Aircraft Accident/Incident Report

Brewton, Alabama 36426
Saturday, September 21, 1991 8:30 CST

NTSB Narrative Summary Released at Completion of Accident

THE LEFT WING SEPARATED FROM THE AIRFRAME WHEN ONE OF THE TWO WING FRONT SPAR FITTING CLEVIS EARS FAILED. EXAMINATION OF THE FAILED COMPONENT UNCOVERED CORROSION BETWEEN THE SECTIONS MAKING UP THE WELDED CLEVIS EAR. THE ACCUMULATION OF CORROSION IS ATTRIBUTED TO CHEMICAL SPRAYED FROM THE AIRPLANE OVER A LONG PERIOD OF TIME. ADDITIONALLY, THERE WAS NO INSPECTION PROCEDURE SPECIFIED FOR THIS AREA OF THE WING FITTING. SUBSEQUENTLY, THE NTSB ISSUED A RECOMMENDATION REQUESTING AN INSPECTION PROCEDURE TO PREVENT THE FORMATION OF CORROSION BETWEEN THE LAYERS OF CLEVIS MATERIAL.

NTSB Probable Cause Narrative

THE INFLIGHT SEPARATION OF THE LEFT WING RESULTING FROM CORROSION OF THE WING FRONT SPAR FITTING ASSEMBLY. A FACTOR WAS INADEQUATE MAINTENANCE PROCEDURES.

Event Information

Type of Event Accident
Event Date 9/21/1991
Event Day of the Week Saturday
Time of Event 830
Event Time Zone Central Standard Time
Event City BREWTON
Event State ALABAMA
Event Country --
Zipcode of the event site 36426
Event Date Year 1991
Event Date Month 9
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 853 Central Standard Time
Direction of event from weather observation facility (degrees) 200
Weather Observation Facility ID MOB
Elevation of weather observation facility 26
Distance of event from weather observation facility (units?) 30
Time Zone of the weather observation CST
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Clear
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) 17
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 40
Variable Wind Indicator Unknown
Wind Speed (knots) 10
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) 95
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Serious
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None --
Injury Total Serious 1
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 1991
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information 46041
Date of most recent change to record Dec 12 2000 10:43AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N7509Z
NTSB Number ATL91LA178
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 137: Agricultural
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire Ground
Aircraft Explosion None
Aircraft Manufacturer's Full Name PIPER
Aircraft Model PA-25-235
Aircraft Series Identifier PA-25-235
Aircraft Serial Number PA25-3543
Certified Max Gross Weight 2100
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 1
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Apr 19 1991 12:00AM
Airframe hours since last inspection 200
Airframe Hours 10700
ELT Installed Unknown
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name WALLACE FLYING SERVICE
Aircraft Owner Street Address STAR ROUTE A, BOX 138
Aircraft Owner City ATMORE
Aircraft Owner State AL
Aircraft Owner Country
Aircraft Owner Zipcode 36502
Operator is an individual? --
Operator Name WALLACE FLYING SERVICE
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address STAR ROUTE A, BOX 138
Operator City ATMORE
Operator State AL
Operator Country
Operator Zip code 36502
Operator Code
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Agriculture
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Unknown
Indicates Domestic or International Flight Unknown
Operator carrying Pax/Cargo/Mail Unknown
Type of Flying (Per_Bus / Primary) Aerial Application
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code NONE
Departure City MC CULLOUGH
Departure State AL
Departure Country
Departure Time 820
Departure Time Zone CST
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 Maneuvering
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:35AM
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 --