Why Airlines Are Allowed to Fly With Broken Parts - And Why It’s Still Safe
If you believe an aircraft must be 100% perfect to be allowed to fly, aviation will surprise you. Every day, commercial airliners depart with inoperative systems, missing panels, or disabled components - and they do it legally, safely, and by design . This is not negligence. It is called controlled unserviceability - a core principle of modern aviation safety. To understand it, we need to look at the four documents that quietly keep global air transport moving: MMEL MEL CDL NEF Together, they form the backbone of airline dispatch reliability . What “Airworthy” Really Means An aircraft is airworthy when: It conforms to its approved type design , and It is in a condition for safe operation Normally, if something breaks, the aircraft is no longer airworthy. But aviation doesn’t operate in a perfect world - systems fail, light bulbs burn out, sensors misbehave. So regulators allow approved deviations from the type design - but only under strict engineering control. That’s where...