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Small aircraft gear indication unsafe. Landing made at hpn. Gear was down and locked, but malfunctioning nose gear switch prevented proper light illumination.
| Attributes | |
| ACN | 160005 |
| Time | |
| Date | 199010 |
| Day | Tue |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | airport : hpn |
| State Reference | NY |
| Altitude | agl bound lower : 0 agl bound upper : 0 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Operator | general aviation : personal |
| Make Model Name | Small Aircraft, High Wing, 1 Eng, Retractable Gear |
| Flight Phase | ground other : taxi landing other |
| Flight Plan | None |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : single pilot |
| Qualification | pilot : instrument pilot : cfi pilot : atp pilot : commercial |
| Experience | flight time last 90 days : 120 flight time total : 21000 flight time type : 500 |
| ASRS Report | 160005 |
| Person 2 | |
| Affiliation | government : faa |
| Function | controller : local |
| Qualification | controller : non radar |
| Events | |
| Anomaly | aircraft equipment problem : less severe |
| Independent Detector | other other : unspecified cockpit |
| Resolutory Action | aircraft : equipment problem dissipated |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | other |
Narrative:
When lowering the landing gear for landing at orange county, ny airport, the green gear safe light didn't illuminate (tested ok) and the hydraulic pump circuit breaker popped. Following instructions in the flight handbook I reset the circuit breaker and cycled the gear with the same results. I then used the emergency gear extension checklist but still could not get a green gear light. Retarding the throttle to idle would not sound the gear horn (indicating the gear was down (no horn sound). I could visually check the left and right main gear and they appeared down and locked. A fly-by at the stewart, ny airport confirmed the gear (all 3) appeared down, but the gear doors were open. I elected to fly to hpn since the aircraft maintenance was done there and I was familiar with the field. A fly-by of the tower at hpn confirmed the findings of the stewart tower personnel. After reviewing and completing all checklists we landed normally at hpn with the emergency equipment standing by. The problem was in the nose gear micro switch which did not close causing the hydraulic pump to run and overload, popping its circuit breaker and not completing the gear cycle. The gear was down and locked, but not indicating down because of a faulty nose wheel micro switch.
Original NASA ASRS Text
Title: SMA GEAR INDICATION UNSAFE. LNDG MADE AT HPN. GEAR WAS DOWN AND LOCKED, BUT MALFUNCTIONING NOSE GEAR SWITCH PREVENTED PROPER LIGHT ILLUMINATION.
Narrative: WHEN LOWERING THE LNDG GEAR FOR LNDG AT ORANGE COUNTY, NY ARPT, THE GREEN GEAR SAFE LIGHT DIDN'T ILLUMINATE (TESTED OK) AND THE HYD PUMP CB POPPED. FOLLOWING INSTRUCTIONS IN THE FLT HANDBOOK I RESET THE CB AND CYCLED THE GEAR WITH THE SAME RESULTS. I THEN USED THE EMER GEAR EXTENSION CHKLIST BUT STILL COULD NOT GET A GREEN GEAR LIGHT. RETARDING THE THROTTLE TO IDLE WOULD NOT SOUND THE GEAR HORN (INDICATING THE GEAR WAS DOWN (NO HORN SOUND). I COULD VISUALLY CHK THE LEFT AND RIGHT MAIN GEAR AND THEY APPEARED DOWN AND LOCKED. A FLY-BY AT THE STEWART, NY ARPT CONFIRMED THE GEAR (ALL 3) APPEARED DOWN, BUT THE GEAR DOORS WERE OPEN. I ELECTED TO FLY TO HPN SINCE THE ACFT MAINT WAS DONE THERE AND I WAS FAMILIAR WITH THE FIELD. A FLY-BY OF THE TWR AT HPN CONFIRMED THE FINDINGS OF THE STEWART TWR PERSONNEL. AFTER REVIEWING AND COMPLETING ALL CHKLISTS WE LANDED NORMALLY AT HPN WITH THE EMER EQUIP STANDING BY. THE PROB WAS IN THE NOSE GEAR MICRO SWITCH WHICH DID NOT CLOSE CAUSING THE HYD PUMP TO RUN AND OVERLOAD, POPPING ITS CB AND NOT COMPLETING THE GEAR CYCLE. THE GEAR WAS DOWN AND LOCKED, BUT NOT INDICATING DOWN BECAUSE OF A FAULTY NOSE WHEEL MICRO SWITCH.
Data retrieved from NASA's ASRS site as of July 2007 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.