NTSB Identification: CHI02FA148

14 CFRPart 121 operation of Air Carrier Northwest Airlines, Inc.
accident occurred Monday, June 03, 2002 at Minneapolis, MN
Aircraft:Douglas DC-9-31, registration: N8986E
Injuries: 70 Uninjured.

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.

HISTORY OF FLIGHT

On June 3, 2002, at 1928 central daylight time (cdt), a Douglas DC-9-31, N8986E, owned and operated by Northwest Airlines, sustained substantial damage when the right main landing gear collapsed during landing rollout on runway 12L (8,200 feet by 150 feet, concrete) at the Minneapolis-St. Paul International Airport (MSP), Minneapolis, Minnesota. The flight was being operated under the provisions of 14 CFR Part 121 as Northwest Airlines flight 877. Visual meteorological conditions prevailed at the time of the accident. The captain, first officer (FO), 2 flight attendants, and 66 passengers reported no injuries. The flight departed Louisville International Airport (SDF), Louisville, Kentucky, at 1836 eastern daylight time and was on an active instrument flight rules (IFR) flight plan.

An instrument landing system (ILS) approach to runway 12L was flown on autopilot until approximately 1,000 feet above ground level (agl) when the airplane was below the overcast cloud layer. The remainder of the approach was hand-flown by the FO and the aircraft touched-down approximately 1,000 feet from the end of the runway. The landing was reported as normal until the airplane had decelerated to approximately 60 knots and the engine reversers were retracted. At that point the brakes gave an initial release followed by a hard tilt to the right with a continuous warning horn. The aircraft came to a complete stop on centerline after about a 1,500 foot slide.

PERSONNEL INFORMATION

The captain holds an airline transport pilot certificate with an airplane multi-engine land rating. The captain is type rated in the Douglas DC-9 aircraft. The captain's last medical examination was conducted on May 15, 2002, and he was issued a first-class medical certificate with no limitations or restrictions.

According to company records, the captain had a total flight time of 8,043 hours, of which 884 hours were in the DC-9. The captain was reported to have flown 177 hours in the last 90 days and 8.0 hours in the last 24 hours. The captain's last currency checkride was satisfactorily completed in a Douglas DC-9 aircraft on January 01, 2002.

The FO holds an airline transport pilot certificate with an airplane multi-engine land rating. The FO was not type rated for the Douglas DC-9 aircraft. The FO's last medical examination was conducted on July 24, 2001, and he was issued a first-class medical certificate with no limitations or restrictions.

According to company records, the FO had a total flight time of 1,844 hours, of which 1,844 hours were in the DC-9. The FO was reported to have flown 227 hours in the last 90 days and 8.0 hours in the last 24 hours. The FO's last proficiency check was satisfactorily completed in a Douglas DC-9 simulator on July 28, 2001.

AIRCRAFT INFORMATION

The aircraft was a Douglas DC-9-31, serial number 47402. The Douglas DC-9-31 is a low-wing monoplane of all-metal construction. The DC-9-31 has fully cantilevered wings, a T-tail empennage, and is powered by two Pratt & Whitney JT8D-7B engines, each producing 14,000 lbs of thrust. The accident airplane was configured to accommodate a maximum of 100 passengers and an 8-person flightcrew. The Douglas DC-9-31 has a certified maximum takeoff weight of 108,000 lbs and a maximum zero fuel weight of 87,000 lbs.

The accident airplane was maintained by compliance with a Federal Aviation Administration (FAA) approved continuous airworthiness program and accumulated a total time of 75,241.57 hours at the time of the accident.

METEOROLOGICAL INFORMATION

A weather observation station located at MSP recorded the weather approximately 11 minutes after the accident as:

Observation Time: 1939 cdt
Wind: 090 degrees magnetic at 9 knots
Visibility: 9 statute miles
Sky Condition: 1,200 feet agl overcast
Temperature: 13 degrees centigrade
Dew Point: 11 degrees centigrade
Pressure: 29.89 inches of mercury

FLIGHT RECORDERS

The solid state flight data recorder (FDR), Fairchild model F1000, serial number 01787, was removed from the accident aircraft and sent to the National Transportation Safety Board's (NTSB) laboratory in Washington, D.C., for readout and evaluation.

WRECKAGE AND IMPACT INFORMATION

The aircraft came to rest 5,220 feet from the runway 12L threshold and 10 feet right of the runway centerline. The outer-cylinder of the right main landing gear strut had fractured into two sections approximately 2 inches above the designed-fuse section of the strut assembly. The lower portion of the right main landing gear (including the wheels, brakes, and hub assembly) was impacted up into the right inboard flap assembly. The outboard 1/2 of the right wing had scraping damage through the lower wing skin and into the main spar and surrounding wing structure.

SURVIVAL ASPECTS

The captain reported that he decided that an evacuation of the aircraft was not necessary after being notified by the control tower that there was no fire and/or smoke observed coming from the airplane. Airport crash/rescue confirmed there was no fire and/or smoke coming from the airplane and instructed the captain to shutdown both engines and the auxiliary power unit (APU). The passengers and flightcrew departed the airplane via a portable stairway loacated at the forward galley left-side entrance. The passengers were transported from the accident site in buses provided by Northwest Airlines. According to airport crash/rescue records, all passengers and flightcrew personnel were clear of the airplane at 2010 cdt. The flightcrew and 66 passengers reported no injuries as result of the accident and/or post-accident activities.

TESTS AND RESEARCH

The right main landing gear strut assembly was disassembled at a Northwest Airlines maintenance facility. The fractured outer-cylinder was sent to the NTSB Materials Laboratory Division in Washington, D.C., for examination.

The outer-cylinder (part number 5925371-502, serial number FA117) had a total flight time of 71,665.47 hours, consisting of 67,467 cycles. The outer-cylinder accumulated 17,866 cycles, over 21,546.47 flight hours, since the last component overhaul.

ADDITIONAL DATA/INFORMATION

The accident aircraft was released back to a representative of Northwest Airlines on June 5, 2002.


Parties to the investigation included the FAA, Northwest Airlines, The Boeing Company, Air Line Pilots Association (ALPA), and Aircraft Mechanics Fraternal Association (AMFA).

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