter setting of 30.08 inches of mercury. The regional radar mosaic from the University Center for Atmospheric Research for 1745 indicated an area of very light intensity echoes in the vicinity of Brunswick, Georgia, in the range of 5 to 15 dBZ. Sounding The Jacksonville (KJAX), Florida 2000 upper air sounding, located approximately 50 miles south of the accident site indicated the freezing level was at 10,000 feet, and implied no in-flight icing in the vicinity. The lifted condensation level (LCL) or approximate base of the clouds was at 1,580 feet agl, with the relative humidity greater than 80% from the LCL to approximately 6,300 feet which supported low stratiform clouds. The sounding indicated a defined low-level frontal inversion from 2,500 to 3,800 feet with a marked change in wind direction and a high probability of moderate turbulence at 3,800 feet. The Lifted Index (LI) was 12, and indicated a stable atmosphere. The wind profile indicated light northeasterly winds at the surface with a low-level wind maximum at 2,000 feet from 060 degrees at 26 knots, with wind veering rapidly to the south above the inversion, and then veering to the southwest and west by 10,000 feet. The mean wind was from 270 degrees at 27 knots. A defined jetstream was over the regions with the maximum wind located above the tropopause at 38,000 feet with wind from 270 degrees at 140 knots. Satellite imagery The GOES-13 infrared image at 1745 indicated a layer of low to mid-level stratocumulus to nimbostratus type clouds with a radiative cloud top temperature of 256 Kelvin or -17 C, which indicated cloud tops near 20,000 feet. No defined cumulonimbus clouds were identified in the vicinity of the accident site. Weather Briefing The pilot obtained a preflight weather briefing prior to departure from a qualified Direct User Access Terminal System (DUATS) provider at 1516, and filed an IFR flight plan through ForeFlight.com with Lockheed Martin Flight Service. While enroute, he also contacted Flight Watch at 1647:32, obtained the latest weather for the destination, obtained the updated AIRMET (Airman's Meteorological Information) Sierra for IFR conditions over Florida, and issued a pilot report (PIREP). The report indicated that the flight was 11.8 miles southeast of Barnwell Regional Airport (BNL), Barnwell, South Carolina; the PIREP indicated 10 miles visibility, no turbulence, no visible weather, and light haze. The recording ended at 1652:28. COMMUNICATION According to recorded air traffic control communications provided by the FAA, the flight contacted Jacksonville Air Route Traffic Control Center (ARTCC) at 1727:23 and reported their altitude as 8,000 feet. The controller then provided the flight with the local altimeter setting. At 1727:32 the flight confirmed the altimeter setting, and no further communications from the flight were received. Several attempts to contact the accident flight were conducted between 1739:27 and 1740:36, all of which were met with no recorded response. The ARTCC controller solicited assistance from another nearby airplane to fly in the vicinity of the last radar return to see if the accident airplane could be located. The ARTCC controller reported to the other airplane that the accident flight was "…at eight thousand in your vicinity uh I uh saw him go down about three hundred feet and then uh completely lost him on radar I don't know if it was full electrical failure or what but I lost him right over the golden isles airport." At 1743:14 the other airplane stated "I'm gonna need you to descend me to probably two thousand five hundred so I can get out of the clouds." At 1745:07 the ARTCC controller reported to the other airplane "…he was just east of the golden isles airport southbound at eight and then uh I showed him at three hundred feet low and then uh I I lost * (everything didn't even get a) primary on him." All further reported communication revealed that the accident flight was unable to be located and no ELT was audibly observed. RADAR DATA Review of radar data provided by the FAA revealed that the flight was cruising at an indicated an altitude of 8,000 feet above mean sea level (msl). The subsequent four recorded radar targets, which occurred over a span of 38 seconds, indicated a recorded altitude of 7,900 feet to 7,200 feet msl. The last recorded radar data, at 1738:10, indicated an altitude of 0 feet and was in the vicinity of the accident location. The last four radar targets, that indicated an altitude above 7,000 feet msl, were consistent with a descending right 180-degree turn. WRECKAGE AND IMPACT INFORMATION The wreckage was found in a marsh area, in about 15 feet of water. The main wreckage was located inverted at N 31:16.793, W 081:24.687 at an elevation of 4 feet msl. The debris path was about 2 miles in length and along a linear path. The engines remained attached to the airplane with lines and cables, and were co-located with the main wreckage. The wreckage debris path was oriented on 225 degree magnetic heading from the main wreckage, which was located on a 130 degree magnetic heading and about one-half mile from the last radar return. Both outboard wing sections were located about nine-tenths of a mile from the main wreckage and the vertical stabilizer was located about 2 miles from the main wreckage. Examination of the recovered airframe and flight control system components revealed no evidence of preimpact mechanical malfunctions. Examination of the engines revealed both vacuum pump shafts (coupling) were sheared; however, no other evidence of preimpact mechanical malfunctions were noted. The only recovered air-driven gyroscopic flight instrument was the horizontal situation indicator (HSI), which exhibited minimal damage to the housing and no evidence of crush damage. Disassembly of the gyro found no scoring or rotational damage to the pendulous vane housing or rotating assembly. A detailed "Airframe and Engine On-Scene Examination Report" with accompanying pictures is contained in the public docket for this investigation. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the right seat pilot on March 27, 2014, by the Georgia Bureau of Investigation, as requested by the Glynn County Coroner. The autopsy findings included "Multiple Injuries due [to] Aircraft Accident." The report listed the specific injuries. Forensic toxicology was performed on specimens from the right seat pilot, by the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The toxicology report stated no carbon monoxide was detected in blood (cavity), no ethanol was detected in Vitreous, and no drugs were detected in the urine. An autopsy was performed on the left seat pilot on March 27, 2014, by the Georgia Bureau of Investigation, as requested by the Glynn County Coroner. The autopsy findings included "Multiple Injuries due [to] Aircraft Accident." The report listed the specific injuries. Forensic toxicology was performed on specimens from the left seat pilot by the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The toxicology report stated no carbon monoxide was detected in blood (cavity), no ethanol or drugs were detected in the urine. TEST AND RESEARCH Both vacuum pumps were found attached to their respective attachment point on the rear of each engine. Examination of the pumps found both drive shafts sheared and salt deposits were noted throughout the units. According to maintenance records for the accident airplane, the left engine vacuum pump had accumulated 1,207.8 total hours since overhaul. The pump was disassembled and examined for wear marks indicative of rotor motion in contact with the housing. The rotor was found fractured in multiple locations, and cracks were present on 4 of the 6 slots and a transverse crack was present across the hole on one of the rotor flanges. The forward and aft faces of the rotor were examined for wear marks indicative of rotor motion as it contacted the housing. These rotor faces exhibited dents and wear consistent with non-rotational or stationary contact with adjacent components. However, on the interior of the housing, there was evidence of circumferential wear marks, consistent with contact during rotation. The pump was disassembled and circumferential score marks were observed on the interior surface of the rotor center hole. The fracture surfaces of the rotor were consistent with brittle overstress fracture and were consistent with multiple crack initiations locations. Horizontal and vertical sliding marks were present on the faces of the vanes and were consistent with sliding of the vanes that occurred during rotational operation of the rotor. The examination also noted that the widths of the vanes in the left vacuum pump were less than, and inconsistent when compared to, the width of the vanes in the right vacuum pump. Replacement Aircraft Parts Co. (RAPCO), Inc "Shear Coupling Force Failure Report," dated August 28, 2008, was a report of shear mode characteristics of the shear coupling after a simulated in flight vacuum pump failure. The report listed four independent force shear failures of the coupler. The four tests were conducted with the same testing sequence and the only change being the post failure run time. Post failure run times were 10 seconds, 30 seconds, 1 minute, and 5 minutes. The report revealed in part "each of the samples shows some melting of the base material after failure. As the run times after failure increase with each different sample the melting of the base material becomes more severe. This is due to the increase exposure to heat." The left engine vacuum pump exhibited melting of the base material similar to the melting noted in both the 30 seconds and 1 minute post-failure run time components. However, the investigation could not conclusively determine how long the left engine vacuum pump operated after the coupling was sheared. ORGANIZATIONAL AND MANAGEMENT INFORMATION At the time of the accident, the operator of the accident airplane, Airline Transport Professionals, Inc., also known as ATP USA. Inc., conducted flight training with 38 training centers located in 18 states, and operated a fleet of 266 aircraft. The fleet consisted of various airplanes, including 104 Piper PA-44 airplanes. The accident pilots were currently flying out of the Jacksonville, Florida, base. ATP also had six maintenance centers and utilized contract maintenance providers located within the United States, of which, one of those maintenance centers was located in Jacksonville, Florida. The operator's corporate headquarters was also located in Jacksonville, Florida. ADDITIONAL INFORMATION RAPCO Service Letter According to the manufacturer of the vacuum pumps, all overhauled units do not contain an inspection port cavity and the most recent overhaul inspection record revealed that the left vacuum pump was overhauled at the manufacturer's facility on February 8, 2008, and the right vacuum pump was overhauled at the manufacturer's facility on June 18, 2013. Service Letter RASL-
An inflight failure of the airplane's only operating vacuum pump, which resulted in the loss of attitude information provided by vacuum-driven flight instruments. Also causal was the pilots' failure to maintain control of the airplane while operating in instrument flight rules (IFR) conditions, likely due to spatial disorientation, following the failure of the vacuum pump. Contributing to the accident was the operator's decision to dispatch the airplane with a known inoperative vacuum pump into IFR conditions.
Source: NTSB Aviation Accident Database
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