Description and Definitions
The term “checklist” can refer to two main types of documents: challenge-and-response checklists and read-and-do lists. Checklists, whether they’re challenge-and-response or read-and-do, paper or electronic, serve as vital tools that support flight crews in their airmanship and memory. They help ensure that all necessary actions are completed without forgetting anything and in a systematic way. Typically, these checklists are found in a user-friendly Quick Reference Handbook (QRH).
Discussion and Considerations
Challenge-and-response checklists are generally related to the normal operation of the aircraft during each flight phase. Actions related to each phase are done from memory, following a set cockpit flow pattern. Specific critical items are checked and cross-checked using a challenge-and-response method. Here, the pilot not flying reads out the items to be checked, and the pilot flying confirms the correct status or configuration of those items, like altimeter settings, flap positions, and ground spoilers arming. In aircraft with electronic checklists, completed actions may be automatically detected by the system, which then erases the checklist items or changes their color. Some aircraft models even allow crew members to mark an item as “checked” with a simple prompt.
Read-and-do lists, on the other hand, deal with non-normal procedures, such as abnormal situations and emergencies, where a memory-based cockpit flow is not suitable. These non-normal procedures often include pre-conditions that both crew members must assess and agree upon before moving forward. Certain non-normal procedures, like recovering from an unusual attitude or dealing with unreliable airspeed indications, contain “memory items” or “survival items”. These are crucial, time-sensitive actions that need to be performed from memory before consulting the QRH for further guidance on handling the situation.
Conclusions
Checklists, whether for normal or non-normal situations, are essential tools that aid flight crews in safely operating the aircraft. They encapsulate the wisdom and experience of both the aircraft manufacturer and its operators, built over many years and countless flight hours. It’s important not to modify these checklists without consulting the manufacturer’s flight operations department. Even the order of action steps or how they are grouped can significantly impact safety, and such details may not be apparent without understanding their background. Altering a non-normal procedure could lead to secondary failures or, in the worst case, worsen the situation, increasing risk rather than reducing it.
