LE BOURGET, France efforts to get
737 MAX jetliners back in the air have been delayed partly by concerns about whether the average pilot has sufficient physical strength to turn a manual tissue into extreme emergencies.
The problem that has not previously been reported has been the focus of weeks of engineering analysis, simulator sessions and flight testing by the aircraft manufacturer and US aviation security officials according to people familiar with the details.
Turning the tissue moves a horizontal panel on the tail, which can help change the angle of the planet's nose. Under certain conditions, including at extremely high speeds with the panel already at a steep angle, it may take a lot of effort to move the tissue in some emergency situations. Among other things, the people who are familiar with the details tell that regulators are worried about whether female carriers ̵
The analysis has been further complicated because the same emergency procedure applies to the generation of jetlines that preceded MAX, known as 737 NG. About 6,300 of these aircraft are used by more than 150 carriers globally, and they are the backbone of short and medium-sized fleets for many carriers.
Neither Boeing nor regulators foresee design or equipment changed as a result of the notification, these people said. But the question has forced a reassessment of some security assumptions for all 737 models.
The global MAX fleet of approx. 400 aircraft were founded in March after two deadly nose-dives triggered by an automated flight management system called MCAS. The two crashes killed a total of 346 people.
Boeings 737 MAX evolved to meet the increasing international demand for air travel and became the best-selling aircraft. WSJ's Jason Bellini looks at how the foundation of the fleet after the Ethiopian Airlines crash could have a significant impact on Boeing's future. Photo: Getty
There are no plans to limit some pilots from coming under control of any 737 models based on their strength, according to people with knowledge of the considerations. However, both Boeing and Federal Aviation Administration leaders are concerned that if such discussions become public, they may be overloaded or sensationalized according to industry and officials familiar with the process.
All 737 MAX's underlying security issues need to be resolved before the FAA can put the founding fleet back in the air, according to US and European aviation officials.
In response to questions, a Boeing spokesman said: "We will provide the FAA and global supervisors with the information they need." Previously, Boeing has said that it provides additional information on "how pilots interact with air traffic controllers and show in different flight scenarios."
Speakers before the Paris Air Show this week, Boeing CEO Dennis Muilenburg said he wanted to do an "end-to-end, comprehensive review of our design and certification processes" as well as other issues.
An FAA spokesman refused to comment on specifications. Former acting FAA chief Daniel Elwell said the agency is pursuing a full study of the two MAX crashes and is looking at everything, including emergency procedures, training and maintenance.
FAA experts also seek to assess how pilot strength issues were addressed during certification approvals of older versions of 737, according to the people familiar with the specifications.
Simulator sessions and flight tests have measured the strength required to turn the tissue into different flight conditions for pilots of both sexes, according to two of the details of the details.
At this time, according to the known people with specifications, government and industry experts are considering potential operational, training and pilot manual changes to address security issues. The results are expected to be included in a package of revised software and training mandates that the FAA is expected to issue later this summer.
The ongoing software fix is intended to make it easier for pilots to override the MCAS, which moves horizontally the tail panel called a horizontal stabilizer to point the nose.
The emergency procedure under control is the last step in a checklist to counter dangerous horizontal stabilizer movements that can be caused for a number of reasons, including an error in MCAS.
FAA testing comes after the Agency has asked Boeing to prepare a new safety assessment for MCAS and the emergency procedure, according to US and European aviation officials.
FAA is not alone in documenting the differences in average strength between men and women in critical security roles. The Pentagon, for example, categorizes such information into the assessment of the suitability of some uniformed individuals for specific tasks.
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