Two accidents of the Boeing flagship aircraft in the 1990s and lawsuits awarding damages worth USD 25.5 million reveal shocking truths about the Boeing Company. The Seattle Times reported the company’s long-standing awareness of the rudder’s propensity to deflect on its own. What’s more, the papers released by the court show Boeing discovered in the early 1980s, that there was little pilots could do to recover from some rogue deflections, yet failed to point out the significance of that finding to safety regulators and airlines.
Boeing insists it did nothing wrong, and everything was done as was required to by federal safety regulations.
The Lion Air B-737 Max accident in Indonesia has drawn the attention towards a similar technical issue. The Maneuvering Characteristics Augmentation System (MCAS) was a design feature incorporated in the ill- fated Lion Air B-737 Max but the pilots did not know about it. The larger engines of the B-737 Max required the airframe to be modified as had been carried out by the Airbus on the A320-NEO. Due to the bigger size of the engines, the Airbus redesigned the wing and raised the nose thereby, altering the centre of gravity slightly, which affects the balance of the aircraft. Boeing, on the other hand, did not re-design the wing but raised the nose and introduced a design feature called MCAS, which would compensate for the change in the aircraft balance and the tendency for the nose to pitch up. The MCAS, whose function was to prevent an excessive nose up pitch, may have malfunctioned-possibly leading to the aircraft pitching down, leaving the crew in a confused state.
The Boeing-737 has been the best selling aircraft in history having taken 14,985 orders till October 2018. Boeing delivered the 10,000th B737 to Southwest Airlines in April 2018. Work on B-737 was started in 1964 and the 1st aircraft flew in 1967. After the huge commercial success of B-737, the Boeing company has another best seller, the B-777 which is about 2,000 aircraft orders behind.
Boeing introduced variants of the B-737 from 1971 onwards to cater for safety, aerodynamic and fuel efficiency issues. The latest variant, the Boeing 737 Max was launched in May 2017.
Technology changes with time, and industry has to keep pace with developments. This is because they have to keep up with the competitors and maintain the superior edge in-terms of hardware and software advances. All these developments and changes have to be made within the purview of the safety bubble. The manufacturer cannot afford to compromise the safety of the passengers, crew and the aircraft in any way. There are detailed systems and processes, which test each system for robustness and reliability. The regulator, who has the final authority and is responsible for safety gives the go ahead when they are convinced beyond doubt that the probability of a failure is kept to the minimum acceptable level.
The B-737 has had a series of technical issues with the aircraft rudder. The Seattle Times has given the chronology of the events, reproduced below:
“The B-737 started having technical issues beginning 1969 after Boeing issued service bulletin regarding rudders moving inadvertently. Between 1980-90 pilots filed hundreds of reports. The pilots reported rudder problems but Boeing blamed the yaw damper. There were two accidents:
- March 3, 1991: On final approach into Colorado Springs, United Flight 585 rolls right and takes a steep drop. All 25 on board die.
- Sept. 8, 1994: Descending in calm skies, USAir Flight 427 peels left and dives into a wooded ravine near Pittsburgh. All 132 on board die.
November 1994: Boeing issued instructions for 737 pilots to shut off yaw damper if a jet veers slightly left or right. A series of tests and modifications were carried out thereafter.
Nov. 1, 1996: Boeing issued a service bulletin recommending that airlines operating 737s test the rudder power-control units of their aircraft to detect a potential jam condition.
After the Lion Air B-737 Max accident 24 years later, Boeing issued a service bulletin followed by a FAA emergency directive.
Nov 2018, Boeing issued a service bulletin informing the crew of uncommanded nose down Stabilizer trim due to Erroneous Angle of Attack during manual flight.”
Above: Extract of the US court ruling
If what the Seattle Times reported, after the US Air 427, as per documents in their possession, after being released by court and the Lion Air 610 accident, is true, there seems to be an issue with respect to ethics rather than with safety. Boeing is a commercial organization, which manufactures the B-737, however there is a dire need to look beyond the balance sheet and commitment to safety. The commitment to safety pays off in the long run, if it becomes a habit and no corners are cut when safety issues are identified. The debate about safety and ethics is for the readers to decide by carrying out more research prior to forming an opinion.