WASHINGTON — Airline regulators will not be rushed into clearing grounded Boeing 737 Max 9 planes after a mid-air blowout, the US government has said. The aircraft, which were suspended in the US following an incident on an Alaska Airlines flight "need to be 100% safe", said Transportation Secretary Pete Buttigieg. It is unclear when the planes will be allowed to fly again. Boeing"s boss, Dave Calhoun, described the incident as a "quality escape". It means the incident was caused by some failure in quality control. The US Federal Aviation Administration (FAA) grounded 171 Boeing jets on Saturday that were installed with the same panel after the Alaska Airlines flight was forced to make an emergency landing on Friday. No-one was injured when the unused cabin door broke away from the Alaska Airlines flight from Portland, Oregon. Mr Buttigieg declined to say when the suspension will end. "The only consideration on the timeline is safety," he said. "Until it is ready, it is not ready. Nobody can or should be rushed in that process." Alaska Airlines has cancelled about 20% of its flights after 65 of its Max 9s were grounded. United Airlines, the other US 737 MAX 9 operator, has 79 of the planes in its fleet out of action. It said it expects "significant" cancellations on Thursday after 167 flights did not go ahead on Wednesday. — BBC