The Federal Aviation Administration (FAA) on Tuesday officially notified operators of Boeing 737 Next-Generation jets to inspect to inspect them for structural cracks and make any necessary repairs.
The October 1 directive affects 752 model 737-700C, -800 and -900 series airplanes. How long airlines and other operators will have to comply has yet to be determined.
In a statement provided by the FAA to news organizations, the agency said cracks in the “bear straps” – large pieces of reinforcing sheet metal fastened around the doors – were discovered by Boeing [NYSE: BA] while conducting modifications of a heavily used aircraft. Subsequent inspections uncovered similar cracks in a small number of additional airplanes.
News of the potential problem began surfacing over the weekend in media reports.
The Federal Register notice states the inspections were ordered because the unsafe condition “is likely to exist or develop in other products of the same type of design.” The combined cost to industry of the inspections is estimated at about $1 million.
The Boeing 737 is one of the airline industry’s primary passenger workhorses for short-to-medium hauls. Newer models, like those subject to the FAA order, are more fuel efficient and technically advanced. But they only carry about 2.4 percent of domestic air cargo volume, based on FreightWaves analysis of data from the U.S. Bureau of Transportation Statistics. The average 737 carries about 350 pounds of cargo, according to industry experts.
The inspections come at an inconvenient time for Boeing, which is scrambling to fix flight system software that was blamed for the deadly crashes of two 737 MAX jets last year and led global regulators to ground the entire fleet. The Chicago-based aircraft manufacturer is still building MAXs at a slower rate, but can’t deliver them to customers, many of whom are seeking compensation for lost revenue from canceled flights.
Development of the next-generation 777X widebody jetliner has been delayed by problems with its GE engines and Boeing is now trying to figure out what went wrong during a load test, when a door blew out under extreme pressurization beyond what normally occurs during flight.
Last week, the U.S. National Transportation Safety Board (NTSB) recommended that the FAA change the way it reaches assumptions about how pilots react to warning signals from the flight control system as part of an airplane’s certification. The fuel-efficient design of the MAX changed the wing position, which can cause the nose to pitch up too much during takeoff. Boeing added anti-stall software, known as MCAS, to automatically push the nose back down, but investigations revealed pilots were not fully aware of the system adjustment or how to respond if the software over corrected.
The NTSB expressed concern that pilot responses to unintended adjustments by the automated maneuvering system differed from Boeing and FAA assumptions. It said the FAA should provide clearer guidance about how to consider pilot response to multiple flight-deck alerts and then address any gaps in design, procedures and training.
On Monday, September 30, Boeing CEO Dennis Muilenburg implemented several board recommendations related to safety following a five-month internal review of company policies and design processes following the Lion Air and Ethiopian Airlines accidents.
Boeing has created a new Product and Services Safety organization tasked with unifying safety-related responsibilities currently managed by teams across several Boeing businesses and operating units. The organization is responsible for reviewing all aspects of product safety, including investigating cases of undue pressure and anonymous product and service safety concerns raised by employees. Co-leader Beth Pasztor, a Boeing vice president, will also oversee the company’s accident investigation team and safety review boards.
Boeing is also realigning its organization so engineers report to one person and taking steps to reinforce how it manages safety across the company and its supply chain, including expanding use of safety review boards and increased investments in enhanced flight simulation and computing capabilities.
Boeing said that over the past several weeks software engineers have run 390,000 flight hours on the 737 MAX – the equivalent of flying 45 years.
