Aircraft Accident/Incident Report

Boston, Massachusetts 02128
Sunday, September 20, 1992 19:53 EDT

NTSB Narrative Summary Released at Completion of Accident

THE PILOT WAS LANDING ON RUNWAY 4R, WHEN ACCORDING TO THE PILOT, HE WAS ESTABLISHED ON THE GLIDE SLOPE WHEN HE FELT A VIBRATION. HE REPORTED THAT THE FLYING CHARACTERISTICS DEGRADED AND HE MADE THE NECESSARY CORRECTION SUCCESSFULLY. THERE WERE NO INDICATIONS IN THE COCKPIT OF ANY FAILURE. THE AIRPLANE TOUCHED DOWN 2 MINUTES LATER AND TAXIED TO THE GATE WITHOUT ANY FURTHER INCIDENCE. INSPECTION OF THE AIRPLANE REVEALED SEPARATION OF THE NO. 2 FLAP VANE FROM THE RIGHT WING. FURTHER TESTING BY THE NTSB LAB REVEALED THE SEPARATION OCCURRED DUE TO STRESS CORROSION AND FATIGUE CRACKING THAT INITIATED AT THE LUG BORE.

NTSB Probable Cause Narrative

INADEQUATE LUBRICATION WHICH CAUSED STRESS CORROSION CRACKING AND THE SEPARATION OF THE RIGHT WING NUMBER TWO FLAP VANE.

Event Information

Type of Event Incident
Event Date 9/20/1992
Event Day of the Week Sunday
Time of Event 1953
Event Time Zone Eastern Daylight Time
Event City BOSTON
Event State MASSACHUSETTS
Event Country --
Zipcode of the event site 02128
Event Date Year 1992
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 --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness Not pertinent
Investigator's weather source Weather Observation Facility
Time of the weather observation 1950 Eastern Daylight Time
Direction of event from weather observation facility (degrees) 1
Weather Observation Facility ID BOS
Elevation of weather observation facility 20
Distance of event from weather observation facility (units?) 1
Time Zone of the weather observation EDT
Lighting Conditions Night/Dark
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) 14
Dew Point at event time (in degress fahrenheit) 10
Wind Direction (degrees magnetic) 140
Variable Wind Indicator Unknown
Wind Speed (knots) 8
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 315
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 5037
NTSB Notification Source --
NTSB Notification Date Sep 20 1992 12:00AM
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information 47664
Date of most recent change to record Dec 11 2000 3:17PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N786DL
NTSB Number BFO92IA145
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 121: Air Carrier
Type of Flight Plan filed IFR
Flight plan Was Activated? --
Damage Minor
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name LOCKHEED
Aircraft Model L1011-385
Aircraft Series Identifier L1011-385
Aircraft Serial Number 193A-1123
Certified Max Gross Weight 450000
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 315
Number of Engines 3
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Sep 12 1992 12:00AM
Airframe hours since last inspection 69
Airframe Hours 39472
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name DELTA AIRLINES
Aircraft Owner Street Address HARTSFIELD ATLANTA INTL ARPT.
Aircraft Owner City ATLANTA
Aircraft Owner State GA
Aircraft Owner Country
Aircraft Owner Zipcode 30320
Operator is an individual? --
Operator Name DELTA AIRLINES
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address HARTSFIELD ATLANTA INTL. ARPT.
Operator City ATLANTA
Operator State GA
Operator Country
Operator Zip code 30320
Operator Code
Owner has at least one certificate Yes - certificate holder
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 Scheduled
Indicates Domestic or International Flight Domestic
Operator carrying Pax/Cargo/Mail Passenger Only
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code ATL
Departure City ATLANTA
Departure State GA
Departure Country
Departure Time 0
Departure Time Zone
Destination Same as Local Flt crash at destination city
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Approach
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Dec 20 2002 12:42PM
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 --