As if the 737 and Boeing haven’t had enough bad news, the US National Transport Safety Bureau has told Boing it must redesign the engine housing and replace it on all 737NG’s.
The NTSB found that the engine nacelle was flawed and failed to contain fan blades if they broke off, for instance in a bird strike.
The casing didn’t contain the blade well enough an the casing itself broke off, and it was able to strike the pressurised cabin with sufficient force to cause penetration, depressurisation and passenger injury.
This has already happened on a 737NG owned by Southwest and resulted in the death of a passenger.
There are around 7,000 NG versions that will need retrofitting: some 14,000 engine casings. It’s the same version that is suffering from the pickle fork crack issues.
This means Boeing will have to design, test and retrofit at its own expense in a given time frame yet to be agreed.
The NTSB was made effective in transport safety through activist Ralph Nader in the 1970’s. It’s no sad irony that his granddaughter was killed in the 737MAX crash in Ethiopia last year.