The Boeing 737 MAX: Is the problem with the plane or the pilots?
ADDIS ABABA, Ethiopia - It’s a new airplane from one of the world’s premier manufacturers, and two have fallen from the sky within five months of each other, killing 346. The causes and the question of whether the accidents are related are of intense concern to travelers, airlines and Boeing, whose stock dropped 5% Monday, a day after the crash of an Ethiopian Airlines 737 MAX 8 that prompted China, Indonesia and a handful of airlines in other countries to ground the plane, reports Jeremy Bogaisky for Forbes.
The Intelligent Aerospace take:
March 12, 2019-China, which has purchased 95 of the 370 Boeing MAX 8 currently in use around the globe, has grounded all of the medium-haul jets. China is joined by a handful of other countries in grounding the jets, including Indonesia, which suffered a similar tragedy this past fall when a Lion Air crash resulted in the deaths of 189 people. The U.S. Federal Aviation Administration were among the majority of agencies and nations who declined to ground the planes.
“Right now the facts don’t support grounding the airplane,” John Goglia, a former accident investigator and board member at the U.S. National Transportation Safety Board, told Forbes.
On March 10, Boeing released a statement on the Ethiopian Airlines Flight 302 crash, writing: "Boeing is deeply saddened to learn of the passing of the passengers and crew on Ethiopian Airlines Flight 302, a 737 MAX 8 airplane. We extend our heartfelt sympathies to the families and loved ones of the passengers and crew on board and stand ready to support the Ethiopian Airlines team. A Boeing technical team will be traveling to the crash site to provide technical assistance under the direction of the Ethiopia Accident Investigation Bureau and U.S. National Transportation Safety Board."
The following day, Boeing announced that it would be enhancing the software on the 737 MAX while reiterating that the 737 was safe. "Safety is a core value for everyone at Boeing and the safety of our airplanes, our customers’ passengers and their crews is always our top priority, wrote the company. "The 737 MAX is a safe airplane that was designed, built and supported by our skilled employees who approach their work with the utmost integrity.
For the past several months and in the aftermath of Lion Air Flight 610, Boeing has been developing a flight control software enhancement for the 737 MAX, designed to make an already safe aircraft even safer. This includes updates to the Maneuvering Characteristics Augmentation System (MCAS) flight control law, pilot displays, operation manuals and crew training. The enhanced flight control law incorporates angle of attack (AOA) inputs, limits stabilizer trim commands in response to an erroneous angle of attack reading, and provides a limit to the stabilizer command in order to retain elevator authority.
Boeing has been working closely with the Federal Aviation Administration (FAA) on development, planning and certification of the software enhancement, and it will be deployed across the 737 MAX fleet in the coming weeks. The update also incorporates feedback received from our customers.
The FAA says it anticipates mandating this software enhancement with an Airworthiness Directive (AD) no later than April. We have worked with the FAA in development of this software enhancement.
It is important to note that the FAA is not mandating any further action at this time, and the required actions in AD2018-23.51 continue to be appropriate.
A pitch augmentation control law (MCAS) was implemented on the 737 MAX to improve aircraft handling characteristics and decrease pitch-up tendency at elevated angles of attack. It was put through flight testing as part of the certification process prior to the airplane entering service. MCAS does not control the airplane in normal flight; it improves the behavior of the airplane in a non-normal part of the operating envelope.
Boeing’s 737 MAX Flight Crew Operations Manual (FCOM) already outlines an existing procedure to safely handle the unlikely event of erroneous data coming from an angle of attack (AOA) sensor. The pilot will always be able to override the flight control law using electric trim or manual trim. In addition, it can be controlled through the use of the existing runaway stabilizer procedure as reinforced in the Operations Manual Bulletin (OMB) issued on Nov. 6, 2018.
Additionally, we would like to express our deepest condolences to those who lost loved ones on Ethiopian Airlines Flight 302. A Boeing technical team is at the crash site to provide technical assistance under the direction of the Ethiopia Accident Investigation Bureau and U.S. National Transportation Safety Board. It is still early in the investigation, as we seek to understand the cause of the accident."
Jamie Whitney, Associate Editor
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