Hartsfield - Jackson Atlanta I Airport
Aircraft Accident/Incident Report

Atlanta, Georgia 30354
Monday, October 10, 2011 15:03 EDT

NTSB Narrative Summary Released at Completion of Accident

The diffuser case of a Pratt & Whitney PW2037(M) engine installed on a B757-200 airplane ruptured during takeoff roll at Hartsfield-Jackson Atlanta International Airport, Atlanta, Georgia (ATL). The force of the case rupture caused the hinge-mounted core cowl halves to distort and strike the leading edge and underside of the airplane's left wing, resulting in minor airplane damage. Metallurgical investigation and review of the engine's maintenance records determined that cracks in the engine's diffuser case rear flange (M-flange) and cracks in the HPT case forward flange (M-flange) were not detected when the cases underwent fluorescent penetrant inspection (FPI) during the engine's last shop visit, 3,479 cycles before the event. The undetected cracks continued to propagate, leading to the in-service diffuser case rupture. The reason for the ineffective inspection was not determined, but was narrowed to chronological- and operator-based scenarios. A suspect population of 50 engines was identified that included sub-populations for both possibilities. The FAA published airworthiness directive (AD) 2014-05-32, requiring the M-flanges of PW2037, PW2037D, PW2037M, PW2040, PW2040D, PW2043, PW2143, PW2240, PW2337, PW2643, and F117-PW-100 engines in the identified suspect population to undergo eddy current inspection within 100 flight cycles or 30 days. No additional cracks were found. As a result of the investigation, the FAA published airworthiness directive (AD) 2014-05-32, which requires the M-flanges of PW2000 engines with certain diffuser and HPT cases installed to undergo eddy current inspection within 100 flight cycles or 30 days. AD 2014-05-32 also requires that high-sensitivity FPI penetrant be used when accomplishing FPI of the PW2037, PW2037D, PW2037M, PW2040, PW2040D, PW2043, PW2143, PW2240, PW2337, PW2643, and F117-PW-100 diffuser case M-flange and the HPT case M-flange. In addition, AD 2014-05-32 makes the performance of diffuser and HPT case M-flange high-sensitivity FPI at every piece part opportunity an airworthiness limitation for PW2037, PW2037D, PW2037M, PW2040, PW2040D, PW2043, PW2146, PW2240, PW2337, PW2643, and F117-PW-100 engines.

NTSB Probable Cause Narrative

the return to service of overhauled airplane engine parts with undetected fatigue cracks, resulting in complete loss of engine power and uncontained engine failure. A contributing factor was the inadequate diffuser and HPT case inspection procedure.

Event Information

Type of Event Incident
Event Date 10/10/2011
Event Day of the Week Monday
Time of Event 1503
Event Time Zone Eastern Daylight Time
Event City Atlanta
Event State GEORGIA
Event Country --
Zipcode of the event site 30354
Event Date Year 2011
Event Date Month 10
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 334548N
Event Location Longitude 0842406W
Event Location Airport HARTSFIELD - JACKSON ATLANTA I
Event Location Nearest Airport ID ATL
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles 8
Degrees magnetic from airport 10
Airport Elevation 1026
Weather Briefing Completeness --
Investigator's weather source Unknown
Time of the weather observation
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID --
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation --
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions --
Sky Condition for Lowest Ceiling --
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) --
Air Temperature at event time (in degrees celsius) --
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) --
Variable Wind Indicator --
Wind Speed (knots) --
Wind Velocity Indicator --
Wind Gust Indicator --
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) --
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 182
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 33301
NTSB Notification Source Delta Air Lines
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Aug 15 2014 4:28PM
User who most recently changed record horc
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N553NW
NTSB Number ENG12IA001
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 121: Air Carrier
Type of Flight Plan filed Unknown
Flight plan Was Activated? --
Damage Minor
Aircraft Fire Ground
Aircraft Explosion Ground
Aircraft Manufacturer's Full Name BOEING
Aircraft Model 757-251
Aircraft Series Identifier --
Aircraft Serial Number 26500
Certified Max Gross Weight --
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 178
Number of Engines 2
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection --
Date of Last Inspection --
Airframe hours since last inspection --
Airframe Hours --
ELT Installed Unknown
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name DELTA AIR LINES INC
Aircraft Owner Street Address ATTN: TREASURER DEPT 856
Aircraft Owner City ATLANTA
Aircraft Owner State GA
Aircraft Owner Country USA
Aircraft Owner Zipcode 30354-1989
Operator is an individual? No
Operator Name Delta Air Lines Inc
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address ATTN: TREASURER DEPT 856
Operator City ATLANTA
Operator State GA
Operator Country USA
Operator Zip code 30354-1989
Operator Code DAL
Owner has at least one certificate Yes - certificate holder
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) --
Second Pilot on Board Yes
Departure Point Same as Event Yes
Departure Airport Code ATL
Departure City Atlanta
Departure State GA
Departure Country USA
Departure Time 1503
Departure Time Zone EDT
Destination Same as Local Flt --
Destination Airport Code DFW
Destination City Dallas
Destination State TX
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jul 22 2014 12:08PM
User who most recently changed record horc
Since inspection or accident --
Event Location Runway Number and Location N/A
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --