San Francisco Intl Airport
Aircraft Accident/Incident Report

San Francisco, California 94128
Monday, March 13, 2000 20:06 PST

NTSB Narrative Summary Released at Completion of Accident

The airplane landed with the right main landing gear partially extended. This was the second leg of the day in the airplane for this crew; the second officer (SO) completed walk around inspections prior to both flights and noted no discrepancies. The captain was hand flying the airplane in the initial takeoff climb, and selected landing gear up passing through 300 to 500 feet above ground level (agl). The red "doors" light illuminated on the front panel and the amber right main gear door light illuminated on the second officer's panel. All attempts to lower the right main gear were unsuccessful, so the captain elected to return to the airport and land with the right main gear extended about 15 degrees. Inspection of the right main landing gear revealed that the safety bar bent down about 20 degrees at the leading edge and 15 degrees at its midpoint. The safety bar's inboard flanges buckled just below the reinforced area. The inner gear door drive rod bent aft about 15 degrees at the upper attachment fitting, and the tube buckled and separated below the four attachment nuts. The outboard section of the clamshell gear door sustained mechanical damage. Examination of the airplane revealed that the door rods were not loose, and all were in good condition. A general inspection of the wheel well revealed no other damage. There was no abnormal wear or movement marks on the up-lock hook, and the hook was properly adjusted. The actuator adjustor plate was properly installed. Delta maintenance technicians installed new clamshell door halves and a new drive rod. They serviced the strut, isolated the right main clamshell gear door, and cycled the gear. Then they cycled the right main wheel with the door. Finally, they cycled all of the landing gear together. All wheels and doors cycled in proper sequence. Metallurgical examination discovered no cracks in the safety plate. There were no fatigue crack arrest marks or corrosion in the fracture faces on the drive rod; it fractured as a result of overstress. A black coating that felt greasy covered the interior side of the outer clamshell door. There was a rectangular scuffmark in the center of the black area, which had its long axis parallel to the longitudinal axis of the airplane. The black coating appeared pushed into a slight ridge along the outer edge of the scuffmark. A small piece of rubber was under a rivet in the middle of the scuffmark. After placing the tire and gear door together to match their positions when the airplane came to rest, the tire did not touch the scuffmark. Fourier Transform Infrared Spectroscopy (FTIR) examination of the small piece of rubber and samples from the tire and a chock determined that they were all hydrocarbon compounds, but could not distinguish between the samples. Whether the scuffmark and rubber piece came from runway debris or another rubber object could not be determined.

NTSB Probable Cause Narrative

failure of the right main landing gear to fully extend for undetermined reasons.

Event Information

Type of Event Incident
Event Date 3/13/2000
Event Day of the Week Monday
Time of Event 2006
Event Time Zone Pacific Standard Time
Event Country --
Zipcode of the event site 94128
Event Date Year 2000
Event Date Month 3
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 373713N
Event Location Longitude 1222248W
Event Location Airport SAN FRANCISCO INTL
Event Location Nearest Airport ID SFO
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 13
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1956 Pacific Standard Time
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID SFO
Elevation of weather observation facility 0
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation PST
Lighting Conditions Night/Dark
Lowest Ceiling Height --
Lowest Non-Ceiling Height 800
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) 10
Air Temperature at event time (in degrees celsius) 12
Dew Point at event time (in degress fahrenheit) 11
Wind Direction (degrees magnetic) 260
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 18
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.18
Density Altitude (feet) --
Intensity of Precipitation --
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 77
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 20578
NTSB Notification Source --
NTSB Notification Date Mar 13 2000 12:00AM
NTSB Notification Time 2015
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Oct 31 2006 8:45AM
User who most recently changed record NTSB\JOHB
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N516DA
NTSB Number LAX00IA127
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 121: Air Carrier
Type of Flight Plan filed IFR
Flight plan Was Activated? Yes
Damage Minor
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Boeing
Aircraft Model 727-232
Aircraft Series Identifier 727-232
Aircraft Serial Number 21432
Certified Max Gross Weight 184200
Aircraft Category Airplane
Aircraft Registration Class Unknown
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 156
Number of Engines 3
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Mar 1 2000 12:00AM
Airframe hours since last inspection 42.1
Airframe Hours 63246.5
ELT Installed --
ELT Activated --
ELT Aided Location of Event Site --
ELT Type --
Aircraft Owner Street Address RODNEY SQ ATTN EQUIP LEASING
Aircraft Owner City WILMINGTON
Aircraft Owner State DE
Aircraft Owner Country USA
Aircraft Owner Zipcode 19890
Operator is an individual? No
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address PO BOX 20706
Operator City ATLANTA
Operator State GA
Operator Country USA
Operator Zip code 30320
Operator Code DALA
Owner has at least one certificate --
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
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 Yes
Departure Airport Code SFO
Departure City SAN FRANCISCO
Departure State CA
Departure Country USA
Departure Time 1835
Departure Time Zone PST
Destination Same as Local Flt --
Destination Airport Code SLC
Destination City SALT LAKE CITY
Destination State UT
Destination Country USA
Specific Phase of Flight Takeoff
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Aug 25 2006 3:33PM
User who most recently changed record COOS
Since inspection or accident --
Event Location Runway Number and Location 28R
Runway Length 11870
Runway Width 200
Sight Seeing flight No
Air Medical Flight No
Medical Flight --