# NTSB SEA06CA018: Piper PA-24-250, N1959P, Tacoma, WA, November 3, 2005 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: November 2, 2005, 17:00 local (Nov 3, 2005, 01:00 UTC) - Place: Tacoma, WA - Coordinates: 47.268054, -122.578056 - Nearby events: https://openairdocs.org/map.md?lat=47.2681&lon=-122.5781&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report March 28, 2006 - Report: Approved by Office Director - NTSB case key (mKey): 62860 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA06CA018 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/62860/pdf - Page: https://openairdocs.org/ntsb/SEA06CA018 ## Probable cause The collapse of the landing gear due to the pilot's failure to use the emergency gear extension system after his aircraft experienced a complete loss of electrical power. Factors include the malfunction of the voltage regulating system, which lead to the almost total discharge of the battery. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, cruise - electrical system - malfunction (contributing factor) - Gear collapsed, landing - roll - gear extension - not verified, pilot in command (cause) ## Analysis After making contact with the tower, and being cleared for a left base entry, the pilot completed his before landing check and lowered the landing gear. He then tried to call the tower to report he was entering the base leg, but realized that his radio was not transmitting. The aircraft subsequently experienced a complete loss of electrical power, and the pilot was therefore unable to confirm the gear was down and locked, as the green Gear Down lights were unable to illuminate. The pilot then flew low over the runway until he felt the main wheels touch the runway surface, and then he executed a go-around. After completing the go-around, the pilot went around the pattern and executed what he thought was going to be a normal full stop landing. But just after the aircraft touched down, the landing gear folded back up into the wheel wells, and the aircraft skidded down the runway on its belly. The investigation later determined that the gear had not fully extended because of the loss of electrical power. It was also determined that although the aircraft's battery and alternator were capable of operating normally, the voltage regulating system had malfunctioned, thus allowing the battery to become almost fully discharged. The pilot did not use the emergency gear extension system/sequence to make sure of the position and condition of the landing gear, but instead trusted the gear to be fully down and locked just because he felt the tires touch the runway surface during the low pass. ## Factual narrative On November 2, 2005, approximately 1700 Pacific standard time, a Piper PA-24-250, N1959P, experienced a collapse of all three landing gear during the landing roll at Tacoma Narrows Airport, Tacoma, Washington. The private pilot and his two passengers were not injured, but the aircraft, which is owned and operated by the pilot, sustained substantial damage. The 14 CFR Part 91 personal pleasure flight, which departed Pierce County Airport, Puyallup, Washington, about 15 minutes prior to the accident, was being operated in visual meteorological conditions. No flight plan had been filed. According to the pilot, after making contact with Tacoma Narrows Tower, and being cleared for a left base entry, he completed his before landing check and lowered the landing gear. He then tried to call the tower to report he was entering the base leg, but realized that his radio was not transmitting. The aircraft subsequently experienced a complete loss of electrical power, and the pilot was therefore unable to confirm the gear was down and locked, as the green Gear Down lights were unable to illuminate. The pilot then flew low over the runway until he felt the main wheels touch the runway surface, and then he executed a go-around. After completing the go-around, the pilot went around the pattern and executed what he thought was going to be a normal full stop landing. But just after the aircraft touched down, the landing gear folded back up into the wheel wells, and the aircraft skidded down the runway on its belly. The investigation later determined that the gear had not fully extended because of the loss of electrical power. It was also determined that although the aircraft's battery and alternator were capable of operating normally, the voltage regulating system had malfunctioned, thus allowing the battery to become almost fully discharged. During the investigation, the pilot told the Investigator-In-charge that he now realized that he should not have trusted the gear to be fully down and locked just because he felt the tires touch the runway surface, but instead should have used the emergency gear extension system/sequence to make sure of their position and condition. ## Aircraft - Registration: [N1959P](https://openairdocs.org/aircraft/N1959P), registered now, S/N 24419, built 1959 (OpenAirDocs) - Reported make and model: Piper PA-24-250 - Registry model: [Piper PA-24-250](https://openairdocs.org/model/piper-pa-24-250) (registry code 7102404) (OpenAirDocs) - Registry engine: [Lycoming TIGO-541SER](https://openairdocs.org/engine/lycoming-tigo-541ser) (registry code 41539, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 24419 - Engines: Lycoming O-540-A1A5 reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Ronald G. Moore - Airworthiness certificate: Standard, Normal - Departed: 1S0, Spanaway, WA - Destination: TIW, Tacoma, WA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 66; private; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 3; flight hours: 769 total, 98 in this make and model ## Weather - Conditions: Visual (VMC), Day From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.