Individually Owned: 150,657
Corporate Owned: 137,281
Merrill Field Airport
Aircraft Accident/Incident Report
Anchorage, Alaska 99513
Thursday, September 17, 2009 9:40 AKD
NTSB Narrative Summary Released at Completion of Accident
The commercial pilot reported that he was landing his tailwheel-equipped amphibious airplane on a dry, paved runway at the conclusion of a local area postmaintenance flight operated under Title 14, Part 91 after a local facility had completed repairs to the right brake assembly. After landing, the pilot applied the brakes to slow the landing roll, and while depressing both brake pedals, the right brake pedal unexpectedly "went to the floor" and the airplane swerved to the left. The airplane ground looped to the left, sustaining substantial damage to the right wing and right aileron. A postaccident investigation revealed that a hydraulic supply line fitting on the airplane's right brake assembly had broken. The maintenance technician that did the repairs on the airplane's brake reported that the hydraulic supply line fitting was not removed during his work. He also said that he strongly suspected that the broken fitting might be an unapproved or "bogus" aircraft part due to an atypical thread pattern. An NTSB metallurgical examination revealed that the fractured fitting had failed due to a fatigue fracture. A Safety Board mechanical engineer noted that the broken fitting was marked with the "AN" (Air Force-Navy standards) identification stamp, signifying that it was approved for use in aircraft. Further investigation revealed that the fractured fitting was consistent in appearance to that of a fitting manufactured to meet the standards of a Joint Industrial Council (JIC), which is not intended for use in aircraft. The Safety Board mechanical engineer also noted that the two types of fitting are nearly indistinguishable except for the "AN" identification stamp. He added that without the aid of magnification, the "JIC" fittings and the "AN" fittings look identical. The "AN" fitting is reported to have a 40 percent increase in fatigue strength over the identical "JIC" fitting. There was no logbook entry which disclosed replacement of the hydraulic fittings, and the airplane's owner said that he was unaware when the brake line fittings had been replaced, but assumed it had been done prior to him purchasing the airplane. On July 22, 2008, the Federal Aviation Administration (FAA) issued an Advisory Circular (AC) 21-29C, change 1, which provides updated information and guidance to the aviation community for detecting suspected unapproved parts and reporting them to the FAA.
NTSB Probable Cause Narrative
A fatigue fracture of an unapproved hydraulic brake line fitting, which resulted in a loss of control during the landing roll. Contributing to the accident was the installation of an unapproved part by an unknown maintenance personnel.
Event Information
| Type of Event | Accident |
| Event Date | 9/17/2009 |
| Event Day of the Week | Thursday |
| Time of Event | 940 |
| Event Time Zone | -- |
| Event City | Anchorage |
| Event State | ALASKA |
| Event Country | -- |
| Zipcode of the event site | 99513 |
| Event Date Year | 2009 |
| Event Date Month | 9 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 651203N |
| Event Location Longitude | 1492213W |
| 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 | -- |
| Airport Elevation | 137 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 853 Atlantic Daylight Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | MRI |
| 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 | -- |
| Lowest Non-Ceiling Height | 7500 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | 8 |
| Dew Point at event time (in degress fahrenheit) | 7 |
| Wind Direction (degrees magnetic) | -- |
| Variable Wind Indicator | -- |
| Wind Speed (knots) | -- |
| Wind Velocity Indicator | Calm |
| Wind Gust Indicator | -- |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.43 |
| 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) | 27282 |
| NTSB Notification Source | FAA ROC |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Sep 14 2010 12:29PM |
| User who most recently changed record | johb |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N86627 |
| NTSB Number | ANC09LA100 |
| 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 | GRUMMAN |
| Aircraft Model | G-44A |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 1453 |
| Certified Max Gross Weight | 5400 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 5 |
| Number of Engines | 2 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Jun 18 2009 12:00AM |
| Airframe hours since last inspection | 22 |
| Airframe Hours | 15267 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | C91 |
| Aircraft Owner Name | RICHARD R. TAYLOR |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | ANCHORAGE |
| Aircraft Owner State | AK |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 99515-4113 |
| Operator is an individual? | No |
| Operator Name | RICHARD R. TAYLOR |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | Anchorage |
| Operator State | AK |
| Operator Country | USA |
| Operator Zip code | 99515-4113 |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | No |
| 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 | Yes |
| Departure Airport Code | MRI |
| Departure City | Anchorage |
| Departure State | AK |
| Departure Country | USA |
| Departure Time | 915 |
| 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 | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Aug 6 2010 1:01PM |
| User who most recently changed record | stam |
| Since inspection or accident | Last Inspection |
| Event Location Runway Number and Location | 07 |
| Runway Length | 4000 |
| Runway Width | 100 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |