Individually Owned: 150,657
Corporate Owned: 137,281
Merrill Field Airport
Aircraft Accident/Incident Report
Anchorage, Alaska 99513
Thursday, October 7, 2004 17:30 AKD
NTSB Narrative Summary Released at Completion of Accident
The private pilot reported he made a hard landing on a paved runway in his tail wheel and tundra tire equipped airplane, and that the left main landing gear assembly subsequently collapsed. The airplane sustained structural damage to the left wing when it struck the runway. An inspection of the main landing gear (MLG) assembly by the NTSB investigator-in-charge and FAA certification engineers, disclosed that the MLG was not an approved component, although it had been stamped "PMA" for Primary Manufacturing Authority, indicating it was an approved part. Further research and analysis of the gear assembly revealed that it had fractured at the shock strut attachment lugs, and that the lugs were approximately one-half strength of the original factory equipment. The MLG assembly has been available for several years, and may be retro-fitted to the entire Piper Cub series airplanes. The FAA aircraft certification branch and the manufacturer are presently conducting a review of the design and have indicated that a manufacturer's Service Bulletin will be published offering a strengthened version of the MLG, and that the FAA will issue either a Special Airworthiness Information Bulletin, or an Airworthiness Directive.
NTSB Probable Cause Narrative
The inadequate and unapproved design of the main landing gear assembly by the manufacturer, which resulted in a failure of the main landing gear during landing, and structural damage to the airplane. A factor in the accident was the pilot's misjudged flare.
Event Information
| Type of Event | Accident |
| Event Date | 10/7/2004 |
| Event Day of the Week | Thursday |
| Time of Event | 1730 |
| Event Time Zone | -- |
| Event City | Anchorage |
| Event State | ALASKA |
| Event Country | -- |
| Zipcode of the event site | 99513 |
| Event Date Year | 2004 |
| Event Date Month | 10 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 611113N |
| Event Location Longitude | 1495755W |
| Event Location Airport | Merrill Field |
| Event Location Nearest Airport ID | PAMR |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | Not pertinent |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1806 Atlantic Daylight Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | PAMR |
| Elevation of weather observation facility | 137 |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | ADT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 6500 |
| Lowest Non-Ceiling Height | 1500 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | Broken |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 11 |
| Dew Point at event time (in degress fahrenheit) | 6 |
| Wind Direction (degrees magnetic) | -- |
| Variable Wind Indicator | -- |
| Wind Speed (knots) | -- |
| Wind Velocity Indicator | Light and Variable |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.65 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 2 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 17855 |
| NTSB Notification Source | Anchorage ROC |
| NTSB Notification Date | Oct 7 2004 12:00AM |
| NTSB Notification Time | 1800 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Jul 7 2005 10:33AM |
| User who most recently changed record | NTSB\JOHB |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N5760D |
| NTSB Number | ANC05LA001 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Piper |
| Aircraft Model | PA-18-150 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 18-5262 |
| Certified Max Gross Weight | 1750 |
| 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 | 2 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Mar 1 2004 12:00AM |
| Airframe hours since last inspection | 84 |
| Airframe Hours | 2735 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Dwight E. Johnson |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Eagle River |
| Aircraft Owner State | AK |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 99577 |
| Operator is an individual? | No |
| Operator Name | -- |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | -- |
| Operator State | -- |
| Operator Country | -- |
| Operator Zip code | -- |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | -- |
| Certified for Part 133 or 137 Operation | -- |
| 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) | Personal |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | ENA |
| Departure City | KENAI |
| Departure State | AK |
| Departure Country | USA |
| Departure Time | 1610 |
| Departure Time Zone | ADT |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | MRI |
| Destination City | Anchorage |
| Destination State | AK |
| Destination Country | USA |
| Specific Phase of Flight | Landing - flare/touchdown |
| Report sent to ICAO? | No |
| Evacuation occurred | No |
| Date of most recent change to record | Apr 15 2005 2:37PM |
| User who most recently changed record | PETL |
| Since inspection or accident | Last Inspection |
| Event Location Runway Number and Location | 33 |
| Runway Length | 2640 |
| Runway Width | 75 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |