# NTSB NYC95IA106: Douglas DC-8-71, N707UP, Louisville, KY, May 13, 1995 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: May 13, 1995, 00:29 local (04:29 UTC) - Place: Louisville, KY - Coordinates: 38.17929, -85.720649 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.1793&lon=-85.7206&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report February 27, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 38872 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC95IA106 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/38872/pdf - Page: https://openairdocs.org/ntsb/NYC95IA106 ## Probable cause preexisting crack(s) on the inside surface of the right main landing gear cylinder, and the subsequent fracture of the cylinder, which resulted in a collapse of the right main landing gear. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Main gear collapsed, landing - roll - landing gear,main gear strut - cracked (cause) - landing gear,main gear strut - fractured (cause) ## Analysis THE DC-8-71 LANDED, AND THEN ON ROLLOUT, IT SETTLED TO THE RIGHT, ALLOWING THE #3 AND #4 ENGINE COWLINGS TO SETTLE ONTO THE RUNWAY. AN INVESTIGATION REVEALED THE RIGHT MAIN LANDING GEAR CYLINDER HAD FAILED CIRCUMFERENTIALLY, JUST ABOVE THE RETRACT CYLINDER ATTACH POINT. THE LANDING GEAR THEN ROTATED AND COLLAPSED REARWARD. METALLURGICAL EXAMINATION OF THE LANDING GEAR CYLINDER REVEALED PREEXISTING CRACKS ON THE INSIDE SURFACE. THE CAUSE OF THE CRACKING WAS NOT VERIFIED. ## Factual narrative On May 13, 1995, at 0029 eastern daylight time, a Douglas DC-8-71, N707UP, operated by United Parcel Service as flight 559, received minor damage while landing at Standiford Field, Louisville, Kentucky. The three airline tansport pilots were not injured. Visual meteorological conditions prevailed, and the flight, which had departed from Minneapolis, Minnesota, at 2304, was operated on an instrument flight rules (IFR) flight plan, under 14 CFR Part 121. In the NTSB Report, the flight crew stated: ...ALL NORMAL CHECKLISTS WERE COMPLETED WITH THE LANDING GEAR CONFIRMED "DOWN - 3 GREEN". A STABILIZED APPROACH WAS FLOWN TO TOUCHDOWN ON SPEED AND A NORMAL LANDING WAS MADE. SHORTLY AFTER THE SPOILERS DEPLOYED, THE AIRCRAFT BEGAN SHUDDERING AND SETTLED TO THE RIGHT. FULL OPPOSITE AILERON COULD NOT BRING THE WING BACK TO LEVEL. ENGINE FIRE WARNINGS SOUNDED FOR ENGINES #3 AND #4 AS WE CONTINUED DOWN THE RUNWAY. FIRE HANDLES WERE PULLED AND THE FIRE WARNING LIGHTS EXTINGUISHED. AIRCRAFT CAME TO A FULL STOP AND THE TOWER WAS ADVISED OF OUR EMERGENCY SITUATION. ACCOMPLISHED SHUTDOWN. DID NOT FIRE BOTTLES. SMOKE STARTED FILLING THE COCKPIT. WE THEN MADE AN EMERGENCY EVACUATION USING THE ESCAPE SLIDE.... Examination of the airplane disclosed that the outer cylinder of the right main landing gear had failed circumferentially, approximately 3 inches above the landing gear retract cylinder attach point. The landing gear wheels swiveled and one tire was blown. When the landing gear collapsed, the number 3 and 4 engines cowlings contacted the runway. The failed portions of the landing gear were forwarded to the NTSB Laboratory for examination. According to the report by the Safety Board Metallurgist: ...Initial visual examination of the as-received fracture faces uncovered chevron and river markings emanating from the forward area of the cylinder where the side brace lugs joined the main body of the cylinder...The deepest crack penetrated about 0.2 inches into the wall of the cylinder. When combined, the area showing crack arrest positions covered about 3 inches of the cylinder's ID circumference. The remaining fracture outside of the crack positions appeared typical of overstress separation.... The small discolored zones...appeared to be the initiation locations for the larger semielliptical areas. All the small discolored zones were less than 0.014 inches deep. It was also noted that many of the larger semielliptical areas were actually made up of several independently initiating and propagating crack fronts that joined together to form a larger front.... Longitudinal metallographic specimens...revealed microstructures typical of quenched and tempered martensite with no indication of grinding burns or other abnormal features.... ## Aircraft - Registration: [N707UP](https://openairdocs.org/deregistered/N707UP-2008-11-20), registration cancelled 2008-11-20, S/N 45907, built 1967 (OpenAirDocs) - Reported make and model: DOUGLAS DC-8-71 - Registry model: [Douglas DC-8-71F](https://openairdocs.org/model/douglas-dc-8-71f) (registry code 302199D) (OpenAirDocs) - Registry engine: [CFM International CFM56 series](https://openairdocs.org/engine/cfm-international-cfm56-series) (registry code 13802, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 45907 - Airframe hours: 3344 - Engines: CFM CFM56-2C 22000 lbs thrust turbo fan - Damage: Minor damage - Flight: Part 121 - Registered owner: United Parcel Service - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, May 12, 1995 - Departed: MSP, MINNEAPOLIS, MN - Destination: SDF - Flight plan: IFR - Airport: SDF, Standiford Field, runway 19, 10,001 × 150 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 37; airline transport, commercial, flight engineer; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 9,600 total, 25 in this make and model, 7,080 as pilot in command, 40 in the last 90 days, 25 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night/bright - Wind: 120° at 6 knots - Visibility: 7 statute miles - Lowest ceiling: none - Temperature: 57 °F, dew point 52 °F - Altimeter: 29.00 inHg - Observed at: SDF ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 19950513011479I](https://openairdocs.org/incident/19950513011479I), May 13, 1995: Doug DC871F, Louisville, KY, Minor damage. Right main landing gear folded on landing. Skidded to stop dragging right engine on runway. From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.