Boeing and its future

The recent two crashes could lead to better coordination between regulators and thorough review of the certification processes

The latest news about Boeing’s 737 Max indicates the grounded airliner could have more defects that may lead to it being indefinitely grounded. Two fatal crashes have been attributed to a flawed software controller system, the MCAS (Man­oeuvring Characteristics Aug_mentation System), which is undergoing a complete overhaul.
 
In addition, there may have been faulty microprocessors that compounded the MCAS issues with the MCAS, and there may be defective wing components that will need replacement in many aircraft of the 737 class, including the Max series.
 
The Allied Pilots Association is considering suing Boeing. The American safety regulator,  the Federal Aviation Administration (FAA), may end up reviewing its certification processes. Other national aviation safety regulators may either check the 737 Max independently, or coordinate with the FAA during the re-certification process as the EU, Brazil and Canada are doing.

 

The MCAS was designed to prevent stalling. In wind tunnel experiments, Boeing engineers had discovered the aircraft tended to stall when the “angle of attack” hit a certain level. The angle of attack is the angle made by the wing and oncoming airflow — this varies as the nose is pointed up or down during flight. The MCAS was supposed to diagnose when the angle hit unacceptable levels when it would activate a physical control in the tail, pushing the tail up and pushing the nose down.
 
Problems with MCAS led to the Ethiopian Air and Lion Air crashes where 346 people died. The MCAS is designed to activate on the basis of data from sensors that monitor air speed, and angle of attack, and so on.

 
But it can activate on the basis of false data from a single faulty sensor. In both crashes, it was triggered by a single sensor and the MCAS repeatedly forced the nose down even though the planes weren’t stalling. That caused steep dives. A rejig of the software will involve the MCAS being modified to ensure that a single sensor cannot trigger the system; it will have to be based on data from at least two sensors. 
 
There were other issues with the MCAS. One was that it assumed the pilot could take corrective action within three seconds. This time span is based on the FAA regulations but it may be too short. Boeing is likely to reduce the power of MCAS as well as to try and obviate steep dives.

 
Boeing was in a hurry to get the Max series certified and cut corners in terms of explaining it to pilots. Pilots trained on the earlier 737 series, which did not have this problem, were given training on an iPad programme rather than a full simulator. The aircraft was offered at a substantial discount to airlines, which did not insist on simulator training for pilots.
 
Hence pilots did not know much about MCAS and indeed, the two crashes may have occurred due to their being unaware of the MCAS and unable to shut it down and take manual control. Senior pilots who have tested the system subsequent to the crashes say that surprised pilots may have taken too long to cope with the emergency. This lack of briefing and training are asking the reasons why pilots are threatening legal action against Boeing.

 
In simulator exercises after the crash, pilots also discovered that microprocessors failure could lead to nosedives. Although faulty microprocessors may not have been responsible for the fatal crashes, there would have to be physical inspections of the MCAS hardware and failsafes must be built into the new MCAS system which Boeing is working on.
 
A new component fault has surfaced. A component called a leading edge slat track that is placed on the wings may have been defective in several batches of 737 Max and the earlier 737 NG series. Although the company claims this is not dangerous, these components are being checked and replaced, with Boeing issuing an advisory for airlines using NG series (these are not grounded). This component is used to control the aerodynamics of the wing surface and if these slats crack, or prove to be faulty, there would be damage to the aircraft. The FAA has asked airlines to carry out inspections within 10 days.

 
The one outcome of those two crashes is that it could lead to thorough review of the certification processes and better coordination between regulators. It’s likely that pilots will receive better training in future. Boeing has suffered huge loss of reputation and taken a beating at the stock market as the damaging information had surfaced. This would also be a disincentive for aircraft manufacturers to cut corners in future.