SEA06CA018

NTSB accident investigation · Piper PA-24-250 · Tacoma, WA · November 3, 2005

Accident · No injuriesData collectionFinal report
Date
November 2, 2005, 17:00 local (Nov 3, 2005, 01:00 UTC)
Place
Tacoma, WA
Injuries
3 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N1959PPiper PA-24-250
Weather
Visual (VMC) · Day
Status
Completed · report March 28, 2006
Report
Approved by Office Director
Case key
62860

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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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

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Airframe/component/system failure/malfunctionCruise
Electrical system - malfunctionFactor
Gear collapsedLanding - roll
Gear extension - not verifiedPilot in commandCause

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
Reported as
Piper PA-24-250
Category
Airplane
Serial number
24419
Engine
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

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
66
Certificate
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