The safety record of commercial aviation is unmatched by any other form of mass transportation. Decades of stringent safety protocols, advanced technological innovations, and rigorous pilot training have contributed to making flying one of the safest ways to travel. With the implementation of regulations from governing bodies such as the Federal Aviation Administration (FAA) and the International Civil Aviation Organization (ICAO), the industry has been able to maintain a high level of safety standards. Additionally, continuous improvements in aircraft design and maintenance procedures have played a crucial role in ensuring the safety of passengers and crew members. Overall, the dedication to safety within the aviation industry has solidified its reputation as a reliable and secure mode of transportation.

However, some organizations have begun to argue for lowering the number of flight crew members on large aircraft, possibly to just one pilot. Those who support single-pilot flights say that reducing crew size will result in cost savings and are looking for ways to advance the concept of “extended Minimum Crew Operations” (eMCO). Those promoting single-pilot operations argue that reducing crew size will lead to cost savings. However, the current body of evidence and experience, including more than a decade of study by the National Aeronautics and Space Administration (NASA) and the Federal Aviation Administration (FAA), shows that the safety risks and challenges associated with single-pilot operations far outweigh the potential benefits.  (Air Line Pilots Association, Int’l, 2019)

Under the proposed eMCO model, a single pilot could be the lone pilot on duty in a commercial airplane under certain conditions using cutting-edge automation and ground support. This marks a fundamental shift in how commercial flights operate. This concept has created a debate in the aviation community about how to strike a balance between technical innovation and the preservation of safety standards, which have long been the foundation of the industry's success. There are several reasons why two highly trained and competent pilots are required to ensure aviation safety, and it is imperative that regulators critically examine the safety implications of eMCO. This includes considering the potential risks and implementing the necessary regulations to maintain the highest level of safety in aviation.

The eMCO concept aims to stretch the maximum Flight Time Limitations (FTLs). To achieve this, only one pilot would be required to remain at the controls for extended periods of the cruise phase while the other pilot would be resting most likely in an area out of the flight deck, thus allowing for fewer total pilots to operate long-duration flights.  (European Union Aviation Safety Agency. (2023). eMCO-SiPO, D-2.2 Detailed Research and Test Activity Plan.)

The Concept of Operation for eMCO

The following fundamental concepts have been proposed as the foundation for the development of the eMCO concept of operation:

• eMCO is only used on aircraft that have been certified as being capable of eMCO, which means that they offer specific design features that simplify the tasks of the pilot and reduce the workload, reduce the risk of error, enhance the aircraft's resilience in abnormal events, and provide the pilot with additional automation to manage aircraft failure and detect incapacitation.
• In the cockpit, a single pilot, who is referred to as "Pilot Flying," (PF) would be responsible for managing all or parts of the cruise phase.
• It is feasible to return to regular two-crew operations at any moment (with the exception of situations in which the pilot could become incapacitated).
• A precise route analysis, flight planning, crew scheduling, and flight dispatch all focus on precise eMCO means and demands, supporting the execution of the eMCO flight.
• The process of integrating eMCO into the existing Air Traffic Management (ATM) environment and processes would be carried out.
• On a particular aircraft, the same group of pilots would be trained to operate both traditional Minimum Crew Operations (MCO) flights and electronic Minimum Crew Operations (eMCO) flights.

Perceived benefits like cost savings, addressing pilot shortages, and improving human resource management in aviation are what are driving the development and evaluation of eMCO. However, the concept is still in the evaluation phase, with various stakeholders from regulatory bodies, pilot associations, and industry groups carefully examining its viability, safety implications, and the technological and procedural changes required to implement it. The safety implications of eMCO are significant, but there are also serious concerns regarding data security, pilot training requirements, and the impact on traditional crew resource management practices.

The aviation industry has a long history of embracing technological advancements to improve safety and efficiency. However, the introduction of eMCO represents a significant departure from the industry's traditional safety standards and practices. The safety of passengers and crew members must always be the top priority in aviation, and any changes to operational procedures must be thoroughly evaluated to ensure that they do not compromise safety. As the aviation industry continues to evolve, it is essential that regulators, industry stakeholders, and pilot associations work together to develop and implement innovative solutions that enhance safety while maintaining the industry's high standards of excellence.Regulatory bodies must work closely with industry stakeholders to ensure that any implementation of eMCO meets safety standards and does not compromise the overall effectiveness of flight crew procedures. As the evaluation process continues, it is essential for all parties involved to collaborate and communicate effectively to address any challenges and critically evaluate all safety implications to civil aviation.

Risks Associated with eMCO

The primary criticisms regarding eMCO revolve around the increased workload for a solo pilot and the elimination of monitoring redundancy that a two-pilot crew provides. Pilots are trained not only to fly but also to constantly monitor aircraft systems and the environment and to cross-check each other's actions for errors. Removing the co-pilot means removing this critical layer of safety redundancy.

In emergency situations, the value of having two pilots becomes even more apparent. Complex emergencies requiring quick, decisive actions could overwhelm a single pilot, whereas two pilots can divide tasks, share cognitive loads, and provide mutual support. This redundancy is crucial for maintaining safety in unforeseen circumstances.

Moreover, while automation has advanced significantly, it cannot replicate human judgment and adaptability. Pilots often must make nuanced decisions based on a combination of experience, intuition, and situational awareness—capabilities that current automation and AI technologies cannot fully replicate. The absence of this human element raises significant safety concerns. Therefore, having two pilots in the cockpit ensures that there is a human presence to make crucial decisions and respond effectively in emergency situations. Effective collaboration between two pilots fosters continuous communication and thorough cross-checking of each other's actions, significantly reducing the likelihood of errors. Ultimately, the combination of human judgment and automation technology is essential for maximizing safety and efficiency in aviation.

The Role of Automation in eMCO

The aviation industry has long embraced automation as a tool to enhance safety and efficiency. Autopilot systems, automated navigation, and advanced flight management systems have all contributed to reducing pilot workload and minimizing human error. eMCO relies heavily on the premise that further advancements in automation can compensate for the absence of a second pilot in the cockpit.

However, automation, regardless of its sophistication, has limitations. It operates within predefined parameters and lacks the ability to make judgment calls outside of its programming. Critical incidents in aviation history have underscored the necessity for human oversight to intercept when automated systems misinterpret sensor data or when unforeseen circumstances arise. The debate within the industry is not about the capability of automation but about its limits. Can it replace human insight and adaptability, especially in critical, high-stress scenarios?

Moreover, the reliance on automation introduces new challenges, including the risk of automation complacency, where pilots may over-rely on systems without maintaining situational awareness. The transition from automated flight back to manual control in emergency situations highlights the need for constant pilot engagement and proficiency, which might be compromised in an eMCO setup.

Cybersecurity Risks

Introducing Extended Minimum Crew Operations (eMCO) poses a unique set of cybersecurity risks, primarily because the scheme relies heavily on automation and, in many cases, remote connectivity to supplement or replace functions traditionally performed by the human crew. Here are the primary cybersecurity risks associated with eMCO:

1. Increased Attack Surface

   eMCO systems would likely require enhanced connectivity, both onboard and with ground operations, to support the single pilot or remote assistance. This increased connectivity potentially expands the attack surface, offering more opportunities for cyber attackers to exploit vulnerabilities in communication channels and onboard systems.

2. Dependence on Remote Communication Systems

   Remote support and control systems essential for eMCO operations depend on secure and reliable communication links. Cyberattacks aiming to obstruct communication, manipulate data, or gain unauthorized access to aircraft systems might target these systems. Interruptions or manipulations in communication could pose significant safety risks, especially in critical phases of flight or during emergency situations.

3. Automation and System Complexity

   The complexity of automated systems and their algorithms could be exploited by cyberattacks. Vulnerabilities in the software that governs automation could lead to unauthorized control of aircraft systems. The reliance on automation for critical flight operations in eMCO heightens the impact of such vulnerabilities.

4. Data Integrity and Manipulation

   The integrity of data is crucial for flight safety. Cybersecurity risks include the potential for malicious actors to manipulate data related to navigation, aircraft performance, or even the remote assistance systems. Ensuring the authenticity and accuracy of data exchanged between the aircraft, ground control, and remote support systems is paramount.

5. Insider Threats

   The shift to eMCO could also exacerbate risks associated with insider threats, where individuals with access to the systems (either onboard or remotely) could intentionally or unintentionally compromise security. The complexity and critical nature of the systems involved in eMCO make them particularly sensitive to insider threats.

6. Software and Hardware Security

   Ensuring the security of both the software and hardware components of eMCO systems is critical. This includes everything from the onboard flight control systems to the ground-based systems that provide remote assistance. Vulnerabilities in these components could be exploited to gain unauthorized access or disrupt flight operations.

7. Compliance and Standardization

   As eMCO represents a significant shift in how commercial aviation operations might be conducted, developing and enforcing cybersecurity standards specific to eMCO operations is challenging. The lack of standardized protocols could lead to inconsistencies in security practices, making some systems more vulnerable than others.

To counter these threats, rigorous cybersecurity measures, including advanced encryption, continuous monitoring of systems, regular security audits, and the development of robust incident response protocols, are essential. Furthermore, the design of eMCO systems must incorporate security by design principles, ensuring that cybersecurity considerations are integrated at every stage of system development and deployment. Collaboration among aviation authorities, technology providers, airlines, and cybersecurity experts will be crucial in addressing these challenges, ensuring that the implementation of advanced technologies do not compromise the safety and security of commercial aviation.

Mitigating cybersecurity risks associated with advanced technologies requires a multi-layered approach that addresses vulnerabilities in communication systems, automation software, data integrity, insider threats, and compliance standards. By implementing robust cybersecurity measures and fostering collaboration among industry stakeholders, regulators can lower cybersecurity vulnerabilities, but maintaining the high standards of aviation safety that passengers and crew members rely on requires the level of safety that two pilots working together provide.

Why Two Pilots are Essential

The presence of two pilots in the cockpit is not only a redundant measure; rather, it is an essential component of flight safety. Cross-checks are carried out between the two members of the crew in order to establish the foundation for the present idea of Threat and Error Management (TEM2). Present-day threat management, much like error management, is dependent on a two-pilot crew, with the roles of the Pilot Flying (PF) and Pilot Monitoring (PM) being assigned to each member of the crew. While the overall workload of the crew that is a direct result of the threats has a significant impact on the management of threats, the ability to make acceptable decisions in order to maintain safety margins is also a significant factor in the management of threats. It is highly dependent on the crew's ability to recognize and evaluate potential dangers at an early stage, which is made possible by the shared situational awareness that they all possess. There would be no Pilot Monitoring (PM) during the eMCO Phase, which would result in an increased frequency of pilot errors that would go unnoticed by the other members of the crew.

Several scenarios underscore the indispensability of this setup:

Emergency Situations: In the event of an emergency, two pilots can divide tasks, share cognitive loads, and provide mutual support, significantly enhancing the crew's ability to respond effectively and safely.

Cross-checking and Decision Support: Two pilots continuously monitor both the flight parameters and each other's actions, providing immediate feedback and correction if necessary. This cross-checking process is vital for catching and correcting errors before they escalate.

Crisis Management: In emergency situations, pilots must rapidly assess the situation, maintain control of the aircraft, decide on a course of action, and execute it while maintaining communication with air traffic control, the airline operations center, and the cabin crew. The cognitive load during such events is immense. Having two pilots allows for the division of responsibilities, ensuring that while one pilot focuses on flying the aircraft, the other can manage communications and system troubleshooting.

Health Emergencies: Incidences where a pilot becomes incapacitated are rare but not unheard of. In such cases, the presence of a second pilot is critical for taking immediate control of the aircraft and ensuring the safety of everyone on board.

Beyond the technical aspects of flying, pilots play a crucial role in security and managing interactions with passengers and cabin crew. They are trained to handle a variety of non-flight-related emergencies that can occur, underscoring the multifaceted nature of their responsibilities, which extend far beyond the operation of the aircraft.

Teamwork in the Cockpit

The cockpit of a commercial airliner is an environment where effective teamwork can be a matter of life and death. The interaction between pilots involves more than just verbal communication; it's built on shared mental models, non-verbal cues, and an implicit understanding that comes from training and experience. This synergy enhances situational awareness, decision-making, and operational safety.

Moreover, the cockpit serves as a learning environment where less experienced pilots benefit from the mentorship of their more experienced counterparts. This aspect of knowledge transfer and continuous learning is pivotal in maintaining high standards of professionalism and skill within the pilot community.

Teamwork extends beyond the immediate actions required to fly the aircraft; it encompasses the ability to manage stress, fatigue, and the unexpected, demonstrating resilience and adaptability. These human factors are critical in ensuring the safe outcome of flights under varying conditions, reinforcing the argument against reducing cockpit crew numbers.

Ground-based pilots and autonomous systems are poor substitutes for a second pilot because they lack the same level of situational awareness, communication abilities, and adaptability as a second pilot in the cockpit. Here are the reasons why:

1. Lack of Nonverbal Communication

   Pilots seated side by side in the cockpit can communicate through nonverbal cues such as head nods and gestures, which are important for smooth and safe flight operations. Remote pilots or ground-based pilots cannot provide the same level of nonverbal communication, leading to potential confusion and misinterpretation of roles and responsibilities.

2. Increased Workload

   Single-pilot operations significantly increase the workload for the remaining pilot, especially during off-nominal conditions. Studies have shown that the increased workload can lead to task shedding, errors, and reduced safety. Ground-based pilots may have difficulty handling multiple flights simultaneously, limiting their ability to effectively support single-pilot operations.

3. Limited Communication

   Communication between the ground-based pilot and the pilot flying the aircraft would have to be performed verbally, adding an impractical number of additional tasks. This can further increase the workload and potentially lead to miscommunication or delays in critical decision-making.

4. Inability to Handle Emergencies

   There have been numerous incidents where two or more pilots were necessary to avert disaster following major in-flight equipment malfunctions or emergencies. Single-pilot operations and reduced-crew operations would compromise the ability to handle such emergencies effectively, posing an unacceptable safety risk.

5. Lack of Redundancy

   Having two pilots in the cockpit provides redundancy in case one pilot becomes incapacitated or impaired for any reason. Ground-based pilots or autonomous systems cannot provide the same level of situational awareness and immediate response as an onboard, alert pilot.

6. Flight Deck Security

   Two pilots in the cockpit play a crucial role in flight deck security, including responding to security threats and coordinating with cabin crew during security events. Single-pilot operations would compromise flight deck security and increase the vulnerability of the cockpit to hijacking threats.

Overall, the limitations of ground-based pilots and autonomous systems in terms of communication, workload management, adaptability, and flight deck security make them poor substitutes for a second pilot in the cockpit.  (Air Line Pilots Association, Int’l, 2019) (R. Bailey, 2017) (W. e. a. Johnson, 2012)

Inflight Emergencies

Inflight emergencies during eMCO may cause an "unplanned transition from eMCO to Normal Crew Operations (NCO)." Inflight emergencies can arise for a variety of reasons, such as mechanical failures, medical emergencies, or severe weather conditions. Pilots must be prepared to quickly assess the situation and take appropriate actions to ensure the safety of the aircraft and passengers. It is probable that during an emergency requiring an unplanned transition from eMCO to MCO, the Pilot Resting (PR) will still be in a condition of sleep inertia for some period of time. The threat or emergency will not pause to wait for the second pilot to reach the end of sleep inertia and regain full situational awareness. The lower performance of the PR and the demands placed on the PF during this transition are things that need to be taken into consideration when determining the influence on safety in this scenario.  (European Union Aviation Safety Agency. (n.d.). 5.4.10 Encounter with adverse flight conditions.)

The Effects of Sleep Inertia

Sleep inertia refers to a transient state of grogginess and disorientation immediately after waking up, during which cognitive performance is impaired. It is a safety risk in extended minimum crew operations because it can affect a pilot's ability to perform tasks and make decisions effectively. When a pilot experiences sleep inertia, their cognitive performance, including attention, reaction time, problem-solving, and logical reasoning, may be impaired. This can pose a significant risk in situations where quick and accurate decision-making is crucial, such as during take-off, landing, and in emergency situations. Sleep inertia can also affect a pilot's alertness, increasing the risk of fatigue-related errors. The duration and impact of sleep inertia are significant safety risks associated with extended minimum crew operations, as they are currently proposed.

The factors that affect the severity of sleep inertia include:

1. Duration of sleep: Longer sleep durations, such as nighttime main sleep or naps of 30 minutes or longer, can result in more severe sleep inertia.
2. Timing of sleep: Sleep inertia is more pronounced when awakening from deep sleep stages, such as slow-wave sleep.
3. Time of awakening: Waking up during the biological night or the circadian nadir can lead to more severe sleep inertia.
4. Sleep deprivation: Sleep deprivation can exacerbate the severity of sleep inertia.
5. Task demands: Complex tasks are more susceptible to the effects of sleep inertia compared to simpler tasks.
6. Age: Younger individuals may be more vulnerable to sleep inertia.
7. Chronotype: Late chronotypes (night owls) may experience more severe and longer-lasting sleep inertia.
8. Individual trait: Some individuals may be generally more susceptible to sleep inertia than others.
9. Prior sleep loss: Sleep inertia effects can be exacerbated and/or extended when an individual has experienced prior sleep loss.
10. Slow-wave sleep (SWS): Naps that contain more SWS tend to result in greater inertia.
11. Individual differences: Different individuals may experience sleep inertia to varying degrees due to factors such as genetics, substance use, hormonal status, and tolerance to caffeine.

Sleep inertia typically lasts between less than 7 minutes to around 30 minutes after main sleep episodes. However, there are some studies that have reported longer durations of sleep inertia, such as up to 35 minutes or even 60 minutes after awakening from a nap. Factors such as nap timing, nap duration, and the specific circumstances of awakening can influence the duration of sleep inertia.

The duration of inertia after a 30-minute nap is typically between 0 and 35 minutes, with some individuals experiencing no inertia and others experiencing inertia for up to 35 minutes. It is significant to note that individual differences in sleep quality, sleep disorders, and other factors may affect the severity of sleep inertia. The effects of sleep inertia on cognitive performance can be particularly pronounced in situations where quick and accurate decision-making is required, such as during emergency situations in aviation.

Risks associated with sleep inertia in responding to an emergency during reduced crew operations can include:

1. Delayed response time: Sleep inertia can impair cognitive and motor functions, leading to a delayed response time in recognizing and reacting to an emergency situation.
2. Decreased situational awareness: Sleep inertia can affect the pilot's ability to process information and maintain situational awareness, potentially leading to errors in decision-making and problem-solving during an emergency.
3. Impaired coordination and communication: Sleep inertia can impact the pilot's ability to effectively coordinate and communicate with other crew members, which is crucial during an emergency situation that requires teamwork and coordination.
4. Increased risk of errors: Sleep inertia can increase the risk of errors in executing emergency procedures, such as selecting the wrong switch or making incorrect adjustments to aircraft systems.
5. Reduced ability to handle high workload: Sleep inertia can decrease the pilot's ability to handle a high workload during an emergency, potentially leading to task overload and decreased performance.

The risks associated with sleep inertia in emergency situations during reduced crew operations highlight the importance of considering the impact of fatigue and sleep-related factors on pilot performance and safety. Effective fatigue management strategies, adequate rest opportunities, and awareness of the effects of sleep inertia are essential for mitigating these risks and ensuring the safety of flight operations.  (European Union Aviation Safety Agency. (2021). Sleep Inertia: State of Knowledge and Countermeasures.)

Augmenting Human Capacity, Not Replacing It

Advancement of technology in aviation should aim to augment the capabilities of human pilots, enhancing safety and efficiency without compromising the invaluable human element. While automation can perform a range of tasks with precision and consistency, it lacks the capacity for judgment and adaptability that humans bring to complex, dynamic situations.

The integration of advanced systems into the cockpit has undoubtedly contributed to the reduction of routine workload, allowing pilots to focus more on monitoring and strategic decision-making. However, this integration should not lead to a reduction in crew numbers. Instead, technology should be seen as a tool that supports the crew, ensuring they have the best possible information and systems support to make decisions and manage the flight.

Pilots bring a level of situational awareness and decision-making skills that machines cannot fully replicate. They can interpret nuanced scenarios, consider the implications of their actions in a broader context, and adapt to rapidly changing conditions. As such, technological advancements in aviation should be designed to complement these human strengths, not attempt to supplant them.

Commercial Pressures and Safety Implications

The aviation industry operates in a highly competitive environment where airlines are constantly seeking ways to reduce costs and improve efficiency. While these pressures drive innovation and efficiency, they must not compromise the paramount objective of aviation safety. The safety of passengers, crew members, and the aircraft itself must always be the top priority in aviation operations.

Potential cost savings, such as decreased crew salaries, training costs, and lodging costs—three major areas targeted for efficiency—are a driving force behind the push toward eMCO. However, the financial benefits of reducing crew numbers must be carefully weighed against the potential safety implications. History has shown that safety compromises in the name of economic efficiency can lead to catastrophic outcomes, with far-reaching consequences beyond any immediate financial savings. Therefore, it is crucial to prioritize safety above all else when making decisions about the required crew numbers.

Commercial pressures should not lead to shortcuts in training, reductions in crew numbers, or over-reliance on automation without comprehensive risk assessments and mitigation strategies. The industry's regulatory bodies must ensure that any changes to operating procedures, such as the implementation of eMCO, undergo rigorous evaluation and testing to uphold the safety standards that have made commercial aviation the safest form of long-distance travel.

The unparalleled safety record of commercial aviation is a testament to the industry's commitment to rigorous safety standards, including the critical role played by having two well-trained and qualified pilots in the cockpit. The consideration of extended Minimum Crew Operations (eMCO) raises important questions about the balance between technological advancement and the maintenance of these safety standards.

While automation and technological advancements offer promising ways to enhance efficiency and support flight operations, they should augment rather than replace the human elements essential to aviation safety. The teamwork, decision-making, and adaptability provided by a two-pilot crew are indispensable aspects of commercial flight operations, ensuring that flights are conducted safely under a wide range of conditions.

As the industry explores the potential of eMCO, it must proceed with caution, prioritizing the rigorous evaluation of safety implications over economic benefits. The lessons learned from decades of aviation safety must guide the future of flight operations, ensuring that the legacy of safety continues for generations to come. In aviation, the focus on safety has always been paramount, and as we look to the future, it must remain at the forefront of any advancements or operational changes. The safety of passengers, crew, and aircraft is a non-negotiable priority for the industry, underscoring the indispensable role of two pilots in upholding safety standards.

The aviation industry has a long history of embracing technological advancements to improve safety and efficiency. However, the introduction of eMCO represents a significant departure from the industry's traditional safety standards and practices. The safety of passengers and crew members must always be the top priority in aviation, and any changes to operational procedures must be thoroughly evaluated to ensure that they do not compromise safety. As the aviation industry continues to evolve, it is essential that regulators, industry stakeholders, and pilot associations work together to develop and implement innovative solutions that enhance safety while maintaining the industry's high standards of excellence.

For more information on the safety implications of eMCO and the critical role of two pilots in commercial aviation, please refer to the references below and to the resources provided by industry organizations and regulatory bodies. An excellent online resource for further reading is the Safety Starts with 2 website, which provides valuable insights into the importance of having two pilots in the cockpit and the safety benefits of traditional crew operations.