The 737 Next Generation (737NG) nacelle design has undergone a thorough modification by Boeing, with the goal of improving the aircraft’s resistance to broken fan blades. To address human-caused failures, including accidentally unlatched doors, the aerospace giant has indicated a need for prolonged deadlines, according to a report.
In a recent regulatory filing dated July 19, Boeing reaffirmed its commitment to meeting the FAA’s upcoming July deadline for introducing design changes. This action was motivated by two safety incidents involving Southwest Airlines 737-700s in which detachable nacelle pieces caused unexpected aircraft damage.
The NTSB suggested that the FAA mandate redesigns of the 737NG-family nacelle that take into account analytical modelling established since the aircraft was certified in the 1990s, and then see to it that the improvements are retrofitted on the 737NG fleet. This recommendation was made in 2019. The FAA and Boeing have been cooperating for almost four years.
Boeing stated in its most recent filing that by July 31, 2023, it would have submitted all design modifications to the FAA and would have issued service bulletins to provide inlet, fan cowl, fan cowl support beam, and exhaust structure modifications for retrofit of these modifications.
Boeing has determined that an extra 17 months will be required to develop a corrective strategy for these maintenance problems. The company is satisfied that its nacelle modifications adhere to the relevant Part 25 requirements.
As a result of the two FBO accidents, one of which had fatal repercussions and resulted in a passenger losing their life, engine manufacturer CFM modified inspection standards and blade life restrictions. These new procedures are a complement to those changes. Boeing has explained its plan to the FAA, highlighting the fact that their combined efforts are intended to reduce the possibility and effects of future FBO accidents.