Astoria, OR, USA
N511FS
PIPER PA-24-250
According to the flight instructor, the student pilot called him while en route during a solo cross-country instructional flight and reported observing an electric current discharge of 10 amperes on the amp meter. The pilot also reported hearing a pulsating tone on the radio. During a subsequent call to the instructor, the student reportedly stated that the airplane had experienced a total electrical failure. The instructor said that he advised the student to immediately extend the airplane's electrically activated landing gear while the airplane still had remaining battery power. During the next hour, the student called his instructor four additional times and a pilot acquaintance three times. Both the instructor and the acquaintance reported that the student sounded extremely disturbed and anxious about the on going situation during these calls. The instructor was located at the home airport when the student flew overhead between about 800 and 1,000 feet above the ground, and he observed that the airplane's landing gear appeared to be extended only halfway. He advised the student to climb to 3,000 feet, and he then instructed the student in detail on how to extend the landing gear using the emergency extension procedure. The instructor estimated that the student flew in the vicinity for about 45 minutes until he stated, “I’ve got it,” which he thought meant that the gear was down and that the student intended to land. The instructor then lost track of the airplane as it flew away from his line of sight. Minutes later, he heard emergency vehicle sirens in the distance. A witness observed the airplane rapidly descending until his view of it was obscured by intervening terrain or vegetation as it approached ground level. The witness said that the airplane was descending with its nose pointed nearly straight down and that it was turning (rolling about its longitudinal axis). He reported that no fire or smoke was trailing from the airplane. The wreckage signatures and ground scar evidence were consistent with a stall-spin type accident sequence and an impact with the ground at a 45-degree nose-down angle. The landing gear was found in the down-and-locked position. No preimpact mechanical malfunctions or failures were found with the airplane control systems or engine that would have precluded normal operation. The electrical generating and storage components were removed for examinations and tests. Impact damage precluded functional tests of the alternator, over voltage relay, and spike guard capacitor; however, the units passed electrical continuity checks. An output wire on the alternator was found half severed, with the ends of the strands oxidized, indicating a preexisting condition. However, the electrical component examinations could not determine the failure mode of the charging system. It is likely that the student pilot remained distracted by the reported failure of the electrical power system and failed to maintain airspeed while preparing for landing, which resulted in the subsequent stall/spin to ground impact.
HISTORY OF FLIGHT On June 4, 2011, about 1741 Pacific daylight time, a Piper PA-24-250, N511FS, crashed into an open field while in an uncontrolled descent. The accident site was in the Lewis and Clark National Historical Park, Astoria, Oregon. The location was about 1.0 mile south of Astoria Regional Airport's (AST) runway 31 landing threshold, and 0.4-miles west of the runway's extended centerline. The airplane was substantially damaged. The student pilot owned and operated the airplane, and he was fatally injured. At the time of the accident, the pilot was completing a solo, round-robin, cross-country instructional flight that had originated from AST, the pilot's home-base airport, between 1000 and 1100. The flight was performed under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. A witness reported to a deputy Clatsop County Sheriff that he observed an airplane rapidly descend until his view of it was obscured by intervening terrain or vegetation as it approached ground level. The witness opined that the airplane had crashed. The witness was subsequently interviewed by the National Transportation Safety Board investigator. In summary, the witness indicated that while he was standing in a field about 0.6-miles west of the crash site, he observed the airplane between 1.5 and 2.5 seconds. During this time interval, the airplane was descending with its nose pointed nearly straight down, and it was turning (rolling about its longitudinal axis). No fire or smoke was trailing from the airplane. The student pilot's certified flight instructor (CFI) was also an airframe and powerplant mechanic. On June 3, 2011, he completed an annual inspection of the airplane. During the late evening of the 3rd, the CFI and student flew the airplane for about 3 hours. The CFI reported to the Safety Board investigator that no evidence of any mechanical malfunction was noted during this instructional flight. The airplane was equipped with main fuel tanks in the wings and auxiliary wing tip fuel tanks. In total, the wing tanks contain a maximum of 60 gallons of fuel, of which 56 gallons are usable. The auxiliary tanks contain a maximum of 30 gallons of fuel, all of which are usable. The CFI stated that he believed the airplane's four fuel tanks were full, or nearly full, when they commenced their evening flight. According to the CFI, on the morning of June 4, he checked the weather for the student's prospective cross-country (accident) flight. Finding it suitable, the CFI endorsed the student's personal flight record logbook, thereby authorizing the flight. As indicated in the logbook endorsement, the student was authorized to make interim landings at Olympia Regional Airport, Olympia, Washington (OLM), Lake Chelan Airport (S10), Chelan, Washington, and Baker City Municipal Airport (BKE), Baker City, Oregon. After taking off from AST, the student flew to OLM. Fueling personnel for an OLM fixed base operator reported that they serviced the pilot's airplane with 32.60 gallons of fuel, which filled the main fuel tanks. The pilot also purchased a current aeronautical chart. The time stamp on the sales transaction was 1201 local time. The pilot purchased and self-pumped 15.00 gallons of fuel upon landing at S10. The fuel sales transaction bore a 1445 time stamp. The CFI reported to the Safety Board investigator that he received a telephone call from the student at 1506 while he was at S10. The student reportedly stated that he was running late, and he was not going to make the planned interim landing at BKE. Instead, the student indicated that he would fly directly back to AST. The Safety Board investigator noted that the distance between S10 and AST is about 190 nautical miles. Under standard atmospheric conditions and at a nominal 75 percent power cruise speed of 155 knots, the airplane has a 3.5-hour main fuel tank endurance, while consuming 16 gallons of fuel per hour. The student departed the uncontrolled S10 airport at an undetermined time. The CFI reported that the student telephoned him at 1542 while en route to AST. The student reported observing an electric current discharge of 10 amperes on the airplane's amp meter. He also reported hearing a pulsating tone in background noise of his airplane's radio. At 1622, during a subsequent telephone call to the CFI, the student reportedly stated that he had experienced a complete electrical failure. The CFI further surmised to the Safety Board investigator that he received this notification telephone call while the student was in the vicinity of Mt. Rainier. This mountain is located nearly midway between S10 and AST. The CFI stated that he advised the student to immediately extend the airplane's electrically activated landing gear while the airplane still had remaining battery power. During the next hour, the student telephoned his CFI at 1632, 1647, 1655, and 1733, which was the last call the CFI received. During this period, the student also telephoned and sought advice from another pilot who was an acquaintance of his. Calls to the acquaintance were made at 1623, 1637, and 1644. Both the CFI and the acquaintance reported to the Safety Board investigator that the pilot sounded extremely disturbed and anxious about the on-going situation. The CFI was located at AST when the student flew overhead between 800 and 1,000 feet above the ground. The CFI observed that the airplane's landing gear appeared to be only half extended. Via telephone, the CFI advised the student to climb to 3,000 feet. Thereafter, the CFI instructed the student in detail how to extend the landing gear using the emergency extension procedure. The CFI estimated that the student flew in the vicinity of AST for about 45 minutes until he reported that the gear was finally extended. According to the CFI, he lost track of the airplane as it flew away from his line of sight. He opined that the student intended to enter the traffic pattern and land. The CFI stated that, minutes later, he heard emergency vehicle sirens in the distance. PERSONNEL INFORMATION The pilot, age 46, held a student pilot certificate and third-class medical certificate that was issued on November 2, 2009. No limitations were listed on the medical certificate. Review of the pilot’s flight records found that he first began taking instruction in October 1987, and, over a 14-month period, flew about 40 hours of combined dual and solo instruction in the Florida area. His last flight during this period was in February 1989. He resumed flying in May 2010 in the accident airplane. His most recent solo endorsement was dated October 12, 2010, and the endorsement for the accident cross-country flight was dated June 4, 2011. The pilot’s flight records record a total flight time of 113 hours, with 67 accrued in the accident airplane. In the preceding 90 and 30 days, he had flown 25 and 15 hours, respectively. His dual instruction time totaled 42 hours AIRCRAFT INFORMAATION The airplane, a Piper PA-24-250, serial number 24-1483, was manufactured in 1959, and purchased by the pilot in May 2010. The airframe logbook showed that the most recent annual inspection was accomplished on June 3, 2011. At the time of the inspection, the airframe had accrued a total time in service of 5,960 hours. Review of the entries from April 2001 to the date of the accident found no evidence of any maintenance related to the alternator, voltage regulator, over voltage relay or spike guard. A Lycoming O-540-A1C5 engine, serial number L-1086-40, was installed in the airframe. The engine logbook recorded a total time in service of 1,966 hours. The most recent major overhaul was accomplished on February 7, 2001, about 82 hours prior to the accident. Review of the entries from April 2001 to the date of the accident found no evidence of any maintenance related to the alternator, voltage regulator, over voltage relay or spike guard. The airplane flight manual section on emergency gear extension discusses the emergency extension system. Emergency gear extension is accomplished by disengaging the electric motor from the gear torque tube, which is accomplished by using an emergency gear extension handle that is located on the floor next to the landing gear brake handle. In its stowed position, the telescoping handle is retracted to within a few inches of the floor. The flight manual section lists the following emergency gear extension procedure: 1. Reduce airspeed to below 100 miles per hour. 2. Place landing gear selector switch in the center “Off” position. 3. Disengage the system motor – raise motor release arm and push forward thru full travel. 4. Extend the emergency gear handle to full length 5. Rotate the handle forward full travel to extend the landing gear. METEOROLOGICAL INFORMATION At 1753, the AWOS at the Astoria airport was reporting in part clear skies, visibility 10 miles, and winds from 320 degrees at 15 knots. The temperature and dewpoint were reported as 22 and 10 degrees Celsius, respectively. No witnesses reported observing any unusual meteorological phenomena in the vicinity. WRECKAGE AND IMPACT INFORMATION The Safety Board investigator examined the airplane at the accident site and following its recovery. No evidence of ground scar (disturbed soil or impacted vegetation) was noted surrounding or leading up to the main wreckage. An imprint of the airplane's wings and fuselage was found beneath the airplane, which was oriented on a west-southwesterly magnetic heading of 245 degrees. Numerous windshield fragments were found several yards in front of the crushed cockpit. Crush line deformation signatures in aft accordioned lower leading edge wing structure were consistent with the estimated 45-degree impact angle observed in the soft, moist, soil of the 3-foot-deep impact crater. The crater contained the engine and attached propeller assembly. The remainder of the airplane was at ground level. All of the airplane's flight control surfaces were observed attached to the airframe. The continuity of the flight control system was confirmed between the flight control surfaces and the impact damaged cockpit floor. Leading edge nicks and abrasions, and scratches in a chordwise direction, were noted over a several inch-long span on the cambered surface of one propeller blade. The second blade appeared mostly undamaged. Wing spar and empennage structure appeared principally straight. The empennage appeared in alignment with the fuselage's longitudinal axis. The landing gear was found in the down and locked position. The two cockpit fuel selectors were found positioned to draw fuel from the main fuel tanks. The airplane's four fuel tanks were observed impact damaged and breached. One day following the accident, an estimated 1 gallon of fuel was observed leaking from the left wing's main fuel tank during recovery of the airplane. Several ounces of fuel were also observed in the main fuel line to the carburetor and inside the carburetor bowl. No evidence of fire or soot was observed in the cockpit, and no evidence of oil residue was noted on the empennage. The engine was examined following the airplane's recovery. The crankshaft was rotated, and thumb compression was detected in all cylinders. The continuity of the valve and gear chain was confirmed. No evidence of preimpact mechanical malfunction was noted. MEDICAL AND PATHOLOGICAL INFORMATION The pilot sustained fatal injuries in the accident and an autopsy was conducted by the Oregon State Medical Examiner. The cause of death was attributed to multiple blunt force injury. Specimens were retained for toxicological analysis by the FAA Civil Aeromedical Institute. The results of the tests were negative for Carbon Monoxide, Cyanide, and all screened drug substances. Positive results were obtained for volatiles in brain tissue and thoracic cavity blood at the following levels: 22 mg/dl Ethanol detected in cavity blood 14 mg/dl Ethanol detected in brain tissue No Ethanol was detected in the muscle tissue specimens 1 mg/dl N-Butanol was also detected in the cavity blood TESTS AND RESEARCH The alternator, voltage regulator, spike guard capacitor, and over voltage relay were removed from the airplane and sent to the manufacturer for evaluation and testing. According to the technicians, by serial number, the units were part of the same “generator to alternator conversion kit that was manufactured and shipped in 2000." No evidence was found that the units had ever been returned for overhaul. The alternator, part number 015-01237, serial number 7813, exhibited impact damage, which precluded bench testing. The front and rear housing was fractured in multiple locations and the shaft would not rotate. The alternator was disassembled. The brush block was removed and the lengths of the brushes were within operable limits. No arcing evidence was present on the slip rings. The finish of the slip rings appeared normal. The internal diodes solder junctures were intact. The mounting bolts and attachment points were safety wired and appeared normal. The external diode plate was bent. All wire connections were tight and secured by the proper nuts and bolts. The rotor resistance tested at the required 3.8 ohms. Approximately 1/2 of the output wire strands were broken at the terminal ring terminal junction, which limited the wire electrical load carrying capacity; the ends of the individual copper strands were oxidized, indicating a pre accident condition. The diodes and solder joints with the external diode plate were intact. No prescribed main ground wire was installed on the alternator as required by the wiring diagram. The voltage regulator, part number 625-6123, serial number 8883, was impact damaged, but testable. The unit was installed on a test bench and tested in accordance with the manufacturers protocols. The unit functioned at both high and low loads. A slight pulsation was noted between 51 and 53 amps at the highest load setting. The over voltage relay, part number 625-62448, had an unreadable serial number. The unit exhibited impact damage. During functional testing with external power supplies and voltmeters, the over voltage relay circuit board appeared to be trying to open, but the relay would not open due to impact damage in the immediate area. The spike guard capacitor, part number 245-23709, is not serialized. The unit exhibited impact damage with a ruptured disc.
The student pilot’s failure to maintain adequate airspeed while maneuvering for landing, which resulted in a stall/spin. Contributing to the accident were the pilot's distraction and anxiety from a reported failure of the airplane's electrical system.
Source: NTSB Aviation Accident Database
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