The Boeing 737 MAX disasters changed aviation forever. Two crashes within five months killed 346 people, both caused by a flight control software system that Boeing designed, the FAA certified, and airlines deployed without adequate understanding of its dangers. The MCAS system has become synonymous with the risks of software-dependent flight control and the devastating consequences when that software fails.
These tragedies also transformed aviation product liability. The MCAS litigation established precedents for software defect claims that will shape cases for decades. Understanding how these claims work—and what made MCAS litigation successful—helps victims of future flight control software failures pursue accountability and compensation.
How MCAS Failed
The Maneuvering Characteristics Augmentation System was designed to address handling differences between the 737 MAX and earlier 737 models. Larger, more efficient engines changed the aircraft's aerodynamic characteristics, creating a tendency to pitch up at high angles of attack. Rather than requiring extensive pilot retraining that might make the MAX less attractive to airlines, Boeing designed MCAS to automatically push the nose down when sensors detected high angle of attack.
The system's design contained fatal flaws. MCAS relied on a single angle-of-attack sensor rather than cross-checking multiple sensors. When that single sensor failed—as happened on both crashed aircraft—MCAS received false readings indicating the nose was too high. The system repeatedly pushed the nose down, eventually overpowering pilot attempts to recover. The aircraft dove into the ground because software designed to prevent one problem created a worse one.
Boeing compounded the design problems through inadequate disclosure. Airlines and pilots weren't told about MCAS or its potential to take control authority from pilots. Training materials didn't address how to recognize or respond to MCAS malfunction. When the system activated unexpectedly, pilots had no knowledge or training to understand what was happening or how to stop it.
Legal Theories in MCAS Litigation
The MCAS claims combined multiple product liability theories. Design defect claims focused on the decision to rely on a single sensor, the system's authority to override pilot inputs, and the absence of pilot notification when MCAS activated. These design choices made the system unreasonably dangerous when sensors failed—a foreseeable condition that the design should have anticipated and accommodated.
Failure to warn claims addressed Boeing's concealment of MCAS from pilots and airlines. Pilots cannot respond appropriately to systems they don't know exist. By hiding MCAS—allegedly to minimize training differences from earlier 737 models—Boeing ensured pilots couldn't recognize or respond to malfunctions. The failure to disclose was itself a defect that contributed to both crashes.
Evidence emerged that Boeing knew about MCAS risks before the crashes. Internal communications showed engineers raising concerns that were dismissed. Test flights revealed problematic system behavior. The FAA's certification process relied heavily on Boeing's own assessments, which allegedly minimized known risks. This evidence supported not just compensatory claims but punitive damages for knowing disregard of safety.
Broader Implications for Flight Control Software
MCAS represents one example of a broader trend toward software-intensive flight control. Modern aircraft—especially the fly-by-wire systems used in most contemporary designs—depend on software to translate pilot inputs into control surface movements. These systems provide benefits: improved handling, envelope protection, and reduced pilot workload. They also create risks when software fails or behaves unexpectedly.
Flight control software failures can occur in any aircraft with fly-by-wire systems. Airbus aircraft have experienced uncommanded control inputs from software malfunctions. Business jets have crashed when flight control computers failed. As software complexity increases, the potential for undiscovered bugs and unexpected interactions grows. MCAS-style failures are not unique to Boeing—they represent a category of risk inherent in software-dependent flight control.
The certification process for flight control software has come under scrutiny following the MAX crashes. Regulators are requiring more rigorous testing, more independent validation, and more transparency about software capabilities and limitations. These changes may reduce future failures but don't eliminate them. When failures occur despite improved processes, product liability provides the mechanism for accountability.
Proving Software Design Defect
Establishing that flight control software was defectively designed requires demonstrating that a reasonable alternative design would have prevented the failure. For MCAS, the alternatives were obvious: use multiple sensors with cross-checking, limit system authority, provide pilot notification and override capability. Boeing chose not to implement these alternatives for reasons of cost and schedule rather than safety.
Expert testimony is essential in software design defect cases. Aviation software experts can explain how the system was supposed to work, what design choices created vulnerabilities, and what alternatives were available. Human factors experts address how pilots interact with automated systems and why inadequate notification or training contributed to the crashes. Technical expertise translates complex systems into terms juries can understand.
Discovery in these cases seeks internal documents showing what the manufacturer knew about risks and what alternatives they considered. Email communications, engineering analyses, test results, and meeting notes may reveal that manufacturers prioritized concerns other than safety. This evidence supports not just defect claims but punitive damages when it shows knowing disregard of risks.
Manufacturer Defenses and How to Overcome Them
Aircraft manufacturers raise predictable defenses in flight control software cases. They argue that FAA certification proves the system wasn't defective—regulators reviewed and approved the design. They blame pilots for failing to respond appropriately. They claim software complexity makes perfect safety impossible and that their systems met the state of the art.
These defenses have weaknesses. Certification doesn't preclude defect findings—it establishes minimum standards, not necessarily reasonable care. Pilot response claims fail when manufacturers concealed information pilots needed. State of the art arguments don't excuse failing to implement known safeguards that would have prevented accidents. Effective plaintiffs' counsel anticipates and counters these defenses with evidence and expert testimony.
The MCAS litigation showed that manufacturer defenses can be overcome even against the world's largest aerospace companies. Boeing ultimately paid billions in settlements and criminal penalties. The evidence of internal knowledge, dismissed warnings, and concealment from regulators proved overwhelming. When documentation reveals that manufacturers knew better and chose worse, their defenses crumble.
Pursuing Flight Control Software Claims
Victims of crashes potentially caused by flight control software failures should engage specialized aviation attorneys promptly. These cases require understanding of both aviation systems and product liability law. They involve technical discovery that must be directed by attorneys who understand what to seek. Expert retention, evidence preservation, and strategic positioning all benefit from early engagement.
Flight data recorders and cockpit voice recorders provide essential evidence of how software systems behaved before crashes. This data must be obtained from investigators and analyzed by experts who can interpret what the systems were doing. Software source code may need to be examined to understand why systems behaved as they did. Technical evidence requirements in these cases are substantial.
The legacy of the MAX crashes is that software failures in flight control systems create substantial manufacturer liability. When the code that controls aircraft proves defective and people die as a result, the manufacturers who created that code bear responsibility. MCAS established that even the largest manufacturers can be held accountable when their software kills.