Boeing 737 Max 9: United and Alaska Airlines discover multiple loose bolts on planes after mid-flight blowout

Multiple loose parts have been found by United Airlines and Alaska Airlines on Boeing 737 Max 9 aircraft - the model that was involved in the window blowout incident that occurred last Friday (5 January). Yesterday (Monday 8 January) Alaska Airlines reported that a preliminary investigation by its technicians had revealed the presence of “loose hardware” on certain aircraft during routine fleet checks.

Formal inspections are pending, awaiting final documentation from Boeing and The Federal Aviation Administration (FAA). The FAA grounded all models of the aircraft following the emergency on an Alaska Airlines flight from Portland which saw a large part of the fuselage ripped out shortly after take-off.

The models of the aircraft have been grounded for safety checks. United Airlines said in a statement. “Since we began preliminary inspections on Saturday, we have found instances that appear to relate to installation issues in the door plug. For example, bolts that needed additional tightening. These findings will be remedied by our Tech Ops team to safely return the aircraft to service.”

It has also been revealed by a US official that a warning light had come on in the plane that was involved in the incident days before it happened. At the time of the incident the plane had been restricted from making flights to Hawaii, after a warning light that could have indicated a pressurisation problem lit up on three different flights. However it remains unclear whether there was any connection between those incidents and Friday’s rapid depressurisation incident.

The Alaska Airlines incident is the latest in a series of safety problems for the Boeing 737 Max aircraft. The aircraft were grounded around the world after two catastrophic crashes in 2018 due to an automated flight-control system called MCAS resulting in 346 fatalities. The 737 Max has also experienced problems with the rudder control system and anti-ice systems.

Yesterday Alaska Airlines cancelled 141 flights and the airline says it expects travel disruptions to continue until at least mid-week. United Airlines, which grounded its 79 Max 9s, cancelled 226 flights on Monday, about eight per cent of its scheduled departures.