CHI01IA211

The McDonnell Douglas MD-83, operated as a scheduled passenger flight, experienced a catastrophic failure of the left engine while flying at 31,000 feet. The flightcrew heard a thud and noticed that the left engine was surging. White smoke filled the cabin and cockpit. The flightcrew donned their oxygen masks, declared an emergency and initiated an emergency descent to Kansas City International Airport (MCI), Kansas City, Missouri. While descending towards MCI, the flight crew changed their emergency landing destination to Whiteman Air Force Base (SZL), Knob Noster, Missouri, when they were approximately 18 miles north of SZL. Flight crews are not issued approach charts for SZL by their operator. The flight crew requested the runway 19 instrument landing system (ILS) frequency from air traffic control (ATC) and were issued the incorrect frequency. The flight crew also requested and was given the inbound course for ILS 19. The flight crew never obtained the correct ILS frequency for the remainder of the flight and relied upon a radar approach to SZL. During the approach, ATC instructed the flight crew to maintain the a minimum vectoring altitude of 2,500 feet mean sea level. The flight crew descended below minimum vectoring altitudes of 2,500 feet mean sea level to 1,800 feet msl in order to descend below a cloud layer which was 1,400 feet above ground level during the radar approach to SZL. A metallurgical examination revealed a fatigue fracture of one fan blade. Examination of the left engine revealed that the fan exit case exhibited a 360 degree fan exit case fracture. Several service bulletins (SBs) applicable to the fan exit case introduce a newer engine case made of steel to replace the older aluminum case and to install stops to restrict the axial separation of the case in the event of case fracturing. The SBs state that there have been 5 instances of full 360 degree fan exit case fracture, all due to fan blade fracture. They further state that when the case fractures, the front of the engine with the cowl shifts forward. The incident engine had an aluminum fan exit case and did not have stops installed.

History of flight

On July, 12, 2001, at 1824 central daylight time, a McDonnell Douglas MD-83, N9413T, operated by TWA Airlines LLC as flight 379 (TWA 379), made an emergency landing at Whiteman Air Force Base (SZL), Knob Noster, Missouri, following a fan blade and fan case separation of the left engine at flight level 310. Marginal visual meteorological conditions prevailed at the time of the emergency landing. The flight was operating under the provisions of Title 14 CFR Part 121 as a passenger flight. The 2 flight crewmembers, 4 flight attendants, and 132 passengers were uninjuried. The flight orignated from St. Louis International Airport, St. Louis, Missouri, at 1727, en route to San Jose Internatinal Airport, San Jose, Califiornia.

TWA 379 was approximately 45 nautical miles (nm) northeast of SZL and 96 nm east of Kansas City International Airport (MCI), Kansas City, Missouri, when the flight crew heard a "thud" come from the airplane. They noticed that the left engine pressure ratio and compressor and turbine speeds were surging with no indication of exhaust gas temperature. Within 2-3 seconds, the cockpit filled with smoke. Flight attendants reported hearing an explosion and the cabin filling with white smoke. The lead flight attendant came to the cockpit to report that smoke had filled the cabin. The captain told her to prepare for an emergency landing. The flight crew donned their oxygen masks, declared an emergency, and initiated an emergency decent. The left engine was still producing thrust; and the captain was reluctant to shut down the left engine due to multiple emergencies occurring at the time. The captain made an announcement over the airplane's public address system that they would be landing in about 10 minutes.

At 1809:00, TWA 379 contacted Kansas City Air Route Traffic Control Center (ZKC) and transmitted, "twa three seven nine emergency we have an engine failure we have smoke in the cockpit we are descending to kansas city vectors to the nearest runway."

At 1809:08, ZKC transmitted, "twa three seventy nine descend and maintain flight level two four zero heading two seven five for uh...well I'll tell you what you want to try to land at whiteman."

At 1809:18, TWA 379 transmitted, "the uh no no we want kansas city uh uh closest airport kansas city."

At 1809:22, ZKC transmitted, "twa three seventy nine heading two seven zero for kansas city."

At 1809:26, TWA 379 transmitted, "twa three seventy nine heading two seven zero kansas city would to have the ils - - - their closest runway given frequency please." Because of the airplane's position and request for descent, TWA 379 was transferred to the arrival and departure sector controller covering the area east of Kansas City. The transferring controller coordinated TWA 379's requests and advised of TWA 379's emergency to the arrival and departure controller.

At 1810:16, TWA 379 transmitted, "we're descending out of twenty two six descending the aircraft for emergency landing in kansas city."

At 1810:21, ZKC transmitted, "twa three seventy nine rodger maintain at or above six thousand."

At 1811:00, ZKC transmitted, "twa three seventy nine uh what what assistance do you need at the airport."

At 1811:15, TWA 379 transmitted, "k twa three seventy nine we'll need emergency equipment standing by we had an engine failure there's smoke in the the ah cockpit and cabin."

At 1811:41, ZKC transmitted, "twa three seventy nine uh kansas city approach say us one right is going to be the uh runway of uh landing is that acceptable."

At 1811:49, TWA 379 transmitted, "twa three seventy nine one right is ah is ah acceptable yes."

At 1811:54, ZKC transmitted, "twa's uh three seventy nine rodger the ILS frequency is one one zero point seven five."

At 1811:59, TWA 379 transmitted, "nineteen seventy five rodger that.".

At 1814:28 and 1814:34, TWA 379 requested vectors to the nearest airport.

At 1814:37, ZKC transmitted, "twa three seventy nine rodger uh would whiteman work."

At 1814:40, TWA 379 transmitted, "could you give us the dme."

At 1814:42, ZKC transmitted, "ah twa three seventy nine whiteman airports off your left wing about eighteen miles."

At 1814:50, TWA 379 transmitted, "twa three seven nine that’s correct uh give us vectors to the airport and the ils frequency please."

At 1815:03, ZKC transmitted, "twa three seventy nine left heading of ah one seven zero vect radar vectors to ah whiteman left head ah let's make it one eight zero one eight zero heading."

At 1815:29, TWA 379 transmitted, "one eight zero for twa one seventy nine three seventy nine."

At 1815:59, ZKC transmitted, "twa three seventy nine uh frequencies we're going to do the ils to one nine at whiteman the ils frequency one one zero point three." The instrument landing frequency for runway 19 at SZL was 108.5.

At 1816:08, TWA 379 transmitted, one zero point three twa three seventy nine. TWA 379 then asked for the inbound course and the ZKC responded "one eight seven" which was acknowledged. TWA 379 then asked for an altitude assignment, and was issued 3,000 feet along with a heading correction to 170 degrees to join the final approach course.

At 1816:51, ZKC told TWA 379 to turn further left to heading 160 to join the final approach course. TWA 379 responded, "one six zero for TWA - three seventy nine it looks like we are left of course at this time." The runway 01 localizer had to be manually shut down by the coordinator. During this period, both localizers were operational. ZKC then stated, "TWA's ah three seventy nine affirmative you are ah left of the localizer at this time ah left heading of one five zero." TWA 379 acknowledged, and then asked for the distance to the airport. ZKC responded, "TWA three seventy nine the airport's ah - twelve miles." TWA 379 then said, "OK - and the localizer frequency?" ZKC again issued frequency 110.3, to which the pilot replied, "OK very good", followed by "well nothing's up..." The controller then issued another heading change to 130 degrees.

At 1818:02, TWA 379 transmitted, "ok we got a local for TWA three seventy nine we're not picking up the localizer at this time we need a distance from the field and ah approximate location." Radar data shows that TWA 379 was at an altitude of 3,300 feet mean sea level (msl). This was ZKC's last radar contact with TWA 379 and all further radar derived position and heading information was being relayed by Whiteman approach controllers to ZKC who in turn provided it to TWA 379.

At 1818:09, ZKC transmitted, "TWA three seventy nine your currently ah one one miles north of the field and you're about a mile and a half make it a (unintelligible) mile and a half west of the localizer."

At 1818:24, TWA 379 transmitted, "any chance of us getting a little bit lower we're just skimming the cloud deck we probably need about ah two thousand feet down to two thousand feet if you can work." At this time ZKC was asking Whiteman how far they could let TWA 379 descend, and Whiteman approved 2,500 feet." The minimum safe altitude within a 25 nm radius of SZL was 3,100 feet msl. The minimum vectoring altitude (MVA) within a 30 nm radius from SZL was 2,500 feet msl. Within the 30 nm radius, there were two buffer areas due to obstructions with MVAs of 2,600 feet msl and 2,900 feet msl.

At 1818:31, ZKC transmitted, twa's two three seventy nine maintain two thousand five hundred twenty five hundred."

At 1818:34, TWA 379 transmitted, "alright twenty five hundred's not going to work it's going to put us in the cloud deck."

At 1818:38, ZKC transmitted, "ok ah twa three seventy nine maintain three thousand now and uh understand your above the clouds at this time."

At 1818:43, TWA 379 transmitted, "yeah three thousand we're above the clouds."

At 1818:45, ZKC transmitted, "alright maintain three thousand have you picked up the localizer yet."

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