In aviation, safety is paramount, and the ability to manage non-normal situations is a critical skill for every pilot. Non-normal situations—also referred to as abnormal or emergency scenarios—are rare, but they demand a high level of precision, communication, and coordination from the flight crew to ensure the aircraft and its passengers remain safe.

Boeing has developed a set of comprehensive guidelines that help crews effectively handle non-normal situations. These guidelines are designed to be systematic and ensure that all critical steps are covered during unexpected events. Here, we explore the key steps that guide pilots through non-normal operations and ensure safety is maintained at every moment.

1. Recognizing the Non-Normal

The first step in managing any non-normal situation is recognizing that something is wrong. Quick identification of a malfunction is crucial. When a crew member spots a warning or system failure, they must immediately and clearly communicate the issue to the rest of the team. This ensures that all crew members are aware of the problem and can begin the necessary actions without delay.

For example, if a warning light indicating engine failure illuminates, the crew member who notices the alert should call it out using clear, concise language. Miscommunication in these critical moments could delay the response, potentially worsening the situation.

2. Maintaining Control of the Aircraft

Once the non-normal situation is identified, the crew’s first and foremost priority is to maintain or regain control of the aircraft. The Pilot Flying (PF) focuses entirely on flying the plane, ensuring the aircraft remains on a stable and safe flight path. Meanwhile, the Pilot Monitoring (PM) assists by maintaining situational awareness, ensuring obstacles are avoided, and that the aircraft's configuration is appropriate for the situation.

During these moments, the use of the autoflight system is highly recommended. Engaging the autopilot can significantly reduce the flight crew's workload, allowing them to focus on analyzing the issue at hand rather than manually flying the aircraft. This system ensures the aircraft follows a stable flight path while the pilots handle other critical tasks.

3. Analyzing and Confirming the Situation

Once the aircraft is under control, the next step is to thoroughly analyze the situation. The crew must review all alerts, warnings, and caution lights to determine exactly what system has malfunctioned. In cases where multiple systems have failed, it is important to prioritize which non-normal checklist (NNC) to follow first.

For instance, if both engine and electrical system warnings occur simultaneously, the flight crew needs to assess which issue requires immediate action and address that first. Good judgment is key in these scenarios, as following the correct procedure in the right order can prevent further complications.

4. Executing Memory Items

Some emergency situations require immediate action without reference to a checklist. These procedures, known as memory items, are ingrained in the flight crew's training and must be performed promptly. The PF directs the crew to perform these tasks, and both pilots execute their responsibilities swiftly.

An example of a memory item is shutting off an engine in the case of an engine fire. The crew knows the specific steps by heart, and they perform these actions immediately, without needing to consult the checklist first.

5. Using the Non-Normal Checklist

Once the immediate steps are taken, the PF will call for the appropriate NNC. However, this happens only after the aircraft’s flight path and configuration have been stabilized. Before reading through the checklist, the crew formulates a basic plan, ensuring they understand what actions need to be taken and communicate these intentions to Air Traffic Control (ATC) if necessary.

The NNC provides detailed instructions to handle the situation, but pilots must ensure they are prepared to execute those steps smoothly and in the correct sequence.

6. Evaluating the Need to Land

Some situations may require the aircraft to land at the nearest suitable airport. If the NNC or Quick Reference Handbook (QRH) dictates a diversion, the flight crew must follow that guidance. In scenarios where landing is not mandatory, the PF must carefully evaluate the condition of the aircraft, weather, and any other external factors to determine if continuing the flight is safe.

This decision is not made lightly, as continuing the flight with unresolved system malfunctions could pose further risks. The crew will consider whether returning to the destination or diverting to another airport is the best course of action, always with passenger safety as the top priority.

7. Following Up After the Checklist

Once the checklist is complete, the crew evaluates the remainder of the flight. This involves reassessing the aircraft’s status, checking fuel levels, performance requirements, and reviewing NOTAMs and weather conditions at the intended destination or diversion airport. Communication with ATC, cabin crew, passengers, and the airline’s operations center is essential to keep everyone informed and ensure a smooth continuation of the flight.

8. The Importance of Clear Communication

In any non-normal situation, clear communication is vital. Typically, the PF communicates with ATC, while the PM reads and executes the NNC. It is crucial that both pilots issue commands clearly and that each command is acknowledged before further actions are taken. This reduces the risk of confusion or misinterpretation, ensuring that the situation is handled efficiently.

Pilots must also avoid overstating or understating the severity of the situation when communicating with the PF or ATC. Precise, factual reporting enables the crew to make informed decisions and prevents unnecessary complications.

9. Handling Multiple Malfunctions

In complex scenarios where multiple malfunctions occur simultaneously, memory items should be executed first, followed by the reference checklist steps. After completing each NNC, the crew reviews all alerts and warnings again to determine if additional checklists are needed. This systematic approach ensures that no malfunction goes unaddressed.

10. Maximizing Use of the Autoflight System

Whenever appropriate, the autoflight system should be utilized to reduce pilot workload. By automating certain tasks, the flight crew can focus more effectively on resolving the non-normal situation. However, it is essential to ensure that the correct flight director modes are engaged, and the system is configured properly for the flight path.

Conclusion

Managing non-normal situations in the Boeing 737 NG is a process that requires skill, teamwork, and clear communication. By following Boeing’s structured guidelines, pilots can ensure they address malfunctions systematically, keeping the aircraft and its passengers safe. These principles, from recognizing the malfunction to deciding whether to land, guide the flight crew through even the most challenging scenarios.

While non-normal situations are rare, thorough preparation and adherence to these protocols ensure that pilots are equipped to handle whatever comes their way. Through practice, training, and reliance on advanced systems like autoflight, pilots maintain control, make informed decisions, and protect the safety of all aboard.

Notice of Liability

The information in the blog post is distributed on an “as is” basis, without warranty. The author shall have no liability to any person or entity with respect to any liability, loss, or damage caused or alleged to be caused, directly or indirectly by the information contained in these study notes or its application in practice.