Individually Owned: 150,657
Corporate Owned: 137,281
Merrill Field Airport
Aircraft Accident/Incident Report
Anchorage, Alaska 99503
Friday, May 28, 1993 14:10 AKD
NTSB Narrative Summary Released at Completion of Accident
THE PILOT SAID THAT DURING FLIGHT, HE ENCOUNTERED AN OVERVOLTAGE CONDITION & TURNED OFF THE ELECTRICAL MASTER SWITCH. HE NOTED THAT THE VHF RADIO CIRCUIT BREAKER HAD TRIPPED & THE TURN & BANK INDICATOR SMOKED. HE SAID THAT ABOUT 10 MILES FROM THE AIRPORT, HE TURNED THE MASTER SWITH BACK ON & TRIED TO RESET THE CIRCUIT BREAKER, BUT AGAIN HE NOTED SMOKE IN THE COCKPIT. HE SAID THE LANDING GEAR EXTENDED VERY FAST & HARD, BUT IT DID NOT LOCK. WHEN HE ATTEMPTED TO FOLLOW THE EMERGENCY GEAR EXTENSION PROCEDURE, THE CRANK DID NOT WORK. THE MAIN GEAR COLLAPSED DURING LANDING. AN EXAM OF THE ELECTRICAL SYSTEM DISCLOSED A CHARRED & EXPANDED BATTERY. THE DOWN LIMIT SWITCH FOR THE LANDING GEAR MOTOR HAD BROKEN FROM ITS MOUNT BY THE UPPER BELL CRANK TRAVELING BEYOND THE DOWN LIMIT; A TEARDOWN OF THE LANDING GEAR ACTUATOR ASSEMBLY DISCLOSED EVIDENCE OF OVERTRAVEL. THE ALTERNATORS, VOLTAGE REGULATORS & OVER VOLTAGE RELAY ALL TESTED WITHIN ALLOWABLE LIMITS.
NTSB Probable Cause Narrative
AN UNDETERMINED FAILURE THAT RESULTED IN AN OVERVOLTAGE CONDITION OF THE ELECTRICAL SYSTEM, OVERHEATING OF THE BATTERY, OVERDRIVE (OVERTORQUE) OF THE LANDING GEAR EXTENSION SYSTEM, A DISCONNECT OF THE EMERGENCY EXTENSION SYSTEM, AND A SUSBSEQUENT COLLAPSE OF THE MAIN GEAR WHEN IT COULD NOT BE LOCKED IN THE EXTENDED POSITION.
Event Information
| Type of Event | Accident |
| Event Date | 5/28/1993 |
| Event Day of the Week | Friday |
| Time of Event | 1410 |
| Event Time Zone | -- |
| Event City | ANCHORAGE |
| Event State | ALASKA |
| Event Country | -- |
| Zipcode of the event site | 99503 |
| Event Date Year | 1993 |
| Event Date Month | 5 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | MERRILL FIELD |
| Event Location Nearest Airport ID | MRI |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | 0 |
| Degrees magnetic from airport | 0 |
| Airport Elevation | 137 |
| Weather Briefing Completeness | Not pertinent |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1402 Atlantic Daylight Time |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | MRI |
| Elevation of weather observation facility | 0 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | ADT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 20000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 90 |
| Air Temperature at event time (in degrees celsius) | 19 |
| Dew Point at event time (in degress fahrenheit) | 6 |
| Wind Direction (degrees magnetic) | 340 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 4 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 30 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 1 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1034 |
| NTSB Notification Source | -- |
| NTSB Notification Date | May 28 1993 12:00AM |
| NTSB Notification Time | 1400 |
| Fiche Number and/or location -used to find docket information | IMAGE |
| Date of most recent change to record | Dec 2 2002 9:04AM |
| User who most recently changed record | NTSB\ZUZL |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N4198T |
| NTSB Number | ANC93FA070 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | VFR |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | Unknown |
| Aircraft Explosion | Unknown |
| Aircraft Manufacturer's Full Name | CESSNA |
| Aircraft Model | 320 |
| Aircraft Series Identifier | 320 |
| Aircraft Serial Number | 0098 |
| Certified Max Gross Weight | 5200 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 6 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Retractable |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Oct 10 1992 12:00AM |
| Airframe hours since last inspection | 143 |
| Airframe Hours | 8097 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | AEROMAP US INC |
| Aircraft Owner Street Address | 2014 MERRILL FILED DRIVE |
| Aircraft Owner City | ANCHORAGE |
| Aircraft Owner State | AK |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 99501 |
| Operator is an individual? | -- |
| Operator Name | AEROMAP US INC |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 2014 MERRILL FIELD DRIVE |
| Operator City | ANCHORAGE |
| Operator State | AK |
| Operator Country | |
| Operator Zip code | 99503 |
| Operator Code | |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | Unknown |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | -- |
| Indicates Domestic or International Flight | -- |
| Operator carrying Pax/Cargo/Mail | -- |
| Type of Flying (Per_Bus / Primary) | Business |
| Second Pilot on Board | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | MRI |
| Departure City | |
| Departure State | |
| Departure Country | |
| Departure Time | 1130 |
| Departure Time Zone | ADT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | MRI |
| Destination City | |
| Destination State | |
| Destination Country | |
| Specific Phase of Flight | Landing |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:34AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 24 |
| Runway Length | 4000 |
| Runway Width | 150 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |