Engine failure due to fatigued engine blade

Engine failure

FAA began working on a directive that would mandate a greater frequency of inspections.(Directive was not implemented till after the incident thus due to the long process of implementation is another reason that led to the incident)

Manufacturer and the general public, U.S. carriers, including Southwest, were already performing more frequent inspections based off the engine maker's warning the blades in the engines could crack

(No standard operating procedure was issued about such further inspections)

Emergency landing procedure

HAZARD:

Fatigue Engine Blades

Pre-existing maintenance checks required by engine manufacturer during scheduled checks and pre and post flight checks.

Poor implementation by FAA

There are instrument manuals and checklist to ensure every part is have been checked for damage

Engineers maintaining the aircraft inspect and check for damage before and after flights

Prior inspections such as it underwent detailed fluorescent penetrant and visual inspections as well as full overhauls in November 2012

Poor design of engine blade (prone to cracking)

Clear runway for the aircraft

First aid facilities

Seatbelt

Crashing on the runway, passengers and crew will be injured if landing was executed poorly.

After the crash in 1953, it is determined that fatigue cracks began to spread through the plane's metal skin because the stress was concentrated at the corners of its squarish windows. That is why aircraft windows now are designed with a rounded shape.

The blade should have been stopped by a surrounding containment ring

The material used for containment ring is a band of durable material such as Kevlar

Fragments of engine cowling shattering compromising aircrafts integrity and passengers safety such as windows

Southwest said it would inspect all its engines, but the company has not said if it had started or completed any checks prior to the accident

All airlines, within six months, to ultrasonically inspect fan blades on CFM56-7Bs that had accumulated more than 15,000 cycles since their last shop visit. Engines with less than 15,000 cycles would need inspections within 18 months

The directive will require an ultrasonic inspection of fan blades when they reach a certain number of takeoffs and landings. Any blades that fail the inspection will have to be replaced

Rupturing of the cowl (likely responsible for the damage to the aircraft's fuselage, wing and stabiliser)

An emergency airworthiness directive issued by the US Federal Aviation Administration on 20 April calls for a one-time ultrasonic inspection of fan blades on all CFM56-7B engines with 30,000 or more accumulated flight cycles since delivery within 20 days

CFM revised its overhaul procedures, adding eddy current inspections

There should be a set of timeline duration for rulemaking processes.

(because this time they took 2 years to implement. Only effectively put it into place due to accidents)

Lapses in checks such as human factors may lead to undetected cracks which may cause similar accidents to happen

Have better trainings for pilots especially for emergency scenarios like engine failures

Every pilot must be certified and be confident in handling situations when one of its engine fail

Implementation of mandatory refresher emergency course on a yearly basis

Modern engine design allows aircraft to be flown even with one working engine

Aircraft goes into a nose dive that lead to an air crash.

References

http://www2.philly.com/philly/health/southwest-philadelphia-1380-metal-fatigue-engine-failure-20180418.html

https://www.mro-network.com/safety-regulatory/inspection-procedures-emerge-focus-cfm56-7b-failures

https://abcnews.go.com/Politics/fatal-accident-senators-faa-speed-aviation-safety-directives/story?id=55417999