ASN Aircraft accident Boeing 737-7H4 (WL) N772SW Philadelphia, PA
ASN logo
 

Status:Accident investigation report completed and information captured
Date:Tuesday 17 April 2018
Time:11:04
Type:Silhouette image of generic B737 model; specific model in this crash may look slightly different
Boeing 737-7H4 (WL)
Operator:Southwest Airlines
Registration: N772SW
MSN: 27880/601
First flight: 2000-06-26 (17 years 10 months)
Total airframe hrs:63043
Cycles:36728
Engines: 2 CFMI CFM56-7B24
Crew:Fatalities: 0 / Occupants: 5
Passengers:Fatalities: 1 / Occupants: 144
Total:Fatalities: 1 / Occupants: 149
Aircraft damage: Substantial
Location:105 km (65.6 mls) NW of Philadelphia, PA (   United States of America)
Phase: En route (ENR)
Nature:Domestic Scheduled Passenger
Departure airport:New York-La Guardia Airport, NY (LGA/KLGA), United States of America
Destination airport:Dallas-Love Field, TX (DAL/KDAL), United States of America
Flightnumber:WN1380
Narrative:
Southwest Airlines flight 1380 diverted to Philadelphia Airport, Pennsylvania, USA, after suffering an in-flight uncontained engine failure.
The aircraft, a Boeing 737-700, originated from New York-La Guardia Airport at 10:43 for a flight to Dallas-Love Field, Texas. About 11:04, when the aircraft was climbing through FL325, the no.1 engine (CFM56-7B24) suffered an uncontained failure. The flight crew noticed that the no.1 engine rpm dropped to zero, as did the oil pressure. The cabin altitude horn sounded and the aircraft experienced a sudden, uncommanded, left roll of a 41° bank angle. The pilots leveled the wing, donned their oxygen masks and initiated an emergency descent. The flight crew then requested air traffic control to give them vectors to the nearest suitable airport.
As a result of the uncontained failure, a fan blade and parts of the engine cowling and engine air inlet cowl had separated. Debris impacted a window frame of row 14, causing the window and frame to break away. This resulted in a decompression of the aircraft. Additional debris impacted and damaged the leading edge of the left hand wing.
The flight was vectored towards Philadelphia Airport, where the crew requested an extended final approach due to concerns of aircraft controllability. It was decided to land with flaps 5 for that reason, and an approach speed of 165 knots. The aircraft landed on runway 27L at 11:19 hours and the aircraft was stopped on a taxiway. ARFF services attended to the no.1 engine while injured passenger who was seated near the lost window was rushed to hospital. The passenger is reported to have died.
Preliminary findings of the NTSB show that the no.13 fan blade of engine no.1 was missing. It appears to have broken away at the hub. There is evidence of metal fatigue in the area where the blade broke.
Also, a part of the no.1 engine cowling was reported to have been found at Burnville, PA.

Probable Cause:

Probable Cause: The National Transportation Safety Board (NTSB) determines that the probable cause of this accident was a low-cycle fatigue crack in the dovetail of fan blade No. 13, which resulted in the fan blade separating in flight and impacting the engine fan case at a location that was critical to the structural integrity and performance of the fan cowl structure. This impact led to the in-flight separation of fan cowl components, including the inboard fan cowl aft latch keeper, which struck the fuselage near a cabin window and caused the window to depart from the airplane, the cabin to rapidly depressurize, and the passenger fatality.

Accident investigation:

cover
Investigating agency: NTSB
Status: Investigation completed
Duration: 1 year and 7 months
Accident number: NTSB/AAR-19/03
Download report: Final report

Classification:
Uncontained engine failure
Forced landing on runway

Follow-up / safety actions

EASA issued 2 Airworthiness Directives
EASA issued 1 Emergency Airworthiness Directive
FAA issued 1 Airworthiness Directive
FAA issued 1 Emergency Airworthiness Directive
NTSB issued 7 Safety Recommendations

Show all...

Photos

photo of Boeing-737-7H4-N772SW
accident date: 17-04-2018
type: Boeing 737-7H4 (WL)
registration: N772SW
photo of Boeing-737-7H4-N772SW
accident date: 17-04-2018
type: Boeing 737-7H4 (WL)
registration: N772SW
photo of Boeing-737-7H4-N772SW
accident date: 17-04-2018
type: Boeing 737-7H4 (WL)
registration: N772SW
photo of Boeing-737-7H4-N772SW
accident date: 17-04-2018
type: Boeing 737-7H4 (WL)
registration: N772SW
photo of Boeing-737-7H4-N772SW
accident date: 17-04-2018
type: Boeing 737-7H4 (WL)
registration: N772SW
photo of Boeing-737-7H4-N772SW
accident date: 17-04-2018
type: Boeing 737-7H4 (WL)
registration: N772SW
photo of Boeing-737-7H4-N772SW
accident date: 17-04-2018
type: Boeing 737-7H4 (WL)
registration: N772SW
photo of Boeing-737-7H4-N772SW
accident date: 17-04-2018
type: Boeing 737-7H4 (WL)
registration: N772SW
photo of Boeing-737-7H4-N772SW
accident date: 17-04-2018
type: Boeing 737-7H4 (WL)
registration: N772SW
photo of Boeing-737-7H4-N772SW
 

Video, social media

Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not display the exact flight path.
Distance from New York-La Guardia Airport, NY to Dallas-Love Field, TX as the crow flies is 2204 km (1377 miles).
Accident location: Approximate; accuracy within a few kilometers.

This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.
languages: languages

Share

Boeing 737-700

  • 1160+ built
  • 4th loss
  • 2nd fatal accident
  • 2nd worst accident
» safety profile

The Aviation Safety Network is an exclusive service provided by:
Quick Links:

CONNECT WITH US: FSF on social media FSF Facebook FSF Twitter FSF Youtube FSF LinkedIn FSF Instagram

©2024 Flight Safety Foundation

1920 Ballenger Av, 4th Fl.
Alexandria, Virginia 22314
www.FlightSafety.org