Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Moose Lake, Minnesota 55767
Tuesady, August 29, 1989 19:45 CDT
NTSB Narrative Summary Released at Completion of Accident
THE ACFT (PIPER PA-22, CONVERTED TO A PA-20, IAW STC SA45AM) WAS BEING USED TO PROVIDE A BIENNIAL FLT REVIEW FOR THE OWNER/PLT (CONSIDERED AS PIC ON THIS FLT). DRG FLT, THE RGT WING FOLDED BACK OVER THE FUSELAGE & THE ACFT CRASHED. AN EXAM OF THE WRECKAGE REVEALED THE FWD LIFT STRUT FOR THE RGT WING HAD FAILED IN AN AREA OF SEVERE CORROSION. THE FAILUREOCCURRED AT THE LOWER PART OF THE LIFT STRUT NEAR THE FUSELAGE ATTACHMENT POINT. AN EXAM OF THE ANNUAL INSPN CHECKLIST INDCD ALL APPLICABLE AIRWORTHINESS DIRECTIVES (AD'S) WERE COMPLIED WITH AS OF 7/21/89 & THAT THE LIFT STRUTS WERE VISUALLY INSPD AT THE ANNUAL INSPN. THE ACFT LOGBOOK SHOWED THAT AD 77-03-08 (REQUIRING MECHANICAL TESTING OF THE LIFT STRUT FOR EVIDENCE OF CORROSION AT 5 YR INTERVALS) HAD BEEN COMPLIED WITH IN JULY 1988. THE AROMA OF LINSEED OIL WAS NOTED IN ALL LIFT STRUTS, BUT POLYMERIZED LINSEED OIL WAS FOUND IN THE RGT & LEFT REAR STRUTS. INTERNAL CORROSION HAD PERFORATED THE RGT FWD LIFT STRUT PRIOR TO ITS FAILURE.
NTSB Probable Cause Narrative
SEVERE CORROSION OF THE LOWER FORWARD LIFT STRUT FOR THE RIGHT WING, INADEQUATE INSPECTION OF THE LIFT STRUT BY MAINTENANCE PERSONNEL, AND SUBSEQUENT FAILURE OF THE LIFT STRUT, WHICH RESULTED IN AN OVERLOAD FAILURE (FOLDING BACK) OF THE WING. RELATED FACTORS WERE: INADEQUATE INSPECTION PROCEDURES PROVIDED BY THE MANUFACTURER & INADEQUATE SURVEILLANCE BY THE FAA.
Event Information
| Type of Event | Accident |
| Event Date | 8/29/1989 |
| Event Day of the Week | Tuesday |
| Time of Event | 1945 |
| Event Time Zone | Central Daylight Time |
| Event City | MOOSE LAKE |
| Event State | MINNESOTA |
| Event Country | -- |
| Zipcode of the event site | 55767 |
| Event Date Year | 1989 |
| Event Date Month | 8 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| Event Location Airport | |
| Event Location Nearest Airport ID | |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | 0 |
| Degrees magnetic from airport | 0 |
| Airport Elevation | -- |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1950 Central Daylight Time |
| Direction of event from weather observation facility (degrees) | 35 |
| Weather Observation Facility ID | DLH |
| Elevation of weather observation facility | 1430 |
| Distance of event from weather observation facility (units?) | 38 |
| Time Zone of the weather observation | CDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 0 |
| Lowest Non-Ceiling Height | 3500 |
| 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) | 15 |
| Air Temperature at event time (in degrees celsius) | 16 |
| Dew Point at event time (in degress fahrenheit) | 14 |
| Wind Direction (degrees magnetic) | 360 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 19 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | 29 |
| Density Altitude (feet) | 1157 |
| Intensity of Precipitation | Unknown |
| METAR weather report | -- |
| Event Highest Injury | Fatal |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | 2 |
| Injury Total Minor | -- |
| Injury Total None | -- |
| Injury Total Serious | -- |
| Injury Total All | 2 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1492 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Aug 29 1989 12:00AM |
| NTSB Notification Time | 2100 |
| Fiche Number and/or location -used to find docket information | 39837 |
| Date of most recent change to record | Dec 13 2000 12:58PM |
| User who most recently changed record | dbo |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N2841P |
| NTSB Number | MKC89FA191 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Destroyed |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | PIPER |
| Aircraft Model | PA-20 |
| Aircraft Series Identifier | PA-20 |
| Aircraft Serial Number | 22-3138 |
| Certified Max Gross Weight | 2000 |
| 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 | 4 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Jul 21 1989 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | -- |
| ELT Installed | No |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | PRACHAR, KENNETH M |
| Aircraft Owner Street Address | 7704 CO HIGHWAY 61 |
| Aircraft Owner City | WILLOW RIVER |
| Aircraft Owner State | MN |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | 55795 |
| Operator is an individual? | -- |
| Operator Name | PRACHAR, KENNETH M |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 7704 CITY HIGHWAY 61 |
| Operator City | WILLOW RIVER |
| Operator State | MN |
| Operator Country | |
| Operator Zip code | 55795 |
| 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) | Instructional |
| Second Pilot on Board | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | 21Y |
| Departure City | MOOSE LAKE |
| Departure State | MN |
| Departure Country | |
| Departure Time | 0 |
| Departure Time Zone | |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | |
| Destination City | |
| Destination State | |
| Destination Country | |
| Specific Phase of Flight | Cruise |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:30AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 0 |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |