Individually Owned: 150,657
Corporate Owned: 137,281
Wasilla Airport
Aircraft Accident/Incident Report
Wasilla, Alaska 99654
Friday, May 27, 2011 16:20 AKD
NTSB Narrative Summary Released at Completion of Accident
The pilot said that, when the tailwheel-equipped airplane touched down during a three-point landing, it immediately veered sharply to the left and exited the runway. She was unable to regain control before the airplane collided with a ditch.
The airplane had recently been purchased, and the pilot did not have any flight time in the make and model prior to the purchase. The airplane had been modified with larger/taller main landing gears, larger diameter tires, and a tailwheel assembly from another model of airplane. The pilot said that when the previous owner demonstrated the airplane, he used heavy braking and excessive thrust to get the tailwheel to straighten out. He told her he always did wheel landings as opposed to three-point full stall landings.
A postaccident examination of the airplane revealed that the rotational plane of the tailwheel was not horizontal/parallel to the ground. There was a pronounced negative camber (aft downward tilt), which caused the tailwheel to rotate forward when weight was applied. The tailwheel spring had been extended aft from its normal position, which added additional negative camber. An engineer from the Federal Aviation Administration aircraft certification office said adjustments to the tailwheel should have been made to make the tailwheel's plane of rotation horizontal.
An examination of the airplane's airframe logbook revealed that the airplane's landing gear had been modified under a supplemental type certificate and multiple field approvals. The airplane had been inspected for maintenance conformity, but not engineering.
Due to the multiple landing gear modifications, it is likely that the airplane's landing characteristics were degraded, requiring greater pilot vigilance and skill, particularly during landing.
NTSB Probable Cause Narrative
The pilot's loss of directional control during landing, which resulted in a runway excursion. Contributing to the accident were the effects of multiple modifications to the main and tailwheel landing gear through the supplemental type certificate and FAA field approval process, which adversely changed their geometry, and resulted in degraded controllability during landing.
Event Information
| Type of Event | Accident |
| Event Date | 5/27/2011 |
| Event Day of the Week | Friday |
| Time of Event | 1620 |
| Event Time Zone | -- |
| Event City | Wasilla |
| Event State | ALASKA |
| Event Country | -- |
| Zipcode of the event site | 99654 |
| Event Date Year | 2011 |
| Event Date Month | 5 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 613220N |
| Event Location Longitude | 1493222W |
| Event Location Airport | Wasilla |
| Event Location Nearest Airport ID | IYS |
| 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 | 354 |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Pilot |
| Time of the weather observation | |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | -- |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | -- |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Clear |
| 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) | 21 |
| Dew Point at event time (in degress fahrenheit) | 5 |
| Wind Direction (degrees magnetic) | 130 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 6 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.98 |
| 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) | 29662 |
| NTSB Notification Source | FAA Anchorage, ROC |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Mar 14 2012 1:38PM |
| User who most recently changed record | johb |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N1742D |
| NTSB Number | ANC11LA039 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | CESSNA |
| Aircraft Model | 170A |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 20185 |
| Certified Max Gross Weight | 2200 |
| 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 | 4 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Mar 10 2011 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | 2804 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | C91 |
| Aircraft Owner Name | Bradley R Subers |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Palmer |
| Aircraft Owner State | AK |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 99645 |
| Operator is an individual? | No |
| Operator Name | Bradley R Subers |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | Palmer |
| Operator State | AK |
| Operator Country | USA |
| Operator Zip code | 99645 |
| 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 | No |
| Departure Airport Code | PAAQ |
| Departure City | Palmer |
| Departure State | AK |
| Departure Country | USA |
| Departure Time | 1545 |
| Departure Time Zone | ADT |
| Destination Same as Local Flt | crash at destination city |
| Destination Airport Code | IYS |
| Destination City | Wasilla |
| Destination State | AK |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Feb 14 2012 5:33PM |
| User who most recently changed record | stam |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 21 |
| Runway Length | 3700 |
| Runway Width | 75 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |