A PA34 pilot inadvertently dimmed the cockpit lights so that when the gear were extended the gear do...

Attributes
ACN	899610
Time
Date	201006
Local Time Of Day	0601-1200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	PA-34-200T Turbo Seneca II
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Route In Use	Visual Approach
Flight Plan	None
Component
Aircraft Component	Cockpit Lighting
Person 1
Function	Single Pilot Pilot Flying
Qualification	Flight Crew Private Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 27 Flight Crew Total 580 Flight Crew Type 53
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy

Narrative:

Lowered gear in pattern; but gear down indicator lights did not illuminate; recycled; no change. [I] confirmed nose gear down in place through left nacelle mirror. [I] checked circuit breakers. Pulled emergency gear down switch to relive hydraulic pressure and allow free fall. Advised tower and requested confirmatory fly-by; permission granted and low approach executed. Tower advised gear appeared in down position. Proceeded to second approach and landed without incident. Post flight examination indicated that gear indicator lights were functioning properly. I concluded that; prior to lowering gear; I must have switched on the right landing light switch and the navigation lights switch rather than both landing lights switches; with the effect of the navigation light switch being to de-illuminate the gear down indication lights as it does for night flying.

Original NASA ASRS Text

Title: A PA34 pilot inadvertently dimmed the cockpit lights so that when the gear were extended the gear down lights could not be seen making him believe the gear didn't come down or that the gear light system malfunctioned.

Narrative: Lowered gear in pattern; but gear down indicator lights did not illuminate; Recycled; no change. [I] confirmed nose gear down in place through left nacelle mirror. [I] checked circuit breakers. Pulled emergency gear down switch to relive hydraulic pressure and allow free fall. Advised Tower and requested confirmatory fly-by; permission granted and low approach executed. Tower advised gear appeared in down position. Proceeded to second approach and landed without incident. Post flight examination indicated that gear indicator lights were functioning properly. I concluded that; prior to lowering gear; I must have switched on the right landing light switch and the navigation lights switch rather than both landing lights switches; with the effect of the navigation light switch being to de-illuminate the gear down indication lights as it does for night flying.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.